Horticulturae

17 pages, 9155 KiB

Open AccessArticle

Physiological Disorder Diagnosis of Plant Leaves Based on Full-Spectrum Hyperspectral Images with Convolutional Neural Network

by Myongkyoon Yang

Horticulturae 2022, 8(9), 854; https://doi.org/10.3390/horticulturae8090854 - 19 Sep 2022

Cited by 4 | Viewed by 2263

Abstract

The prediction and early detection of physiological disorders based on the nutritional conditions and stress of plants are extremely vital for the growth and production of crops. High-throughput phenotyping is an effective nondestructive method to understand this, and numerous studies are being conducted [...] Read more.

The prediction and early detection of physiological disorders based on the nutritional conditions and stress of plants are extremely vital for the growth and production of crops. High-throughput phenotyping is an effective nondestructive method to understand this, and numerous studies are being conducted with the development of convergence technology. This study analyzes physiological disorders in plant leaves using hyperspectral images and deep learning algorithms. Data on seven classes for various physiological disorders, including normal, prediction, and the appearance of symptom, were obtained for strawberries subjected to artificial treatment. The acquired hyperspectral images were used as input for a convolutional neural network algorithm without spectroscopic preprocessing. To determine the optimal model, several hyperparameter tuning and optimizer selection processes were performed. The Adam optimizer exhibited the best performance with an F1 score of ≥0.95. Moreover, the RMSProp optimizer exhibited slightly similar performance, confirming the potential for performance improvement. Thus, the novel possibility of utilizing hyperspectral images and deep learning algorithms for nondestructive and accurate analysis of the physiological disorders of plants was shown. Full article

(This article belongs to the Special Issue Recent Advances in Horticultural Practices for Strawberries and Other Small Fruit Crops)

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20 pages, 4830 KiB

Open AccessEditor’s ChoiceArticle

Functional Characterization of Tea Plant (Camellia sinensis L.) CsCBF2 Gene Involved in Multiple Abiotic Stress Response in Tobacco (Nicotiana tabacum L.)

by Qiying Zhou, Dongxiao Liu, Yiwan Wei, Ning Ma, Ruijiao Zhang, Zengya Zhang, Changjun Jiang and Hongyu Yuan

Horticulturae 2022, 8(9), 853; https://doi.org/10.3390/horticulturae8090853 - 19 Sep 2022

Cited by 2 | Viewed by 1484

Abstract

C-repeat binding factors/dehydration responsive element binding factors 1 (CBFs/DREB1s) are a small family of transcription factors that play important roles in plant resistance to various external stresses. However, functional characterization of tea plant (Camellia sinensis L.) CBF gene (CsCBF) was [...] Read more.

C-repeat binding factors/dehydration responsive element binding factors 1 (CBFs/DREB1s) are a small family of transcription factors that play important roles in plant resistance to various external stresses. However, functional characterization of tea plant (Camellia sinensis L.) CBF gene (CsCBF) was still seldom reported. Here, functional study of the cold-responsive CBF gene (CsCBF2) was done. Results showed that CsCBF2 had conserved AP2 DNA-binding domain and the typical PKK/RPAGRxKFxETRHP and DSAWR signature sequences of CBF/DREB1. Yeast one-hybrid and transcription activation assays revealed that the activation domain of CsCBF2 could activate the reporter gene expression, and the N terminal of CsCBF2 displayed an inhibitory effect. Although CsCBF2 was conserved to bind the C-repeat/dehydration-responsive element (CRT/DRE), intact CsCBF2 protein preferred the CRT cis element. Under normal growth conditions, CsCBF2-overexpressing tobacco plants (CsCBF2-OX) exhibited lighter green leaf color, growth retardation, and dwarfism. Smaller leaf of CsCBF2-OX was only seen in eight weeks after been sown in soil. Under cold, salinity, or drought stress, CsCBF2-OX displayed better growing with longer roots, heavier fresh weight, higher germination rate, and accumulated more proline and sugar contents, but lower electrolyte leakage. The results demonstrated that CsCBF2 enhanced plant tolerance to multiple abiotic stresses. Full article

(This article belongs to the Special Issue Advances in Tea Plant Biology and Tea Quality Regulation)

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12 pages, 1373 KiB

Open AccessArticle

Maturity, Ripening and Quality of ‘Donghong’ Kiwifruit Evaluated by the Kiwi-Meter™

by Wenjun Huang, Zhouqian Wang, Qi Zhang, Shaoran Feng, Jeremy Burdon and Caihong Zhong

Horticulturae 2022, 8(9), 852; https://doi.org/10.3390/horticulturae8090852 - 18 Sep 2022

Cited by 2 | Viewed by 2158

Abstract

Traditional destructive fruit assessment methodologies are currently being replaced by non-destructive alternatives. The Kiwi-Meter™ is promoted as a non-destructive device for assessment of kiwifruit maturation and ripening. In this study, three trials evaluated the feasibility of using the Kiwi-Meter and its I_AD [...] Read more.

Traditional destructive fruit assessment methodologies are currently being replaced by non-destructive alternatives. The Kiwi-Meter™ is promoted as a non-destructive device for assessment of kiwifruit maturation and ripening. In this study, three trials evaluated the feasibility of using the Kiwi-Meter and its I_AD™ index data for monitoring maturation, ripening, and quality of Actinidia chinensis var. chinensis ‘Donghong’ kiwifruit. The findings from the trials suggest that the Kiwi-Meter provides a non-destructive tool for measuring the color or chlorophyll content of the outer tissues of ‘Donghong’ kiwifruit. Since the timing of harvest of kiwifruit is not determined solely by flesh color, the utility of the Kiwi-Meter in any wider evaluation of fruit maturation (or ripening or quality) is dependent on there being a strong association between other fruit characteristics of interest with flesh color. The ‘Donghong’ fruit used in this trial degreened fully before ripening and thus the Kiwi-Meter could not provide a measure of maturation, ripening, or fruit quality. It is concluded that the Kiwi-Meter can assess fruit for flesh color, although even for this purpose, it must be considered that the I_AD measurement may be limited to only the outer area of the fruit flesh. Full article

(This article belongs to the Special Issue Innovative Nondestructive Techniques to Improve Quality Measurement of Fruits and Vegetables)

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17 pages, 8397 KiB

Open AccessArticle

Effects of Exogenous Salicylic Acid (SA), 6-Benzylaminopurine (6-BA), or Abscisic Acid (ABA) on the Physiology of Rosa hybrida ‘Carolla’ under High-Temperature Stress

by Kaixuan Wang, Yuxiao Shen, Han Wang, Songlin He, Wan Soon Kim, Wenqian Shang, Zheng Wang and Liyun Shi

Horticulturae 2022, 8(9), 851; https://doi.org/10.3390/horticulturae8090851 - 18 Sep 2022

Cited by 10 | Viewed by 2487

Abstract

The study of the regulatory mechanism of exogenous plant growth regulators (PGRs) on the relevant physiological indicators is essential to maintain the normal growth of Rosa hybrida under high-temperature conditions. The photosynthetic and physiological characteristics of the ornamental cut rose Rosa hybrida ‘Carolla’ [...] Read more.

