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Horticulturae, Volume 9, Issue 11 (November 2023) – 88 articles

Cover Story (view full-size image): To model the onset of sweet cherry blossom, it is necessary to know the cycle of bud development, including the timings of unobservable dormancy phases. This study compares three phenology models (M1–M3); only M3 contains enough physiological insight to outperform the other models. Our results suggest that, for a physiologically based modeling approach, at least the date of endodormancy release (t1), the onset of ontogenetic development (t1*), and the bud abscisic acid (ABA) content during ecodormancy (t1–t1*) should be known. The study highlights the time-dependent inhibition of bud development by ABA during ecodormancy. Thus, simple inverse modeling approaches, such as M1, are not able to capture the ecodormancy phase and carry the risk of incorrect parameter estimation, which may lead to erroneous conclusions about the cultivation of fruit varieties due to climate change. View this paper
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15 pages, 2399 KiB  
Article
Effect of Drying Post-Harvest on the Nutritional Compounds of Edible Flowers
Horticulturae 2023, 9(11), 1248; https://doi.org/10.3390/horticulturae9111248 - 20 Nov 2023
Viewed by 860
Abstract
The post-harvest techniques are the most critical point to ensure the quality of edible flowers (EFs) and to keep the bioactive metabolites available for human nutrition. The different species of EFs also represent a problem in improving their consumption with safety. The present [...] Read more.
The post-harvest techniques are the most critical point to ensure the quality of edible flowers (EFs) and to keep the bioactive metabolites available for human nutrition. The different species of EFs also represent a problem in improving their consumption with safety. The present study focused on the description of the effects of the commonly used drying treatments in the phytonutritional composition of four species of EFs, Callianthe megapotamica, Callianthe striata, Nemesia strumosa and Salvia elegans. The bioactive metabolites and antioxidant activity were determined after freeze-drying (FD) and hot-air-drying (HA) treatments in comparison to fresh flowers. All EFs showed different mineral/trace compositions with potassium as the main element and 70–86% water loss. Both post-harvest treatments increased all the metabolites and antioxidant activity in each species. C. striata with FD treatment had the highest content of primary and secondary metabolites. N. strumosa has the highest ascorbic acid content with the HA treatment. All species had significant antioxidant activity, increasing with FD for C. striata while HA is more recommended for the other species. The post-harvest techniques are able to preserve and increase the bioactive metabolites and must be chosen according to each EF species. Full article
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15 pages, 573 KiB  
Article
Influence of Sunn Hemp Biomass Incorporation on Organic Strawberry Production
Horticulturae 2023, 9(11), 1247; https://doi.org/10.3390/horticulturae9111247 - 20 Nov 2023
Viewed by 716
Abstract
Sunn hemp (Crotalaria juncea L.), a warm season leguminous cover crop, is commonly used in rotation with organic strawberry production in Florida’s subtropical environment. This study was conducted to explore the impacts of sunn hemp on growth and yield performance of the [...] Read more.
Sunn hemp (Crotalaria juncea L.), a warm season leguminous cover crop, is commonly used in rotation with organic strawberry production in Florida’s subtropical environment. This study was conducted to explore the impacts of sunn hemp on growth and yield performance of the subsequent organic strawberry crop in sandy soils, taking into consideration the nutrient contribution from soil incorporation of sunn hemp biomass. Sunn hemp was seeded during the summer off-season and terminated before flowering, three weeks prior to the fall planting of two strawberry cultivars (‘Strawberry Festival’ and ‘Camino Real’). With sunn hemp residues incorporated into the soil, two application rates of nitrogen (N) through pre-plant organic fertilization for the strawberry season were used, including N at a rate of 84 kg/ha, without consideration of the N credit from sunn hemp, and N at a rate of 19.8 kg/ha, with consideration of the estimated N credit from sunn hemp. A summer fallow without cover crop and with a pre-plant organic fertilizer application at the N rate of 84 kg/ha was included as the control. Overall, the sunn hemp incorporation at three weeks after termination did not benefit the strawberry plant growth or fruit yield in this study, with rather low levels of soilborne pathogen and nematode infestations. Both sunn hemp treatments exhibited a significantly lower level of total soil N compared to the summer fallow plots at the end of the strawberry season. The reduction in the pre-plant N fertilization resulted in lower above-ground plant dry weight and accumulation of N, phosphorus (P), and potassium (K) at the end of the strawberry season, along with fewer leaves and smaller crowns of the strawberry plants during the early season. Both sunn hemp treatments decreased early fruit yields, while the sunn hemp treatment with the reduced N fertilization also led to a significant reduction in the total fruit number and weight, although no significant differences in the whole-season marketable fruit yield were observed among the nutrient management treatments. Overall, ‘Strawberry Festival’ yielded higher than ‘Camino Real’, but the effects of nutrient management did not vary with the strawberry cultivars. Further studies are needed to enhance organic strawberry nutrient management involving rotational cover crops. Full article
(This article belongs to the Special Issue Berry Crops Production: Cultivation, Breeding and Health Benefits)
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12 pages, 3191 KiB  
Article
Effect of Nitric Oxide on Browning of Stem Tip Explants of Malus sieversii
Horticulturae 2023, 9(11), 1246; https://doi.org/10.3390/horticulturae9111246 - 20 Nov 2023
Viewed by 579
Abstract
Browning is a major problem in the tissue culture of woody plants. Previous studies have shown that nitric oxide (NO) plays a role in regulating plant responses to stress, but its effect on browning in the tissue culture of Malus remains unclear. This [...] Read more.
