Agronomy

10 pages, 488 KiB

Open AccessEditor’s ChoiceArticle

Hot Pressurized Liquid Extraction of Polyphenols from the Skin and Seeds of Vitis vinifera L. cv. Negra Criolla Pomace a Peruvian Native Pisco Industry Waste

by Erik E. Allcca-Alca, Nilton C. León-Calvo, Olivia M. Luque-Vilca, Maximiliano Martínez-Cifuentes, José Ricardo Pérez-Correa, María Salomé Mariotti-Celis and Nils Leander Huamán-Castilla

Agronomy 2021, 11(5), 866; https://doi.org/10.3390/agronomy11050866 - 28 Apr 2021

Cited by 23 | Viewed by 3847

Abstract

The pisco industry in Peru generates large amounts of grape pomace, which is a natural source of bioactive compounds with potential nutraceutical applications. Hot pressurized liquid extraction (HPLE) with water-ethanol solvent mixtures (20–60%) at high temperatures (100–160 °C) was applied to recover polyphenols [...] Read more.

The pisco industry in Peru generates large amounts of grape pomace, which is a natural source of bioactive compounds with potential nutraceutical applications. Hot pressurized liquid extraction (HPLE) with water-ethanol solvent mixtures (20–60%) at high temperatures (100–160 °C) was applied to recover polyphenols from the skin and seeds of a Peruvian pisco-industry grape-pomace waste. At the same HPLE conditions (60% ethanol, 160 °C), the seed fraction extracts contained ~6 times more total polyphenol and presented ~5 times more antioxidant activity than the extract from the skin fraction. The lowest ethanol concentration (20%) and the highest temperature (160 °C) achieved the highest recovery of flavanols with 163.61 µg/g dw from seeds and 10.37 µg/g dw from skins. The recovery of phenolic acids was maximized at the highest ethanol concentration and temperature with 45.34 µg/g dw from seeds and 6.93 µg/g dw from skins. Flavonols were only recovered from the skin, maximized (17.53 µg/g dw) at 20% of ethanol and the highest temperature. The recovery of specific polyphenols is maximized at specific extraction conditions. These conditions are the same for seed and skin extractions. This alternative method can be used in other agroindustrial wastes in order to recover bioactive compounds with potential applications in the pharmaceutical and food industry. Full article

(This article belongs to the Special Issue Safety and Bioactivity of Agri-Food Products—Methods for Chemicals Residues Analysis and Phytochemicals Investigation)

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9 pages, 622 KiB

Open AccessEditor’s ChoiceArticle

Mineral and Antioxidant Attributes of Petroselinum crispum at Different Stages of Ontogeny: Microgreens vs. Baby Greens

by Christophe El-Nakhel, Antonio Pannico, Giulia Graziani, Maria Giordano, Marios C. Kyriacou, Alberto Ritieni, Stefania De Pascale and Youssef Rouphael

Agronomy 2021, 11(5), 857; https://doi.org/10.3390/agronomy11050857 - 28 Apr 2021

Cited by 14 | Viewed by 2403

Abstract

Parsley is an aromatic herb native to the Mediterranean region and treasured for its phytochemical profile and bioactive properties. Developmental stage at harvest is a factor that modulates the nutritional quality of vegetables, including young greens. Accordingly, an experiment under strictly controlled conditions [...] Read more.

Parsley is an aromatic herb native to the Mediterranean region and treasured for its phytochemical profile and bioactive properties. Developmental stage at harvest is a factor that modulates the nutritional quality of vegetables, including young greens. Accordingly, an experiment under strictly controlled conditions was carried out to compare the mineral macronutrient and phytochemical composition as well as the antioxidant activity of plain-leaf parsley (Petroselinum crispum cv. Comune 2) at two different harvest maturity stages, microgreens and baby greens. Macronutrients, carotenoids (lutein and β-carotene) and polyphenols were quantified through ion chromatography, high-performance liquid chromatography with a diode-array detector (HPLC-DAD) and UHPLC-Q-Orbitrap high-resolution mass spectrometry (HRMS), respectively. Microgreens accumulated more potassium and phosphorus, whereas baby greens accumulated more calcium and magnesium, and 65.5% less nitrate. In addition, microgreens provided 1.8-fold more lutein and 2.8-fold more β-carotene, whereas baby greens provided 183.6% more total ascorbic acid, 64.2% more total polyphenols and 170.3% higher hydrophilic antioxidant activity. Based on the culinary and phytonutritive scope of the consumers, different harvest maturity stages can be opted for and production schemes designed. Future studies are warranted to appraise the importance of ontogeny as a determinant factor for the composition and bioactive value of additional micro-herb genotypes, including underutilized Mediterranean species. Full article

(This article belongs to the Special Issue Sprouts, Microgreens and Edible Flowers as Novel Functional Foods)

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20 pages, 804 KiB

Open AccessEditor’s ChoiceReview

The Challenge of Combining High Yields with Environmentally Friendly Bioproducts: A Review on the Compatibility of Pesticides with Microbial Inoculants

by Mariana Sanches Santos, Thiago Fernandes Rodrigues, Marco Antonio Nogueira and Mariangela Hungria

Agronomy 2021, 11(5), 870; https://doi.org/10.3390/agronomy11050870 - 28 Apr 2021

Cited by 14 | Viewed by 7084

Abstract

Inoculants or biofertilizers aiming to partially or fully replace chemical fertilizers are becoming increasingly important in agriculture, as there is a global perception of the need to increase sustainability. In this review, we discuss some important results of inoculation of a variety of [...] Read more.

Inoculants or biofertilizers aiming to partially or fully replace chemical fertilizers are becoming increasingly important in agriculture, as there is a global perception of the need to increase sustainability. In this review, we discuss some important results of inoculation of a variety of crops with rhizobia and other plant growth-promoting bacteria (PGPB). Important improvements in the quality of the inoculants and on the release of new strains and formulations have been achieved. However, agriculture will continue to demand chemical pesticides, and their low compatibility with inoculants, especially when applied to seeds, represents a major limitation to the success of inoculation. The differences in the compatibility between pesticides and inoculants depend on their active principle, formulation, time of application, and period of contact with living microorganisms; however, in general they have a high impact on cell survival and metabolism, affecting the microbial contribution to plant growth. New strategies to solve the incompatibility between pesticides and inoculants are needed, as those that have been proposed to date are still very modest in terms of demand. Full article

(This article belongs to the Special Issue Recent Advances in Biological Nitrogen Fixation)

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20 pages, 9082 KiB

Open AccessEditor’s ChoiceArticle

Using UAV Borne, Multi-Spectral Imaging for the Field Phenotyping of Shoot Biomass, Leaf Area Index and Height of West African Sorghum Varieties under Two Contrasted Water Conditions

by Boubacar Gano, Joseph Sékou B. Dembele, Adama Ndour, Delphine Luquet, Gregory Beurier, Diaga Diouf and Alain Audebert

Agronomy 2021, 11(5), 850; https://doi.org/10.3390/agronomy11050850 - 27 Apr 2021

Cited by 34 | Viewed by 5549

Abstract

Meeting food demand for the growing population will require an increase to crop production despite climate changes and, more particularly, severe drought episodes. Sorghum is one of the cereals most adapted to drought that feed millions of people around the world. Valorizing its [...] Read more.

Meeting food demand for the growing population will require an increase to crop production despite climate changes and, more particularly, severe drought episodes. Sorghum is one of the cereals most adapted to drought that feed millions of people around the world. Valorizing its genetic diversity for crop improvement can benefit from extensive phenotyping. The current methods to evaluate plant biomass, leaves area and plants height involve destructive sampling and are not practical in breeding. Phenotyping relying on drone based imagery is a powerful approach in this context. The objective of this study was to develop and validate a high throughput field phenotyping method of sorghum growth traits under contrasted water conditions relying on drone based imagery. Experiments were conducted in Bambey (Senegal) in 2018 and 2019, to test the ability of multi-spectral sensing technologies on-board a UAV platform to calculate various vegetation indices to estimate plants characteristics. In total, ten (10) contrasted varieties of West African sorghum collection were selected and arranged in a randomized complete block design with three (3) replicates and two (2) water treatments (well-watered and drought stress). This study focused on plant biomass, leaf area index (LAI) and the plant height that were measured weekly from emergence to maturity. Drone flights were performed just before each destructive sampling and images were taken by multi-spectral and visible cameras. UAV-derived vegetation indices exhibited their capacity of estimating LAI and biomass in the 2018 calibration data set, in particular: normalized difference vegetative index (NDVI), corrected transformed vegetation index (CTVI), seconded modified soil-adjusted vegetation index (MSAVI2), green normalize difference vegetation index (GNDVI), and simple ratio (SR) (r² of 0.8 and 0.6 for LAI and biomass, respectively). Developed models were validated with 2019 data, showing a good performance (r² of 0.92 and 0.91 for LAI and biomass accordingly). Results were also promising regarding plant height estimation (RMSE = 9.88 cm). Regression plots between the image-based estimation and the measured plant height showed a r² of 0.83. The validation results were similar between water treatments. This study is the first successful application of drone based imagery for phenotyping sorghum growth and development in a West African context characterized by severe drought occurrence. The developed approach could be used as a decision support tool for breeding programs and as a tool to increase the throughput of sorghum genetic diversity characterization for adaptive traits. Full article

(This article belongs to the Section Innovative Cropping Systems)

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19 pages, 3728 KiB

Open AccessEditor’s ChoiceArticle

Biological Control of Pythium aphanidermatum, the Causal Agent of Tomato Root Rot by Two Streptomyces Root Symbionts

by Mohadeseh Hassanisaadi, Gholam Hosein Shahidi Bonjar, Akbar Hosseinipour, Roohollah Abdolshahi, Essaid Ait Barka and Ismail Saadoun

Agronomy 2021, 11(5), 846; https://doi.org/10.3390/agronomy11050846 - 26 Apr 2021

Cited by 36 | Viewed by 4867

Abstract

Damping-off caused by Pythium aphanidermatum, as one of the most infamous plant diseases, is considered as a significant disease that causes severe damages in greenhouse and field crops in a vast range of hosts especially vegetables. The application of chemical fungicides as [...] Read more.

Damping-off caused by Pythium aphanidermatum, as one of the most infamous plant diseases, is considered as a significant disease that causes severe damages in greenhouse and field crops in a vast range of hosts especially vegetables. The application of chemical fungicides as a common method to control this disease poses negative side effects on humans and the environmental components. Actinobacteria, especially members of the genus Streptomyces, are fascinating biocontrol agents and plant growth-promoting rhizobacteria, which exhibit safer alternative managements to control this disease. The present study aims to explore for bioactives soil Streptomyces isolates that are able to control P. aphanidermatum, which is the causal agent of damping-off in tomato. Out of a total of 116 actinobacteria isolates collected from the soil, 53 have showed an antagonistic activity against P. aphanidermatum, as deduced through in vitro dual cultures. Based on in vitro Petri plate seedling-bioassays (IPSB), from the 53 tested isolates in dual cultures, two isolates coded as H2 and H3, considered as the most bioactive agents, were selected to assess their biocontrol performances against P. aphanidermatum in the Sandwich bed-mix technique in greenhouse experiments. In vivo greenhouse statistical studies were performed to compare seven treatments using completely randomized design experiments. Metalaxyl fungicide was applied as the chemical-control treatment. To evaluate biocontrol efficiencies of the two Streptomyces symbionts, disease incidence recorded throughout the course of experiment and criteria of number of leaves, length of the plants, plant fresh and dry weights, were measured at the end of experiment and analyzed statistically. The resulted disease incidences for all treatments indicated that the two Streptomyces strains had PGPR activity, and they were effective in decreasing disease incidence and improving plant performances regarding number of leaves, height, and plant fresh and dry weights. Based on the phylogenetic analysis of the partial sequences of the 16S rRNA gene, the strain H2 revealed a close relation to six Streptomyces species, namely S. badius, S. caviscabies, S. globisporus, S. parvus, S. sindenensis, and S. griseoplanus, with 99.9% similarity. The strain H3 also indicated a close relation of the same similarity to two species, namely S. flavogriseus and S. pratensis. In overall, collected data dictated that the two bioactive root symbiont Streptomyces strains effectively controlled the damping-off disease caused by P. aphanidermatum. Full article

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9 pages, 831 KiB

Open AccessEditor’s ChoiceArticle

A New Method to Recycle Dairy Waste for the Nutrition of Wheat Plants

by Saif Alharbi, Ali Majrashi, Adel M. Ghoneim, Esmat F. Ali, Abdullah S. Modahish, Fahmy A. S. Hassan and Mamdouh A. Eissa

Agronomy 2021, 11(5), 840; https://doi.org/10.3390/agronomy11050840 - 25 Apr 2021

Cited by 14 | Viewed by 3811

Abstract

Dairy products are vital components of human food, however, they are rapidly spoiled due to their high content of organic matter which encourages the growth of decomposing microbes. The recycling of dairy wastes is an ideal solution to preserve the environment, as it [...] Read more.