The study of the regulatory mechanism of exogenous plant growth regulators (PGRs) on the relevant physiological indicators is essential to maintain the normal growth of Rosa hybrida under high-temperature conditions. The photosynthetic and physiological characteristics of the ornamental cut rose Rosa hybrida ‘Carolla’ under high temperature were studied by spraying leaves with various concentrations of exogenous salicylic acid (SA; 0.5, 1.0, 1.5, or 2.0 mmol·L⁻¹), 6-benzylaminopurine (6-BA; 10, 20, 30, or 50 μmol·L⁻¹), abscisic acid (ABA; 10, 20, 30, or 50 mg·L⁻¹), or distilled water (control). The results indicated that a foliar spray of either SA, 6-BA, or ABA could mitigate the impact of high temperatures. Compared to the control, the application of SA, 6-BA, or ABA increased the net CO₂ assimilation rate (A_n), transpiration rate (E), stomatal conductance (G_s), and water use efficiency (WUE) of ‘Carolla’, while decreasing the leaf relative electrical conductivity (REC) and malondialdehyde (MDA) content. The applications of SA, 6-BA, or ABA increased the activities of the antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), and ascorbate peroxidase (APX) and altered the proline (Pro), soluble protein, and soluble sugar contents. The results showed that foliar sprays of SA, 6-BA, or ABA could enhance the heat tolerance of ‘Carolla’ by promoting photosynthesis, cell membrane structural stability, antioxidant enzyme activity, and osmoregulation in plants under high-temperature stress. The experiment showed that 1.5 mmol·L⁻¹ SA, 20 μmol·L⁻¹ 6-BA, or 75 μmol·L⁻¹ ABA could alleviate the damage caused by high temperatures, with 20 μmol·L⁻¹ 6-BA having the best effect. Full article

(This article belongs to the Special Issue Biostimulants and Plant Elicitors to Mitigate the Effect of Biotic and Abiotic Stress)

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17 pages, 3008 KiB

Open AccessArticle

UVA Enhanced Promotive Effects of Blue Light on the Antioxidant Capacity and Anthocyanin Biosynthesis of Pak Choi

by Jing Huang, Xinying Liu, Qichang Yang, Bingfu Lei, Yinjian Zheng, Zhonghua Bian, Sen Wang, Wei Li, Pengpeng Mao and Yaliang Xu

Horticulturae 2022, 8(9), 850; https://doi.org/10.3390/horticulturae8090850 - 17 Sep 2022

Cited by 1 | Viewed by 2203

Abstract

Anthocyanins are widely common natural antioxidants and represent an important economic feature in vegetables, but the potential response of UVA–blue co-irradiation on the anthocyanin biosynthesis of pak choi is not clear. Here, we investigated the effects of the supplement of four doses of [...] Read more.

Anthocyanins are widely common natural antioxidants and represent an important economic feature in vegetables, but the potential response of UVA–blue co-irradiation on the anthocyanin biosynthesis of pak choi is not clear. Here, we investigated the effects of the supplement of four doses of UVA to blue light on growth, metabolites and the anthocyanin biosynthesis of two cultivars of pak choi. The results revealed that supplementing UVA light to blue light positively affected the growth of the pak choi and elevated the soluble protein content and antioxidant capacity. Especially, when compared with a monochromatic blue light, the anthocyanin synthesis was enhanced with an increase in UVA light strength, which reached a peak value at the strength of 10 μmol·m⁻²·s⁻¹. Further study revealed that the UVA–blue co-irradiation enhanced the transcription of partial light-induced and anthocyanin structural genes. The intraspecific difference in the expression patterns of MYB1 and PAP1 were observed in these two tested cultivars. MYB1 was significantly up-regulated in red-leaf pak choi, but down-regulated in purple-leaf pak choi. On the contrary, PAP1 was significantly up-regulated in purple-leaf pak choi, but down-regulated in red-leaf pak choi. To sum up, this study established an efficient pre-harvest lighting strategy to elevate the economic value of pak choi. Full article

(This article belongs to the Special Issue Physiology and Biochemistry in Relation to Quality of Fruits and Vegetables)

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7 pages, 714 KiB

Open AccessCommunication

Improvements for the Micropropagation of Hybrid Hazelnut (C. americana × C. avellana)

by Renata P. Pincelli-Souza, Laise Sousa Moreira and Jerry D. Cohen

Horticulturae 2022, 8(9), 849; https://doi.org/10.3390/horticulturae8090849 - 16 Sep 2022

Cited by 3 | Viewed by 1695

Abstract

The micropropagation of hybrid hazelnut (Corylus americana × Corylus avellana) has been limited in its agricultural application due to the lack of efficient procedures for tissue culture and root organogenesis. We established an efficient sterilization protocol for hazelnut micropropagation suitable for [...] Read more.

The micropropagation of hybrid hazelnut (Corylus americana × Corylus avellana) has been limited in its agricultural application due to the lack of efficient procedures for tissue culture and root organogenesis. We established an efficient sterilization protocol for hazelnut micropropagation suitable for in vitro root induction that permitted us to approach the poor root organogenesis experienced with the micropropagation of hazelnut hybrids in vitro. Typically, with standard protocols, root organogenesis had yields of well under 20%. We found that cuttings grown in vitro to the four-leaf stage can be successfully rooted using a combination of indole-3-butyric acid (IBA) pretreatment, followed by a one-week growth period in absolute darkness. The dark period was then followed by a transition to continuous light. In many cases, prolific visible roots formed between 12 and 14 days. Full article

(This article belongs to the Section Propagation and Seeds)

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11 pages, 1467 KiB

Open AccessReview

Effects of Pruning Mulch on Nutrient Concentration of Avocado (Persea americana Mill.) Fruit under Subtropical Conditions

by Antonio Aguirre-Arcos, Minerva García-Carmona, Marino Pedro Reyes-Martín, Layla M. San-Emeterio, Emilia Fernández-Ondoño and Irene Ortiz-Bernad

Horticulturae 2022, 8(9), 848; https://doi.org/10.3390/horticulturae8090848 - 15 Sep 2022

Cited by 1 | Viewed by 1615

Abstract

In this study, avocados of the Hass variety cultivated in Almuñécar (Granada, Spain) are analyzed after soil mulching with pruning debris. The mulch treatment assay was composed of pruning wastes from subtropical crops (avocado, cherimoya, and mango) and garden wastes from the surrounding [...] Read more.

In this study, avocados of the Hass variety cultivated in Almuñécar (Granada, Spain) are analyzed after soil mulching with pruning debris. The mulch treatment assay was composed of pruning wastes from subtropical crops (avocado, cherimoya, and mango) and garden wastes from the surrounding areas. The aim of this work is to analyze the nutrient content in avocado fruit and the effect of pruning-waste mulching on fruit development over four years. Avocado fruits collected in 2013, 2016, and 2017 were weighed, their volume and their sugar content were calculated, and macro- and micronutrients were analyzed in the peel, pulp, and stone (endocarp and seed). The pulp contained the highest concentration of nutrients, especially Cu, Zn, P, Na, and Ca. The peel presented high concentrations of Mn, K, and N, while the stone recorded the lowest values in nutrients, with the greatest decreases in years with the lowest precipitations registered. Over the study period, a decline was detected in the nutrient concentrations related to the alternation of high and low yields, typical of this crop, due to environmental factors. In the years 2016 and 2017, avocados accumulated higher amounts of micronutrients and P, presumably because of greater water availability in the soil. During the study period, the application of pruning wastes did not affect the nutrient concentration of fruits except for the garden pruning waste in certain elements in the pulp during the last study year. Full article

(This article belongs to the Section Fruit Production Systems)

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12 pages, 3022 KiB

Open AccessArticle

Fertilizer Nitrogen Application for Short-Day Onion Production: From Field to Table

by Andre Luiz Biscaia Ribeiro da Silva, Camila Rodrigues, Laurel Dunn, George Cavender and Timothy Coolong

Horticulturae 2022, 8(9), 847; https://doi.org/10.3390/horticulturae8090847 - 15 Sep 2022

Cited by 3 | Viewed by 1732

Abstract

Long growing seasons, relatively shallow root system, coarse textured soils, and variability of the subtropical environmental conditions of the southeastern U.S. create challenges for nitrogen (N) fertilizer management of short-day onions. The objectives of this study were: (i) to evaluate the impact of [...] Read more.

Long growing seasons, relatively shallow root system, coarse textured soils, and variability of the subtropical environmental conditions of the southeastern U.S. create challenges for nitrogen (N) fertilizer management of short-day onions. The objectives of this study were: (i) to evaluate the impact of fertilizer N rates on the yield and bulb quality of three short-day onion cultivars grown under the subtropical conditions of the southeastern U.S., and (ii) to assess the impact of fertilizer N rate for short-day onions on consumers’ preference. Field experiments were conducted in 2019 and 2020 at the Vidalia Onion and Vegetable Research Center at the University of Georgia located in Lyons, GA, in which a two factorial experimental design of five fertilizer N rates (84, 101, 117, 134, and 151 kg of N ha⁻¹) and three short-day onion cultivars (Sweet Agent, Vidora, and Quick Start) was evaluated in a randomized complete block design. During both growing seasons, rainfall events directly impacted soil mineral N content. While soil mineral N availability increased with fertilizer N application, there was no significant difference among fertilizer N rate treatments due to rainfall distribution in both years studied, except at bulb initiation when the application of 117 kg of N ha⁻¹ sustained soil mineral N availability that maximized with the application of 128 kg of N ha⁻¹. Onion total yield averaged 37,365 kg ha⁻¹ in 2019 and 34,699 kg ha⁻¹ in 2020. In general, colossal, jumbo, and medium-sized onions represented 7%, 76%, and 17% of total yield, respectively. Jumbo-sized onions are of most interest to growers due to their high value, and the yield of jumbo-sized onions was maximized with 158 kg of N ha⁻¹ in 2019 and with 138 kg of N ha⁻¹ in 2020. Bulb bacterial rots were not impacted by fertilizer N rate treatments. Contrarily, bulb gallic acid (GAE) linearly increased and pyruvic acid quadratically increased with the application of fertilizer N rate. Ultimately, a taste panel indicated that sensory characteristics were also not affected by different rates. Overall, a fertilizer N rate application of 117 to 134 kg of N ha⁻¹ could sustain soil mineral N availability without impacting yield; however, an investigation on the timing of application should be conducted to determine a fertilizer N strategy that will promote optimum yield, bulb quality, flavor, and consumer acceptability. Full article