Browning is a major problem in the tissue culture of woody plants. Previous studies have shown that nitric oxide (NO) plays a role in regulating plant responses to stress, but its effect on browning in the tissue culture of Malus remains unclear. This study aimed to investigate the impact of exogenous NO donor sodium nitroprusside (SNP) on the browning of Malus sieversii stem tip explants. The results demonstrated that the addition of 50 μM SNP significantly reduced explant browning. Further analysis revealed that exogenous NO decreased the browning index (BD) and levels of malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide anion radical O2. Additionally, NO treatment increased the activity of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). NO treatment also enhanced the activity of phenylalanine ammonia lyase (PAL), which contributed to the accumulation of flavonoids and inhibited the activity of polyphenol oxidase (PPO) and peroxidase (POD), which are key enzymes involved in the browning process. Furthermore, 50 μM SNP significantly promoted the accumulation of non-enzymatic antioxidants such as proline (Pro), soluble sugar (SS), and soluble protein (SP). Therefore, the results suggest that NO is able to counteract excessive reactive oxygen species (ROS) damage by enhancing both the enzymatic and non-enzymatic antioxidant systems, resulting in a reduction in browning in stem tip explants. Consequently, an improvement in the in vitro propagation efficiency of Malus sieversii shoot tip explants can be achieved. Full article
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10 pages, 242 KiB  
Article
The Variability of Proximate Composition, Sugars, and Vitamin C in Natural, Organic, and Biodynamic, and Fermented Leaves of Fireweed (Chamerion angustifolium (L.) Holub (Onagraceae))
Horticulturae 2023, 9(11), 1245; https://doi.org/10.3390/horticulturae9111245 - 19 Nov 2023
Viewed by 619
Abstract
Functional foods and herbs are becoming more and more popular as a way to improve health and at the same time improve diet. One of these plants is fireweed, which is abundant in fibers, proteins, and vitamin C in addition to polyphenols and [...] Read more.
Functional foods and herbs are becoming more and more popular as a way to improve health and at the same time improve diet. One of these plants is fireweed, which is abundant in fibers, proteins, and vitamin C in addition to polyphenols and carotenoids. Limited study is being carried out and there is limited information available about how the solid-phase fermentation and different growth systems change the proximate composition, as well as quantities of vitamin C, and sugars in the fireweeds leaves. The experiment was conducted in 2022 on an organic farm (Jonava district, Lithuania). The objective of this research was to determinate the impact of various growing systems (naturally, organically, and biodynamically) and duration (24, 48, and 72 h) effect of solid-phase aerobic fermentation on the changes of fibers, ash, proteins, vitamin C, and sugars. The fibers were established using the Kjeldahl method. High-performance liquid chromatography was used for sugars and vitamin C identification. The study found significant differences in the effects of various growing systems and solid-phase fermentation on the quantitative composition of substances in the fireweed leaves. Based on the data available, it is recommended to consume fermented fireweed leaves that are organically grown and fermented for a period of 48 h as they are a good source of vitamin C and fibers. Biodynamically grown fireweed leaves are a good source of ash and proteins. Naturally grown fireweed leaves, which are not fermented, are a good source of sugars. Full article
(This article belongs to the Section Medicinals, Herbs, and Specialty Crops)
12 pages, 802 KiB  
Article
Effect of Organic Additives on the Micropropagation of Asparagus officinalis
Horticulturae 2023, 9(11), 1244; https://doi.org/10.3390/horticulturae9111244 - 18 Nov 2023
Viewed by 700
Abstract
In vitro propagation is one of the most promising techniques for the large-scale clonal propagation of Asparagus officinalis. The aim of this study was to investigate the effect of organic additives, including coconut water (CW), banana homogenate (BH), and potato homogenate (PH), [...] Read more.
In vitro propagation is one of the most promising techniques for the large-scale clonal propagation of Asparagus officinalis. The aim of this study was to investigate the effect of organic additives, including coconut water (CW), banana homogenate (BH), and potato homogenate (PH), on A. officinalis shoot and root proliferation. The results revealed that CW, specifically at 20% (v/v), was the most effective organic additive for promoting shoot and root formation in the in vitro plantlets. Furthermore, the longest shoot and root lengths were also observed in the MS medium supplemented with 20% (v/v) CW. In the supporting medium of 1:1 peat moss and vermiculite, the in vitro plantlets exhibited a high survival rate with a morphology comparable to that of the mother plant. The results of this study demonstrate that CW can be applied as a supplemental material for large-scale A. officinalis micropropagation. Full article
(This article belongs to the Section Propagation and Seeds)
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16 pages, 4995 KiB  
Article
Physiological and Molecular Responses of Camellia oleifera Seedlings to Varied Nitrogen Sources
Horticulturae 2023, 9(11), 1243; https://doi.org/10.3390/horticulturae9111243 - 17 Nov 2023
Viewed by 679
Abstract
Camellia oleifera Abel. is a unique woody edible oil tree species in China mainly distributed in red soil areas. Nitrogen is one of the important growth-limiting factors for C. oleifera, and the nitrogen form has a vital impact on the growth and [...] Read more.
Camellia oleifera Abel. is a unique woody edible oil tree species in China mainly distributed in red soil areas. Nitrogen is one of the important growth-limiting factors for C. oleifera, and the nitrogen form has a vital impact on the growth and development of the plants. Ammonium and nitrate are the two nitrogen forms that are maximally absorbed and utilized by the plants. Here, we used one-year-old seedlings of the main varieties of C. oleifera (‘Xianglin No. 1’, ‘Xianglin No. 27’, and ‘Xianglin No. 210’) to set up six experimental groups treated with different nitrogen forms ([NO3:NH4+] 0:0, 10:0, 7:3, 5:5, 3:7, and 0:10) and investigated the effects of nitrogen on the vegetative growth and photosynthetic characteristics of the seedlings. This study showed that mixed nitrogen sources could significantly increase the seedling height, ground diameter, biomass accumulation, and photosynthesis efficiency. Transcriptome sequencing analysis led to the identification of 3561 differentially expressed genes in the leaves. Preliminary screening identified several key enzyme genes from nitrogen nutrient metabolic pathways that were differentially expressed among seedlings grown with different nitrogen forms, and their expression pattern changes were further characterized. All the results demonstrate that the same proportion of ammonium nitrate ratio promoted the expression of genes encoding glutamine synthetase and glutamate synthase, thereby improving nitrogen assimilation and utilization efficiency. This study could provide a theoretical basis for scientific and rational fertilization and the improvement of nitrogen utilization efficiency in C. oleifera seedlings. Full article
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19 pages, 3909 KiB  
Article
Differences in Physiological Characteristics of Green Prickly Ash Germplasm Resources in Response to Low-Temperature Stress
Horticulturae 2023, 9(11), 1242; https://doi.org/10.3390/horticulturae9111242 - 17 Nov 2023
Cited by 1 | Viewed by 699
Abstract
In this study, we investigated the physiological response to low-temperature stress and comprehensively evaluated the cold resistance of green prickly ash germplasms. One-year-old branches of 23 green prickly ash varieties were used as experimental materials, three branches were selected from each variety, and [...] Read more.