Dairy products are vital components of human food, however, they are rapidly spoiled due to their high content of organic matter which encourages the growth of decomposing microbes. The recycling of dairy wastes is an ideal solution to preserve the environment, as it is in line with the principles of sustainable agriculture. In this experiment, an organic fertilizer was extracted from dairy wastes and was used for the nutrition of wheat grown on sandy soils under two-year field studies. The application rate of the extracted organic fertilizer was 8 ton ha⁻¹. Moreover, the same rates of N, P, and K were added from inorganic fertilizers. The extracted organic fertilizer significantly (p < 0.05) enhanced the wheat growth and increased chlorophyll by 11% and 16% in the first and second season, respectively, in comparison to the inorganic fertilization. The extracted organic fertilizer significantly minimized the soil pH from an initial value of 8.00 to 7.05. The tested organic fertilizer increased the uptake of N, P, and K by 55%, 49%, and 51% above the inorganic nutrition, respectively. The wheat straw and grain yield increased by 16% and 29% as a result of the addition of the organic fertilizer extracted from dairy wastes. The dairy wastes organic fertilizer caused a notable improvement in the soil quality. The extracted organic fertilizer was able to supply wheat with its nutrient requirements as it showed a remarkable superiority over the mineral fertilization. The disposal of expired dairy waste can be managed in a way that preserves the environment by converting it to organic fertilizers. Laboratory and field experiments have proven the efficiency of the extracted organic fertilizer in nutrition of wheat plants in sandy soils with low fertility. Full article

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14 pages, 3197 KiB

Open AccessEditor’s ChoiceReview

Applications and Development of LEDs as Supplementary Lighting for Tomato at Different Latitudes

by Onofrio Davide Palmitessa, Marco Antonio Pantaleo and Pietro Santamaria

Agronomy 2021, 11(5), 835; https://doi.org/10.3390/agronomy11050835 - 23 Apr 2021

Cited by 20 | Viewed by 5176

Abstract

High-tech greenhouses and artificial light applications aim to improve food production, in line with one of the sustainable development goals of the UN Agenda 2030, namely, “zero hunger”. In the past, the incandescent lamps have been used for supplementary lighting (SL) at higher [...] Read more.

High-tech greenhouses and artificial light applications aim to improve food production, in line with one of the sustainable development goals of the UN Agenda 2030, namely, “zero hunger”. In the past, the incandescent lamps have been used for supplementary lighting (SL) at higher latitudes to increase greenhouse production during the dark season. Light-emitting diodes (LED) have been replacing gas discharge and incandescent lamps, and their development is expanding SL applications in different agricultural scenarios (e.g., urban farming, middle latitudes). In fact, recent research on LED applications in Mediterranean greenhouses have produced encouraging results. Since middle latitudes have a higher daily light integral (DLI) than higher latitudes in the dark season and climate conditions influence the installed power load of greenhouses, LED installation and management in Mediterranean greenhouses should be different and less expensive in terms of investment and energy consumption. Accordingly, the aim of this review is to outline the state of the art in LED applications and development, with a focus on latitude-related requirements. Tomato was used as a representative crop. Full article

(This article belongs to the Special Issue Sustainable Urban Agriculture in the 21st Century)

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25 pages, 11030 KiB

Open AccessEditor’s ChoiceReview

Review of Two Mechanical Separation Technologies for the Sustainable Management of Agricultural Phosphorus in Nutrient-Vulnerable Zones

by Gary A. Lyons, Ashley Cathcart, J. Peter Frost, Michael Wills, Christopher Johnston, Rachael Ramsey and Beatrice Smyth

Agronomy 2021, 11(5), 836; https://doi.org/10.3390/agronomy11050836 - 23 Apr 2021

Cited by 20 | Viewed by 7812

Abstract

This work reviews two mechanical separation technologies (screw press and decanting centrifuge) which could be used in the dairy, beef, pig and anaerobic digestion sectors in nutrient-vulnerable zones in order to improve the sustainability of manure and anaerobic digestate management by decreasing agricultural [...] Read more.

This work reviews two mechanical separation technologies (screw press and decanting centrifuge) which could be used in the dairy, beef, pig and anaerobic digestion sectors in nutrient-vulnerable zones in order to improve the sustainability of manure and anaerobic digestate management by decreasing agricultural phosphorus loss and reducing environmental impact on water quality. Capital and operating costs, separation efficiency and throughput, and management and processing of separated fractions, including transport costs, environmental impacts and the biosecurity of separated solids for export, were considered. Of the two technologies reviewed, screw press separation is a more cost-effective option (5-fold cheaper per tonne of feedstock) when lower amounts of export of phosphorus off farm are acceptable. For farms and those with anaerobic digesters managing larger volumes of manure/digestate, screw press separation is possible. However if higher levels of phosphorus removal are required, the use of decanting centrifugation is a viable option. Centralised processing facilities could also make use of decanting centrifuge technology to act as processing hubs for local farms within a distance that makes it economical for transport of manure/treated manure to/from the processor (the maximum distance for economical transport of raw manure and separated solids is approximately 70 km and 84 km, respectively). Both separation technologies could be integrated into agricultural manure and digestate management systems in order to provide a more sustainable approach to managing agricultural phosphorus loss and its associated impact on water quality. Screw press and decanting centrifuge separation could reduce phosphorous loss to water bodies by 34% and from 30 to 93%, respectively. Full article

(This article belongs to the Special Issue Managing Nutrient Balances in Agriculture - Agronomy, Animal Manure and the Circularity of Nitrogen and Phosphorus)

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24 pages, 5742 KiB

Open AccessEditor’s ChoiceArticle

LoRa-LBO: An Experimental Analysis of LoRa Link Budget Optimization in Custom Build IoT Test Bed for Agriculture 4.0

by Mahendra Swain, Dominik Zimon, Rajesh Singh, Mohammad Farukh Hashmi, Mamoon Rashid and Saqib Hakak

Agronomy 2021, 11(5), 820; https://doi.org/10.3390/agronomy11050820 - 22 Apr 2021

Cited by 47 | Viewed by 5149

Abstract

The Internet of Things (IoT) is transforming all applications into real-time monitoring systems. Due to the advancement in sensor technology and communication protocols, the implementation of the IoT is occurring rapidly. In agriculture, the IoT is encouraging implementation of real-time monitoring of crop [...] Read more.

The Internet of Things (IoT) is transforming all applications into real-time monitoring systems. Due to the advancement in sensor technology and communication protocols, the implementation of the IoT is occurring rapidly. In agriculture, the IoT is encouraging implementation of real-time monitoring of crop fields from any remote location. However, there are several agricultural challenges regarding low power use and long-range transmission for effective implementation of the IoT. These challenges are overcome by integrating a long-range (LoRa) communication modem with customized, low-power hardware for transmitting agricultural field data to a cloud server. In this study, we implemented a custom-based sensor node, gateway, and handheld device for real-time transmission of agricultural data to a cloud server. Moreover, we calibrated certain LoRa field parameters, such as link budget, spreading factor, and receiver sensitivity, to extract the correlation of these parameters on a custom-built LoRa testbed in MATLAB. An energy harvesting mechanism is also presented in this article for analyzing the lifetime of the sensor node. Furthermore, this article addresses the significance and distinct kinds of localization algorithms. Based on the MATLAB simulation, we conclude that hybrid range-based localization algorithms are more reliable and scalable for deployment in the agricultural field. Finally, a real-time experiment was conducted to analyze the performance of custom sensor nodes, gateway, and handheld devices. Full article

(This article belongs to the Special Issue Photovoltaics and Electrification in Agriculture)

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28 pages, 530 KiB

Open AccessEditor’s ChoiceReview

Metabolomics, a Powerful Tool for Understanding Plant Abiotic Stress

by Fredy P. Carrera, Carlos Noceda, María G. Maridueña-Zavala and Juan M. Cevallos-Cevallos

Agronomy 2021, 11(5), 824; https://doi.org/10.3390/agronomy11050824 - 22 Apr 2021

Cited by 26 | Viewed by 5502

Abstract

Metabolomics is a technology that generates large amounts of data and contributes to obtaining wide and integral explanations of the biochemical state of a living organism. Plants are continuously affected by abiotic stresses such as water scarcity, high temperatures and high salinity, and [...] Read more.

Metabolomics is a technology that generates large amounts of data and contributes to obtaining wide and integral explanations of the biochemical state of a living organism. Plants are continuously affected by abiotic stresses such as water scarcity, high temperatures and high salinity, and metabolomics has the potential for elucidating the response-to-stress mechanisms and develop resistance strategies in affected cultivars. This review describes the characteristics of each of the stages of metabolomic studies in plants and the role of metabolomics in the characterization of the response of various plant species to abiotic stresses. Full article

(This article belongs to the Special Issue Recent Advances in Metabolic Processes and Metabolites of Agricultural Crops)

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25 pages, 1131 KiB

Open AccessEditor’s ChoiceReview

Agronomic Efficiency of Animal-Derived Organic Fertilizers and Their Effects on Biology and Fertility of Soil: A Review

by Shantanu Bhunia, Ankita Bhowmik, Rambilash Mallick and Joydeep Mukherjee

Agronomy 2021, 11(5), 823; https://doi.org/10.3390/agronomy11050823 - 22 Apr 2021

Cited by 63 | Viewed by 11231

Abstract

Healthy soils are essential for progressive agronomic activities. Organic fertilization positively affects agro-ecosystems by stimulating plant growth, enhancing crop productivity and fruit quality and improving soil fertility. Soil health and food security are the key elements of Organic Agriculture 3.0. Landfilling and/or open-dumping [...] Read more.

Healthy soils are essential for progressive agronomic activities. Organic fertilization positively affects agro-ecosystems by stimulating plant growth, enhancing crop productivity and fruit quality and improving soil fertility. Soil health and food security are the key elements of Organic Agriculture 3.0. Landfilling and/or open-dumping of animal wastes produced from slaughtering cause environmental pollution by releasing toxic substances, leachate and greenhouse gases. Direct application of animal carcasses to agricultural fields can adversely affect soil microbiota. Effective waste management technologies such as thermal drying, composting, vermicomposting and anaerobic digestion transform animal wastes, making them suitable for soil application by supplying soil high in organic carbon and total nitrogen. Recent agronomic practices applied recycled animal wastes as organic fertilizer in crop production. However, plants may not survive at a high fertilization rate due to the presence of labile carbon fraction in animal wastes. Therefore, dose calculation and determination of fertilizer application frequency are crucial for agronomists. Long-term animal waste-derived organic supplementation promotes copiotrophic microbial abundance due to enhanced substrate affinity, provides micronutrients to soils and protects crops from soil-borne pathogens owing to formation of plant-beneficial microbial consortia. Animal waste-derived organically fertilized soils possess higher urease and acid phosphatase activities. Furthermore, waste to fertilizer conversion is a low-energy requiring process that promotes circular bio-economy. Thus, considering the promotion of soil fertility, microbial abundance, disease protection and economic considerations application of animal-waste-derived organic fertilizer should be the mainstay for sustainable agriculture. Full article

(This article belongs to the Special Issue Soil Healthy in Agro-ecosystems)

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38 pages, 563 KiB

Open AccessEditor’s ChoiceReview

Polysaccharides as Edible Films and Coatings: Characteristics and Influence on Fruit and Vegetable Quality—A Review

by Anna Kocira, Katarzyna Kozłowicz, Katarzyna Panasiewicz, Mariola Staniak, Ewa Szpunar-Krok and Paulina Hortyńska

Agronomy 2021, 11(5), 813; https://doi.org/10.3390/agronomy11050813 - 21 Apr 2021

Cited by 116 | Viewed by 13355

Abstract

There has been a significant increase in the development of edible films and coatings in recent times, and this is expected to have a significant impact on the quality of fruit and vegetables in the coming years. Consumers expect fresh fruit and vegetables [...] Read more.

There has been a significant increase in the development of edible films and coatings in recent times, and this is expected to have a significant impact on the quality of fruit and vegetables in the coming years. Consumers expect fresh fruit and vegetables free from pesticide residues, with high quality, nutritional value and an extended shelf life. The application of coatings and edible films to fruits and vegetables represents an environmentally friendly approach to an innovative solution to this problem. Coatings and edible films can act as ecological and biodegradable packaging. The coating strategy involves a combination of natural biopolymers and appropriate preservation methods. The article presents the applicability, trends and perspectives of polysaccharide coatings and edible films and their impact on the quality of fruit and vegetables, providing an understanding of their main functions and benefits. Numerous studies show that natural polysaccharides are well suited for use as packaging material for fresh fruit and vegetables and can often be an important alternative to synthetic compounds. Natural polymer materials are a good barrier to oxygen and carbon dioxide; however, they are characterised by excessive solubility in the water environment, water vapour permeability and low extensibility. The properties of edible coatings can be modified by the addition of plasticisers, surfactants, cross-linkers, antimicrobial agents, functional additives, nanosilver particles or fruit and vegetable residues. The use of an electric field is also a promising technology here. The use of polysaccharides for the preparation of edible films and coatings is justified not only by the possibility of reducing the consumption of packaging made of synthetic polymer materials but also by the fact that the production of some natural polymers can be made using waste products generated during the processing of food raw materials. Full article

(This article belongs to the Special Issue Innovative Technologies for Conservation, Protection, and Quality of Vegetables and Fruits in a Postharvest Period)

11 pages, 1673 KiB

Open AccessEditor’s ChoiceArticle

Optimizing Biocontrol Activity of Paenibacillus xylanexedens for Management of Hairy Root Disease in Tomato Grown in Hydroponic Greenhouses

by Pablo Vargas, Lien Bosmans, Stefan Van Kerckhove, Bart Van Calenberge, Jos M. Raaijmakers, Bart Lievens and Hans Rediers

Agronomy 2021, 11(5), 817; https://doi.org/10.3390/agronomy11050817 - 21 Apr 2021

Cited by 6 | Viewed by 3202

Abstract

Hairy root disease (HRD) caused by rhizogenic Agrobacterium biovar 1 strains affect tomato, cucumber, eggplant, and bell pepper grown in hydroponic greenhouses and can cause considerable yield losses worldwide. Recently, Paenibacillus xylanexedens strains (ST15.15/027 and AD117) with antagonistic activity against rhizogenic agrobacteria were [...] Read more.