(This article belongs to the Topic Soil Fertility and Plant Nutrition for Sustainable Agriculture)

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19 pages, 4151 KiB

Open AccessEditor’s ChoiceArticle

Comparative Study of Different Crassulaceae Species for Their Potential Use as Plant Covers to Improve Thermal Performance of Green Roofs

by Gonzalo Gurrea-Ysasi, Vicente Blanca-Giménez, Pascual Fernández de Córdova, Carles Cortés-Olmos, Adrián Rodríguez-Burruezo and Inmaculada C. Fita

Horticulturae 2022, 8(9), 846; https://doi.org/10.3390/horticulturae8090846 - 14 Sep 2022

Cited by 3 | Viewed by 1411

Abstract

The presence of green roofs in urban areas improves the energy efficiency of buildings; contributes to the capture of CO₂, decreasing pollution; and improves the appearance of cities, increasing their sustainability. Additionally, green roofs must include plant species with low requirements [...] Read more.

The presence of green roofs in urban areas improves the energy efficiency of buildings; contributes to the capture of CO₂, decreasing pollution; and improves the appearance of cities, increasing their sustainability. Additionally, green roofs must include plant species with low requirements and maintenance, and thus, succulent species could be useful in Mediterranean semi-arid regions. In this work, the thermal inertia and the effect of different succulent species as thermal barriers on mitigating the increase in temperature inside experimental compartments were studied in comparison to conventional covers used in the Spanish Mediterranean for a whole year. In general, green covers were more efficient than conventional ones for controlling temperature. Thus, temperatures under green covers were up to 8 °C lower than conventional covers and 3–5 °C lower than the ambient temperature at noon on summer days. Furthermore, significant differences were found between green covers. Thus, despite having high thermal inertia, Aptenia cordifolia showed the worst temperature records, while Aeonium arboreum was the most efficient at mitigating temperature changes both on cold winter nights and hot summer days—even better than Sedum spp., a usual succulent used commercially. Our results demonstrate that succulent species are efficient materials to use as green covers to improve thermal conditions in buildings in Mediterranean cities. This also suggests that the mixture of succulent species (i.e., not only made of Sedum spp.) with different colors and textures could beautify green roofs without compromising their energy efficiency. Full article

(This article belongs to the Special Issue Green Roofs, Green Walls, Urban Greenhouses and Hi-Tech City Landscape for Sustainability)

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14 pages, 1404 KiB

Open AccessArticle

The Inheritance Pattern of Key Desirable Agronomic and Fruit Quality Traits in Elite Red Papaya Genotypes

by Fawad Ali, Chutchamas Kanchana-udomkan and Rebecca Ford

Horticulturae 2022, 8(9), 845; https://doi.org/10.3390/horticulturae8090845 - 14 Sep 2022

Viewed by 1259

Abstract

Knowledge of the heritability, genetic advance, and stability of key traits, such as the height to the first fruit, trunk circumference, number of marketable fruit, wasted fruit, fruit weight, fruit width, fruit length, flesh thickness, cavity width, cavity length, and soluble solid contents, [...] Read more.

Knowledge of the heritability, genetic advance, and stability of key traits, such as the height to the first fruit, trunk circumference, number of marketable fruit, wasted fruit, fruit weight, fruit width, fruit length, flesh thickness, cavity width, cavity length, and soluble solid contents, is required. These were determined in ten advanced generation red papaya recombinant inbred lines (RIL; F5 generation). The F5 RIL were grown in four field sites, two each within two distinct agroecological climates: the Tablelands and Coastal regions. At each site, biological replicates (trees) of each RIL and the industry-standard red papaya cultivar, RB1, were grown. Agronomic traits and fruit-specific traits were assessed at five and 10 months, respectively, after seedling transplantation to the field. Height to first fruit, trunk circumference, fruit weight, and soluble solid contents were highly heritable and stable at all field sites (h²_b.s, 0.7–0.9) with genetic gains of almost 18% observed for height to first fruit and fruit weight. Across all sites, the trunks of the F5 lines were 37% wider, the trees set fruit 47% closer to the ground and had 20% more marketable fruit with 33% smaller fruit cavity widths, and their fruit was 11% heavier and 12% sweeter than RB1. Full article

(This article belongs to the Section Fruit Production Systems)

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17 pages, 13985 KiB

Open AccessEditor’s ChoiceArticle

Assessment of Fruit Quality and Genes Related to Proanthocyanidins Biosynthesis and Stress Resistance in Persimmon (Diospyros kaki Thunb.)

by Sichao Yang, Meng Zhang, Ming Zeng, Meihua Wu, Qinglin Zhang, Zhengrong Luo and Xinlong Hu

Horticulturae 2022, 8(9), 844; https://doi.org/10.3390/horticulturae8090844 - 14 Sep 2022

Cited by 1 | Viewed by 1640

Abstract

Persimmon (Diospyros kaki Thunb.) is becoming a fruit that is used worldwide because it contains high nutritional and medicinal value. However, the trait evaluation of persimmon is still needed and is critical for marketing and breeding, especially in China. Here, we evaluated [...] Read more.

Persimmon (Diospyros kaki Thunb.) is becoming a fruit that is used worldwide because it contains high nutritional and medicinal value. However, the trait evaluation of persimmon is still needed and is critical for marketing and breeding, especially in China. Here, we evaluated thirteen quality indicators (fruit weight, horizontal length, vertical length, firmness, titratable acid content, vitamin C content, flavonoid content, anthocyanin content, soluble sugar content, pectinase activity, soluble protein content, tannin content, and tannin cell size) in six Chinese pollination-constant, astringent (PCA) persimmon cultivars (‘Jinxi 3′, ‘Ganfang 1′, ‘Poyang 5′, ‘Poyang 6′, ‘Yifeng 1′, and ‘Yifeng 3′) and a Japanese pollination-constant non-astringent (PCNA) persimmon cultivar (‘Youhou’). The quality indicator data were normalized and subjected to variant analysis and principal component analysis (PCA). The results showed that 10 of 13 indicators among the seven persimmon cultivars were significantly different, and the contribution rates of the first principal component reached 40.582%. The principal component comprehensive scores for ‘Poyang 5′ and ‘Ganfang 1′ ranked second and third, respectively, and were clustered with that of ‘Youhou.’ In addition, we also measured the expression levels of three stress resistance genes and three proanthocyanidin (PA, also called condensed tannins) pathway genes in these persimmon cultivars by quantitative reverse transcription PCR (qRT—PCR). The qRT—PCR analysis of DkCBF and DkWRKY3/8 showed low resistance to cold in ‘Ganfang 1′ but stronger resistance to anthracnose. Moreover, the expression of the PA pathway genes demonstrated that the PA content in ‘Ganfang 1′ was at a moderate level in the seven varieties. Together, our study revealed relatively comprehensive profiles of persimmon quality evaluation and demonstrated that ‘Ganfang 1′ may have the potential to be used as a breeding parent for future persimmon breeding programs. Full article

(This article belongs to the Collection Epigenetic Modifications and Breeding Application in Horticultural Plants)

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15 pages, 6313 KiB

Open AccessArticle

Transcriptome Analysis of Berries of Spine Grape (Vitis davidii Föex) Infected by Colletotrichum viniferum during Symptom Development

by Yan Lei, Xiaojian Yuan, Ting Chen, Yuan Yuan, Xinming Liu, Xinbiao Tang and Qingxi Chen

Horticulturae 2022, 8(9), 843; https://doi.org/10.3390/horticulturae8090843 - 14 Sep 2022

Cited by 5 | Viewed by 1602

Abstract

Grape ripe rot (Colletotrichum viniferum) causes huge losses in grape production in vineyards in southern China. However, the molecular mechanism against ripe rot in grape species and the responsive genes implicated in these processes are relatively unknown. Here, we present the [...] Read more.