In this study, we investigated the physiological response to low-temperature stress and comprehensively evaluated the cold resistance of green prickly ash germplasms. One-year-old branches of 23 green prickly ash varieties were used as experimental materials, three branches were selected from each variety, and three replicates of single branches were established. Subsequently, the physiological responses of the 23 green prickly ash germplasm resources to low-temperature stress were analyzed based on the relative conductivity (REC), osmotic adjustment substances, and antioxidant enzyme activities. We found that as the temperature decreased, the REC of each germplasm increased. The most rapid REC increase occurred from 0 to −10 °C and continued to gradually gently increase from −10 to −30 °C. The lethal dose-50 temperature (LT50) of the germplasms was between 3.16 and −12.37 °C. The top three cold-resistant varieties were TJ, SCHJ, and CJ, and the last three cold-resistant varieties were EWJ, DYSJ, and HYXJ. The results of a correlation analysis revealed a significant correlation between superoxide dismutase (SOD) activity and REC, between REC and free protein, and between SOD activity and catalase. The results of the PCA revealed that the first category includes 5 pepper varieties of CJ, LFJ, and XYTJ with higher cold-resistance score indexes; the second category includes 13 pepper varieties of YQ2 H, WCFZ, and TZJ with appropriate scores; and the third category includes 5 pepper varieties of HYXJ, HNJ, and DYSJ with lower scores. Cluster analysis was performed to classify the cold-resistance physiological indices, and four groups were obtained. The most cold-resistant groups included CJ and LFHJ, whereas the most cold-sensitive groups included HYXJ, DYSJ, and HNJ. Finality, the subordinate function method was used to determine the cold resistance from strong to weak. The varieties with the strongest cold resistance were LFJ, EWJ, and CJ, and the weakest varieties were DYSJ, YQ1H, and HYXJ. The strongest cold-resistant varieties were LFHJ and CJ, followed by DYSJ, YQ1H, and HYXJ. Based on multiple lines of evidence, the most cold-resistant varieties were CJ and LFJ, while the most cold-sensitive varieties were DYSJ and HYXJ. In conclusion, in this study, we elucidated the low-temperature tolerance of different varieties of green prickly ash, and varieties with high cold resistance were selected. These findings provide theoretical guidance and technical support for the screening of cold-resistant green prickly ash germplasms, which will facilitate their introduction to northern China. Full article
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13 pages, 4731 KiB  
Article
Establishment of an Efficient In Vitro Propagation Protocol for Cannabis sativa L. subsp. ruderalis Janish
Horticulturae 2023, 9(11), 1241; https://doi.org/10.3390/horticulturae9111241 - 17 Nov 2023
Viewed by 869
Abstract
Cannabis sativa L., subsp. ruderalis Janish., ‘Finola’ is a dioecious cultivar of Finnish origin. This cultivar is very interesting because its cultivation cycle lasts less than 3 months. The aim of this study was to define an efficient micropropagation protocol to ensure in [...] Read more.
Cannabis sativa L., subsp. ruderalis Janish., ‘Finola’ is a dioecious cultivar of Finnish origin. This cultivar is very interesting because its cultivation cycle lasts less than 3 months. The aim of this study was to define an efficient micropropagation protocol to ensure in vitro multiplication and rooting and in vivo acclimatization. Two different explant sources were tested: seed-derived in vitro explants and nodal segments containing axillary buds from selected mother plants. Shoot proliferation was tested on different growth media enriched with cytokinin alone or cytokinin in combination with auxins. Among all combinations, the best results were obtained by combining the Basal Medium (BM—a Murashige and Skoog modified medium) with sucrose (20 g L−1), thidiazuron (TDZ 0.4 mg L−1), and 1-naphthalenacetic acid (NAA 0.2 mg L−1). Regarding rooting induction, the plants developed an extensive root system under red/blue lights on BM enriched with sucrose (30 g L−1) and indol-3 butyric acid (0.1 mg L−1), which allowed the survival of more than 90 percent of the plantlets once transplanted into the climate-controlled greenhouse. Full article
(This article belongs to the Special Issue In Vitro Technology and Micropropagated Plants)
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18 pages, 4497 KiB  
Article
Colored Shading Nets Differentially Affect the Phytochemical Profile, Antioxidant Capacity, and Fruit Quality of Piquin Peppers (Capsicum annuum L. var. glabriusculum)
Horticulturae 2023, 9(11), 1240; https://doi.org/10.3390/horticulturae9111240 - 17 Nov 2023
Viewed by 756
Abstract
Piquin pepper fruits, a semi-domesticated wild pepper species highly valued in Mexico, currently face the threat of unsustainable harvesting practices that endanger the species. For this reason, it is necessary to establish sustainable agricultural practices for the cultivation of these peppers. Solar radiation, [...] Read more.