Hairy root disease (HRD) caused by rhizogenic Agrobacterium biovar 1 strains affect tomato, cucumber, eggplant, and bell pepper grown in hydroponic greenhouses and can cause considerable yield losses worldwide. Recently, Paenibacillus xylanexedens strains (ST15.15/027 and AD117) with antagonistic activity against rhizogenic agrobacteria were identified. In this study, we present results of greenhouse trials of two consecutive growing seasons (2019 and 2020) to examine the potential of these two biocontrol organisms (BCOs) under practical conditions. BCO-treatment at a 10⁷ colony forming units (CFU)/mL density resulted in a considerable reduction of the HRD infestation rate, confirming the biocontrol potential of the two P. xylanexedens strains. Results revealed that a single BCO strain (ST15.15/027) performed equally well as the mixed inoculum of both strains. The same level of biocontrol activity was even achieved when the BCO inoculum density was reduced to 10⁵ CFU/mL. qPCR analysis further showed that Paenibacillus was still present in rockwool substrate near the end of both trials, indicating that they persist well in a rockwool environment and that application at the start of the trial is sufficient to protect tomato plants until the end of the trial. Altogether, these results are highly valuable for further optimization and exploitation of P. xylanexedens as a biocontrol product for the control of HRD in hydroponic greenhouses. Full article

(This article belongs to the Special Issue Plant Root Diseases and Integrated Pest Management)

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4 pages, 189 KiB

Open AccessEditor’s ChoiceEditorial

Consumption and Production Patterns for Agricultural Sustainable Development

by Riccardo Testa

Agronomy 2021, 11(5), 814; https://doi.org/10.3390/agronomy11050814 - 21 Apr 2021

Cited by 4 | Viewed by 1983

Abstract

Agriculture has always played a key role in feeding the world population and ensuring the development of sustainable food production systems [...] Full article

(This article belongs to the Special Issue Consumption and Production Patterns for Agricultural Sustainable Development)

17 pages, 1764 KiB

Open AccessEditor’s ChoiceArticle

Soil Productivity Degradation in a Long-Term Eroded Olive Orchard under Semiarid Mediterranean Conditions

by Manuel González-Rosado, Luis Parras-Alcántara, Jesús Aguilera-Huertas and Beatriz Lozano-García

Agronomy 2021, 11(4), 812; https://doi.org/10.3390/agronomy11040812 - 20 Apr 2021

Cited by 14 | Viewed by 2546

Abstract

Olive groves are one of the most important agro-systems in the Mediterranean basin, and the Andalusia region produces the highest quantity of olive oil in Europe. The aim of this work was to evaluate the long-term (15 years) influence of two management practices [...] Read more.

Olive groves are one of the most important agro-systems in the Mediterranean basin, and the Andalusia region produces the highest quantity of olive oil in Europe. The aim of this work was to evaluate the long-term (15 years) influence of two management practices in olive orchards—conventional tillage (CT) and no tillage with bare soil and herbicide application (NT + H)—on soil physical properties, infiltration capacity, erosion rates, and soil productivity. In addition, the short-term (2 years) influence of no tillage with cover crop management (NT-CC) on these parameters was also assessed. In the study area, CT and NT + H management practices showed unsustainable erosion values, 9.82 and 13.88 Mg ha⁻¹ year⁻¹, respectively, while NT-CC inclusion decreased the erosion rates (2.06 Mg ha⁻¹ year⁻¹). The implementation of NT-CC not only reduced erosion rates but also caused a change in the trend of soil productivity loss observed under CT and NT + H. In this sense, NT-CC showed a positive influence on soil quality. However, tillage removal led to a significant reduction in the infiltration capacity of soils under NT + H and NT-CC, which will be a serious handicap for water storage in an environment with continuous processes of water deficit. Full article

(This article belongs to the Special Issue Conservation Tillage in Sustainable Agro-Ecosystems)

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11 pages, 15062 KiB

Open AccessEditor’s ChoiceArticle

Experimental Study and Design of Biomass Co-Firing in a Full-Scale Coal-Fired Furnace with Storage Pulverizing System

by Xuebin Wang, Zia Ur Rahman, Zhaomin Lv, Yiming Zhu, Renhui Ruan, Shuanghui Deng, Lan Zhang and Houzhang Tan

Agronomy 2021, 11(4), 810; https://doi.org/10.3390/agronomy11040810 - 20 Apr 2021

Cited by 20 | Viewed by 3190

Abstract

Co-firing coal and biomass in existing power plants facilitates influential advancement in the use of renewable energy resources and carbon emissions reduction. Biomass is intended as a CO₂-zero net emission because, during its rise, it uses the same fraction of CO [...] Read more.

Co-firing coal and biomass in existing power plants facilitates influential advancement in the use of renewable energy resources and carbon emissions reduction. Biomass is intended as a CO₂-zero net emission because, during its rise, it uses the same fraction of CO₂ from the air as that released during its combustion. In addition, the content of nitrogen and sulfur in biomass is lower than in coal. Therefore, the emissions of NO_x and SO_x can be minimized by co-firing it with coal. In general, the effect of biomass direct co-firing on safety, pulverizing system performance, furnace efficiency, and NO_x emission in full-scale furnaces is rarely studied. In this study, biomass direct co-firing was carried out in a 55 MW tangentially fired pulverized coal furnace. The effects of biomass co-firing on safety, the performance of the pulverizing system, furnace efficiency, and pollutant emissions (unburned carbon and NO_x) are studied. The results show that the blending of biomass fuel with less than 20% of coal has no issue with respect to auto-ignition and safety. The performance of the pulverizing system is affected up to a certain limit due to the difficulty of grinding the biomass particles into required fineness. The biomass co-firing up to 20% is feasible, but greater than this percentage will severely affect the furnace efficiency. The co-firing of biomass enhanced the NO_x reduction significantly and further improved the performance of the SNCR process. This study could provide guidance for the application of biomass co-firing in industrial furnaces. Full article

(This article belongs to the Special Issue Valorization of Agricultural Residues to Renewable Energy and Value-Added Products)

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22 pages, 367 KiB

Open AccessEditor’s ChoiceArticle

Early Sowing Combined with Adequate Potassium and Sulfur Fertilization: Promoting Beta vulgaris (L.) Yield, Yield Quality, and K- and S-Use Efficiency in a Dry Saline Environment

by Ali A. A. Mekdad, Mostafa M. Rady, Esmat F. Ali and Fahmy A. S. Hassan

Agronomy 2021, 11(4), 806; https://doi.org/10.3390/agronomy11040806 - 19 Apr 2021

Cited by 12 | Viewed by 1811

Abstract

Field trials for two seasons (2018/2019 and 2019/2020) were conducted to investigate the influence of the addition of three levels of potassium (K) (K₁ = 60, K₂ = 120, and K₃ = 180 kg K₂O ha⁻¹) [...] Read more.

Field trials for two seasons (2018/2019 and 2019/2020) were conducted to investigate the influence of the addition of three levels of potassium (K) (K₁ = 60, K₂ = 120, and K₃ = 180 kg K₂O ha⁻¹) and/or sulfur (S) (S₁ = 175, S₂ = 350, and S₃ = 525 kg CaSO₄ ha⁻¹) to the soil, as well as the sowing date (the 1st of September, D₁; or the 1st of October, D₂) on the potential improvement of physiology, growth, and yield, as well as the quality characteristics of sugar beet yield under soil salinity conditions. With three replicates specified for each treatment, each trial was planned according to a split-split plot in a randomized complete block design. The results revealed that early sowing (D₁) led to significant improvements in all traits of plant physiology and growth, in addition to root, top, and biological yields and their quality, gross and pure sugar, and K- and S-use efficiencies based on root yield (R-KUE and R-SUE). The K₃ level (180 kg K₂O ha⁻¹) positively affected the traits of plant physiology, growth, yield and quality, and R-SUE, and reduced the attributes of impurities, impurity index, and R-KUE. Additionally, the S₃ level (525 kg CaSO₄ ha⁻¹) affirmatively affected plant physiology, growth, yield and quality traits, and R-KUE, and decreased impurity traits, impurity index, and R-SUE. The interaction of D₁ × K₃ × S₃ maximized the yield of roots (104–105 ton ha⁻¹) and pure sugar (21–22 ton ha⁻¹). Path coefficient analysis showed that root yield and pure sugar content had positive direct effects with 0.62 and 0.65, and 0.38 and 0.38 in both studied seasons, respectively, on pure sugar yield. Significant (p ≤ 0.01) positive correlations were found between pure sugar yield and root yield (r = 0.966 ** and 0.958 **). The study results recommend the use of the integrative D₁ × K₃ × S₃ treatment for sugar beet to obtain maximum yields and qualities under salt stress (e.g., 8.96 dS m⁻¹) in dry environments. Full article

23 pages, 1100 KiB

Open AccessEditor’s ChoiceArticle

Fusarium Head Blight and Associated Mycotoxins in Grains and Straw of Barley: Influence of Agricultural Practices

by Dimitrios Drakopoulos, Michael Sulyok, Eveline Jenny, Andreas Kägi, Irene Bänziger, Antonio F. Logrieco, Rudolf Krska and Susanne Vogelgsang

Agronomy 2021, 11(4), 801; https://doi.org/10.3390/agronomy11040801 - 19 Apr 2021

Cited by 8 | Viewed by 2761

Abstract

Fusarium head blight (FHB) is a devastating fungal disease of small-grain cereals that causes significant yield losses and mycotoxin contamination, diminishing food and feed safety worldwide. In contrast to wheat, little is known about the agricultural practices that influence FHB and Fusarium mycotoxins [...] Read more.

Fusarium head blight (FHB) is a devastating fungal disease of small-grain cereals that causes significant yield losses and mycotoxin contamination, diminishing food and feed safety worldwide. In contrast to wheat, little is known about the agricultural practices that influence FHB and Fusarium mycotoxins in barley. Thus, a nationwide survey was conducted across Switzerland for harvest samples in 2016 and 2017, accompanied with a questionnaire to obtain information about the agricultural practices in each barley field. In total, 253 grain and 237 straw samples were analyzed. In both years, F. graminearum was the predominant Fusarium species in grains followed by F. avenaceum and F. poae. Growing maize before barley was associated with increased amount of F. graminearum DNA in grains and straw as well as with elevated concentrations of deoxynivalenol in grains of barley. On the other hand, growing pasture before barley resulted in increased incidence of F. poae and concentration of numerous mycotoxins in grains (e.g., enniatins) and straw (e.g., beauvericin). Reduced tillage practices were linked to increased incidence of F. graminearum and deoxynivalenol content in grains and straw. In contrast, conventional tillage was linked to higher incidence of F. poae. Moreover, use of spring barley was associated with decreased amount of F. graminearum DNA in grains and straw, but increased incidence of F. poae and F. avenaceum. Use of the spring variety Eunova was linked to increased concentrations of several Fusarium mycotoxins in grains (e.g., enniatins and nivalenol). Furthermore, the application of strobilurin-based fungicides was associated with higher deoxynivalenol and beauvericin contents in grains. The application of plant growth regulators was associated with increased concentration of some Fusarium mycotoxins in grains (e.g., culmorin), while absence of growth regulators application was linked to elevated concentration of some other mycotoxins (e.g., nivalenol). We conclude that individual agricultural practices can suppress some FHB causing species and reduce the associated mycotoxins, but can promote others. Hence, integrated control measures combining numerous prevention and intervention strategies should be applied for the sustainable management of mycotoxins in barley. Full article

(This article belongs to the Special Issue Strategies for the Control of Fusarium Head Blight in Cereals)

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12 pages, 1017 KiB

Open AccessEditor’s ChoiceArticle

Allometric Individual Leaf Area Estimation in Chrysanthemum

by Dimitrios Fanourakis, Filippos Kazakos and Panayiotis A. Nektarios

Agronomy 2021, 11(4), 795; https://doi.org/10.3390/agronomy11040795 - 18 Apr 2021

Cited by 28 | Viewed by 5388

Abstract

A model for estimating the area of individual leaves (LA) by employing their dimensions was developed for chrysanthemum. Further hypotheses were tested: (a) LA estimation is improved by considering blade length (L_b) rather than leaf length (L), and (b) a reasonable [...] Read more.

