Agronomy

21 pages, 22822 KiB

Open AccessEditor’s ChoiceArticle

A Mixed Data-Based Deep Neural Network to Estimate Leaf Area Index in Wheat Breeding Trials

by Orly Enrique Apolo-Apolo, Manuel Pérez-Ruiz, Jorge Martínez-Guanter and Gregorio Egea

Agronomy 2020, 10(2), 175; https://doi.org/10.3390/agronomy10020175 - 26 Jan 2020

Cited by 32 | Viewed by 7520

Remote and non-destructive estimation of leaf area index (LAI) has been a challenge in the last few decades as the direct and indirect methods available are laborious and time-consuming. The recent emergence of high-throughput plant phenotyping platforms has increased the need to develop [...] Read more.

Remote and non-destructive estimation of leaf area index (LAI) has been a challenge in the last few decades as the direct and indirect methods available are laborious and time-consuming. The recent emergence of high-throughput plant phenotyping platforms has increased the need to develop new phenotyping tools for better decision-making by breeders. In this paper, a novel model based on artificial intelligence algorithms and nadir-view red green blue (RGB) images taken from a terrestrial high throughput phenotyping platform is presented. The model mixes numerical data collected in a wheat breeding field and visual features extracted from the images to make rapid and accurate LAI estimations. Model-based LAI estimations were validated against LAI measurements determined non-destructively using an allometric relationship obtained in this study. The model performance was also compared with LAI estimates obtained by other classical indirect methods based on bottom-up hemispherical images and gaps fraction theory. Model-based LAI estimations were highly correlated with ground-truth LAI. The model performance was slightly better than that of the hemispherical image-based method, which tended to underestimate LAI. These results show the great potential of the developed model for near real-time LAI estimation, which can be further improved in the future by increasing the dataset used to train the model. Full article

(This article belongs to the Special Issue Selected Papers from 10th Iberian Agroengineering Congress)

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11 pages, 419 KiB

Open AccessEditor’s ChoiceReview

Natural Compounds as Elicitors of Plant Resistance Against Diseases and New Biocontrol Strategies

by Agnieszka Jamiołkowska

Agronomy 2020, 10(2), 173; https://doi.org/10.3390/agronomy10020173 - 25 Jan 2020

Cited by 90 | Viewed by 14246

Abstract

The goal of sustainable and organic agriculture is to optimize the health and productivity of interdependent communities of soil life, plants, animals, and people. Organic plant production uses natural products and natural self-regulation processes occurring in the ecosystem. The availability of innovative applications [...] Read more.

The goal of sustainable and organic agriculture is to optimize the health and productivity of interdependent communities of soil life, plants, animals, and people. Organic plant production uses natural products and natural self-regulation processes occurring in the ecosystem. The availability of innovative applications and molecular techniques opens up new possibilities in the approach to plant protection for sustainable and organic agriculture. New strategies not only directly protect plants against pathogens but can also induce enhanced immunity that permanently protects against pathogenic strains. This review focuses on the bioactive properties of selected natural compounds (of plant and animal origin), their action on pathogens, and their roles in the mechanism of inducing plant resistance. The author presents selected activities of organic bioactive compounds, such as allicin, naringin, terpenes, laminarin, carrageenans, chitin and chitosan, and outlines the possibilities for their application in protecting crop plants against diseases. In addition, this mini review describes the mechanism of action of the above compounds as elicitors of defense reactions in the plant and the possibility of their utilization in the production of biological preparations as elements of a new plant protection strategy. Full article

(This article belongs to the Special Issue Biocontrol of Mycotoxins Contamination of Crops)

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18 pages, 1513 KiB

Open AccessEditor’s ChoiceArticle

Effects of Different Microbial Inocula on Tomato Tolerance to Water Deficit

by Giuseppe Mannino, Luca Nerva, Takoua Gritli, Mara Novero, Valentina Fiorilli, Mnasri Bacem, Cinzia Margherita Bertea, Erica Lumini, Walter Chitarra and Raffaella Balestrini

Agronomy 2020, 10(2), 170; https://doi.org/10.3390/agronomy10020170 - 24 Jan 2020

Cited by 32 | Viewed by 4933

Abstract

Several recent reports have highlighted some of the mechanisms involved in the enhanced tolerance to abiotic stresses induced by root-associated microorganisms, although additional efforts are still required to exploit and optimize these strategies. Particularly, arbuscular mycorrhizal fungi (AMF) play an important role as [...] Read more.

Several recent reports have highlighted some of the mechanisms involved in the enhanced tolerance to abiotic stresses induced by root-associated microorganisms, although additional efforts are still required to exploit and optimize these strategies. Particularly, arbuscular mycorrhizal fungi (AMF) play an important role as “bio-fertilizing microorganisms”, establishing mutualistic symbioses with the roots of most crops. In this work, different microbial inocula (a single AMF species, a combination of three different AMF species, a combination of two plant growth-promoting bacteria (PGPB) strains and a more complex commercial inoculum) have been used to inoculate tomato plants (cv San Marzano nano), in order to verify their effects on the tolerance to a water deficit condition in pots, through the evaluation of biochemical stress markers and hormonal profiles (ABA and IAA). Results showed differences among tomato responses to water limitation depending on microbial inocula, confirming the importance to characterize the optimal plant/microorganism genotype combination(s) to maximize plant performance and tolerance. These findings open new perspectives for a better exploitation of these microorganisms. Full article

(This article belongs to the Special Issue Toward a Sustainable Agriculture Through Plant Biostimulants: From Experimental Data to Practical Applications)

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23 pages, 3388 KiB

Open AccessEditor’s ChoiceArticle

Study of Allelopathic Interaction of Essential Oils from Medicinal and Aromatic Plants on Seed Germination and Seedling Growth of Lettuce

by Somayeh Mirmostafaee, Majid Azizi and Yoshiharu Fujii

Agronomy 2020, 10(2), 163; https://doi.org/10.3390/agronomy10020163 - 23 Jan 2020

Cited by 35 | Viewed by 6798

Abstract

Medicinal and aromatic plants have the ability to transmit volatile allelochemicals and affect their surrounding organisms. In this regard, their interaction should also be considered. The inhibitory effects of 112 essential oils on lettuce seed and seedling were investigated by cotton swab method. [...] Read more.