Piquin pepper fruits, a semi-domesticated wild pepper species highly valued in Mexico, currently face the threat of unsustainable harvesting practices that endanger the species. For this reason, it is necessary to establish sustainable agricultural practices for the cultivation of these peppers. Solar radiation, a critical determinant in crop production, plays a crucial role in plant development, influencing a spectrum of physiological and morphological processes, including the synthesis of phytochemicals. Our study evaluated the effect of light manipulation through colored shading nets on the phytochemical profile, antioxidant capacity, and fruit quality of semi-domesticated piquin peppers at two maturation stages: immature and mature (green and red fruits). Our hypothesis posits that these shading treatments may induce changes in these fruits’ phytochemical composition and antioxidant properties, as well as quality. Our results indicate that the shading treatments and maturity stage have significant on capsaicinoid and carotenoid levels, with the highest levels observed in mature fruits. Notably, red fruits grown under black shading treatments resulted in the highest capsaicinoid levels. Carotenoid levels were higher in the black shading treatment during the first cycle, while in the second cycle, the blue shading treatment showed elevated carotenoid levels, suggesting that high irradiance conditions could reduce carotenoid contents. Although no significant differences were observed among the treatments in green fruits, in red fruits, both black and blue treatments exhibited the highest total phenolic compounds in both production cycles. Furthermore, the antioxidant capacity revealed that red fruits exhibited higher antioxidant levels than green fruits. Color analysis showed that red fruits had higher chroma and hue angle values, indicating their brighter and more intense red color than green fruits. The morphological changes in fruit width, length, and weight can be attributed to shading treatments and maturation stages. These results indicate the potential of piquin peppers to act as rich sources of bioactive compounds, emphasizing the benefits of shading as an effective strategy to improve the quality and quantity of phytochemical compounds in piquin peppers. Our findings provide substantial insights into the intricate relationship between maturation, shading treatments, and phytochemical composition, offering a path to improve the nutritional value and quality of piquin peppers. Full article
(This article belongs to the Special Issue Effects of Light Quantity and Quality on Horticultural Crops)
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14 pages, 794 KiB  
Article
Sustainable Viticulture of Italian Grapevines: Environmental Evaluation and Societal Cost Estimation Using EU Farm Accountancy Data Network Data
Horticulturae 2023, 9(11), 1239; https://doi.org/10.3390/horticulturae9111239 - 17 Nov 2023
Viewed by 923
Abstract
Since the agriculture sector, such as Italian grapevine production, exert a pressure on the environment to some extent, this research aims to evaluate the environmental impacts and estimate the societal costs of four current grapevine production systems (i.e., vine grapes cultivated to produce [...] Read more.
Since the agriculture sector, such as Italian grapevine production, exert a pressure on the environment to some extent, this research aims to evaluate the environmental impacts and estimate the societal costs of four current grapevine production systems (i.e., vine grapes cultivated to produce common or quality wine using organic and non-organic agricultural practices), based on the Italian Farm Accountancy Network Data. For these purposes, the Life Cycle Analysis and Shadow Price techniques have been used. The results revealed that the levels of environmental impacts differed considerably between every cultivation system. Hence, the agricultural land occupation indicator induced the highest external costs, followed by climate change, terrestrial acidification, and freshwater eutrophication among the four grapevine cultivation systems. Accordingly, the assessment offers valuable insights into organic and non-organic viticulture practices to produce consistent and high-quality wine, as well as helping farmers make informed decisions that may improve environmental and societal impacts, leading to cost-effective management of their vineyards. We conclude that organic vineyard farming represents a promising sustainable viticulture production but is also important in exploring consumer perceptions and behavior towards this kind of grapevine production. Full article
(This article belongs to the Special Issue Advancements in the Sustainable Viticulture of Grapes)
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12 pages, 3170 KiB  
Article
Development of Cleaved Amplified Polymorphic Sequence Marker for Cap Color Identification in Pleurotus cornucopiae
Horticulturae 2023, 9(11), 1238; https://doi.org/10.3390/horticulturae9111238 - 16 Nov 2023
Viewed by 742
Abstract
Cap color is one of the most crucial commercial traits for oyster mushrooms, and dark-colored varieties are highly favored by consumers, yet they are relatively scarce on the market. There is an urgent need for the selection and breeding of dark oyster mushrooms. [...] Read more.
Cap color is one of the most crucial commercial traits for oyster mushrooms, and dark-colored varieties are highly favored by consumers, yet they are relatively scarce on the market. There is an urgent need for the selection and breeding of dark oyster mushrooms. Previous studies identified PcTYR, a key gene that controls the cap color of Pleurotus cornucopiae, and four SNPs were identified based on a genome-level sequence comparison of the black and white gene pools for extreme traits in the segregating populations. In this study, we verified whether these SNPs were color-specific sites via specific primer design, PCR amplification, and enzyme digestion of the entire isolated population strains and developed CAPS/dCAPS markers for the early visual identification of cap color to assist material screening in cap color breeding. One CAPS marker, TYR-CAPS-3-2, was developed for identifying the cap color of oyster mushrooms. After digestion with the restriction endonuclease Mse I, the marker generated polymorphic bands that accurately and visually distinguished dark-colored (non-white) and white strains from the cap color-segregating population. Consequently, the application of this marker during the early growth stage of oyster mushrooms can facilitate molecular-marker-assisted selection, expediting the breeding process for dark-colored varieties. Full article
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14 pages, 2734 KiB  
Article
Improves the Resilience of Cucumber Seedlings under High-Light Stress through End-of-Day Addition of a Low Intensity of a Single Light Quality
Horticulturae 2023, 9(11), 1237; https://doi.org/10.3390/horticulturae9111237 - 16 Nov 2023
Viewed by 689
Abstract
In order to investigate whether an end-of-day (EOD) addition of a single light quality could help alleviate high-light stress in a cucumber, cucumber seedlings were subjected to a 9 d period of high-light stress (light intensity was 1300 ± 50 μmol·m−2·s [...] Read more.