A model for estimating the area of individual leaves (LA) by employing their dimensions was developed for chrysanthemum. Further hypotheses were tested: (a) LA estimation is improved by considering blade length (L_b) rather than leaf length (L), and (b) a reasonable LA estimation can be attainable by considering L in conjunction to a shape trait, which is cultivar dependent. For the model development, six cultivars were employed (1500 leaves in total), while for model validation, an independent set of nine cultivars was utilized (1125 leaves in total). Several characteristics were digitally assessed in fully expanded leaves which included petiole length, leaf L, width (W), perimeter, shape traits (aspect ratio, circularity, roundness, solidity), together with LA. LA estimation was more accurate by considering both L and W, as compared to a single dimension. A linear model, employing the product of L by W as independent variable, provided the most accurate LA estimation (R² = 0.84). The model validation indicated a highly significant correlation between computed and measured LA (R² = 0.88). Replacing L by L_b reasonably predicted LA (R² = 0.832) but at some expense of accuracy. Contrary to expectation, considering L (or W) and a cultivar-specific shape trait generally led to poor LA estimations. Full article

(This article belongs to the Special Issue Biodiversity and Biocontrol in Horticulture: Methods and Statistical Analysis)

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18 pages, 3400 KiB

Open AccessEditor’s ChoiceArticle

Effects of Various Quantities of Three Irrigation Water Types on Yield and Fruit Quality of ‘Succary’ Date Palm

by Mohamed A. Mattar, Said S. Soliman and Rashid S. Al-Obeed

Agronomy 2021, 11(4), 796; https://doi.org/10.3390/agronomy11040796 - 18 Apr 2021

Cited by 15 | Viewed by 3275

Abstract

A field experiment was conducted on date palm trees (Phoenix dactylifera ‘Succary’) cultivated on sandy loam soil from 2017 to 2018. This study investigated the effects of providing water of three different qualities, namely freshwater (FR) and two saline water sources: reclaimed [...] Read more.

A field experiment was conducted on date palm trees (Phoenix dactylifera ‘Succary’) cultivated on sandy loam soil from 2017 to 2018. This study investigated the effects of providing water of three different qualities, namely freshwater (FR) and two saline water sources: reclaimed wastewater (RW) and well-water (WE) applied through three irrigation levels representing 50% (I₅₀), 100% (I₁₀₀), and 150% (I₁₅₀) of crop evapotranspiration (ET_c), on the soil water and salt distribution patterns, yield, water productivity (WP), and fruit quality of the ′Succary′ date palm. The electrical conductivity (EC_w) of FR, RW, and WE were 0.18, 2.06, and 3.94 dS m⁻¹, respectively. Results showed that WE applied by the I₁₅₀ treatment had the highest soil water content, followed by RW used in the I₁₀₀ irrigation level and FR with I₅₀, whereas the soil salt content was high for WE applied in the I₅₀ level and low for FR applied by the I₁₅₀ treatment. Deficit irrigation (I₅₀) of date palms with either RW or WE reduced date yields on average 86 kg per tree, whereas the yield increased under over-irrigation (I₁₅₀) with FR to 123.25 kg per tree. High WP values were observed in the I₅₀ treatments with FR, RW, or WE (on average 1.82, 1.68, and 1.67 kg m⁻³, respectively), whereas the I₁₅₀ treatment with each of the three water types showed the lowest WP values. Fruit weight and size were the lowest in the full irrigation (I₁₀₀) with WE, whereas the I₁₅₀ treatment with RW showed the highest values. There were no significant differences in either total soluble solids (TSS) or acidity values when the irrigation level decreased from 100% to 50% ET_c. Compared with both I₅₀ and I₁₀₀ treatments, reduced values of both TSS and acidity were observed in the I₁₅₀ treatment when EC_w decreased from 3.94 to 0.18 dS m⁻¹,. Fruit moisture content decreased with the application of saline irrigation water (i.e., RW or WE). Total sugar and non-reducing sugar contents in fruits were found to be decreased in the combination of RW and I₁₅₀, whereas the 50% ET_c irrigation level caused an increment in both parameters. These results suggest that the application of deficit irrigation to date palm trees grown in arid regions, either with FR or without it, can sufficiently maximize WP and improve the quality of fruits but negatively affects yield, especially when saline water is applied. The use of saline water for irrigation may negatively affect plants because of salt accumulation in the soil in the long run. Full article

(This article belongs to the Special Issue Physiological Effect of Saline Water and Recycled Wastewater on Horticultural Plants)

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17 pages, 836 KiB

Open AccessEditor’s ChoiceArticle

Dynamic of Morphological and Physiological Parameters and Variation of Soil Characteristics during Miscanthus × giganteus Cultivation in the Diesel-Contaminated Land

by Valentina Pidlisnyuk, Andriy Herts, Volodymyr Khomenchuk, Aigerim Mamirova, Oleksandr Kononchuk and Sergey Ust’ak

Agronomy 2021, 11(4), 798; https://doi.org/10.3390/agronomy11040798 - 18 Apr 2021

Cited by 16 | Viewed by 2135

Abstract

Miscanthus × giganteus (M. × giganteus) is a perspective plant produced on marginal and contaminated lands with biomass used for energy or bioproducts. In the current study, M. × giganteus development was tested in the diesel-contaminated soils (ranged from 250 mg [...] Read more.

Miscanthus × giganteus (M. × giganteus) is a perspective plant produced on marginal and contaminated lands with biomass used for energy or bioproducts. In the current study, M. × giganteus development was tested in the diesel-contaminated soils (ranged from 250 mg kg⁻¹ to 5000 mg kg⁻¹) and the growth dynamic, leaves quantity, plants total area, number of harvested stems and leaves, SPAD and NPQt parameters were evaluated. Results showed a remarkable M. × giganteus growth in a selected interval of diesel-contaminated soil with sufficient harvested biomass. The amendment of soil by biochar 1 (produced from wastewater sludge) and biochar 2 (produced from a mixture of wood waste and biohumus) improved the crop’s morphological and physiological parameters. Biochar 1 stimulated the increase of the stems’ biomass, while biochar 2 increased the leaves biomass. The plants growing in the uncontaminated soil decreased the content of NO₃, pH (KCl), P₂O₅ and increased the content of NH₄. Photosynthesis parameters showed that incorporating biochar 1 and biochar 2 to the diesel-contaminated soil prolonged the plants’ vegetation, which was more potent for biochar 1. M. × giganteus utilization united with biochar amendment can be recommended to remediate diesel-contaminated land in concentration range 250–5000 mg kg⁻¹. Full article

(This article belongs to the Special Issue Impact of Biochar and Compost on Soil Quality and Crop Yield)

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17 pages, 1823 KiB

Open AccessEditor’s ChoiceArticle

Effect of Low Temperature on Germination, Growth, and Seed Yield of Four Soybean (Glycine max L.) Cultivars

by Anna Szczerba, Agnieszka Płażek, Jakub Pastuszak, Przemysław Kopeć, Marta Hornyák and Franciszek Dubert

Agronomy 2021, 11(4), 800; https://doi.org/10.3390/agronomy11040800 - 18 Apr 2021

Cited by 24 | Viewed by 9592

Abstract

During germination at low temperatures, seeds rich in proteins may experience damage to their cytoplasmic membranes. The study aimed to investigate the influence of the germination temperature on growth, development, and yield of four cultivars of soybean, a typical thermophilic species. The seeds [...] Read more.

During germination at low temperatures, seeds rich in proteins may experience damage to their cytoplasmic membranes. The study aimed to investigate the influence of the germination temperature on growth, development, and yield of four cultivars of soybean, a typical thermophilic species. The seeds were germinated at 10, 15, and 25 °C in the dark. After 48 h, one part of the seeds was analyzed for their amylase and dehydrogenase activity, cell membrane permeability, and germination vigor. The other part was transferred into soil and cultivated up to yielding. Chlorophyll fluorescence, fresh (FW) and dry weight (DW) of shoots, pod and seed number, and seed DW were analyzed. The plants of cvs. ‘Abelina’, ‘Malaga’, and ‘Merlin’, germinating at low temperature, produced the highest number of seeds. Seed number negatively correlated with their DW and positively with the number of active reaction centers (RC/CS_m) in all cultivars. In cvs. ‘Abelina’ and ‘Malaga’, the number of seeds also positively correlated with the index performance of photosystem II (PSII), which was the highest in all plants germinating at low temperature. We suggest cultivating cv. ‘Abelina’ in cooler regions, while cvs. ‘Petrina’ and ‘Malaga’ in warmer areas. Full article

(This article belongs to the Special Issue Frost Tolerance and Cold Acclimation of Crops)

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12 pages, 2141 KiB

Open AccessEditor’s ChoiceArticle

Compost Tea Induces Growth and Resistance against Rhizoctonia solani and Phytophthora capsici in Pepper

by Ana Isabel González-Hernández, M. Belén Suárez-Fernández, Rodrigo Pérez-Sánchez, María Ángeles Gómez-Sánchez and María Remedios Morales-Corts

Agronomy 2021, 11(4), 781; https://doi.org/10.3390/agronomy11040781 - 16 Apr 2021

Cited by 20 | Viewed by 5344

Abstract

Compost teas (CTs) are organic solutions that constitute an interesting option for sustainable agriculture. Those that come from garden waste have been applied in vitro and in vivo on pepper plants to determine its suppressive effect against both Phytophthora capsici and Rhizoctonia solani [...] Read more.

Compost teas (CTs) are organic solutions that constitute an interesting option for sustainable agriculture. Those that come from garden waste have been applied in vitro and in vivo on pepper plants to determine its suppressive effect against both Phytophthora capsici and Rhizoctonia solani. The studied CT showed relevant content in NO₃⁻, K₂O, humic acids, and microorganisms such as aerobic bacteria, N-fixing bacteria, and actinobacteria, which play a role in plant growth and resistance. This rich abundance of microbiota in the CT induced a reduction in the relative growth rate of both P. capsici and R. solani (31.7% and 38.0%, respectively) in in vitro assays compared to control. In addition, CT-irrigated plants displayed increased growth parameters and showed the first open flower one week before those treatments without CTs, which suggests that its application advanced the crop cycle. Concerning pathogen infection, damage caused by both pathogens became more apparent with a one-week inoculation compared to a four-week inoculation, which may indicate that a microbiological and chemical balance had been reached to cope with biotic stresses. Based on these results, we conclude that CT application induces plant growth and defense in pepper plants against P. capsici and R. solani because of its relevant soluble nutrient content and microbiota richness, which provides a novel point for plant nutrition and protection in horticultural crops. Full article

(This article belongs to the Special Issue New Advances on Nutrients Recovery from Agro-Industrial and Livestock Wastes for Sustainable Farming)

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8 pages, 861 KiB

Open AccessEditor’s ChoiceCommunication

Induction of Promoter DNA Methylation Upon High-Pressure Spraying of Double-Stranded RNA in Plants

by Athanasios Dalakouras and Ioannis Ganopoulos

Agronomy 2021, 11(4), 789; https://doi.org/10.3390/agronomy11040789 - 16 Apr 2021

Cited by 14 | Viewed by 2992

Abstract

Exogenous application of RNA molecules is a potent method to trigger RNA interference (RNAi) in plants in a transgene-free manner. So far, all exogenous RNAi (exo-RNAi) applications have aimed to trigger mRNA degradation of a given target. However, the issue of concomitant epigenetic [...] Read more.

Exogenous application of RNA molecules is a potent method to trigger RNA interference (RNAi) in plants in a transgene-free manner. So far, all exogenous RNAi (exo-RNAi) applications have aimed to trigger mRNA degradation of a given target. However, the issue of concomitant epigenetic changes was never addressed. Here, we report for the first time that high-pressure spraying of dsRNAs can trigger de novo methylation of promoter sequences in plants. Full article

(This article belongs to the Special Issue Breeding of Horticulture Plants: High-Throughput Sequencing Strategies in an Omics Era)

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17 pages, 2858 KiB

Open AccessEditor’s ChoiceArticle

Foliar Application of Auxin or Cytokinin Can Confer Salinity Stress Tolerance in Vicia faba L.

by Arafat Abdel Hamed Abdel Latef, Ayasha Akter and Md. Tahjib-Ul-Arif

Agronomy 2021, 11(4), 790; https://doi.org/10.3390/agronomy11040790 - 16 Apr 2021

Cited by 27 | Viewed by 3873

Abstract

Soil salinity severely declines the availability of water and essential minerals to the plants, which hinders growth. The present study evaluates the potential roles of indole-3-acetic acid (IAA) and 6-benzyladenine (BA) for mitigating the adverse effects of soil-salinity in faba bean (Vicia [...] Read more.