Medicinal and aromatic plants have the ability to transmit volatile allelochemicals and affect their surrounding organisms. In this regard, their interaction should also be considered. The inhibitory effects of 112 essential oils on lettuce seed and seedling were investigated by cotton swab method. Germination (G%), Mean germination time (MGT), Lethal of embryo (L%), dormancy (D%), radicle growth (R%), and hypocotyl growth (H%) were measured. Two methods were used for evaluating allelopathic interaction effects: the simplified modified dilution check-board technique (SMCT) and the isobologram. Thymus daenensis had the highest inhibitory effect on G% (IC₅₀ = 2.9 ppm) and the most lethal effect on the embryo (LC₅₀ = 7.2 ppm). Thymus transcaspicus, Dracocephalum moldavica, Artemisia sieberi and Amomum subulatum had the greatest effect on MGT. Ziziphora tenuior, Trachyspermum ammi and Pelargonium graveolens had the highest effect on D%. Origanum vulgare was the strongest growth inhibitor. The highest synergistic effect on G% was in A. subulatum + Mentha suaveolens, on H% was related to Perovskia abrotanoides + T. daenensis, and on R% was observed in Artemisia vulgaris + M. suaveolens. The results of this study can lead to identification of new phytotoxic compounds in EOs and control weeds more effectively. Full article

(This article belongs to the Special Issue Effects of Biostimulants and Bioeffectors on Plant Growth)

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14 pages, 1788 KiB

Open AccessEditor’s ChoiceArticle

Biostimulant Seed Coating Treatments to Improve Cover Crop Germination and Seedling Growth

by Yi Qiu, Masoume Amirkhani, Hilary Mayton, Zhi Chen and Alan G. Taylor

Agronomy 2020, 10(2), 154; https://doi.org/10.3390/agronomy10020154 - 22 Jan 2020

Cited by 42 | Viewed by 11091

Abstract

Biostimulant seed coating formulations were investigated in laboratory experiments for their potential to increase maximum germination, germination rate, germination uniformity, and seedling growth of red clover (Trifolium pratense L.) and perennial ryegrass (Lolium perenne L.) seeds. Red clover and perennial ryegrass [...] Read more.

Biostimulant seed coating formulations were investigated in laboratory experiments for their potential to increase maximum germination, germination rate, germination uniformity, and seedling growth of red clover (Trifolium pratense L.) and perennial ryegrass (Lolium perenne L.) seeds. Red clover and perennial ryegrass seeds were coated with different combinations of soy flour, diatomaceous earth, micronized vermicompost, and concentrated vermicompost extract. Coated and non-coated seeds of red clover and perennial ryegrass were evaluated for germination and growth after 7 and 10 days, respectively. Red clover seed was maintained at a constant 20 °C with a 16/8 h photoperiod, whereas for perennial ryegrass seed, the germinator was maintained at 15/25 °C, with the same photoperiod as red clover. Coated treatments significantly improved germination rate and uniformity with no reduction in total germination, compared to the non-treated controls in red clover. In contrast, for perennial ryegrass, the total germination percentage of all coated seeds was reduced and displayed a delayed germination rate, compared with the non-treated controls. Shoot length, seedling vigor index, and dry weight of seedlings of coated seed treatments of both crops were significantly higher when compared to controls for both species. In addition to growth metrics, specific surface mechanical properties related to seed coating quality of seeds of both species were evaluated. Increasing the proportion of soy flour as a seed treatment binder in the coating blend increased the integrity and compressive strength of coated seeds, and the time for coatings to disintegrate. These data show that seed coating technologies incorporating nutritional materials and biostimulants can enhance seedling growth and have the potential to facilitate the establishment of cover crops in agriculture and land reclamation. Full article

(This article belongs to the Special Issue Toward a Sustainable Agriculture Through Plant Biostimulants: From Experimental Data to Practical Applications)

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22 pages, 4186 KiB

Open AccessEditor’s ChoiceArticle

The Influence of Bio-Stimulants and Foliar Fertilizers on Yield, Plant Features, and the Level of Soil Biochemical Activity in White Lupine (Lupinus albus L.) Cultivation

by Alicja Niewiadomska, Hanna Sulewska, Agnieszka Wolna-Maruwka, Karolina Ratajczak, Zyta Waraczewska and Anna Budka

Agronomy 2020, 10(1), 150; https://doi.org/10.3390/agronomy10010150 - 20 Jan 2020

Cited by 27 | Viewed by 5794

Abstract

The aim of this study is to assess the effect of two biostimulators (Titanit, Rooter) and six foliar fertilizers (Optysil, Metalosate Potassium, Bolero Bo, ADOB 2.0 Zn IDHA, ADOB B, ADOB 2.0 Mo) on white lupine. In addition, we evaluated the enzymatic activity [...] Read more.

The aim of this study is to assess the effect of two biostimulators (Titanit, Rooter) and six foliar fertilizers (Optysil, Metalosate Potassium, Bolero Bo, ADOB 2.0 Zn IDHA, ADOB B, ADOB 2.0 Mo) on white lupine. In addition, we evaluated the enzymatic activity of dehydrogenase, acid, and alkaline phosphatases, catalase, the level of biological nitrogen fixation, yield, plant biometric, chlorophyll fluorescence and chlorophyll content. A field experiment was conducted between 2016 and 2018 at the Gorzyń Experimental and Educational Station, Poznań University of Life Sciences in Poland. The best effects in plant yield were obtained after the application of Optysil or ADOB Zn IDHA. The three years results of dehydrogenase (DHA), alkaline phosphatase (PAL), and the biological index of soil fertility (BIF), show that the bio-stimulants and most of the foliar fertilizers used did not always stimulate the activity of these enzymes and index in the white lupine crops, as compared with the control treatment. Analysis of the results of the acid phosphatase activity (PAC) shows that during the entire white lupine growing season the foliar fertilizers and bio-stimulants decreased the activity of this enzyme. This effect was not observed when the Metalosate potassium foliar fertilizer was applied. The field analyses of biological nitrogen fixation showed that the fertilizers and bio-stimulants significantly stimulated nitrogenase activity under the white lupine plantation. The best effects in plant yield were obtained after application Optysil or ADOB Zn IDHA. Full article