Grape ripe rot (Colletotrichum viniferum) causes huge losses in grape production in vineyards in southern China. However, the molecular mechanism against ripe rot in grape species and the responsive genes implicated in these processes are relatively unknown. Here, we present the transcriptome analysis of berries from a C. viniferum-resistant species (Vitis davidii Föex). Uninfected berries at day zero were used as control samples (CK), an inoculation was made at day zero, and the berries were subsequently analyzed at 1 day, 3 days, and 7 days post inoculation (dpi), which exhibited a sequential disease-progression stage. There were a total of 1810 differentially expressed genes, including 1315 up-regulated and 495 down-regulated transcripts. At 7 dpi, these differentially expressed genes (DEGs) were predominantly enriched in berries. In addition, in C. viniferum-infected grape fruits at 7 dpi, considerable changes in gene expression were induced, and those up-regulated genes involved in MAPK cascade, calcium ion binding, and serine/threonine kinase activity were enriched. According to our KEGG pathway analysis, numerous enriched biological processes, such as plant–pathogen interaction, phenylpropanoid biosynthesis, and metabolism, were implicated in grape–fungus interactions. Our research also revealed alterations in the expression pattern of phenylalanine-pathway-related transcription factors (TFs) and genes. We proposed a model in which C. viniferum invasion produces intracellular and extracellular Ca²⁺ deregulation to stimulate the MAPK pathway to activate TFs’ (WRKY, ERF, and MYB) up-regulation, thus initiating disease-resistant responses in the tolerant Vitis species. Our results offer comprehensive transcriptomic data about molecular responses in C. viniferum-infected grape, and these data will aid in understanding of processes underlying plant responses to C. viniferum. Full article

(This article belongs to the Special Issue Stress Biology of Horticultural Plants)

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20 pages, 2453 KiB

Open AccessArticle

High-Density Genetic Linkage Map Construction and QTLs Identification Associated with Four Leaf-Related Traits in Lady’s Slipper Orchids (Paphiopedilum concolor × Paphiopedilum hirsutissimum)

by Dong-Mei Li and Gen-Fa Zhu

Horticulturae 2022, 8(9), 842; https://doi.org/10.3390/horticulturae8090842 - 14 Sep 2022

Cited by 4 | Viewed by 1661

Abstract

Lady’s slipper orchids (Paphiopedilum spp.) are highly valuable within the flower industry. Recently, both Paphiopedilum concolor and Paphiopedilum hirsutissimum (2n = 2x = 26) have been widely used for hybrid parents, ornamental, and economic purposes. However, high-density genetic maps and leaf traits [...] Read more.

Lady’s slipper orchids (Paphiopedilum spp.) are highly valuable within the flower industry. Recently, both Paphiopedilum concolor and Paphiopedilum hirsutissimum (2n = 2x = 26) have been widely used for hybrid parents, ornamental, and economic purposes. However, high-density genetic maps and leaf traits related to quantitative trait loci (QTLs) in these two Paphiopedilum species have been poorly studied. Herein, an interspecific F1 population of 95 individuals was developed from the cross between P. concolor and P. hirsutissimum with contrasting leaf length (LL), leaf width (LW), leaf thickness (LT), and leaf number (LN). RNA extracted from the F1 population and their parents was subjected to high-throughput RNA sequencing. Approximately 745.59 Gb of clean data were generated, and were assembled into 349,730 transcripts and 185,089 unigenes. In total, 165,196 high-resolution polymorphic single nucleotide polymorphism (SNP) markers were initially identified. Finally, 8410 SNP markers satisfied the requirements and were used to construct a genetic map. The integrated map contained 13 linkage groups (LGs) and spanned 1616.18 cM, with an average distance of 0.19 cM between adjacent markers. QTL analysis in the F1 population identified 12 QTLs linked to four leaf-related traits, including LL, LW, LT, and LN. These QTLs by composition interval mapping, explained 11.86% to 21.58% of the phenotypic variance, and were distributed on eight LGs, but not on LGs 4, 6, 8, 12, and 13. Furthermore, 25 unigenes were identified via BLAST searches between the SNP markers in the QTL regions and our assembled transcriptome, of which 11 unigenes were enriched with 59 gene ontology (GO) terms. The information generated in this study will be useful for candidate genes for further molecular regulation studies on leaf traits, future marker-assisted selection of leaf ornamental improvement breeding, genome assembly, and comparative genome analyses. Full article

(This article belongs to the Topic Plant Breeding, Genetics and Genomics)

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14 pages, 612 KiB

Open AccessArticle

Use Optimization of Organic Wastes in Anaerobic Soil Disinfestation against Strawberry Charcoal Rot Root

by Ana Márquez-Caro, Celia Borrero, Paloma Hernández-Muñiz and Manuel Avilés

Horticulturae 2022, 8(9), 841; https://doi.org/10.3390/horticulturae8090841 - 13 Sep 2022

Cited by 1 | Viewed by 1486

Abstract

The imminent removal of agrochemicals in Europe is directly affecting the strawberry sector in Spain, specifically in the Huelva province. Huelva is currently the main producer in the country. The lack of efficient fumigants has led to the rise of soilborne diseases. Macrophomina [...] Read more.

The imminent removal of agrochemicals in Europe is directly affecting the strawberry sector in Spain, specifically in the Huelva province. Huelva is currently the main producer in the country. The lack of efficient fumigants has led to the rise of soilborne diseases. Macrophomina phaseolina (the causal agent of charcoal rot in strawberries) is generating serious problems with strawberry farmers. This work proposes to optimize the process of anaerobic soil disinfestation (ASD) against M. phaseolina in strawberry crops as a more sustainable alternative than chemical fumigation. Two trials with different inoculum doses were conducted, amending the soil with rice bran and residual strawberry extrudate as the carbon source for the ASD to evaluate the propagule reduction. After the ASD, these soils were used to crop strawberries in a growth chamber under controlled conditions to assay the disease reduction. Strawberry extrudate and rice bran favored disease reduction over the control, equaling the efficacy of Metam Sodium or even improving it in some cases. Trichoderma spp. and microbial activity could influence the suppressive effect of the ASD. All amended ASD treatments reduced the M. phaseolina propagules and charcoal rot severity. Rice bran and residual strawberry extrudate are suitable amendments to be used in ASD against the pathogen. The resulting soil disinfestation against M. phaseolina with residual strawberry extrudate at 16.89 t/ha and 25 days was similar to the most effective treatment with rice bran (20 t/ha and 40 days) based on the disease foliar severity. Additionally, both treatments were equivalent in efficacy to the Metam Sodium treatment. Full article

(This article belongs to the Special Issue The State of The Art of Horticulture Science in Spain)

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16 pages, 1193 KiB

Open AccessEditor’s ChoiceArticle

Jasmonic Acid and Salicylic Acid Levels in Defense Response of Azalea (Rhododendron simsii Hybrid) to Broad Mite (Polyphagotarsonemus latus)

by Leen Leus, Gil Luypaert, Emmy Dhooghe, Johan Witters, Els Pauwels, Christof Van Poucke, Els Van Pamel, Johan Van Huylenbroeck and Joachim Audenaert

Horticulturae 2022, 8(9), 840; https://doi.org/10.3390/horticulturae8090840 - 13 Sep 2022

Viewed by 1658

Abstract

The broad mite (Polyphagotarsonemus latus (Banks)) is an important pest in many crops, including azalea (Rhododendron simsii Planch. hybrid). Broad mites cause the malformation of shoot tips, leaves and flowers in azalea. It is known that the jasmonic acid (JA)- and [...] Read more.