In order to investigate whether an end-of-day (EOD) addition of a single light quality could help alleviate high-light stress in a cucumber, cucumber seedlings were subjected to a 9 d period of high-light stress (light intensity was 1300 ± 50 μmol·m−2·s−1) when they were growing to 3 leaves and 1 heart, while the red light (R), blue light (B), green light (G), far-red light (FR), and ultraviolet A (UVA) light were added in the end-of-day period. The present study was conducted to measure antioxidants, chlorophyll content, and its synthetic degradative enzymes and chlorophyll a fluorescence in response to the degree of stress in cucumber seedlings. The experimental results demonstrated that the addition of blue light, UVA light, and green light significantly decreased the SOD and POD activities in the middle of the treatment (6th day) compared to the dark (D) treatment and improved the absorption performance of the PSI reaction centre of the cucumber seedling leaves to a certain extent (PIABS), but the PSII capacity capture ability (TRo/RC) of the three treatments decreased compared to the D treatment. The MDA content of all the treatments had a significant decrease compared to that of the D treatment. The MDA content of all the treatments was significantly lower than that of D, and its FV/FM was increased to different degrees; the chlorophyll degrading enzyme PPH activity was significantly lower than that of the D treatment when a single light quality was added at the EOD period on the 9th d of treatment. In conclusion, cucumber seedlings subjected to short-term high-light stress can be added during the EOD period with a low-light intensity of a single R, G, B, or UVA light. Full article
(This article belongs to the Section Biotic and Abiotic Stress)
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14 pages, 4902 KiB  
Article
Targeted Metabolome and Transcriptome Analyses Reveal the Molecular Mechanism of Color Variation between Sepals and Petals in Fuchsia hybrida
Horticulturae 2023, 9(11), 1236; https://doi.org/10.3390/horticulturae9111236 - 16 Nov 2023
Viewed by 600
Abstract
The sepal color of Fuchsia hybrida is colorful instead of green and usually varies from the petal colors, which greatly increases its ornamental value and attract customers’ preference. However, the potential molecular mechanism underlying the color variation between sepals and petals remains unclear. [...] Read more.
The sepal color of Fuchsia hybrida is colorful instead of green and usually varies from the petal colors, which greatly increases its ornamental value and attract customers’ preference. However, the potential molecular mechanism underlying the color variation between sepals and petals remains unclear. The present study collected F. hybrida with red sepals and purple petals to explore the key pigments and genes involved in color development using a targeted metabolome and transcriptome. A total of 43 metabolites with diverse hydroxylation, glycosylation, methylation and acylation patterns were isolated and identified by UPLC-MS/MS. The quantification analysis showed that peonidin-3,5-O-diglucoside and malvidin-3,5-O-diglucoside were the most abundant anthocyanins accumulating in the sepals and petals, respectively. Then, six libraries from the sepals and petals were constructed for the transcriptome and 70,135 unigenes were generated. The transcript level of FhF3′H was significantly higher in the sepals, while Fh3′5′H showed more abundant expression in the petals, which can account for the abundant peonidin and malvidin accumulation in the sepals and petals, respectively. The subsequent multiomics analysis showed that both the differentially accumulated anthocyanins and expressed unigenes were enriched in the anthocyanin biosynthesis pathway. Additionally, FhMYBs potentially regulating anthocyanin biosynthesis were screened out by correlation analysis and protein interaction prediction. These findings help to elucidate the molecular mechanisms underlying the color variation between the sepals and petals in F. hybrida. Full article
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14 pages, 10048 KiB  
Article
Theoretical Analysis and Experimental Research on the Apple Auto-Orientation Based on Flexible Roller
Horticulturae 2023, 9(11), 1235; https://doi.org/10.3390/horticulturae9111235 - 16 Nov 2023
Viewed by 748
Abstract
After automatic in-field picking, apple stem shortening requires fixing the apple position and maintaining a relatively stable posture, which puts high demands on the automatic apple-orienting structure. In this paper, a novel dual roller compact apple field orientation structure with dual rollers rotating [...] Read more.
After automatic in-field picking, apple stem shortening requires fixing the apple position and maintaining a relatively stable posture, which puts high demands on the automatic apple-orienting structure. In this paper, a novel dual roller compact apple field orientation structure with dual rollers rotating in the same direction is proposed. It can realize the uniform orientation of apples after automatic picking in any attitude, and the apple auto-orientation phenomenon is theoretically analyzed based on the accurately established apple model, then the apple orientation test platform was set up and a monocular camera combined with YOLOv5m was used to determine the time of apple orientation. The results showed that 70.21% and 96.81% of the apples were respectively oriented within 7 s and 28 s with only two flexible rollers rotating in the corresponding direction. All the apples were oriented, and 95.24% of them moved along the axis toward the calyx end. The generalizability of the apple orientation device for different shapes of apples was then verified, and the relationship between the shape characteristics of apples and orientation speed was later illustrated. A structural basis was finally presented for automatic stem shortening and surface damage detection in the apple field. Full article
(This article belongs to the Special Issue Advances in Intelligent Orchard)
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18 pages, 2035 KiB  
Article
Effect of the Ozone Application in the Nutrient Solution and the Yield and Oxidative Stress of Hydroponic Baby Red Chard
Horticulturae 2023, 9(11), 1234; https://doi.org/10.3390/horticulturae9111234 - 16 Nov 2023
Viewed by 910
Abstract
Novel ozone (O3) sanitizing treatments can be used to decrease the microbial load during cultivation, but they would affect the composition of the nutrient solution. Variations in the nutrient composition decrease crop yields, especially if a strong oxidizing agent such as [...] Read more.
Novel ozone (O3) sanitizing treatments can be used to decrease the microbial load during cultivation, but they would affect the composition of the nutrient solution. Variations in the nutrient composition decrease crop yields, especially if a strong oxidizing agent such as ozone is used. In this study, O3 was applied throughout the culture every two days at doses of 0.0 (control); 0.5; 1.0; and 2.0 mg·L−1 for 3 min on baby red chard (Beta vulgaris L. cv. SCR 107) grown in a floating hydroponic system. Macronutrients and micronutrients in the nutrient solution, yield, antioxidant compounds, and oxidative stress enzymes were evaluated in plants. Macronutrients in the nutrient solution were not affected by O3, whereas micronutrients, such as Fe and Mn, decreased by 88.2 and 39.6%, respectively, at the 0.5 mg·L−1 dose. The dose of 0.5 mg·L−1 produced more fresh matter and leaf area than the control. Antioxidant capacity and total phenols were not significantly affected by O3 treatments; however, higher SOD, CAT, and APX activity after O3 applications were found. It is concluded that ozone applications to the nutrient solution affect the availability of some micronutrients and increase oxidative stress and yield in baby red chard plants. Full article
(This article belongs to the Special Issue Soilless Culture in Vegetable Production)
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17 pages, 3516 KiB  
Article
Establishment and Optimization of Flavonoid Extraction and Detection System for Hemerocallis
Horticulturae 2023, 9(11), 1233; https://doi.org/10.3390/horticulturae9111233 - 15 Nov 2023
Viewed by 727
Abstract
Hemerocallis is a characteristic vegetable with outstanding edible and medicinal value. Flavonoids are important bioactive components of Hemerocallis. To improve the extraction efficiency and detection accuracy of flavonoids from Hemerocallis, we established a high-performance liquid chromatography (HPLC) detection system, which can [...] Read more.