(This article belongs to the Special Issue Toward a Sustainable Agriculture Through Plant Biostimulants: From Experimental Data to Practical Applications)

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16 pages, 2102 KiB

Open AccessEditor’s ChoiceArticle

Performance Evaluation of Two Commercially Available Portable Spectrometers to Non-Invasively Determine Table Grape and Peach Quality Attributes

by Irwin R. Donis-González, Constantino Valero, Md Abdul Momin, Amanjot Kaur and David C. Slaughter

Agronomy 2020, 10(1), 148; https://doi.org/10.3390/agronomy10010148 - 19 Jan 2020

Cited by 31 | Viewed by 5563

Abstract

Near-infrared (NIR) spectroscopy has been used to non-destructively and rapidly evaluate the quality of fresh agricultural produce. In this study, two commercially available portable spectrometers (F-750: Felix Instruments, WA, USA; and SCiO: Consumer Physics, Tel Aviv, Israel) were evaluated in the wavelength range [...] Read more.

Near-infrared (NIR) spectroscopy has been used to non-destructively and rapidly evaluate the quality of fresh agricultural produce. In this study, two commercially available portable spectrometers (F-750: Felix Instruments, WA, USA; and SCiO: Consumer Physics, Tel Aviv, Israel) were evaluated in the wavelength range between 740 and 1070 nm to non-invasively predict quality attributes, including the dry matter (DM), and total soluble solids (TSS) content of three fresh table grape cultivars (‘Autumn Royal’, ‘Timpson’, and ‘Sweet Scarlet’) and one peach cultivar (‘Cassie’). Prediction models were developed using partial least-square regression (PLSR) to correlate the NIR absorbance spectra with the invasive quality measurements. In regard to grapes, the best DM prediction models yielded an R² of 0.83 and 0.81, a ratio of standard error of performance to standard deviation (RPD) of 2.35 and 2.29, and a root mean square error of prediction (RMSEP) of 1.40 and 1.44; and the best TSS prediction models generated an R² of 0.97 and 0.95, an RPD of 5.95 and 4.48, and an RMSEP of 0.53 and 0.70 for the F-750 and SCiO spectrometers, respectively. Overall, PLSR prediction models using both spectrometers were promising to predict table grape quality attributes. Regarding peach, the PLSR prediction models did not perform as well as in grapes, as DM prediction models resulted in an R² of 0.81 and 0.67, an RPD of 2.24 and 1.74, and an RMSEP of 1.28 and 1.66; and TSS resulted in an R² of 0.62 and 0.55, an RPD of 1.55 and 1.48, and an RMSEP of 1.19 and 1.25 for the F-750 and SCiO spectrometers, respectively. Overall, the F-750 spectrometer prediction models performed better than those generated by using the SCiO spectrometer data. Full article

(This article belongs to the Special Issue Selected Papers from 10th Iberian Agroengineering Congress)

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21 pages, 40290 KiB

Open AccessEditor’s ChoiceArticle

Deep Learning for Mango (Mangifera indica) Panicle Stage Classification

by Anand Koirala, Kerry B. Walsh, Zhenglin Wang and Nicholas Anderson

Agronomy 2020, 10(1), 143; https://doi.org/10.3390/agronomy10010143 - 18 Jan 2020

Cited by 29 | Viewed by 7989

Abstract

Automated assessment of the number of panicles by developmental stage can provide information on the time spread of flowering and thus inform farm management. A pixel-based segmentation method for the estimation of flowering level from tree images was confounded by the developmental stage. [...] Read more.

Automated assessment of the number of panicles by developmental stage can provide information on the time spread of flowering and thus inform farm management. A pixel-based segmentation method for the estimation of flowering level from tree images was confounded by the developmental stage. Therefore, the use of a single and a two-stage deep learning framework (YOLO and R²CNN) was considered, using either upright or rotated bounding boxes. For a validation image set and for a total panicle count, the models MangoYOLO(-upright), MangoYOLO-rotated, YOLOv3-rotated, R²CNN(-rotated) and R²CNN-upright achieved weighted F1 scores of 76.5, 76.1, 74.9, 74.0 and 82.0, respectively. For a test set of the images of another cultivar and using a different camera, the R² for machine vision to human count of panicles per tree was 0.86, 0.80, 0.83, 0.81 and 0.76 for the same models, respectively. Thus, there was no consistent benefit from the use of rotated over the use of upright bounding boxes. The YOLOv3-rotated model was superior in terms of total panicle count, and the R²CNN-upright model was more accurate for panicle stage classification. To demonstrate practical application, panicle counts were made weekly for an orchard of 994 trees, with a peak detection routine applied to document multiple flowering events. Full article

(This article belongs to the Special Issue In-Field Estimation of Fruit Quality and Quantity)

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35 pages, 2864 KiB

Open AccessEditor’s ChoiceReview

A Review of Current and Potential Applications of Remote Sensing to Study the Water Status of Horticultural Crops

by Deepak Gautam and Vinay Pagay

Agronomy 2020, 10(1), 140; https://doi.org/10.3390/agronomy10010140 - 17 Jan 2020

Cited by 35 | Viewed by 7409

Abstract

With increasingly advanced remote sensing systems, more accurate retrievals of crop water status are being made at the individual crop level to aid in precision irrigation. This paper summarises the use of remote sensing for the estimation of water status in horticultural crops. [...] Read more.