Soil salinity severely declines the availability of water and essential minerals to the plants, which hinders growth. The present study evaluates the potential roles of indole-3-acetic acid (IAA) and 6-benzyladenine (BA) for mitigating the adverse effects of soil-salinity in faba bean (Vicia faba L.). Plants were exposed to 150 mM NaCl stress and were sprayed with IAA (1.15 mM) or BA (0.9 mM). Our results revealed that foliar application of IAA or BA improved the growth traits of salinized faba bean due to the increased uptake of K⁺, Ca²⁺, and Mg²⁺ ions, accumulation of free amino acids, soluble sugars, and soluble proteins, and activity of superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase. The principal component analysis (PCA) and heatmap clustering indicated that salinity-exposed plants exhibited lower growth and biomass production, which correlated with higher accumulation of Na⁺ and malondialdehyde. Moreover, electrophoretic patterns of protein showed new bands in IAA- or BA-treated salt-stressed plants, indicating that IAA or BA treatment can reprogram the metabolic processes to confer salinity tolerance. We also found that IAA has a greater capacity to ameliorate the salt stress than BA, although there is no significant difference in yield between these treatments. Finally, these findings can be helpful for a better understanding of IAA- and BA-mediated salt tolerance mechanisms and increasing production of faba bean in saline soils. Full article

(This article belongs to the Special Issue Hormone Signaling Underlying Defense Responses and environmental Stresses in Crop Plants)

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11 pages, 268 KiB

Open AccessEditor’s ChoiceArticle

Supplementation of Organic Amendments Improve Yield and Adaptability by Reducing the Toxic Effect of Copper in Cocksfoot Grass (Dactylis glomerata L. Cv Amera)

by Beata Kuziemska, Joanna Trębicka, Andrzej Wysokinski and Dawid Jaremko

Agronomy 2021, 11(4), 791; https://doi.org/10.3390/agronomy11040791 - 16 Apr 2021

Cited by 7 | Viewed by 1854

Abstract

Copper is an element necessary for the proper growth and development of plants, but when taken in excess amounts, it can be toxic. Its availability for plant can be reduced by using organic fertilizers or soil liming. The aim of the study was [...] Read more.

Copper is an element necessary for the proper growth and development of plants, but when taken in excess amounts, it can be toxic. Its availability for plant can be reduced by using organic fertilizers or soil liming. The aim of the study was to investigate the effect of increasing doses of copper (100, 200, and 300 mg Cu·kg⁻¹ of soil) application in combination with various organic amendments (cattle manure, chicken manure, and spent mushroom substrate) on the yield of cocksfoot and its content and uptake of this metal, and to determine its coefficient of bioaccumulation and tolerance indices. The toxic effect of copper manifested by significant decrease in the yield of the test plant was after the application of 300 mg·kg⁻¹ of soil. Increasing doses of copper application increased its content and uptake by the test plant, while observing the decreasing bioaccumulation factor. All the soil amendments reduced the toxic effect of copper on cocksfoot. The most effective organic amendment in terms of yield and protective effects against high levels of copper was cattle manure, in the case of which the Org/Cu and Cu/Org tolerance indices were highest. Full article

(This article belongs to the Special Issue Heavy Metal Pollution and Its Effects on Agriculture)

15 pages, 1126 KiB

Open AccessEditor’s ChoiceArticle

Rice Blast (Magnaporthe oryzae) Occurrence Prediction and the Key Factor Sensitivity Analysis by Machine Learning

by Li-Wei Liu, Sheng-Hsin Hsieh, Su-Ju Lin, Yu-Min Wang and Wen-Shin Lin

Agronomy 2021, 11(4), 771; https://doi.org/10.3390/agronomy11040771 - 15 Apr 2021

Cited by 19 | Viewed by 4289

Abstract

This study aimed to establish a machine learning (ML)-based rice blast predicting model to decrease the appreciable losses based on short-term environment data. The average, highest and lowest air temperature, average relative humidity, soil temperature and solar energy were selected for model development. [...] Read more.

This study aimed to establish a machine learning (ML)-based rice blast predicting model to decrease the appreciable losses based on short-term environment data. The average, highest and lowest air temperature, average relative humidity, soil temperature and solar energy were selected for model development. The developed multilayer perceptron (MLP), support vector machine (SVM), Elman recurrent neural network (Elman RNN) and probabilistic neural network (PNN) were evaluated by F-measures. Finally, a sensitivity analysis (SA) was conducted for the factor importance assessment. The study result shows that the PNN performed best with the F-measure (β = 2) of 96.8%. The SA was conducted in the PNN model resulting in the main effect period is 10 days before the rice blast happened. The key factors found are minimum air temperature, followed by solar energy and equaled sensitivity of average relative humidity, maximum air temperature and soil temperature. The temperature phase lag in air and soil may cause a lower dew point and suitable for rice blast pathogens growth. Through this study’s results, rice blast warnings can be issued 10 days in advance, increasing the response time for farmers preparing related preventive measures, further reducing the losses caused by rice blast. Full article

(This article belongs to the Special Issue Machine Learning Applications in Digital Agriculture)

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13 pages, 249 KiB

Open AccessEditor’s ChoiceArticle

The Effect of Salicylic Acid on the Performances of Salt Stressed Strawberry Plants, Enzymes Activity, and Salt Tolerance Index

by Alaa El-Den Roshdy, Abdullah Alebidi, Khalid Almutairi, Rashid Al-Obeed and Ahmed Elsabagh

Agronomy 2021, 11(4), 775; https://doi.org/10.3390/agronomy11040775 - 15 Apr 2021

Cited by 26 | Viewed by 2545

Abstract

The influence of salicylic acid (SA) on growth, yield, fruits’ quality and enzymes’ activities was monitored in strawberry plants cv. Camarosa grown under salinity stress via two pot experiments in two successive years of 2018 and 2019. The examined concentrations of SA were [...] Read more.

The influence of salicylic acid (SA) on growth, yield, fruits’ quality and enzymes’ activities was monitored in strawberry plants cv. Camarosa grown under salinity stress via two pot experiments in two successive years of 2018 and 2019. The examined concentrations of SA were 30, 60, and 90 ppm, which foliary applied in addition to control (sprayed with water), while the used levels of salinity were 20, and 40 mM as NaCl as irrigation application in addition to control (without salinity). The results showed a significant effect of salinity at 40 mM where the mean values of shoot fresh and dry weights, chlorophyll, leaves’ NPK, yield plant⁻¹, yield ha⁻¹, and fruits’ ascorbic acid were significantly decreased. However, the 40 mM salinity resulted in a significant increase in leaves’ content of Na and proline as well as catalase (CAT) and peroxidase (POD) enzymes’ activity and the fruits’ TSS and acidity. The application with 90 ppm SA was found to be the most significant positive treatment for all of the studied characters except the Na leaves’ content. Regarding tolerance index percentages (STI%), the high values of CAT, POD, and proline referred to the ability to use them as indicators for strawberry salinity response in other physiological and plant breeding studies. The findings of this study suggest that the 90 ppm SA foliar application can ameliorate the negative effect of salinity on the growth of strawberry cv. Camarosa. Full article

(This article belongs to the Section Horticultural and Floricultural Crops)

21 pages, 3099 KiB

Open AccessEditor’s ChoiceArticle

The Soil Organic Matter in Connection with Soil Properties and Soil Inputs

by Václav Voltr, Ladislav Menšík, Lukáš Hlisnikovský, Martin Hruška, Eduard Pokorný and Lubica Pospíšilová

Agronomy 2021, 11(4), 779; https://doi.org/10.3390/agronomy11040779 - 15 Apr 2021

Cited by 61 | Viewed by 6158

Abstract

The content of organic matter in the soil, its labile (hot water extractable carbon–HWEC) and stable (soil organic carbon–SOC) form is a fundamental factor affecting soil productivity and health. The current research in soil organic matter (SOM) is focused on individual fragmented approaches [...] Read more.

The content of organic matter in the soil, its labile (hot water extractable carbon–HWEC) and stable (soil organic carbon–SOC) form is a fundamental factor affecting soil productivity and health. The current research in soil organic matter (SOM) is focused on individual fragmented approaches and comprehensive evaluation of HWEC and SOC changes. The present state of the soil together with soil’s management practices are usually monitoring today but there has not been any common model for both that has been published. Our approach should help to assess the changes in HWEC and SOC content depending on the physico-chemical properties and soil´s management practices (e.g., digestate application, livestock and mineral fertilisers, post-harvest residues, etc.). The one- and multidimensional linear regressions were used. Data were obtained from the various soil´s climatic conditions (68 localities) of the Czech Republic. The Czech farms in operating conditions were observed during the period 2008–2018. The obtained results of ll monitored experimental sites showed increasing in the SOC content, while the HWEC content has decreased. Furthermore, a decline in pH and soil´s saturation was documented by regression modelling. Mainly digestate application was responsible for this negative consequence across all soils in studied climatic regions. The multivariate linear regression models (MLR) also showed that HWEC content is significantly affected by natural soil fertility (soil type), phosphorus content (−30%), digestate application (+29%), saturation of the soil sorption complex (SEBCT, 21%) and the dose of total nitrogen (N) applied into the soil (−20%). Here we report that the labile forms (HWEC) are affected by the application of digestate (15%), the soil saturation (37%), the application of mineral potassium (−7%), soil pH (−14%) and the overall condition of the soil (−27%). The stable components (SOM) are affected by the content of HWEC (17%), soil texture 0.01–0.001mm (10%), and input of organic matter and nutrients from animal production (10%). Results also showed that the mineral fertilization has a negative effect (−14%), together with the soil depth (−11%), and the soil texture 0.25–2 mm (−21%) on SOM. Using modern statistical procedures (MRLs) it was confirmed that SOM plays an important role in maintaining resp. improving soil physical, biochemical and biological properties, which is particularly important to ensure the productivity of agroecosystems (soil quality and health) and to future food security. Full article

(This article belongs to the Special Issue Humic Substances: A Novel Eco-Friendly Fertilizer)

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22 pages, 1266 KiB

Open AccessEditor’s ChoiceArticle

Integrated Application of K and Zn as an Avenue to Promote Sugar Beet Yield, Industrial Sugar Quality, and K-Use Efficiency in a Salty Semi-Arid Agro-Ecosystem

by Ali A. A. Mekdad, Ahmed Shaaban, Mostafa M. Rady, Esmat F. Ali and Fahmy A. S. Hassan

Agronomy 2021, 11(4), 780; https://doi.org/10.3390/agronomy11040780 - 15 Apr 2021

Cited by 13 | Viewed by 2092

Abstract

Salinity combined with a deficiency of potassium (K) and zinc (Zn) negatively affect sugar beet yield and quality. A two-year (2017/18–2018/19) field trial was undertaken to investigate the mediating role of soil-applied K [120 (K₁₂₀) and 180 (K₁₈₀) kg [...] Read more.

Salinity combined with a deficiency of potassium (K) and zinc (Zn) negatively affect sugar beet yield and quality. A two-year (2017/18–2018/19) field trial was undertaken to investigate the mediating role of soil-applied K [120 (K₁₂₀) and 180 (K₁₈₀) kg ha⁻¹] and foliar-applied Zn [0 (Zn₀), 150 (Zn₁₅₀), and 300 (Zn₃₀₀) ppm] in alleviating salt-stress (8.60 dS m⁻¹) based on sugar beet morpho-physiological responses, sugar yield and quality, and K-use efficiency in the BTS 301 and Kawemira cultivars. Application of K₁₈₀ × Zn₃₀₀ was more effective and resulted in 23.39 and 37.78% higher root yield (RY) and pure sugar yield (PSY), respectively, compared to control (K₁₂₀ × Zn₀). It also enhanced sucrose, pure sugar (PS), and purity but decreased impurities (α-amino N, K, and Na), alkalinity index, and sugar loss. However, the K₁₂₀ × Zn₃₀₀ recorded higher K-use efficiency. PSY correlated positively (r = 0.776 **, 0.629 **, 0.602 **, 0.549 **, and 0.513 **) with RY, root fresh weight (RFW), top yield, PS, and root diameter, respectively. The stepwise and path-coefficient analysis demonstrated that RY, PS, and RFW were the most influential PSY-affected attributes. Integration of K₁₈₀ + Zn₃₀₀ can correct K and Zn deficiencies in the soil and mitigate salt-stress effects via improving sugar beet growth, yield and quality, and K-use efficiency. Full article

(This article belongs to the Special Issue Improving Mineral Nutrition to Obtain Stress Tolerant Crops)

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30 pages, 2923 KiB

Open AccessEditor’s ChoiceReview

Factors That Influence Nitrous Oxide Emissions from Agricultural Soils as Well as Their Representation in Simulation Models: A Review

by Cong Wang, Barbara Amon, Karsten Schulz and Bano Mehdi

Agronomy 2021, 11(4), 770; https://doi.org/10.3390/agronomy11040770 - 14 Apr 2021

Cited by 104 | Viewed by 12357

Abstract

Nitrous oxide (N₂O) is a long-lived greenhouse gas that contributes to global warming. Emissions of N₂O mainly stem from agricultural soils. This review highlights the principal factors from peer-reviewed literature affecting N₂O emissions from agricultural soils, by [...] Read more.