Hemerocallis is a characteristic vegetable with outstanding edible and medicinal value. Flavonoids are important bioactive components of Hemerocallis. To improve the extraction efficiency and detection accuracy of flavonoids from Hemerocallis, we established a high-performance liquid chromatography (HPLC) detection system, which can simultaneously detect multiple flavonoids. In addition to the previously developed organic solvent extraction method, an ultrasonic-assisted extraction technique that uses fewer samples was established to extract flavonoids from Hemerocallis. The extraction conditions of the ultrasonic-assisted extraction were optimized via a single-factor experiment and a response surface experiment. The HPLC system detected and determined the contents of rutin, isoquercetin, myricetin, quercetin, apigenin, and diosmetin from 70 Hemerocallis germplasm resources. In addition, we evaluated the antioxidant activity of flavonoids in Hemerocallis using DPPH free radical scavenging capacity with ascorbic acid (Vc) as a positive control. The results showed that the optimum conditions for the ultrasonic extraction process were as follows: sample weight of 0.25 g, ethanol volume fraction of 72%, ethanol volume of 2.5 mL, and ultrasonic extraction time of 17 min. Under these conditions, flavonoid extraction had a strong scavenging effect on DPPH. With the increase in the sample solutions’ concentrations, its antioxidant capacity was gradually enhanced, and the DPPH scavenging rate reached 70.2%. The optimized ultrasonic-assisted extraction technology can increase the total content of six flavonoids in day lily bud by 59.01%, especially the content of rutin (increased by 64.41%) in Hemerocallis flower buds. Among 70 Hemerocallis plant resources, we selected materials H0087 and H0059 with high and stable flavonoid content, with the total content of six substances being 4390.54 ug/g and 3777.13 ug/g. Thus, this study provides a reference for extracting and determining flavonoid contents in Hemerocallis materials. It also provides a theoretical basis for high-quality individual plant breeding. Full article
(This article belongs to the Topic Bioactive Substances, Pharmacognosy and Metabolomics)
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22 pages, 1876 KiB  
Article
Variability in Chemical Profile and Bioactivities of the Flesh of Greek Pumpkin Landraces
Horticulturae 2023, 9(11), 1232; https://doi.org/10.3390/horticulturae9111232 - 15 Nov 2023
Viewed by 966
Abstract
The aim of this study was to evaluate the chemical profile of the flesh and yield parameters of Greek pumpkin genotypes, including nine local landraces and two commercially available cultivars, focusing on valorizing the genetic pool of Cucurbita sp. with high added value [...] Read more.
The aim of this study was to evaluate the chemical profile of the flesh and yield parameters of Greek pumpkin genotypes, including nine local landraces and two commercially available cultivars, focusing on valorizing the genetic pool of Cucurbita sp. with high added value products. Yield parameters (mean fruit weight and total fruit yield) recorded high variability with genotypes V8 and V2 showing the highest fruit yield. Moreover, genotype V11 was the most abundant in glucose and total sugars and scored the highest sweetness index suggesting good taste and promising marketing attributes. The highest antioxidant activity (OxHLIA assay) was assessed in the V8 genotype, while the V2 genotype showed the highest α-, β- and total tocopherols content. Oxalic acid was the main organic acid, followed by malic and citric acids, while organic acid composition varied among the tested genotypes. Moreover, the flesh extracts showed varied antimicrobial activity against several bacteria and fungi, while no toxicity against non-tumor cells was recorded. In conclusion, our results make evident the presence of high innate variability in terms of crop performance, chemical composition and bioactive properties not only between the different genotypes but also at the intra-populational level. This finding is of high importance for the valorization of the local genetic pool of Cucurbita species through the selection of elite genotypes with high yield and quality of fruit, contributing to the conservation of valuable genetic material and limitation of the risk of genetic erosion due to neglect of local landraces. Full article
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15 pages, 336 KiB  
Article
Influence of Selenium, Titanium, and Silicon Nanoparticles on the Growth, Yield, and Fruit Quality of Mango under Drought Conditions
Horticulturae 2023, 9(11), 1231; https://doi.org/10.3390/horticulturae9111231 - 15 Nov 2023
Viewed by 919
Abstract
Weather fluctuations significantly affect the growth and production of orchard crops such as mango, leading to a substantial decrease in tree growth, flowering rate, yield, and fruit quality. One of these weather factors is drought, which negatively influences multiple physiological processes in plants. [...] Read more.
Weather fluctuations significantly affect the growth and production of orchard crops such as mango, leading to a substantial decrease in tree growth, flowering rate, yield, and fruit quality. One of these weather factors is drought, which negatively influences multiple physiological processes in plants. It increases the transpiration rate and decreases the cell turgidity, stomatal regulation, osmoregulation, water utilization efficiency, and the development of the deep root system; consequently, it decreases the final production and fruit quality. Therefore, the present study was performed in the 2022–2023 seasons to study the role of the spraying of Selenium (Se), Titanium (Ti), and Silicon (Si) nanoparticles on the growth parameters, yielding, fruit physical and chemical characteristics, and leaf mineral composition of mango cv. Keitt. Mango trees were sprayed during the vegetative season 2022–2023 three times, starting in April with three weeks intervals, by 5, 10, and 20 mg/L Se; 40, 60, and 80 mg/L Ti; and 50, 100, and 150 mg/L Si. The results showed that the extern spray of nanoparticles from these micronutrients improved the growth attributes, yielding and fruit quality of mango trees by reducing the effect of undesirable stressful conditions. The results also indicated that the extern implementation of 150 mg/L Si, 60 mg/L Ti and 20 mg/L Se gave the best increments in the shoot number, length, thickness, leaf area, and leaf chlorophyll contrasted to the else sprayed treatments. Besides, they also improved the fruit set percentages, fruit yields, fruit physical and chemical characteristics and nutritional status of mango trees in both tested seasons. Full article
(This article belongs to the Special Issue Horticultural Plant Nutrition, Fertilization, Soil Management)
13 pages, 5934 KiB  
Article
Effects of Zeolite and Deficit Irrigation on Sweet Pepper Growth
Horticulturae 2023, 9(11), 1230; https://doi.org/10.3390/horticulturae9111230 - 15 Nov 2023
Viewed by 719
Abstract
The use of zeolites in agriculture as a soil conditioner is becoming an important field of research in crop growth. To study the effect of synthetic zeolites and deficit irrigation on sweet pepper (Capsicum annuum L.) cultivation, an experiment was conducted in [...] Read more.