With increasingly advanced remote sensing systems, more accurate retrievals of crop water status are being made at the individual crop level to aid in precision irrigation. This paper summarises the use of remote sensing for the estimation of water status in horticultural crops. The remote measurements of the water potential, soil moisture, evapotranspiration, canopy 3D structure, and vigour for water status estimation are presented in this comprehensive review. These parameters directly or indirectly provide estimates of crop water status, which is critically important for irrigation management in farms. The review is organised into four main sections: (i) remote sensing platforms; (ii) the remote sensor suite; (iii) techniques adopted for horticultural applications and indicators of water status; and, (iv) case studies of the use of remote sensing in horticultural crops. Finally, the authors’ view is presented with regard to future prospects and research gaps in the estimation of the crop water status for precision irrigation. Full article

(This article belongs to the Special Issue Increasing Agricultural Water Productivity in a Changing Environment)

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14 pages, 480 KiB

Open AccessEditor’s ChoiceArticle

Using Digestate and Biochar as Fertilizers to Improve Processing Tomato Production Sustainability

by Domenico Ronga, Federica Caradonia, Mario Parisi, Guido Bezzi, Bruno Parisi, Giulio Allesina, Simone Pedrazzi and Enrico Francia

Agronomy 2020, 10(1), 138; https://doi.org/10.3390/agronomy10010138 - 17 Jan 2020

Cited by 57 | Viewed by 5902

Abstract

The principal goal of the organic farming system (OFS) is to develop enterprises that are sustainable and harmonious with the environment. Unfortunately, the OFS yields fewer products per land than the non-organic farming system in many agricultural products. The objective of our study [...] Read more.

The principal goal of the organic farming system (OFS) is to develop enterprises that are sustainable and harmonious with the environment. Unfortunately, the OFS yields fewer products per land than the non-organic farming system in many agricultural products. The objective of our study was to assess the effects of digestate and biochar fertilizers on yield and fruit quality of processing tomato produced under the OFS. The experiment was carried out in Po Valley, during the 2017 and 2018 growing seasons. Liquid digestate (LD), LD + biochar (LD + BC) and pelleted digestate (PD) were evaluated and compared to biochar (BC) application and unfertilized control. The results showed that plants fertilized with LD + BC recorded the maximum marketable yield (72 t ha⁻¹), followed by BC (67 t ha⁻¹), PD (64 t ha⁻¹) and LD (59 t ha⁻¹); while the lowest production (47 t ha⁻¹) was recorded in unfertilized plants. Over the two cropping seasons, LD + BC, BC, PD, and LD, increased fruit number per plant (+15%), fruit weight (+24%), Brix t ha⁻¹ (+41%) and reduced Bostwick index (−16%), if compared to the untreated control. Considering the overall agronomic performances, digestate and biochar can be useful options for increasing yield and quality of processing tomato production in the OFS. Hence, these fertilizers can be assessed in future research both on other crops and farming systems. Full article

(This article belongs to the Special Issue Herbaceous Field Crops Cultivation)

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16 pages, 1083 KiB

Open AccessEditor’s ChoiceArticle

Chlorophyll Fluorescence, Photosynthesis and Growth of Tomato Plants as Affected by Long-Term Oxygen Root Zone Deprivation and Grafting

by Rosario Paolo Mauro, Michele Agnello, Miriam Distefano, Leo Sabatino, Alberto San Bautista Primo, Cherubino Leonardi and Francesco Giuffrida

Agronomy 2020, 10(1), 137; https://doi.org/10.3390/agronomy10010137 - 16 Jan 2020

Cited by 32 | Viewed by 4690

Abstract

A greenhouse experiment was conducted to study the effects of the O₂ root zone level and grafting on chlorophyll fluorescence, photosynthesis and growth of cherry tomato grown in a hydroponic system. Two O₂ concentrations in the root zone, namely Ox (saturation [...] Read more.

A greenhouse experiment was conducted to study the effects of the O₂ root zone level and grafting on chlorophyll fluorescence, photosynthesis and growth of cherry tomato grown in a hydroponic system. Two O₂ concentrations in the root zone, namely Ox (saturation level) and Ox- (2–3 mg L⁻¹), were applied for 30 days on self-grafted cherry tomato Dreamer or grafted onto the hybrids Arnold, Beaufort, Maxifort and Top Pittam. Root hypoxia increased minimum fluorescence (by 10%) while it decreased variable fluorescence and the maximum quantum yield of PSII (up to 16 and 8%, respectively). Moreover, it reduced leaf photosynthesis, transpiration and stomatal conductance (by 12, 17 and 13%, respectively), whereas it increased leaf electrolyte leakage (by 2.1%). The graft combinations showed a different ability in buffering the effects of root hypoxia on plant growth and related components, and these differences were related to their root biomass. The minimum fluorescence was negatively correlated to plant growth, so it may be a useful indicator to select tolerant rootstocks to root hypoxia. Our results suggest the occurrence of both diffusive and metabolic constraints to tomato photosynthesis under root hypoxia, a condition that can be mitigated by selecting rootstocks with a more developed root system. Full article

(This article belongs to the Special Issue Recent Advances in Rootstock of Vegetable Plants)

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15 pages, 2934 KiB

Open AccessEditor’s ChoiceArticle

Comparison of Biochemical, Anatomical, Morphological, and Physiological Responses to Salinity Stress in Wheat and Barley Genotypes Deferring in Salinity Tolerance

by Muhammad Zeeshan, Meiqin Lu, Shafaque Sehar, Paul Holford and Feibo Wu

Agronomy 2020, 10(1), 127; https://doi.org/10.3390/agronomy10010127 - 15 Jan 2020

Cited by 130 | Viewed by 10609

Abstract

A greenhouse hydroponic experiment was performed using salt-tolerant (cv. Suntop) and -sensitive (Sunmate) wheat cultivars and a salt-tolerant barley cv. CM72 to evaluate how cultivar and species differ in response to salinity stress. Results showed that wheat cv. Suntop performed high tolerance to [...] Read more.