Nitrous oxide (N₂O) is a long-lived greenhouse gas that contributes to global warming. Emissions of N₂O mainly stem from agricultural soils. This review highlights the principal factors from peer-reviewed literature affecting N₂O emissions from agricultural soils, by grouping the factors into three categories: environmental, management and measurement. Within these categories, each impact factor is explained in detail and its influence on N₂O emissions from the soil is summarized. It is also shown how each impact factor influences other impact factors. Process-based simulation models used for estimating N₂O emissions are reviewed regarding their ability to consider the impact factors in simulating N₂O. The model strengths and weaknesses in simulating N₂O emissions from managed soils are summarized. Finally, three selected process-based simulation models (Daily Century (DAYCENT), DeNitrification-DeComposition (DNDC), and Soil and Water Assessment Tool (SWAT)) are discussed that are widely used to simulate N₂O emissions from cropping systems. Their ability to simulate N₂O emissions is evaluated by describing the model components that are relevant to N₂O processes and their representation in the model. Full article

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16 pages, 3722 KiB

Open AccessEditor’s ChoiceArticle

Maize Seedling Establishment, Grain Yield and Crop Water Productivity Response to Seed Priming and Irrigation Management in a Mediterranean Arid Environment

by AbdAllah M. El-Sanatawy, Ahmed S. M. El-Kholy, Mohamed M. A. Ali, Mohamed F. Awad and Elsayed Mansour

Agronomy 2021, 11(4), 756; https://doi.org/10.3390/agronomy11040756 - 13 Apr 2021

Cited by 29 | Viewed by 4628

Abstract

Water shortage is a major environmental stress that destructively impacts maize production, particularly in arid regions. Therefore, improving irrigation management and increasing productivity per unit of water applied are needed, especially under the rising temperature and precipitation fluctuations induced by climate change. Laboratory [...] Read more.

Water shortage is a major environmental stress that destructively impacts maize production, particularly in arid regions. Therefore, improving irrigation management and increasing productivity per unit of water applied are needed, especially under the rising temperature and precipitation fluctuations induced by climate change. Laboratory and field trials were carried out in the present study, which were aimed at assessing the possibility of promoting maize germination, growth, grain yield and crop water productivity (CWP) using seed priming under different irrigation regimes. Two seed priming treatments, i.e., hydro-priming and hardening versus unprimed seeds, were applied under four irrigation regimes, i.e., 120, 100, 80 and 60% of estimated crop evapotranspiration (ETc). The obtained results indicated that increasing irrigation water from 100% up to 120% ETc did not significantly increase grain yield or contributing traits, while it decreased CWP. Deficit irrigation of 80 and 60% ETc gradually decreased grain yield and all attributed traits. Seed priming significantly ameliorated seedlings’ vigor as indicated by earlier germination, higher germination percentage, longer roots and shoots, and heavier fresh and dry weight than unprimed seeds with the superiority of hardening treatment. Additionally, under field conditions, seed priming significantly increased grain yield, yield contributing traits and CWP compared with unprimed treatment. Interestingly, the results reflect the role of seed priming, particularly hardening, in mitigating negative impacts of drought stress and enhancing maize growth, grain yield and attributed traits as well as CWP under deficit irrigation conditions. This was demonstrated by a significant increase in grain yield and CWP under moderate drought and severe drought conditions compared with unprimed treatment. These results highlight that efficient irrigation management and seed priming can increase maize yield and water productivity in arid environments. Full article

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17 pages, 706 KiB

Open AccessEditor’s ChoiceReview

Recent Advances on Nitrogen Use Efficiency in Rice

by Sichul Lee

Agronomy 2021, 11(4), 753; https://doi.org/10.3390/agronomy11040753 - 13 Apr 2021

Cited by 32 | Viewed by 6082

Abstract

Rice (Oryza sativa L.) is a daily staple food crop for more than half of the global population and improving productivity is an important task to meet future demands of the expanding world population. The application of nitrogen (N) fertilization improved rice [...] Read more.

Rice (Oryza sativa L.) is a daily staple food crop for more than half of the global population and improving productivity is an important task to meet future demands of the expanding world population. The application of nitrogen (N) fertilization improved rice growth and productivity in the world, but excess use causes environmental and economic issues. One of the main goals of rice breeding is reducing N fertilization while maintaining productivity. Therefore, enhancing rice nitrogen use efficiency (NUE) is essential for the development of sustainable agriculture and has become urgently needed. Many studies have been conducted on the main steps in the use of N including uptake and transport, reduction and assimilation, and translocation and remobilization, and on transcription factors regulating N metabolism. Understanding of these complex processes provides a base for the development of novel strategies to improve NUE for rice productivity under varying N conditions. Full article

(This article belongs to the Special Issue Rice Genetics: Trends and Challenges for the Future Crops Production)

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15 pages, 3729 KiB

Open AccessEditor’s ChoiceArticle

Simultaneous Determination of Carotenoids and Chlorophylls by the HPLC-UV-VIS Method in Soybean Seeds

by Berhane Sibhatu Gebregziabher, Shengrui Zhang, Jie Qi, Muhammad Azam, Suprio Ghosh, Yue Feng, Yuanyuan Huai, Jing Li, Bin Li and Junming Sun

Agronomy 2021, 11(4), 758; https://doi.org/10.3390/agronomy11040758 - 13 Apr 2021

Cited by 14 | Viewed by 4846

Abstract

Soybean contains nutritional bioactive compounds, including carotenoids associated with human health benefits. Carotenoids are applicable in pharmaceuticals/nutreceuticals, cosmetic, and mainly food industries. However, an efficient and accurate method for carotenoid and chlorophyll detection and quantification has not yet been developed and validated for [...] Read more.

Soybean contains nutritional bioactive compounds, including carotenoids associated with human health benefits. Carotenoids are applicable in pharmaceuticals/nutreceuticals, cosmetic, and mainly food industries. However, an efficient and accurate method for carotenoid and chlorophyll detection and quantification has not yet been developed and validated for soybean seeds. The need for a rapid and reliable analysis method has become increasingly important. Thus, this study was initiated to develop and validate a simple, rapid, and selective reversed-phase high-performance liquid chromatographic (RP-HPLC) method for the simultaneous determination of lutein, zeaxanthin, α-carotene, β–carotene, β–cryptoxanthin, and chlorophyll–a and –b in soybean flour sample (100.00 mg) extracted using ethanol-acetone (1:1) solvents at a volume of 1.50 mL. Interestingly, the effective separation technique was achieved using the mobile phases of methyl tert-butyl ether, methanol containing 10 mM ammonium acetate, and water delivered at a 0.90 mL min⁻¹ flow rate through a C₃₀YMC Carotenoid (250 × 4.6 mm I.D., S-5 µm) column coupled with a UV-VIS detector set at 450 nm. The detector response was linear from 0.05–30.00 μg mL⁻¹ with a coefficient of determination (R²) of 0.9993–0.9999. The validated method was sensitive with a detection limit (LOD) of 0.0051–0.0300 μg mL⁻¹ and 0.0155–0.0909 μg mL⁻¹ for the quantification limit (LOQ). The recovery values were from 83.12–106.58%, and the repeatability precision ranged from 1.25–4.20% and 0.15–0.81% for the method and system, respectively. The method showed adequate precision with a relative standard deviation smaller than 3.00%. This method was also found to be applicable for profiling carotenoids and chlorophylls in other legumes. In summary, this method was successfully implemented for qualitative and quantitative determination of major carotenoids and chlorophylls in soybean and other legume seeds, which are beneficial to food industry and quality breeding programs to meet human nutrition demands globally. Full article

(This article belongs to the Section Crop Breeding and Genetics)

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17 pages, 6094 KiB

Open AccessEditor’s ChoiceArticle

Leaf Age-Dependent Effects of Boron Toxicity in Two Cucumis melo Varieties

by Theocharis Chatzistathis, Dimitrios Fanourakis, Sasan Aliniaeifard, Anastasios Kotsiras, Costas Delis and Georgios Tsaniklidis

Agronomy 2021, 11(4), 759; https://doi.org/10.3390/agronomy11040759 - 13 Apr 2021

Cited by 20 | Viewed by 2456

Abstract

Boron (B) is an essential nutrient for plant growth and development, exhibiting extremely narrow margins between deficiency and toxicity. B toxicity is devastating for productivity and apparent for a continuously increasing part of agricultural land, under the influence of on-going climate change. In [...] Read more.

Boron (B) is an essential nutrient for plant growth and development, exhibiting extremely narrow margins between deficiency and toxicity. B toxicity is devastating for productivity and apparent for a continuously increasing part of agricultural land, under the influence of on-going climate change. In this study, the effects of increased B supply (by using H₃BO₃) were addressed by examining critical physiological responses of young and mature leaves, which were devoid of toxicity symptoms, in two melon varieties (Armenian cucumbers, cantaloupes). B was primarily translocated through the transpiration stream, and secondarily via the active cell membrane transport system. The B distribution pattern was independent of leaf age, and remained rather unchanged under increased B supply. Armenian cucumbers, exhibiting higher leaf B levels, underwent an enhanced adverse impact on (root and shoot) growth, photosynthetic pigment content, cellular membrane integrity, and also exhibited attenuated antioxidant defense stimulation. Notably, and unlike other abiotic stressors, no evidence of B toxicity-induced systemic reaction was apparent. B toxicity greatly enhanced the transcription of the genes coding for borate influx and efflux channels, an effect that was mostly evident in mature leaves. In conclusion, shoot physiological responses to B toxicity are highly localized. Moreover, the obstruction of the diffusion and the B translocation to the aerial organs under increased B supply is genotype-dependent, governing plant physiological responses. Full article

(This article belongs to the Special Issue Valorization of Plant-Genetic Resources and Microbial Communities to Cope with Biotic/Abiotic Stress)

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13 pages, 6354 KiB

Open AccessEditor’s ChoiceArticle

Nozzle Selection and Adjuvant Impact on the Efficacy of Glyphosate and PPO-Inhibiting Herbicide Tank-Mixtures

by Jesaelen G. Moraes, Thomas R. Butts, Vitor M. Anunciato, Joe D. Luck, Wesley C. Hoffmann, Ulisses R. Antuniassi and Greg R. Kruger

Agronomy 2021, 11(4), 754; https://doi.org/10.3390/agronomy11040754 - 13 Apr 2021

Cited by 10 | Viewed by 3109

Abstract

PPO-inhibiting herbicides in combination with glyphosate for postemergence applications is a common approach to manage glyphosate- and ALS-inhibitor-resistant weeds. PPO-inhibitors can reduce glyphosate translocation when applied in tank-mixtures, but adjuvants may be used to overcome this effect. Additionally, optimal droplet size may be [...] Read more.

PPO-inhibiting herbicides in combination with glyphosate for postemergence applications is a common approach to manage glyphosate- and ALS-inhibitor-resistant weeds. PPO-inhibitors can reduce glyphosate translocation when applied in tank-mixtures, but adjuvants may be used to overcome this effect. Additionally, optimal droplet size may be affected by tank-mixtures of different herbicides and it can be crucial to herbicide efficacy. Field and greenhouse studies were conducted to investigate the impact of nozzle selection and adjuvants on weed control and interactions when applying PPO-inhibitors (fomesafen or lactofen) alone or in tank-mixture with glyphosate to five weed species using six nozzle types. Ultra-coarse droplets were just as effective as medium droplets regardless of the spray solution, but have a lower likelihood of off-target movement. Tank-mixtures applied were consistently antagonistic to common lambsquarters, horseweed, and Palmer amaranth. Only fomesafen was antagonistic to kochia whereas synergistic interactions were observed when glyphosate plus lactofen were applied in combination with COC, DRA + COC, or NIS. Separate applications are advisable with herbicide- and weed-specific situations to avoid antagonism, which is necessary to achieve optimum weed control and maintain the effectiveness of PPO-inhibitors. Future research should continue to look at these important interactions across a wide range of weed species. Full article

(This article belongs to the Section Weed Science and Weed Management)

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14 pages, 6212 KiB

Open AccessEditor’s ChoiceArticle

The Protective Biochemical Properties of Arbuscular Mycorrhiza Extraradical Mycelium in Acidic Soils Are Maintained throughout the Mediterranean Summer Conditions

by Jorge M. S. Faria, Dora Martins Teixeira, Ana Paula Pinto, Isabel Brito, Pedro Barrulas and Mário Carvalho

Agronomy 2021, 11(4), 748; https://doi.org/10.3390/agronomy11040748 - 12 Apr 2021

Cited by 14 | Viewed by 2070

Abstract

In acidic soils with manganese (Mn) toxicity, arbuscular mycorrhizal fungi (AMF) can improve plant host growth by enhancing nutrition and protecting against environmental stress. The intact extraradical mycelium (ERM) of AMF is able to survive Mediterranean summer conditions and provide an earlier colonization [...] Read more.