The broad mite (Polyphagotarsonemus latus (Banks)) is an important pest in many crops, including azalea (Rhododendron simsii Planch. hybrid). Broad mites cause the malformation of shoot tips, leaves and flowers in azalea. It is known that the jasmonic acid (JA)- and salicylic acid (SA)-dependent signaling pathways are related to the presence of herbivorous mites. Here, we describe the levels of the two main plant defense-related hormones, SA and JA, in mite-infested plants. The plant hormones were analyzed using liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). We studied both short-term hormonal responses under controlled conditions with artificial inoculation, and long-term responses under culture conditions with natural infestation. The long-term development of broad mite populations and hormone response were studied during two subsequent growing seasons on 3 and 18 different cultivars, respectively. During the experiments on 18 azalea cultivars under natural infestation, the presence of different species of tarsonemid mites was also examined. JA concentrations only showed variation in the early phase of infestation. Subsequently, the SA levels increased significantly for all the cultivars where broad mites were detected. Based on the observed timing of the defense responses, we suggest that the interaction of the JA and SA pathways as a defense response for pot azalea against P. latus involves a primary plant response through the JA pathway. In the presence of the mites, the production of SA increased in the plants in a later phase as the P. latus population grew. Our results also show that the hormone response depends on type of mite. Changes in hormone levels were found upon infestation with P. latus, but not in the presence of another frequently occurring tarsonemid mite, Tarsonemus confusus Ewing. Full article

(This article belongs to the Special Issue Advancement in Propagation, Breeding, Cultivation and Marketing of Ornamentals)

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11 pages, 2701 KiB

Open AccessArticle

Wild Chrysanthemums Core Collection: Studies on Leaf Identification

by Toan Khac Nguyen, L. Minh Dang, Hyoung-Kyu Song, Hyeonjoon Moon, Sung Jae Lee and Jin Hee Lim

Horticulturae 2022, 8(9), 839; https://doi.org/10.3390/horticulturae8090839 - 13 Sep 2022

Cited by 3 | Viewed by 2562

Abstract

Wild chrysanthemums mainly present germplasm collections such as leaf multiform, flower color, aroma, and secondary compounds. Wild chrysanthemum leaf identification is critical for farm owners, breeders, and researchers with or without the flowering period. However, few chrysanthemum identification studies are related to flower [...] Read more.

Wild chrysanthemums mainly present germplasm collections such as leaf multiform, flower color, aroma, and secondary compounds. Wild chrysanthemum leaf identification is critical for farm owners, breeders, and researchers with or without the flowering period. However, few chrysanthemum identification studies are related to flower color recognition. This study contributes to the leaf classification method by rapidly recognizing the varieties of wild chrysanthemums through a support vector machine (SVM). The principal contributions of this article are: (1) an assembled collection method and verified chrysanthemum leaf dataset that has been achieved and improved; (2) an adjusted SVM model that is offered to deal with the complex backgrounds presented by smartphone pictures by using color and shape classification results to be more attractive than the original process. As our study presents, the proposed method has a viable application in real-picture smartphones and can help to further investigate chrysanthemum identification. Full article

(This article belongs to the Special Issue Smart Horticulture, Plant Secondary Compounds and Their Applications)

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13 pages, 2337 KiB

Open AccessArticle

Fruit Characterization of Prunus serotina subsp. capuli

by Sakshi Pathania, Rachel A. Itle, Carlos R. Chávez, Luis F. Lema, Veronica Caballero-Serrano, Juan C. Carrasco and Dario J. Chavez

Horticulturae 2022, 8(9), 838; https://doi.org/10.3390/horticulturae8090838 - 12 Sep 2022

Cited by 2 | Viewed by 2504

Abstract

Prunus serotina is divided into five subspecies. Among these, P. serotina subsp. capuli, commonly known as capuli, is native to Central and South America. Its fruits are big, sweet, and consumed by locals in various forms, with the Ecuadorian Andes region providing [...] Read more.

Prunus serotina is divided into five subspecies. Among these, P. serotina subsp. capuli, commonly known as capuli, is native to Central and South America. Its fruits are big, sweet, and consumed by locals in various forms, with the Ecuadorian Andes region providing the best fruit forms of capuli. The objective of this study was to characterize a collection of different genotypes of capuli’s fruit, and their endocarps, found growing in the wild in the Chimborazo, Tungurahua, and Cotopaxi provinces of Ecuador. The fruits were characterized for weight (11.7–50.3 g), diameter (12.4–21.7 mm), height (11.4–19.7 mm), and soluble solids content (SSC) (13.4–27.6 °Brix) across two years. Similarly, the endocarps’ diameters (7.5–12.2 mm) and heights (8.1–13.6 mm) were measured. Significant differences were found for all the fruit and endocarp variables studied. A multivariate analysis showed that all the fruit and endocarp size characteristics, except SSC, were positively correlated with each other within a season. No clear population differentiation was seen among the genotypes from different provinces, suggesting a lack of clear morphological differentiation. The future breeding and selection of a capuli with superior, commercial, large fruit and a high SSC shows great potential. Full article

(This article belongs to the Collection Prospects of Using Wild Plant Species in Horticulture)

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11 pages, 3188 KiB

Open AccessArticle

Analysis of Greenness Value and Photosynthetic Rate of Tomato Leaves Based on Spectral Technologies

by Jitong Xu, Fang Wang, Zhe Zhang, Yuhang Guo, Yufeng Liu and Xiaofeng Ning

Horticulturae 2022, 8(9), 837; https://doi.org/10.3390/horticulturae8090837 - 12 Sep 2022

Viewed by 1379

Abstract

Tomatoes, a major vegetable crop, are not only delicious but can also prevent cancer and lower blood pressure. However, they are easily infected with diseases during the growth process, so it is of great significance to find a technology for nondestructive testing of [...] Read more.

Tomatoes, a major vegetable crop, are not only delicious but can also prevent cancer and lower blood pressure. However, they are easily infected with diseases during the growth process, so it is of great significance to find a technology for nondestructive testing of the tomato growth state. In this study, partial least squares regression (PLSR) was used to establish a prediction model of the tomato leaf greenness value and photosynthetic rate based on laser-induced fluorescence spectroscopy and a hyperspectral imaging system. The results showed that the best preprocessing method for the fluorescence spectral model was SD+SNV, and the best methods for the hyperspectral model were FD+SNV and FD+MSC. The results for the prediction of the photosynthetic rate based on the fluorescence spectral and hyperspectral models were as follows: the coefficient of determination (R²) values were 0.9982 and 0.9739, respectively, and the root-mean-square error of prediction (RMSEP) values were 0.2781 and 0.3374, respectively. When measuring greenness, the R² values were 0.9816 and 0.9595, and the RMSEP values were 0.1696 and 0.4032, respectively. The experimental results showed that the model based on the fluorescence spectrum had higher accuracy and lower deviation in the detection and prediction of the tomato growth state; these results provide a specific method and reference for subsequent research. Full article

(This article belongs to the Special Issue Abiotic Stress Responses of Vegetable Crops)

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10 pages, 2005 KiB

Open AccessArticle

Seed Dormancy and Germination Characteristics of Vaccinium oldhamii Miq. (Ericaceae)

by Da Hyun Lee, Chung Youl Park, Young Ho Jung, Jun Hyeok Kim, Sung Hyuk Park, Ho Jun Son, Chae Sun Na and Wan Geun Park

Horticulturae 2022, 8(9), 836; https://doi.org/10.3390/horticulturae8090836 - 11 Sep 2022

Viewed by 1712

Abstract

Vaccinium oldhamii Miq. is an edible berry; however, little is known about its seed dormancy-break and germination. Therefore, the aim of this study was to elucidate the seed-dormancy break and germination characteristics of V. oldhamii. The results showed that the length [...] Read more.