A greenhouse hydroponic experiment was performed using salt-tolerant (cv. Suntop) and -sensitive (Sunmate) wheat cultivars and a salt-tolerant barley cv. CM72 to evaluate how cultivar and species differ in response to salinity stress. Results showed that wheat cv. Suntop performed high tolerance to salinity, being similar tolerance to salinity with CM72, compared with cv. Sunmate. Similar to CM72, Suntop recorded less salinity induced increase in malondialdehyde (MDA) accumulation and less reduction in plant height, net photosynthetic rate (Pn), chlorophyll content, and biomass than in sensitive wheat cv. Sunmate. Significant time-course and cultivar-dependent changes were observed in the activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) in roots and leaves after salinity treatment. Higher activities were found in CM72 and Suntop compared to Sunmate. Furthermore, a clear modification was observed in leaf and root ultrastructure after NaCl treatment with more obvious changes in the sensitive wheat cv. Sunmate, rather than in CM72 and Suntop. Although differences were observed between CM72 and Suntop in the growth and biochemical traits assessed and modified by salt stress, the differences were negligible in comparison with the general response to the salt stress of sensitive wheat cv. Sunmate. In addition, salinity stress induced an increase in the Na⁺ and Na⁺/K⁺ ratio but a reduction in K⁺ concentrations, most prominently in Sunmate and followed by Suntop and CM72. Full article

(This article belongs to the Special Issue Physiological and Molecular Characterization of Crop Resistance to Abiotic Stresses)

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21 pages, 6311 KiB

Open AccessEditor’s ChoiceArticle

A Combined Method of Image Processing and Artificial Neural Network for the Identification of 13 Iranian Rice Cultivars

by Yousef Abbaspour-Gilandeh, Amir Molaee, Sajad Sabzi, Narjes Nabipur, Shahaboddin Shamshirband and Amir Mosavi

Agronomy 2020, 10(1), 117; https://doi.org/10.3390/agronomy10010117 - 14 Jan 2020

Cited by 25 | Viewed by 4449

Abstract

Due to the importance of identifying crop cultivars, the advancement of accurate assessment of cultivars is considered essential. The existing methods for identifying rice cultivars are mainly time-consuming, costly, and destructive. Therefore, the development of novel methods is highly beneficial. The aim of [...] Read more.

Due to the importance of identifying crop cultivars, the advancement of accurate assessment of cultivars is considered essential. The existing methods for identifying rice cultivars are mainly time-consuming, costly, and destructive. Therefore, the development of novel methods is highly beneficial. The aim of the present research is to classify common rice cultivars in Iran based on color, morphologic, and texture properties using artificial intelligence (AI) methods. In doing so, digital images of 13 rice cultivars in Iran in three forms of paddy, brown, and white are analyzed through pre-processing and segmentation of using MATLAB. Ninety-two specificities, including 60 color, 14 morphologic, and 18 texture properties, were identified for each rice cultivar. In the next step, the normal distribution of data was evaluated, and the possibility of observing a significant difference between all specificities of cultivars was studied using variance analysis. In addition, the least significant difference (LSD) test was performed to obtain a more accurate comparison between cultivars. To reduce data dimensions and focus on the most effective components, principal component analysis (PCA) was employed. Accordingly, the accuracy of rice cultivar separations was calculated for paddy, brown rice, and white rice using discriminant analysis (DA), which was 89.2%, 87.7%, and 83.1%, respectively. To identify and classify the desired cultivars, a multilayered perceptron neural network was implemented based on the most effective components. The results showed 100% accuracy of the network in identifying and classifying all mentioned rice cultivars. Hence, it is concluded that the integrated method of image processing and pattern recognition methods, such as statistical classification and artificial neural networks, can be used for identifying and classification of rice cultivars. Full article

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14 pages, 1543 KiB

Open AccessEditor’s ChoiceArticle

Trichoderma parareesei Favors the Tolerance of Rapeseed (Brassica napus L.) to Salinity and Drought Due to a Chorismate Mutase

by Jorge Poveda

Agronomy 2020, 10(1), 118; https://doi.org/10.3390/agronomy10010118 - 13 Jan 2020

Cited by 56 | Viewed by 5129

Abstract

Both drought and salinity represent the greatest plant abiotic stresses in crops. Increasing plant tolerance against these environmental conditions must be a key strategy in the development of future agriculture. The genus of Trichoderma filament fungi includes several species widely used as biocontrol [...] Read more.

Both drought and salinity represent the greatest plant abiotic stresses in crops. Increasing plant tolerance against these environmental conditions must be a key strategy in the development of future agriculture. The genus of Trichoderma filament fungi includes several species widely used as biocontrol agents for plant diseases but also some with the ability to increase plant tolerance against abiotic stresses. In this sense, using the species T. parareesei and T. harzianum, we have verified the differences between the two after their application in rapeseed (Brassica napus) root inoculation, with T. parareesei being a more efficient alternative to increase rapeseed productivity under drought or salinity conditions. In addition, we have determined the role that T. parareesei chorismate mutase plays in its ability to promote tolerance to salinity and drought in plants by increasing the expression of genes related to the hormonal pathways of abscisic acid (ABA) under drought stress, and ethylene (ET) under salt stress. Full article

(This article belongs to the Special Issue GMO, New Breeding Techniques and Novel Technologies for Abiotic Stress Tolerance in Crop Plants)

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14 pages, 639 KiB

Open AccessEditor’s ChoiceReview

Arbuscular Mycorrhizal Fungi and Associated Microbiota as Plant Biostimulants: Research Strategies for the Selection of the Best Performing Inocula

by Luca Giovannini, Michela Palla, Monica Agnolucci, Luciano Avio, Cristiana Sbrana, Alessandra Turrini and Manuela Giovannetti

Agronomy 2020, 10(1), 106; https://doi.org/10.3390/agronomy10010106 - 11 Jan 2020

Cited by 107 | Viewed by 24660

Abstract

Arbuscular mycorrhizal fungi (AMF) are beneficial soil microorganisms establishing mutualistic symbioses with the roots of the most important food crops and playing key roles in the maintenance of long-term soil fertility and health. The great inter- and intra-specific AMF diversity can be fully [...] Read more.