In acidic soils with manganese (Mn) toxicity, arbuscular mycorrhizal fungi (AMF) can improve plant host growth by enhancing nutrition and protecting against environmental stress. The intact extraradical mycelium (ERM) of AMF is able to survive Mediterranean summer conditions and provide an earlier colonization of winter crops. This study evaluated if summer season conditions hindered the beneficial effects of wheat colonization by the intact ERM associated with a native plant, in acidic soil. Wheat was grown in soil with intact or disrupted ERM associated with Ornithopus compressus (ORN), developed for 7 or 24 weeks, to simulate ERM summer survival. The activity of antioxidant enzymes was determined, and the quantitative analysis of Mn and macronutrients was performed by inductively coupled plasma mass spectrometry (ICP-MS), in wheat shoots and respective subcellular fractions. Wheat colonization by intact ERM decreased shoot Mn concentration but increased the proportion of Mn in the apoplast. Overall, antioxidant enzymatic activity decreased but the proportion of Mn-superoxide dismutase activity over the remaining isoforms increased, suggesting its important role in the AMF-mediated mitigation of Mn toxicity. Summer conditions did not substantially reduce the benefits provided by ORN ERM. A no-till strategy allied to the development of native microbiota can contribute to the sustainable optimization of acidic soil use. Full article

(This article belongs to the Section Farming Sustainability)

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16 pages, 2859 KiB

Open AccessEditor’s ChoiceArticle

Agro-Environmental Sustainability of Anaerobic Digestate Fractions in Intensive Cropping Systems: Insights Regarding the Nitrogen Use Efficiency and Crop Performance

by Federico Grillo, Ilaria Piccoli, Ivan Furlanetto, Francesca Ragazzi, Silvia Obber, Tiziano Bonato, Francesco Meneghetti and Francesco Morari

Agronomy 2021, 11(4), 745; https://doi.org/10.3390/agronomy11040745 - 12 Apr 2021

Cited by 18 | Viewed by 2403

Abstract

Digestate is an anaerobic digestion by-product rich in inorganic-nitrogen (N) that can be used as an organic fertilizer. Digestate agronomic efficiency and its impact on the environment have not yet been studied in detail, therefore this study tries to fill this gap. The [...] Read more.

Digestate is an anaerobic digestion by-product rich in inorganic-nitrogen (N) that can be used as an organic fertilizer. Digestate agronomic efficiency and its impact on the environment have not yet been studied in detail, therefore this study tries to fill this gap. The agro-environmental sustainability of digestate fractions was evaluated in a holistic way by comparing the best management practices available in the Veneto Region agroecosystem. A farm experiment involving mineral fertilizer and both liquid and solid digestate fractions was established involving silage winter wheat and silage maize as main crops. Agro-environmental sustainability was investigated coupling crop performance analysis (e.g., yield, N uptake and N use efficiency (NUE)) with a novel proposed agro-environmental sustainability index (AESI) (i.e., product of the dry yield and NUE). The results showed that the liquid digestate fraction gave agronomic performances comparable to mineral fertilizers and a satisfying AESI while solid digestate showed lower performances. In conclusion, liquid digestate fractions might be an effective substitute for mineral fertilizers in the Veneto region agroecosystem reaching encouraging levels of agro-environmental sustainability. On the contrary, longer-term experiments are requested to evaluate solid digestate fraction sustainability. Full article

(This article belongs to the Special Issue New Methods for Plant Nutrition Management)

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26 pages, 17645 KiB

Open AccessEditor’s ChoiceArticle

Remote and Proximal Sensing-Derived Spectral Indices and Biophysical Variables for Spatial Variation Determination in Vineyards

by Nicoleta Darra, Emmanouil Psomiadis, Aikaterini Kasimati, Achilleas Anastasiou, Evangelos Anastasiou and Spyros Fountas

Agronomy 2021, 11(4), 741; https://doi.org/10.3390/agronomy11040741 - 11 Apr 2021

Cited by 23 | Viewed by 3400

Abstract

Remote-sensing measurements are crucial for smart-farming applications, crop monitoring, and yield forecasting, especially in fields characterized by high heterogeneity. Therefore, in this study, Precision Viticulture (PV) methods using proximal- and remote-sensing technologies were exploited and compared in a table grape vineyard to monitor [...] Read more.

Remote-sensing measurements are crucial for smart-farming applications, crop monitoring, and yield forecasting, especially in fields characterized by high heterogeneity. Therefore, in this study, Precision Viticulture (PV) methods using proximal- and remote-sensing technologies were exploited and compared in a table grape vineyard to monitor and evaluate the spatial variation of selected vegetation indices and biophysical variables throughout selected phenological stages (multi-seasonal data), from veraison to harvest. The Normalized Difference Vegetation Index and the Normalized Difference Red-Edge Index were calculated by utilizing satellite imagery (Sentinel-2) and proximal sensing (active crop canopy sensor Crop Circle ACS-470) to assess the correlation between the outputs of the different sensing methods. Moreover, numerous vegetation indices and vegetation biophysical variables (VBVs), such as the Modified Soil Adjusted Vegetation Index, the Normalized Difference Water Index, the Fraction of Vegetation Cover, and the Fraction of Absorbed Photosynthetically Active Radiation, were calculated, using the satellite data. The vegetation indices analysis revealed different degrees of correlation when using diverse sensing methods, various measurement dates, and different parts of the cultivation. The results revealed the usefulness of proximal- and remote-sensing-derived vegetation indices and variables and especially of Normalized Difference Vegetation Index and Fraction of Absorbed Photosynthetically Active Radiation in the monitoring of vineyard condition and yield examining, since they were demonstrated to have a very high degree of correlation (coefficient of determination was 0.87). The adequate correlation of the vegetation indices with the yield during the latter part of the veraison stage provides valuable information for the future estimation of production in broader areas. Full article

(This article belongs to the Special Issue Smart Farming in Service of Modernizing Agriculture)

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25 pages, 7470 KiB

Open AccessEditor’s ChoiceArticle

Metabonomic Profiling Analyses Reveal ANS Upregulation to Enhance the Flavonoid Pathway of Purple-Fleshed Sweet Potato Storage Root in Response to Deep Shading

by Ying He, Dan Zhu, Yujun Sun, Qian Wang, Lan Zhu and Hanlai Zeng

Agronomy 2021, 11(4), 737; https://doi.org/10.3390/agronomy11040737 - 10 Apr 2021

Cited by 8 | Viewed by 2064

Abstract

Intercropping, as a common worldwide cultivation pattern, provides opportunities for sustainable agriculture with fuller use of light, temperature and land resources and greater yield per unit of land. The intercropping impact on crop quality is a current focus. This study found that shading [...] Read more.

Intercropping, as a common worldwide cultivation pattern, provides opportunities for sustainable agriculture with fuller use of light, temperature and land resources and greater yield per unit of land. The intercropping impact on crop quality is a current focus. This study found that shading cultivation of purple-fleshed sweet potato can improve the storage root pigment accumulation by more than 20% to increase economic benefits. We performed gas chromatography and mass spectrometry analysis of storage roots of the anthocyanin-enriched cultivar Jihei-1 under 60% shading and nonshaded treatments. A total of 224 differential metabolites were identified, among which N-acetyl-5-hydroxytryptamine, 1-monopalmitin, 4-pyridoxic acid, dodecano, arbutin, tryptophan, citrulline and phenylalanine were significantly upregulated under shading with a more than 10-fold change. Furthermore, metabolic pathway enrichment maps were based on the biological processes and stratification level selected. These metabolites mainly influenced the pathways of phenylpropanoid biosynthesis, the citrate cycle, organic acid biosynthesis and metabolism and amino acid metabolism. Through tissue-specific dynamic changes in amino acids, soluble sugars, starch and anthocyanins during storage root development, we proposed a variety-specific strategy of purple-fleshed sweet potato in response to prolonged deep shading, that is, utilizing and enhancing broad aboveground-tissue photosynthesis and transferring photosynthates into roots in advance, leading to a rapid increase in storage root anthocyanin synthesis. With comprehensive qPCR, western blot and enzyme activity analyses, we identified three key enzymes, CHS, ANS and 3GT, in purple-fleshed sweet potato storage roots in response to shading, which affect the root anthocyanin content by influencing the flavonoid metabolism pathway. This study provides a theoretical basis for revealing the regulation of anthocyanin synthesis in crops and a guidance for high-quality sweet potato cultivation and nutritional improvement using shade facilities. Full article

(This article belongs to the Special Issue Study of Primary Metabolism of Plants)

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17 pages, 3273 KiB

Open AccessEditor’s ChoiceArticle

Effects on Crop Development, Yields and Chemical Composition of Celeriac (Apium graveolens L. var. rapaceum) Cultivated Underneath an Agrivoltaic System

by Axel Weselek, Andrea Bauerle, Sabine Zikeli, Iris Lewandowski and Petra Högy

Agronomy 2021, 11(4), 733; https://doi.org/10.3390/agronomy11040733 - 10 Apr 2021

Cited by 40 | Viewed by 5281

Abstract

Agrivoltaic (AV) systems increase land productivity through the combined production of renewable energy and food. Although several studies have addressed their impact on crop production, many aspects remain unexplored. The objective of this study was to determine the effects of AV on the [...] Read more.

Agrivoltaic (AV) systems increase land productivity through the combined production of renewable energy and food. Although several studies have addressed their impact on crop production, many aspects remain unexplored. The objective of this study was to determine the effects of AV on the cultivation of celeriac, a common root vegetable in Central Europe. Celeriac was cultivated in 2017 and 2018 as part of an organically managed on-farm experiment, both underneath an AV system and in full-sun conditions. Under AV, photosynthetic active radiation was reduced by about 30%. Monitoring of crop development showed that in both years, plant height increased significantly under AV. Fresh bulb yield decreased by about 19% in 2017 and increased by about 12% in 2018 in AV, but the changes were not significant. Aboveground biomass increased in both years under AV, but only increased significantly in 2018. As aboveground biomass is a determinant of root biomass at harvest in root vegetables, bulb yields may be further increased by a prolonged vegetation period under AV. Compound analysis of celeriac bulbs did not show any clear effects from treatment. As harvestable yields were not significantly reduced, we concluded that celeriac can be considered a suitable crop for cultivation under AV. Full article

(This article belongs to the Special Issue Photovoltaics and Electrification in Agriculture)

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23 pages, 25421 KiB

Open AccessEditor’s ChoiceArticle

Seed Morphology in Key Spanish Grapevine Cultivars

by Emilio Cervantes, José Javier Martín-Gómez, Francisco Emmanuel Espinosa-Roldán, Gregorio Muñoz-Organero, Ángel Tocino and Félix Cabello-Sáenz de Santamaría

Agronomy 2021, 11(4), 734; https://doi.org/10.3390/agronomy11040734 - 10 Apr 2021

Cited by 13 | Viewed by 2557

Abstract

Ampelography, the botanical discipline dedicated to the identification and classification of grapevine cultivars, was grounded on the description of morphological characters and more recently is based on the application of DNA polymorphisms. New methods of image analysis may help to optimize morphological approaches [...] Read more.

Ampelography, the botanical discipline dedicated to the identification and classification of grapevine cultivars, was grounded on the description of morphological characters and more recently is based on the application of DNA polymorphisms. New methods of image analysis may help to optimize morphological approaches in ampelography. The objective of this study was the classification of representative cultivars of Vitis vinifera conserved in the Spanish collection of IMIDRA according to seed shape. Thirty eight cultivars representing the diversity of this collection were analyzed. A consensus seed silhouette was defined for each cultivar representing the geometric figure that better adjusted to their seed shape. All the cultivars tested were classified in ten morphological groups, each corresponding to a new model. The models are geometric figures defined by equations and similarity to each model is evaluated by quantification of percent of the area shared by the two figures, the seed and the model (J index). The comparison of seed images with geometric models is a rapid and convenient method to classify cultivars. A large proportion of the collection may be classified according to the new models described and the method permits to find new models according to seed shape in other cultivars. Full article

(This article belongs to the Special Issue Application of Computer Vision on Quality Monitoring of Agricultural Products)

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12 pages, 311 KiB

Open AccessEditor’s ChoiceArticle

The Most Important Fungal Diseases of Cereals—Problems and Possible Solutions

by Marcin Różewicz, Marta Wyzińska and Jerzy Grabiński

Agronomy 2021, 11(4), 714; https://doi.org/10.3390/agronomy11040714 - 09 Apr 2021

Cited by 50 | Viewed by 7560

Abstract

The level of cereal yields and the quality of these yields depend, to a large extent, on a crop management system, the genetic potential of a given cultivar, but also on factors that may cause damage to plants or a reduction in yield. [...] Read more.