Vaccinium oldhamii Miq. is an edible berry; however, little is known about its seed dormancy-break and germination. Therefore, the aim of this study was to elucidate the seed-dormancy break and germination characteristics of V. oldhamii. The results showed that the length and width of the seeds of V. oldhamii were 2.4588 ± 0.0273 mm and 1.7028 ± 0.0248 mm, respectively, the filled percentage was 49.0 ± 3.0%, and the 1000-seed weight was 0.9453 g. Additionally, water imbibition test showed that the seed weight of V. oldhamii increased by more than 70% after 24 h, indicating the absence of physical dormancy. Embryo length measured at dispersal and just before germination did not differ significantly. There was no significant difference in E:S (Embryo:Seed) ratio in length at the time of seed dispersal (0.6780 ± 0.0258) and before germination (0.7370 ± 0.0469), indicating the absence of morphological dominance. Temperature treatments showed that the germination of the seed was 0, 6.0, 6.0, 20.0, and 0% under 15, 20, 25, 25/15, and 15/6 °C, respectively. However, treatment with 250 ppm of GA₃ increased the germination of the seeds to 22.0, 36.0, 32.0, 40.0, and 1.0%, respectively. Additionally, treatment with 500 ppm of GA₃ increased the germination to 34.6, 40.0, 40.0, 46.0 %, respectively. These results indicated that the seeds of V. oldhamii exhibited Nondeep physiological dormancy (Nondeep PD). Overall, the findings of this study showed that treatment with 500 ppm of GA₃ at 25/15 °C can effectively break the dormancy of V. oldhamii seeds, which could facilitate further research on the species. Full article

(This article belongs to the Collection Seed Dormancy and Germination of Horticultural Plants)

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13 pages, 3144 KiB

Open AccessArticle

Identification of Reliable Reference Genes for the Expression of Hydrangea macrophylla ‘Bailmer’ and ‘Duro’ Sepal Color

by Gaitian Zhang, Suxia Yuan, Hui Qi, Zhiyun Chu and Chun Liu

Horticulturae 2022, 8(9), 835; https://doi.org/10.3390/horticulturae8090835 - 11 Sep 2022

Cited by 3 | Viewed by 1605

Abstract

Hydrangea spp. is renowned for its variety of color changes in its developmental stage and before and after aluminum treatment. We analyzed gene expression in hydrangeas sepals to study the causes of color change. The accuracy of quantitative RT-qPCR analysis depends on the [...] Read more.

Hydrangea spp. is renowned for its variety of color changes in its developmental stage and before and after aluminum treatment. We analyzed gene expression in hydrangeas sepals to study the causes of color change. The accuracy of quantitative RT-qPCR analysis depends on the reliability of reference genes. We selected reference genes for hydrangea of varying cultivars, at different developmental stages, and in aluminum treatment groups. We chose ‘Bailmer’ and ‘Duro’ as subject species. We selected eight candidate genes, all of which were ranked by geNorm, NormFinder, BestKeeper, and RefFinder. CCR, NHX1, and LODX were used to verify the exactitude of reference genes. According to the ranking result of RefFinder, the top-ranked reference genes in each group were different; the top four candidate reference genes in each group mostly included EF1-β, RPL34, GADPH, and RPL10. EF1-β and RPL34 ranked top in the ‘all materials’ group, and their expression trends, obtained from the analysis of CCR, NHX1, and LODX, were consistent. From the results, we gather that EF1-β and RPL34 can be used as reference genes to quantify target gene expression. In this study, we screened for reference genes in hydrangeas to provide a technical basis for hydrangea sepal formation and transformation for further experiments. Full article

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19 pages, 2920 KiB

Open AccessArticle

Intercropping Gramineae Herbage in Semiarid Jujube Cultivar ‘LingwuChangzao’ (Ziziphus jujuba Mill. cv. LingwuChangzao) Orchard Improves Productivity, Plant Nutritional Quality, and Soil Quality

by Xiaojia Wang, Bing Cao, Jin Zou, Aiyun Xu and Xuerui Feng

Horticulturae 2022, 8(9), 834; https://doi.org/10.3390/horticulturae8090834 - 10 Sep 2022

Cited by 2 | Viewed by 1595

Abstract

Forest-grass intercropping has great advantages in exploiting the potential of biological resources, improving the productivity of agriculture. Nevertheless, research on intercropping of ‘LingwuChangzao’ (Ziziphus jujuba Mill. cv. LingwuChangzao) with Gramineae herbage is less frequently reported. In this study, we measured the [...] Read more.

Forest-grass intercropping has great advantages in exploiting the potential of biological resources, improving the productivity of agriculture. Nevertheless, research on intercropping of ‘LingwuChangzao’ (Ziziphus jujuba Mill. cv. LingwuChangzao) with Gramineae herbage is less frequently reported. In this study, we measured the land equivalent ratio (LER), the nutritional quality of fruit and forage, and soil properties when ‘LingwuChangzao’ jujube was intercropped with Gramineae herbage compared to when grown in a corresponding monoculture, using clean tillage as a control. The results indicated that ‘LingwuChangzao’ jujube/Gramineae herbage intercropping significantly improved the LER in the system, the appearance traits, and the quality of jujube fruit (e.g., the total soluble solids, soluble sugar, vitamin C, anthocyanin, and flavonoids). Conversely, some nutritional quality indicators, such as dry matter, crude protein, crude fat, and neutral detergent fiber of forage, were lower than the corresponding monoculture. The physical properties in the soil improved with increased soil water content, electrical conductivity, total nitrogen, available phosphorus, etc. Further, intercropping systems had significant effects on soil organic carbon fractions and most of the C-N cycling enzyme activities. Redundancy analyses (RDA) revealed that electrical conductivity and total nitrogen were the dominant soil factors that influenced the C-N cycling enzyme activities and four soil organic carbon fractions correlated with C-N cycling soil enzyme activities. In conclusion, these results demonstrated that ‘LingwuChangzao’ jujube/Gramineae herbage intercropping significantly altered C-N cycling enzyme activities by driving the soil physicochemical properties and soil organic carbon fractions. Our findings show how to improve the productivity of ‘LingwuChangzao’ jujube and they provide insights into the mechanisms underlying healthy, biodiverse soils in agroecosystems. Full article

(This article belongs to the Section Fruit Production Systems)

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30 pages, 3796 KiB

Open AccessFeature PaperArticle

Research Trends on Greenhouse Engineering Using a Science Mapping Approach

by Ileana Blanco, Andrea Luvisi, Luigi De Bellis, Evelia Schettini, Giuliano Vox and Giacomo Scarascia Mugnozza

Horticulturae 2022, 8(9), 833; https://doi.org/10.3390/horticulturae8090833 - 09 Sep 2022

Cited by 7 | Viewed by 4044

Abstract

Horticultural protected cultivation has spread throughout the world as it has proven to be extremely effective. In recent years, the greenhouse engineering research field has become one of the main research topics within greenhouse farming. The main objectives of the current study were [...] Read more.

Horticultural protected cultivation has spread throughout the world as it has proven to be extremely effective. In recent years, the greenhouse engineering research field has become one of the main research topics within greenhouse farming. The main objectives of the current study were to identify the major research topics and their trends during the last four decades by analyzing the co-occurrence network of keywords associated with greenhouse engineering publications. A total of 3804 pertinent documents published, in 1981–2021, were analyzed and discussed. China, the United States, Spain, Italy and the Netherlands have been the most active countries with more than 36% of the relevant literature. The keyword cluster analysis suggested the presence of five principal research topics: energy management and storage; monitoring and control of greenhouse climate parameters; automation of greenhouse operations through the internet of things (IoT) and wireless sensor network (WSN) applications; greenhouse covering materials and microclimate optimization in relation to plant growth; structural and functional design for improving greenhouse stability, ventilation and microclimate. Recent research trends are focused on real-time monitoring and automatic control systems based on the IoT and WSN technologies, multi-objective optimization approaches for greenhouse climate control, efficient artificial lighting and sustainable greenhouse crop cultivation using renewable energy. Full article

(This article belongs to the Special Issue Advances in Protected Vegetable Cultivation)

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13 pages, 1334 KiB

Open AccessArticle

Health Risk Assessment of Hazardous Heavy Metals in Two Varieties of Mango Fruit (Mangifera indica L. var. Dasheri and Langra)

by Ivan Širić, Ebrahem M. Eid, Mohamed H. E. El-Morsy, Hanan E. M. Osman, Bashir Adelodun, Sami Abou Fayssal, Boro Mioč, Madhumita Goala, Jogendra Singh, Archana Bachheti, Ashish Kumar Arya, Kyung Sook Choi, Vinod Kumar and Pankaj Kumar

Horticulturae 2022, 8(9), 832; https://doi.org/10.3390/horticulturae8090832 - 09 Sep 2022

Cited by 13 | Viewed by 2309

Abstract

The spatial assessment of four heavy metals (Cd, Cr, Pb, and As) in two mango fruit (Mangifera indica L.) varieties (Dasheri and Langra) collected from the Saharanpur district, Uttar Pradesh, India, was investigated in this study. The samples of ripe mango fruits [...] Read more.