Arbuscular mycorrhizal fungi (AMF) are beneficial soil microorganisms establishing mutualistic symbioses with the roots of the most important food crops and playing key roles in the maintenance of long-term soil fertility and health. The great inter- and intra-specific AMF diversity can be fully exploited by selecting AMF inocula on the basis of their colonization ability and efficiency, which are affected by fungal and plant genotypes and diverse environmental variables. The multiple services provided by AMF are the result of the synergistic activities of the bacterial communities living in the mycorrhizosphere, encompassing nitrogen fixation, P solubilization, and the production of phytohormones, siderophores, and antibiotics. The tripartite association among host plants, mycorrhizal symbionts, and associated bacteria show beneficial emerging properties which could be efficiently exploited in sustainable agriculture. Further in-depth studies, both in microcosms and in the field, performed on different AMF species and isolates, should evaluate their colonization ability, efficiency, and resilience. Transcriptomic studies can reveal the expression levels of nutrient transporter genes in fungal absorbing hyphae in the presence of selected bacterial strains. Eventually, newly designed multifunctional microbial consortia can be utilized as biofertilizers and biostimulants in sustainable and innovative production systems. Full article

(This article belongs to the Special Issue Toward a Sustainable Agriculture Through Plant Biostimulants: From Experimental Data to Practical Applications)

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33 pages, 3324 KiB

Open AccessEditor’s ChoiceReview

Recent Advances in Evapotranspiration Estimation Using Artificial Intelligence Approaches with a Focus on Hybridization Techniques—A Review

by Min Yan Chia, Yuk Feng Huang, Chai Hoon Koo and Kit Fai Fung

Agronomy 2020, 10(1), 101; https://doi.org/10.3390/agronomy10010101 - 10 Jan 2020

Cited by 57 | Viewed by 5740

Abstract

Difficulties are faced when formulating hydrological processes, including that of evapotranspiration (ET). Conventional empirical methods for formulating these possess some shortcomings. The artificial intelligence approach emerges as the best possible solution to map the relationships between climatic parameters and ET, even with limited [...] Read more.

Difficulties are faced when formulating hydrological processes, including that of evapotranspiration (ET). Conventional empirical methods for formulating these possess some shortcomings. The artificial intelligence approach emerges as the best possible solution to map the relationships between climatic parameters and ET, even with limited knowledge of the interactions between variables. This review presents the state-of-the-art application of artificial intelligence models in ET estimation, along with different types and sources of data. This paper discovers the most significant climatic parameters for different climate patterns. The characteristics of the basic artificial intelligence models are also explored in this review. To overcome the pitfalls of the individual models, hybrid models which use techniques such as data fusion and ensemble modeling, data decomposition as well as remote sensing-based hybridization, are introduced. In particular, the principles and applications of the hybridization techniques, as well as their combinations with basic models, are explained. The review covers most of the related and excellent papers published from 2011 to 2019 to keep its relevancy in terms of time frame and field of study. Guidelines for the future prospects of ET estimation in research are advocated. It is anticipated that such work could contribute to the development of agriculture-based economy. Full article

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15 pages, 2662 KiB

Open AccessEditor’s ChoiceArticle

Assessment of Main Cereal Crop Trade Impacts on Water and Land Security in Iraq

by Salam Hussein Ewaid, Salwan Ali Abed and Nadhir Al-Ansari

Agronomy 2020, 10(1), 98; https://doi.org/10.3390/agronomy10010098 - 09 Jan 2020

Cited by 90 | Viewed by 9077

Abstract

Growing populations, socio-economic development, the pollution of rivers, and the withdrawal of fresh water are all signs of increasing water scarcity, and with 85% of global use, agriculture is the biggest freshwater user. The water footprint (WF) and virtual water (VW) are concepts [...] Read more.

Growing populations, socio-economic development, the pollution of rivers, and the withdrawal of fresh water are all signs of increasing water scarcity, and with 85% of global use, agriculture is the biggest freshwater user. The water footprint (WF) and virtual water (VW) are concepts used recently for freshwater resources assessment. The WF reflects how much, when and where the water was used whereas VW reveals the volume of water embedded in goods when traded. The first goal of this research is to determine the WF per ton and the WF of production (Mm³/yr) of wheat, barley, rice, and maize in Iraq. The second goal is estimating the quantities of the 4 main cereal crops imported into Iraq and assessing the impact on reducing WF and land savings for 10 years from 2007 to 2016. The results showed that the WF per ton was 1736, 1769, 3694, 2238 m³/ton and the WF of production was 5271, 1475, 997, 820 Mm³/yr for wheat, barley, rice, and maize, respectively. The median total VW imported was 4408 Mm³/yr, the largest volume was 3478 Mm³/yr from wheat, and Iraq saved about 2676 Mm³ of irrigated water and 1,239,539 M ha of land by importing crops every year during 2007–2016. The study revealed the significance of better irrigation management methods to decrease the WF through a selection of crops that need less water and cultivation in rain-fed areas, as well as the use of cereal import to conserve scarce water resources, which is crucial both in terms of water resource management and preservation of the environment. The results of this research could be used as a guideline for better water management practices in Iraq and can provide helpful data for both stakeholders and policymakers. Full article

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18 pages, 5505 KiB

Open AccessEditor’s ChoiceArticle

Response Surface Modeling and Optimization of Polyphenols Extraction from Apple Pomace Based on Nonionic Emulsifiers

by Liubov Skrypnik and Anastasia Novikova

Agronomy 2020, 10(1), 92; https://doi.org/10.3390/agronomy10010092 - 09 Jan 2020

Cited by 34 | Viewed by 4362

Abstract

The factors affecting the efficiency of micelle-mediated extraction of phenolic compounds from apple pomace was investigated. Higher extraction efficiency by using as a solvent an aqueous solution of Tween 80 in comparison to Triton X-100, Span 20, Tween 20, 70% ethanol, and water [...] Read more.