The use of zeolites in agriculture as a soil conditioner is becoming an important field of research in crop growth. To study the effect of synthetic zeolites and deficit irrigation on sweet pepper (Capsicum annuum L.) cultivation, an experiment was conducted in a controlled environment. In particular, sweet peppers were cultivated in a glasshouse using polypropylene pots filled with sandy loam soil, to which 2% zeolite was added. The zeolite employed in the experiments was obtained using coal fly ash as a raw material. The experiment consisted of two main treatments: (a) soil with a zeolite at 2% (Z) and (b) soil without a zeolite as a control (C). Three subplot treatments consisted of (1) full irrigation at 100% of the available water content (AWC) (100); (2) deficit irrigation at 70% of the AWC (70); and (3) deficit irrigation at 50% of the AWC (50). Sweet pepper cultivation started on 24 April 2023 and lasted until 23 June 2023; during the trial, the environmental data, such as the soil humidity, air temperature, and relative humidity, and some crop parameters, such as the plant height, leaf number, and the SPAD index, were monitored. At the end of the trial, the fresh and dry plant weights, the dry matter content, and the leaf water potential were measured. The results showed that, for the plant fresh weight and dry matter content, no significant differences were observed in the treatments and their interactions, whereas, for the other parameters, the statistical analysis showed significant differences. The study suggests that the soil’s structural benefits, resulting from zeolite application, are not followed by an equal positive effect in terms of sweet pepper growth under deficit irrigation conditions. Full article
(This article belongs to the Section Vegetable Production Systems)
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47 pages, 10775 KiB  
Review
Technological Trends and Engineering Issues on Vertical Farms: A Review
Horticulturae 2023, 9(11), 1229; https://doi.org/10.3390/horticulturae9111229 - 15 Nov 2023
Cited by 1 | Viewed by 2935
Abstract
Vertical farming has emerged as a promising solution to cope with increasing food demand, urbanization pressure, and limited resources and to ensure sustainable year-round urban agriculture. The aim of this review was to investigate the evolving technological landscape and engineering considerations, with a [...] Read more.
Vertical farming has emerged as a promising solution to cope with increasing food demand, urbanization pressure, and limited resources and to ensure sustainable year-round urban agriculture. The aim of this review was to investigate the evolving technological landscape and engineering considerations, with a focus on innovative developments and future prospects. This paper presents technological trends in vertical farming, covering advances in sensing technologies, monitoring and control systems, and unmanned systems. It also highlights the growing role of artificial intelligence (AI) in contributing to data-driven decision-making and the optimization of vertical farms. A global perspective on vertical farming is presented, including the current status and advanced technological trends across regions like Asia, the USA, and Europe. Innovative concepts and upcoming enterprises that could shape the future of vertical agriculture are explored. Additionally, the challenges and future prospects of vertical farming are also addressed, focusing on crop production limitations, environmental sustainability, economic feasibility, and contributions to global food security. This review provides guidance on the state of vertical farming, technological advancements, global trends, challenges, and prospects, offering insights into the roles of researchers, practitioners, and policymakers in advancing sustainable vertical agriculture and food security. Full article
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36 pages, 6391 KiB  
Article
Novel Insights into Phytoplasma Effectors
Horticulturae 2023, 9(11), 1228; https://doi.org/10.3390/horticulturae9111228 - 14 Nov 2023
Viewed by 1057
Abstract
Effectoromics has become integral to the identification of pathogen targets and/or host-resistant proteins for the genetic improvement of plants in agriculture and horticulture. Phytoplasmas are the causal agents of more than 100 plant diseases in economically important crops such as vegetables, spices, medicinal [...] Read more.
Effectoromics has become integral to the identification of pathogen targets and/or host-resistant proteins for the genetic improvement of plants in agriculture and horticulture. Phytoplasmas are the causal agents of more than 100 plant diseases in economically important crops such as vegetables, spices, medicinal plants, ornamentals, palms, fruit trees, etc. To date, around 20 effectors in phytoplasmas have been experimentally validated but the list of putative effectors comprises hundreds of different proteins. Very few families (tribes) have been identified based on homology, such as the SAP05-like, SAP11-like, SAP54-like and TENGU-like families. The lack of conservation in amino acid sequences slows the progress of effectoromics in phytoplasmas since many effectors must be studied individually. Here, 717 phytoplasma effector candidates and 21 validated effectors were characterized in silico to identify common features. We identified functional domains in 153 effectors, while 585 had no known domains. The most frequently identified domain was the sequence-variable mosaic domain (SVM domain), widely distributed in 87 phytoplasma effectors. Searching for de novo amino acid motifs, 50 were found in the phytoplasma effector dataset; 696 amino acid sequences of effectors had at least 1 motif while 42 had no motif at all. These data allowed us to organize effectors into 15 tribes, uncovering, for the first time, evolutionary relationships largely masked by lack of sequence conservation among effectors. We also identified 42 eukaryotic linear motifs (ELMs) in phytoplasma effector sequences. Since the motifs are related to common functions, this novel organization of phytoplasma effectors may help further advance effectoromics research to combat phytoplasma infection in agriculture and horticulture. Full article
(This article belongs to the Section Plant Pathology and Disease Management (PPDM))
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14 pages, 1280 KiB  
Article
Study of the Chemical Composition of Carica papaya L. Seed Oils of Various Geographic Origins
Horticulturae 2023, 9(11), 1227; https://doi.org/10.3390/horticulturae9111227 - 14 Nov 2023
Viewed by 1422
Abstract
The papaya plant (Carica papaya L.) is tree-like fruit plant cultivated throughout the tropics and subtropics. The aim of this study was to compare the physicochemical properties, fatty acid, sterols, and triterpenic alcohols composition of Carica papaya L. seed oils grown in [...] Read more.