The spatial assessment of four heavy metals (Cd, Cr, Pb, and As) in two mango fruit (Mangifera indica L.) varieties (Dasheri and Langra) collected from the Saharanpur district, Uttar Pradesh, India, was investigated in this study. The samples of ripe mango fruits were collected from the orchards of 12 major towns in the Saharanpur district from May to June 2022. Heavy metal analysis using atomic absorption spectroscopy (AAS) showed the presence of all selected heavy metals. Specifically, the concentration (mg/kg dry weight basis) range of Cd (0.01–0.08), Cr (0.11–0.82), Pb (0.02–0.15), and As (0.01–0.14) did not exceed the safe limits. The geospatial variation in the heavy metal concentration was significantly (p < 0.05) different as indicated by the inverse distance weighting (IDW) interpolation and analysis of variance (ANOVA) results. The multivariate statistical analysis using principal component (PC) and agglomerative hierarchical cluster (AHC) analyses revealed that the Saharanpur city location had the highest levels of selected heavy metals out of the 12 sampling locations. In this, the Dasheri variety was identified to have higher heavy metal concentrations in comparison to the Langra variety. Moreover, the health risk study using the target hazard quotient (THQ) confirmed that the levels did not exceed the safe health risk index (HRI) limit of 1. However, the health risk assessment for the child group showed relatively high HRI values (<0.35) compared to those of the adult group (<0.09). Therefore, considering the importance of the Saharanpur district in massive mango fruit production, this study provides vital information regarding the biomonitoring of heavy metals in the two most consumed varieties. Full article

(This article belongs to the Special Issue Physico-Chemical Characterization of Fruits and Vegetables)

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8 pages, 639 KiB

Open AccessEditor’s ChoiceArticle

Sweet Potato (Ipomoea batatas L.) Response to Incremental Application Rates of Potassium Fertilizer in Mississippi

by Lorin M. Harvey, Mark W. Shankle, Callie J. Morris, Mark A. Hall, Amitava Chatterjee and Kelsey M. Harvey

Horticulturae 2022, 8(9), 831; https://doi.org/10.3390/horticulturae8090831 - 09 Sep 2022

Cited by 3 | Viewed by 1901

Abstract

Potassium (K) fertilization is a crucial component of sweet potato (Ipomoea batatas L.) production. The basis for K fertilizer recommendations in sweet potato production varies greatly and relies on studies conducted in the late 1950s–1970s. Changes in agronomic practices and increasing [...] Read more.

Potassium (K) fertilization is a crucial component of sweet potato (Ipomoea batatas L.) production. The basis for K fertilizer recommendations in sweet potato production varies greatly and relies on studies conducted in the late 1950s–1970s. Changes in agronomic practices and increasing costs emphasize the need to revisit fertilizer recommendations. A field experiment was conducted to investigate the impact of seven different K fertilizer (K₂O) application rates on sweet potato storage root yield, tissue K concentration, and economic implications in Mississippi. Incremental applications of K fertilizer did not influence sweet potato yield at any grade. Leaf tissue K concentration exhibited a quadratic trend in response to K fertilizer rate, with maximum leaf and root K content achieved at 269 and 404 kg·ha⁻¹ K₂O, respectively. Both the predicted K application rate for maximum yield and maximum profitability were the same, at 174 kg·ha⁻¹ K₂O. Accordingly, comparable sweet potato yields were achieved while applying substantially less fertilizer than the recommended rate. Further research is warranted to examine the impacts of only potassium fertilizer applications on soil characteristics and temporal trends in sweet potato potassium uptake, as well as refine fertilization recommendations for sweet potato production. Full article

(This article belongs to the Section Plant Nutrition)

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14 pages, 12031 KiB

Open AccessArticle

Combined Use of Spent Mushroom Substrate Biochar and PGPR Improves Growth, Yield, and Biochemical Response of Cauliflower (Brassica oleracea var. botrytis): A Preliminary Study on Greenhouse Cultivation

by Ivan Širić, Ebrahem M. Eid, Mostafa A. Taher, Mohamed H. E. El-Morsy, Hanan E. M. Osman, Pankaj Kumar, Bashir Adelodun, Sami Abou Fayssal, Boro Mioč, Željko Andabaka, Madhumita Goala, Sonika Kumari, Archana Bachheti, Kyung Sook Choi and Vinod Kumar

Horticulturae 2022, 8(9), 830; https://doi.org/10.3390/horticulturae8090830 - 08 Sep 2022

Cited by 29 | Viewed by 3386

Abstract

This paper investigated the impact of the combined use of spent mushroom substrate (SMS) biochar and plant-growth-promoting rhizobia (PGPR) on the growth, yield, and biochemical response of cauliflower (Brassica oleracea var. botrytis). A preliminary study was conducted under greenhouse condition using [...] Read more.

This paper investigated the impact of the combined use of spent mushroom substrate (SMS) biochar and plant-growth-promoting rhizobia (PGPR) on the growth, yield, and biochemical response of cauliflower (Brassica oleracea var. botrytis). A preliminary study was conducted under greenhouse condition using six treatments (sextuplicate) as control (no addition), T1 (PGPR), T2 (5 g/Kg biochar), T3 (5 g/Kg biochar + PGPR), T4 (10 g/Kg biochar), and T5 (10 g/Kg biochar + PGPR) under greenhouse conditions. The Scanning Electron Microscopy (SEM-Zeiss), Energy Dispersive Spectroscopy (EDS), and Fourier’s transform infrared spectroscopy (FTIR) analyses showed that biochar produced from slow pyrolysis of SMS had advantageous structural, functional, and morphological properties for agricultural use. Results showed that SMS biochar addition aids the acceleration of soil nutrient properties. SMS biochar and PGPR application also significantly (p < 0.05) improved the selected growth, yield, and biochemical parameters of cauliflower. In particular, the highest cauliflower yield (550.11 ± 10.05 g), fresh plant biomass (1.66 ± 0.04 Kg), dry plant biomass (149.40 ± 4.18 g), plant height (22.09 ± 0.14 cm), root length (11.20 ± 0.05 cm), plant spread (28.35 ± 0.18 cm), and the number of leaves (12.50 ± 0.50) were observed in T5 treatment. Similarly, the best values for biochemical parameters and enzyme activities such as total chlorophyll (TC: 3.13 ± 0.07 mg/g), superoxide dismutase (SOD: 79.12 ± 1.29 µg/g), catalase (CAT: 55.70 ± 2.52 µg/g), peroxidase (POD 30.18 ± 0.37 µg/g), total phenolics (TP: 19.50 ± 0.31 mg/g), ascorbic acid (AA: 14.18 ± 0.55 mg/g), and total carotenoids (TCT: 150.17 ± 8.20 µg/100 g) were also recorded in the T5 treatment. The application of SMS biochar and PGPR showed a positive correlation with growth, yield, and biochemical response of cauliflower, as indicated by the Pearson correlation analysis. The findings of this study suggest efficient recycling of mushroom industry waste for biochar production and the use of PGPR to improve nutrient utilization in sustainable agriculture. Full article

(This article belongs to the Collection Sustainable Mushroom Cultivation)

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14 pages, 963 KiB

Open AccessArticle

Falanghina Grapevine (Vitis vinifera L.) Yield and Berry Quality under Different Pedoclimatic Conditions in Southern Italy

by Nicola Damiano, Chiara Cirillo, Francesca Petracca, Rosanna Caputo, Arturo Erbaggio, Marco Giulioli and Veronica De Micco

Horticulturae 2022, 8(9), 829; https://doi.org/10.3390/horticulturae8090829 - 08 Sep 2022

Cited by 3 | Viewed by 2091

Abstract

Climate is a determinant driver for grapevine geographical distribution, influencing yield and berry quality. The current environmental changes are intensifying the need to improve the knowledge of the soil–plant–atmosphere system in the vineyard, to properly manage cultivation factors and to increase berry yield [...] Read more.