The factors affecting the efficiency of micelle-mediated extraction of phenolic compounds from apple pomace was investigated. Higher extraction efficiency by using as a solvent an aqueous solution of Tween 80 in comparison to Triton X-100, Span 20, Tween 20, 70% ethanol, and water was shown. Four independent variables (Tween 80 concentration, time, solvent-to material ratio, and pH) to enhance the recovery of polyphenols from apple pomace was investigated. Applying response surface methodology, the second order polynomial regression equation showing dependence of the yield of polyphenols on the extraction parameters was derived. The adjusted regression coefficient (R² = 98.73%) and the lack-of-fit test (p > 0.05) showed a good accuracy of the developed model. The difference between observed and predicted values was no more than 3%. The optimal extraction conditions were found to be Tween 80 concentration of 1.14%, time of 65 min, solvent-to-material ratio of 104 mL g⁻¹, pH of 3.8. Under optimal conditions the predicted total phenolic compounds content was 7.75 mg g⁻¹. The obtained apple pomace extracts were characterized in terms of their antioxidant activity. The proposed extraction technology by using Tween 80 aqueous solution as a solvent allows obtaining the extracts with high content of polyphenols which are suitable for the applications in food, cosmetic, and pharmaceutical products requiring a surfactant to stabilize them. Full article

(This article belongs to the Special Issue Extraction and Analysis of Natural Product in Plant)

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10 pages, 3143 KiB

Open AccessEditor’s ChoiceArticle

Soil Erosion by Wind and Dust Emission in Semi-Arid Soils Due to Agricultural Activities

by Itzhak Katra

Agronomy 2020, 10(1), 89; https://doi.org/10.3390/agronomy10010089 - 09 Jan 2020

Cited by 40 | Viewed by 7557

Abstract

Many soils throughout the world are currently associated with soil erosion by wind and dust emissions. Dust emission processes have major implications for loss of soil resources (such as clays and nutrients) and human exposure to air pollution. This work provides a review [...] Read more.

Many soils throughout the world are currently associated with soil erosion by wind and dust emissions. Dust emission processes have major implications for loss of soil resources (such as clays and nutrients) and human exposure to air pollution. This work provides a review on field experiments of dust emission based on previous studies, with new insight into the role of soil aggregation. The work focuses on dust processes in semi-arid soils that are subjected to increased agricultural land use. A boundary-layer wind tunnel has been used to study dust emission and soil loss by simulation and quantification of high-resolution wind processes. Field experiments were conducted in soil plots representing long-term and short-term influences of land uses such as agriculture, grazing, and natural preserves. The results show the impacts of soil disturbances by human activities on the soil aggregation and dust fluxes and provide quantitative estimates of soil loss over time. Substantial loss of PM10 (particulate matter [PM] that is less than 10 micrometers in diameter) was recorded in most experimental conditions. The measured PM10 fluxes highlight the significant implications for soil nutrient resources in annual balance and management strategies, as well as for PM loading to the atmosphere and the risk of air pollution. Full article

(This article belongs to the Special Issue Surface Runoff and Soil Erosion under Various Climate Conditions)

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14 pages, 1310 KiB

Open AccessEditor’s ChoiceReview

Is Phytomelatonin a New Plant Hormone?

by Marino B. Arnao and Josefa Hernández-Ruiz

Agronomy 2020, 10(1), 95; https://doi.org/10.3390/agronomy10010095 - 09 Jan 2020

Cited by 100 | Viewed by 8629

Abstract

Melatonin (N-acetyl-5-methoxytryptamine) is of particular importance as a chronobiological hormone in mammals, acting as a signal of darkness that provides information to the brain and peripheral organs. It is an endogenous synchronizer for both endocrine (i.e., via neurotransmitter release) and other [...] Read more.

Melatonin (N-acetyl-5-methoxytryptamine) is of particular importance as a chronobiological hormone in mammals, acting as a signal of darkness that provides information to the brain and peripheral organs. It is an endogenous synchronizer for both endocrine (i.e., via neurotransmitter release) and other physiological rhythms. In this work we will try to add to the series of scientific events and discoveries made in plants that, surprisingly, confirm the great similarity of action of melatonin in animals and plants. The most relevant milestones on the 25 years of phytomelatonin studies are presented, from its discovery in 1995 to the discovery of its receptor in plants in 2018, suggesting it should be regarded as a new plant hormone. Full article

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16 pages, 1445 KiB

Open AccessEditor’s ChoiceArticle

The Use of Appropriate Cultivar of Basil (Ocimum basilicum) Can Increase Water Use Efficiency under Water Stress

by Iakovos Kalamartzis, Christos Dordas, Pantazis Georgiou and George Menexes

Agronomy 2020, 10(1), 70; https://doi.org/10.3390/agronomy10010070 - 03 Jan 2020

Cited by 31 | Viewed by 4291

Abstract

Drought is one of the major yield constraints of crop productivity for many crops. In addition, nowadays, climate change creates new challenges for crop adaptation in stressful environments. The objective of the present study was to determine the effect of water stress on [...] Read more.

Drought is one of the major yield constraints of crop productivity for many crops. In addition, nowadays, climate change creates new challenges for crop adaptation in stressful environments. The objective of the present study was to determine the effect of water stress on five cultivars of basil (Mrs Burns, Cinnamon, Sweet, Red Rubin, Thai) and whether water use efficiency (WUE) can be increased by using the appropriate cultivar. Water stress affected the fresh and dry weight and also the partitioning of dry matter to leaves, flowers, and stems. Also, there are cultivars, such as Mrs Burns and Sweet, which were not affected by the limited amount of water and continued to produce a high amount of dry matter and also showed high essential oil yield. Essential oil content was not affected by the irrigation; however, essential oil yield was affected by the irrigation, and the highest values were found at Mrs Burns. The water use efficiency was affected by the cultivar and irrigation level, and the highest was found at Mrs Burns. The results show that using appropriate cultivars basil can achieve higher WUE and allow saving water resources and utilizing fields in areas with limited water resources for irrigation. Full article

(This article belongs to the Special Issue Herbaceous Field Crops Cultivation)

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15 pages, 1362 KiB

Open AccessEditor’s ChoiceArticle

Comparative Performance of Organic Fertilizers in Maize (Zea mays L.) Growth, Yield, and Economic Results

by Joseph Jjagwe, Keneth Chelimo, Jeninah Karungi, Allan John Komakech and Jakob Lederer

Agronomy 2020, 10(1), 69; https://doi.org/10.3390/agronomy10010069 - 03 Jan 2020

Cited by 38 | Viewed by 15244

Abstract

Maize is a major crop grown and consumed in Uganda and it requires a high fertilizer input. However, the existing inorganic fertilizers in the market are often not affordable especially to small scale farmers, which results in decreased maize yields in the country. [...] Read more.