The level of cereal yields and the quality of these yields depend, to a large extent, on a crop management system, the genetic potential of a given cultivar, but also on factors that may cause damage to plants or a reduction in yield. Such factors include fungal diseases of cereals, which may cause a reduction in yield by 15–20%, and in extreme cases even by 60%. The main factors determining the occurrence of these pathogens are the weather conditions during the growing season of plants, crop rotation, the previous crop, the soil tillage system, and nitrogen fertilisation. Fungal diseases of cereals limit plant growth and development, as well as reduce grain yield and quality. This paper reviews the literature on fungal diseases of cereals. Full article

18 pages, 1379 KiB

Open AccessEditor’s ChoiceArticle

Physiochemical Characterization of Biochars from Six Feedstocks and Their Effects on the Sorption of Atrazine in an Organic Soil

by Shagufta Gaffar, Sanku Dattamudi, Amin Rabiei Baboukani, Saoli Chanda, Jeffrey M. Novak, Donald W. Watts, Chunlei Wang and Krishnaswamy Jayachandran

Agronomy 2021, 11(4), 716; https://doi.org/10.3390/agronomy11040716 - 09 Apr 2021

Cited by 23 | Viewed by 3129

Abstract

Application of biochars in agricultural soils has the potential to reduce groundwater contamination of atrazine, a widely used herbicide in the US, therefore sustaining environmental quality and reducing human health issues. This study was conducted to characterize biochars produced from six feedstocks and [...] Read more.

Application of biochars in agricultural soils has the potential to reduce groundwater contamination of atrazine, a widely used herbicide in the US, therefore sustaining environmental quality and reducing human health issues. This study was conducted to characterize biochars produced from six feedstocks and investigate their ability to remove and retain atrazine in an organic-rich soil. Australian pine (AP), Brazilian pepper (BP), coconut husk (CH), cypress (Cy), loblolly pine (L), and pecan shell (P) feedstocks were pyrolyzed at 350 °C and 500 °C. Adsorption and desorption behaviors of atrazine were explained using Freundlich isotherms. Higher pyrolysis temperature increased specific surface area (5 times), total pore volume (2.5 times), and aromaticity (1.4 times) of the biochars. CH feedstock produced the most effective biochars (CH350 and CH500), which adsorb 8–12% more atrazine than unamended soils. CH350 biochar performed the best (K_{d ads} = 13.80, K_OC = 153.63, K_{d des} = 16.98) and had significantly higher (p < 0.05) adsorption than unamended soil, possibly resulting from its highest cation exchange capacity (16.32 cmol kg⁻¹). The K_{d des} values for atrazine desorption were greater than the K_{d ads} for adsorption, indicating retention of a considerable amount of atrazine by the biochar-amended soils following desorption. Full article

(This article belongs to the Special Issue Recycling Agricultural, Industrial, and Municipal Byproducts While Enhancing Agricultural Production and Protecting the Environment – Volume I)

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14 pages, 6207 KiB

Open AccessEditor’s ChoiceArticle

Sowing Date and Genotype Influence on Yield and Quality of Dual-Purpose Barley in a Salt-Affected Arid Region

by Ehab S. A. Moustafa, El-Sayed E. A. El-Sobky, Hossam I. A. Farag, Mohamed A. T. Yasin, Ahmed Attia, Mohamed O. A. Rady, Mohamed F. Awad and Elsayed Mansour

Agronomy 2021, 11(4), 717; https://doi.org/10.3390/agronomy11040717 - 09 Apr 2021

Cited by 29 | Viewed by 4077

Abstract

Dual-purpose barley is an alternative approach to producing high-quality forage yield plus an acceptable grain yield in marginal environments of arid regions that are characterized by lack of forage. Field experiment was performed in two consecutive growing seasons at an arid region affected [...] Read more.

Dual-purpose barley is an alternative approach to producing high-quality forage yield plus an acceptable grain yield in marginal environments of arid regions that are characterized by lack of forage. Field experiment was performed in two consecutive growing seasons at an arid region affected by salinity in irrigation water and soil at Western Sinai Peninsula in Egypt. The study aimed to optimize sowing date and screen salt-tolerant barley genotypes that perform better in terms of forage yield and quality as well as grain and biomass yield production in salt-affected environment. Sowing dates, genotypes, and their interaction significantly impacted most of the studied variables such as forage yield, crude protein yield, and grain and biomass yields. The early sowing in late October yielded higher than intermediate sowing in mid-November and late sowing in early December. Some of the tested genotypes performed better than others as indicated by about 50% higher forage yield, 6% crude protein content, 39% grain and 21% biological yields (total aboveground dry matter), suggesting higher adaptation capacity. Interestingly, grain and biological yields did not differ significantly between dual-purpose approach and grain-only pattern. In conclusion, dual-purpose barley was found favorable for producing grain and forage production in similar environments under early sowing date. Full article

(This article belongs to the Special Issue New Crops for Arid Regions)

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16 pages, 1420 KiB

Open AccessEditor’s ChoiceArticle

Seed Priming and Coating by Nano-Scale Zinc Oxide Particles Improved Vegetative Growth, Yield and Quality of Fodder Maize (Zea mays)

by Manisha Tondey, Anu Kalia, Alla Singh, Gurmeet Singh Dheri, Monica Sachdeva Taggar, Eugenie Nepovimova, Ondrej Krejcar and Kamil Kuca

Agronomy 2021, 11(4), 729; https://doi.org/10.3390/agronomy11040729 - 09 Apr 2021

Cited by 51 | Viewed by 5103

Abstract

Nano-fertilizers of essential plant nutrients, including micronutrients, have the potential to improve nutrient use efficiency and productivity of field crops in deficient soils. The present study reports the comparative influence of zinc oxide nanoparticles (ZnONPs) and bulk Zn salt (ZnSO₄) on [...] Read more.

Nano-fertilizers of essential plant nutrients, including micronutrients, have the potential to improve nutrient use efficiency and productivity of field crops in deficient soils. The present study reports the comparative influence of zinc oxide nanoparticles (ZnONPs) and bulk Zn salt (ZnSO₄) on the growth, yield, and quality of fodder maize (Zea mays) (var. J-1006) cultivated under field conditions in the year 2019. Three levels (0, 20, and 40 mg L⁻¹) of Zn fertilizers were used for seed priming and coating in triplicate following the randomized complete block design model. An increase in vegetative and yield parameters (number of plants, plant height, stover yield, plant biomass), acid detergent fiber (ADF%), and hemicellulose contents and shoot zinc (Zn) content on treatment of seeds with ZnONPs (20 mg L⁻¹) concentration as compared to bulk ZnSO₄ and control treatments was observed. The application of ZnONPs (40 mg L⁻¹) significantly enhanced the total chlorophyll content, available soil nitrogen and phosphorus, neutral detergent fiber (NDF%), and cellulose contents and improved the total soil microbial counts and soil enzyme activities (dehydrogenase, acid and alkaline phosphatase enzyme activities), whereas a significant increase in available soil potassium and zinc contents was recorded under ZnONPs (20 mg L⁻¹) treatments. These findings suggest an encouraging effect on the growth and yield attributing characteristics of fodder maize after ZnONPs seed coating at low concentration. Furthermore, ZnONPs seed coating can also be considered an effective tool for the delivery of Zn micronutrient to fodder maize crop. Full article

(This article belongs to the Special Issue Application of Nanotechnology in Sustainable Agriculture)

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11 pages, 2087 KiB

Open AccessEditor’s ChoiceArticle

Combined Use of Two Trichoderma Strains to Promote Growth of Pakchoi (Brassica chinensis L.)

by Dawei Chen, Qinzheng Hou, Lingyun Jia and Kun Sun

Agronomy 2021, 11(4), 726; https://doi.org/10.3390/agronomy11040726 - 09 Apr 2021

Cited by 25 | Viewed by 2569

Abstract

Trichoderma spp., which widely exist in nature, are always used as plant growth-promoting stimulants. However, there is little reporting about the combined use of Trichoderma strains to promote growth of plants. We explored two different Trichoderma strains (Trichoderma atroviride LX-7 and Trichoderma [...] Read more.

Trichoderma spp., which widely exist in nature, are always used as plant growth-promoting stimulants. However, there is little reporting about the combined use of Trichoderma strains to promote growth of plants. We explored two different Trichoderma strains (Trichoderma atroviride LX-7 and Trichoderma citrinoviride HT-1) and a mixture of the two on the growth-promoting effects of pakchoi. In this study, in vitro-promoting traits of two Trichoderma strains were determined, and six treatments were used: T. atroviride LX-7, T. citrinoviride HT-1, different mixtures of these two (1:1, 1:2 and 2:1) and no inoculation in the seed germination and pot experiment. The results showed that T.atroviride LX-7 and T. citrinoviride HT-1 had the ability of siderophore and indol acetic acid (IAA) production, and LX-7 had the capacity for potassium solubilization. The highest seed germination percentage (GP), germination energy (GE), germination index (GI), vitality index (VI) and growth of radicles and plumules was observed in the LX-7 + HT-1 (1:1) combination, the highest biomass and quality of plants was observed in the LX-7 + HT-1 (1:2) inoculation (followed by a single LX-7 or HT-1 strain inoculation), while the lowest values were obtained in the untreated seeds or plants. On the basis of this study, combined use of two Trichoderma strains had greater benefits for growth and quality of pakchoi, making this formulation attractive for future field applications. Full article

(This article belongs to the Section Farming Sustainability)

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4 pages, 189 KiB

Open AccessEditor’s ChoiceEditorial

Towards Sustainable Intensification of Crop Production—Yield Gaps and Water Use Efficiency in Farming Systems

by Anita Ierna

Agronomy 2021, 11(4), 710; https://doi.org/10.3390/agronomy11040710 - 08 Apr 2021

Cited by 2 | Viewed by 1435

Abstract

The primary objective of any cropping system continues to be increasing the productivity and profitability of crops [...] Full article

(This article belongs to the Collection Towards Sustainable Intensification of Crop Production—Yield Gaps and Water Use Efficiency in Farming Systems)

12 pages, 6355 KiB

Open AccessEditor’s ChoiceReview

Nosema locustae (Protozoa, Microsporidia), a Biological Agent for Locust and Grasshopper Control

by Long Zhang and Michel Lecoq

Agronomy 2021, 11(4), 711; https://doi.org/10.3390/agronomy11040711 - 08 Apr 2021

Cited by 15 | Viewed by 4659

Abstract

Effective locust and grasshopper control is crucial as locust invasions have seriously threatened crops and food security since ancient times. However, the preponderance of chemical insecticides, effective and widely used today, is increasingly criticized as a result of their adverse effects on human [...] Read more.

Effective locust and grasshopper control is crucial as locust invasions have seriously threatened crops and food security since ancient times. However, the preponderance of chemical insecticides, effective and widely used today, is increasingly criticized as a result of their adverse effects on human health and the environment. Alternative biological control methods are being actively sought to replace chemical pesticides. Nosema locustae (Synonyms: Paranosema locustae, Antonospora locustae), a protozoan pathogen of locusts and grasshoppers, was developed as a biological control agent as early as the 1980s. Subsequently, numerous studies have focused on its pathogenicity, host spectrum, mass production, epizootiology, applications, genomics, and molecular biology. Aspects of recent advances in N. locustae show that this entomopathogen plays a special role in locust and grasshopper management because it is safer, has a broad host spectrum of 144 orthopteran species, vertical transmission to offspring through eggs, long persistence in locust and grasshopper populations for more than 10 years, and is well adapted to various types of ecosystems in tropical and temperate regions. However, some limitations still need to be overcome for more efficient locust and grasshopper management in the future. Full article

(This article belongs to the Special Issue How to Manage Migratory Pests and Potential Food Crises: Locusts Plagues in the 2020’s)

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21 pages, 4220 KiB

Open AccessEditor’s ChoiceArticle

Can We Use Machine Learning for Agricultural Land Suitability Assessment?

by Anders Bjørn Møller, Vera Leatitia Mulder, Gerard B. M. Heuvelink, Niels Mark Jacobsen and Mogens Humlekrog Greve

Agronomy 2021, 11(4), 703; https://doi.org/10.3390/agronomy11040703 - 07 Apr 2021

Cited by 20 | Viewed by 5715

Abstract

It is vital for farmers to know if their land is suitable for the crops that they plan to grow. An increasing number of studies have used machine learning models based on land use data as an efficient means for mapping land suitability. [...] Read more.

It is vital for farmers to know if their land is suitable for the crops that they plan to grow. An increasing number of studies have used machine learning models based on land use data as an efficient means for mapping land suitability. This approach relies on the assumption that farmers grow their crops in the best-suited areas, but no studies have systematically tested this assumption. We aimed to test the assumption for specialty crops in Denmark. First, we mapped suitability for 41 specialty crops using machine learning. Then, we compared the predicted land suitabilities with the mechanistic model ECOCROP (Ecological Crop Requirements). The results showed that there was little agreement between the suitabilities based on machine learning and ECOCROP. Therefore, we argue that the methods represent different phenomena, which we label as socioeconomic suitability and ecological suitability, respectively. In most cases, machine learning predicts socioeconomic suitability, but the ambiguity of the term land suitability can lead to misinterpretation. Therefore, we highlight the need for increasing awareness of this distinction as a way forward for agricultural land suitability assessment. Full article

(This article belongs to the Special Issue Machine Learning Applications in Digital Agriculture)

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