Climate is a determinant driver for grapevine geographical distribution, influencing yield and berry quality. The current environmental changes are intensifying the need to improve the knowledge of the soil–plant–atmosphere system in the vineyard, to properly manage cultivation factors and to increase berry yield and quality. Since most of the berry growth and ripening phases occur during the driest period in the Mediterranean area, increasing environmental constraints are expected to impose more and more limitations on grapevine productivity and finally on wine quality. The aim of this study was to evaluate whether different pedoclimatic conditions in four proximally located vineyards of the Campania Region in Southern Italy determine differences in crop yield and must quality of Vitis vinifera L. subsp. vinifera “Falanghina”. This study was conducted over three growing seasons, by monitoring vine growth and characterizing yield and must quality. The overall results showed differences in yield and berry quality characteristics for the four vineyards, with the field CA (Calvese) and GR (Grottole) showing pedoclimatic conditions limiting growth and yield compared to SL (Santa Lucia) and AC (Acquefredde). Full article

(This article belongs to the Collection Nutritive Value, Polyphenolic Content, and Bioactive Constitution of Green, Red and Flowering Plants-Volume II)

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16 pages, 2151 KiB

Open AccessArticle

Nutritional Composition and Bioactivity of Salicornia europaea L. Plants Grown in Monoculture or Intercropped with Tomato Plants in Salt-Affected Soils

by Antonella Castagna, Giada Mariottini, Morena Gabriele, Vincenzo Longo, Aymen Souid, Xavier Dauvergne, Christian Magné, Giulia Foggi, Giuseppe Conte, Marco Santin and Annamaria Ranieri

Horticulturae 2022, 8(9), 828; https://doi.org/10.3390/horticulturae8090828 - 08 Sep 2022

Cited by 12 | Viewed by 2343

Abstract

The increasing salinization of agricultural soils urges us to find alternative and sustainable farming systems in order to allow the exploitation of areas that are otherwise becoming less suitable for conventional crops. Thanks to their adaptation to extreme saline conditions, halophytes are promising [...] Read more.

The increasing salinization of agricultural soils urges us to find alternative and sustainable farming systems in order to allow the exploitation of areas that are otherwise becoming less suitable for conventional crops. Thanks to their adaptation to extreme saline conditions, halophytes are promising plants for resilient farming systems, such as intercropping with glycophytes, to ameliorate their productivity in saline soils. This research aimed to evaluate whether the nutritional profile and the content of some health-promoting compounds of the edible portion of Salicornia europaea were influenced by its cultivation in consociation with tomato plants. Moreover, the antioxidant, antibacterial, and anti-inflammatory properties of S. europaea were studied to characterize its bioactivity. The farming system did not influence the concentration of nutrients and bioactive compounds, except for flavonoids. The antimicrobial and anti-inflammatory properties of Salicornia extract suggested the importance of this halophyte for animal and human health. Full article

(This article belongs to the Collection Biosaline Agriculture)

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11 pages, 2078 KiB

Open AccessCommunication

Effect of Parental Components and Pollination Frequency on the Setting and Germination of Chrysanthemum Seeds

by Natalia Miler and Dariusz Kulus

Horticulturae 2022, 8(9), 827; https://doi.org/10.3390/horticulturae8090827 - 08 Sep 2022

Cited by 1 | Viewed by 2446

Abstract

The chrysanthemum is one of the most economically important ornamental plants in the Asteraceae family. Unfortunately, the efficacy of breeding through the traditional crossing in this species is highly limited due to inefficient seed setting. Therefore, this study aimed to investigate the effect [...] Read more.

The chrysanthemum is one of the most economically important ornamental plants in the Asteraceae family. Unfortunately, the efficacy of breeding through the traditional crossing in this species is highly limited due to inefficient seed setting. Therefore, this study aimed to investigate the effect of parental components and crossing frequency on the set and germination of chrysanthemum seeds. For this purpose, seven chrysanthemum cultivars were used as parental components in 10 crossing combinations. The crossing was performed either once or twice a week, for three successive weeks, starting from November. Next, the obtained chrysanthemum seeds were collected, sown in pots in a greenhouse, and seedling growth was observed. The efficacy of the seed set, germination rate, and plant development was evaluated. The plants of the F₁ generation were brought to flowering and evaluated phenotypically in the three successive vegetative propagation cycles. Both the arrangement of parental components and pollination frequency affected the production of seeds. More seeds were obtained if pollination was performed twice a week and if the ‘Wda’ cultivar was used as the maternal component. Approximately 50–100% of the seeds were able to germinate in the greenhouse, depending on the parental components, which also affected the developmental pace of the seedlings. Nearly all of the seedlings (80–100%) developed into properly growing plants. Out of 10 parental combinations tested, 7 produced the F₁ offspring. The obtained plants varied in the shape, size, and color of their flowers. A total of eight new phenotypes were found, among which six new cultivars granted plant breeders’ rights, so far. The present research expands knowledge on how effective crossing should be performed. Full article

(This article belongs to the Special Issue Seed Germination and Micropropagation of Ornamental Plants)

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25 pages, 3247 KiB

Open AccessArticle

Root Exploration, Initial Moisture Conditions, and Irrigation Scheduling Influence Hydration of Stratified and Non-Stratified Substrates

by Kristopher S. Criscione, Jeb S. Fields and James S. Owen, Jr.

Horticulturae 2022, 8(9), 826; https://doi.org/10.3390/horticulturae8090826 - 08 Sep 2022

Cited by 7 | Viewed by 1508

Abstract

Soilless substrate stratification (i.e., layering unique substrates within a single container) is an emerging substrate management strategy that may provide opportunities to augment nursery resource use. As such, this research aimed to analyze water movement through containers during hydration events under different initial [...] Read more.

Soilless substrate stratification (i.e., layering unique substrates within a single container) is an emerging substrate management strategy that may provide opportunities to augment nursery resource use. As such, this research aimed to analyze water movement through containers during hydration events under different initial moisture conditions. The results indicated substrate stratification had minimal influence on water movement compared to non-stratified systems (uniformly filled nursery containers). Cyclic irrigation significantly increased the stratified substrates’ ability to retain water when irrigated at 20% volumetric water content (p < 0.0001) and significantly decreased the total volume leached (p < 0.0001). Moreover, irrigating the substrate profile with shallow and more frequent irrigations facilitated stratified substrates ty reach effective container capacity conditions (p < 0.0001n compared to non-stratified systems. The stratified systems took longer to leach all gravitational pores (p = 0.0266). In dry moisture conditions, non-stratified substrates were more hydrated when cyclic irrigation applications were applied compared to single applications (p = 0.0492). This study demonstrated that cyclic irrigation scheduling enhanced water retention in both non-stratified and stratified profiles under different initial moisture conditions and can be used as an irrigation strategy when dry substrate conditions prevail. Full article

(This article belongs to the Special Issue Horticultural Crops Water and Fertilizer Management)

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14 pages, 11743 KiB

Open AccessFeature PaperArticle

Living Mulch with Subterranean Clover (Trifolium subterraneum L.) Is Effective for a Sustainable Weed Management in Globe Artichoke as Annual Cropping in Puglia (Southern Italy)

by Mariano Fracchiolla, Cesare Lasorella, Eugenio Cazzato and Massimiliano Renna

Horticulturae 2022, 8(9), 825; https://doi.org/10.3390/horticulturae8090825 - 08 Sep 2022

Cited by 1 | Viewed by 2205

Abstract

Italy represents the world leading producer of globe artichoke, and Puglia (Southern Italy) supplies about one-third of the nation’s production. In this research, the influence of mulching (both living mulch with subterranean clover and biodegradable mulch film) on both weed infestation and globe [...] Read more.

Italy represents the world leading producer of globe artichoke, and Puglia (Southern Italy) supplies about one-third of the nation’s production. In this research, the influence of mulching (both living mulch with subterranean clover and biodegradable mulch film) on both weed infestation and globe artichoke yield in comparison with conventional tillage was evaluated. Two globe artichoke genotypes (Capriccio—hybrid cultivar—and Brindisino—sanitized local variety) were tested in an open field located in Puglia. The following parameters were evaluated: weed infestation, yield and canopy of globe artichoke, and biomass and canopy of subterranean clover. Yield of globe artichoke (on average 16 buds plant⁻¹) was not influenced by soil management although the total weed cover was lower by using conventional tillage. Mean canopy of T. subterraneum was higher under Brindisino (about 65%) in comparison with Capriccio (about 45%). Dry weight was higher in Brindisino (about 12 g m⁻²) than Capriccio (about 6 m⁻²) without differences among soil management treatments. Subterranean clover showed a good ability to control weed cover especially under Brindisino genotype (weed infestation always less than 1%) highlighting its particularly suitability for local varieties of globe artichoke instead of hybrid cultivars (weed infestation up to 5%). In conclusion, the results of this study suggest the positive effects of living mulch with subterranean clover for a sustainable weed management in globe artichoke as annual cropping in Puglia. Full article

(This article belongs to the Special Issue Ongoing Research on Role and Sustainable Weed Management in the Horticultural Crops)

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Horticulturae, Volume 8, Issue 9 (September 2022) – 99 articles

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