Maize is a major crop grown and consumed in Uganda and it requires a high fertilizer input. However, the existing inorganic fertilizers in the market are often not affordable especially to small scale farmers, which results in decreased maize yields in the country. On the other hand, there is an abundance of unutilized animal manure, which, when treated, can be used to increase maize yields. This study evaluated the response of maize to products of different cattle manure treatment methods as well as inorganic fertilizer. The treatments such as cattle manure stored under shade (T), cattle manure stored in the open (M), cattle manure slurry digestate (S), vermicompost (V), and an inorganic fertilizer, DAP (D) were all applied in completely randomized block plots at an equal application rate of 50 kg N ha⁻¹ with four replications per treatment. Control plots (C) where no fertilizer was applied were also considered. The experiment was done for two planting seasons in 2018. Number of leaves, plant height, cob, and grain yields were used to evaluate the performance of different fertilizer treatments. Economic assessment of all the six treatments was also carried out to determine the economic viability of applying these fertilizers on maize. Maize growth parameters and yields were all significantly increased (p < 0.05) with an application of both organic and inorganic fertilizers when compared with the control. However, there was no significant difference (p > 0.05) in the maize yields under the different fertilizer treatments. Vermicomposting was the most economically viable manure treatment method due to low operating costs and higher returns on investment that are supplemented with the production of chicken fodder (earthworm biomass) and, thus, can be recommended to farmers for production of a fertilizer that increases maize yields with assurance of economic returns. Full article

(This article belongs to the Section Innovative Cropping Systems)

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28 pages, 743 KiB

Open AccessEditor’s ChoiceReview

Advances in Genomic Interventions for Wheat Biofortification: A Review

by Dinesh Kumar Saini, Pooja Devi and Prashant Kaushik

Agronomy 2020, 10(1), 62; https://doi.org/10.3390/agronomy10010062 - 02 Jan 2020

Cited by 42 | Viewed by 7036

Abstract

Wheat is an essential constituent of cereal-based diets, and one of the most significant sources of calories. However, modern wheat varieties are low in proteins and minerals. Biofortification is a method for increasing the availability of essential elements in the edible portions of [...] Read more.

Wheat is an essential constituent of cereal-based diets, and one of the most significant sources of calories. However, modern wheat varieties are low in proteins and minerals. Biofortification is a method for increasing the availability of essential elements in the edible portions of crops through agronomic or genetic and genomic interventions. Wheat biofortification, as a research topic, has become increasingly prevalent. Recent accomplishments in genomic biofortification could potentially be helpful for the development of biofortified wheat grains, as a sustainable solution to the issue of “hidden hunger”. Genomic interventions mainly include quantitative trait loci (QTL) mapping, marker-assisted selection (MAS), and genomic selection (GS). Developments in the identification of QTL and in the understanding of the physiological and molecular bases of the QTLs controlling the biofortification traits in wheat have revealed new horizons for the improvement of modern wheat varieties. Markers linked with the QTLs of desirable traits can be identified through QTL mapping, which can be employed for MAS. Besides MAS, a powerful tool, GS, also has great potential for crop improvement. We have compiled information from QTL mapping studies on wheat, carried out for the identification of the QTLs associated with biofortification traits, and have discussed the present status of MAS and different prospects of GS for wheat biofortification. Accelerated mapping studies, as well as MAS and GS schemes, are expected to improve wheat breeding efficiency further. Full article

(This article belongs to the Special Issue Biofortification of Crops)

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13 pages, 3517 KiB

Open AccessEditor’s ChoiceArticle

Assessing the Impacts of Tillage and Mulch on Soil Erosion and Corn Yield

by Devraj Chalise, Lalit Kumar, Reena Sharma and Paul Kristiansen

Agronomy 2020, 10(1), 63; https://doi.org/10.3390/agronomy10010063 - 02 Jan 2020

Cited by 26 | Viewed by 4721

Abstract

Conventional tillage practices have been regarded as the major reason for the loss of fertile topsoil in the sloping agricultural lands of the middle hills of Nepal. Reports on the effects of no-till and mulch on soil and corn yield in these regions [...] Read more.

Conventional tillage practices have been regarded as the major reason for the loss of fertile topsoil in the sloping agricultural lands of the middle hills of Nepal. Reports on the effects of no-till and mulch on soil and corn yield in these regions are scarce, although these farming practices have been recommended to reduce soil erosion and increase crop yields. To assess the impacts of tillage (with +T, without −T) and mulch (with +M, without −M) on soil and soil nutrient losses, and corn yield, we conducted an experiment with five treatments: −T+M, −T−M, +T+M, +T−M, and bare fallow (BF), replicated four times each in an unbalanced complete random block design in Salyan district of Nepal. The results showed the presence of corn and no-till significantly lowered the soil losses. Losses of soil organic matter (SOM) and total nitrogen were also significantly reduced by the presence of corn, no-till, and mulch. However, no effects of mulch on soil losses, and no effects of tillage, mulch and corn on soil phosphorus losses were observed. Soil loss was found to be significantly and positively correlated with total seasonal rainfall, monsoon being the most severe season for soil erosion. While no-till and mulch did not affect corn height, cob height, and stover yield, no-till significantly increased the corn yield by 0.52 Mg ha⁻¹ compared to conventional till. We confirm the synergistic interaction of mulch with tillage to reduce the losses of SOM and total nitrogen, and effectiveness of no-till to reduce the soil losses and increase the corn yield in the middle hills of Nepal. As this study is based on the results of two year’s data, long-term studies are required to identify the long-term impacts of no-till and mulch on soil losses and corn yield across the country. Full article

(This article belongs to the Section Innovative Cropping Systems)

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