The papaya plant (Carica papaya L.) is tree-like fruit plant cultivated throughout the tropics and subtropics. The aim of this study was to compare the physicochemical properties, fatty acid, sterols, and triterpenic alcohols composition of Carica papaya L. seed oils grown in a typical geographical location and Carica papaya L. seed oils grown in an untypical geographical location in greenhouse conditions (Saratov Region, Russia). The oils were extracted from the seeds of Carica papaya L. fruits collected in Kenya, the Dominican Republic, Angola, Ghana, and Brazil, as well as from the seeds of fruit plants grown in a similar environment (Russian Federation, Saratov). Parameters such as the oil yield, refractive index, peroxide value, iodine value, saponification value, and acid value of the extracted Carica papaya L. seed oils were determined. The qualitative and quantitative chemical compositions of the seed oils were determined by a combination of mass spectrometry and NMR spectroscopy. The profiles as well as the content of fatty acids, sterols, triterpenic alcohols, and benzyl isothiocyanate were established. The saponifiable fraction of the oils is mainly represented by triglycerides (98.7–99.4%), while di-(0.4–1.1%) and monoglycerides (0.1–0.3%) are also present but in smaller amounts. The content of sterols and triterpene alcohols was (537.5–918.2) mg/100 g of oil (0.54–0.92%), and up to 75% of the fraction was represented by β-sitosterol (55.9–66.7%) and its saturated analogue-sitostanol (11.0–15.7%). The physicochemical properties and the fatty acid, sterol, and triterpenic alcohol composition of seed oils from Carica papaya L. fruits, cultivated in Russia, is in the quantitative range of other samples, which suggests that Carica papaya L. can be grown in Russia for obtaining the seed oil. Full article
(This article belongs to the Special Issue Phytochemical Composition and Bioactivity of Horticultural Products)
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18 pages, 1868 KiB  
Article
Antioxidant and Cytotoxic Activities of Leaf and Stem Extracts of Barleria albostellata C.B. Clarke
Horticulturae 2023, 9(11), 1226; https://doi.org/10.3390/horticulturae9111226 - 13 Nov 2023
Viewed by 828
Abstract
Barleria albostellata C.B. Clarke (Acanthaceae) is a plant native to South Africa and relatively few studies have been performed on it. Species in this genus are known for their ethnopharmacological and phyto-medicinal values. In this study, the total flavonoid and phenolic contents and [...] Read more.
Barleria albostellata C.B. Clarke (Acanthaceae) is a plant native to South Africa and relatively few studies have been performed on it. Species in this genus are known for their ethnopharmacological and phyto-medicinal values. In this study, the total flavonoid and phenolic contents and the antioxidant and cytotoxic activities of hexane, chloroform, and methanol extracts were evaluated at five different concentrations (15, 30, 60, 120, and 240 μg/mL). The antioxidant activity of the extracts of B. albostellata was assessed in vitro using the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) scavenging and ferric reducing antioxidant power (FRAP) assays, while the phenolic content was determined using a Folin–Ciocalteu assay. The extracts’ cytotoxicity was established using a 3-[(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) assay in human embryonic kidney (HEK293), cervical cancer (HeLa), and breast adenocarcinoma (MCF-7) cell lines. Methanolic leaf extracts had the highest total flavonoid content (42.39 ± 1.14 mg GAE/g DW) compared to other solvents. Additionally, the total phenolic content was the greatest in the methanol leaf extract (6.05 ± 0.09 GAE/g DW), followed by the methanol stem extracts (2.93 ± 0.73 GAE/g DW). The methanolic leaf and stem extract concentrations needed for 50% inhibition (DPPH) were 16.95 µg/mL and 14.27 µg/mL, respectively, whereas for FRAP, the reducing powers of all extracts were considerably lower than the ascorbic acid standard. The IC50 values of extracts tested in the three cell lines were >63 µg/mL. According to the findings of our study, the leaves and stems of B. albostellata are rich in several bioactive compounds that may be a possible source of natural antioxidants and may have the potential to treat certain diseases. The extraction of the bioactive compounds from the leaves and stems of B. albostellata using bioassay-guided fractionation and the assessment of their safety will be essential for further investigations into this species in the search of potential novel therapeutic drug leads. To the best of our knowledge, this is the first report of the cytotoxic activities of leaf and stem extracts of Barleria albostellata. Full article
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17 pages, 1835 KiB  
Article
How to Diagnose Potassium Abundance and Deficiency in Tomato Leaves at the Early Cultivation Stage
Horticulturae 2023, 9(11), 1225; https://doi.org/10.3390/horticulturae9111225 - 13 Nov 2023
Viewed by 819
Abstract
Potassium is one of the indispensable nutrient elements for plant growth, fruit development, and yield. The research and application of potassium nutrition diagnosis technology is the premise of scientific potassium management. However, potassium deficiency in tomato leaves, from vegetative to reproductive growth, is [...] Read more.
Potassium is one of the indispensable nutrient elements for plant growth, fruit development, and yield. The research and application of potassium nutrition diagnosis technology is the premise of scientific potassium management. However, potassium deficiency in tomato leaves, from vegetative to reproductive growth, is not easy to diagnose. To alleviate this problem, this paper proposes a suitable method of supplying potassium to tomatoes via a nutrient solution and diagnosing potassium abundance and deficiency through diagnosis methods based on ecological morphology, biological accumulation, and the photosynthetic characteristics of tomato plants. The relationship between the ecological morphology and biomass accumulation of tomatoes cultivated in the nutrient solution with potassium supply levels of 1, 4, 8, and 16 mmol/L is also discussed, and the potassium supply in the nutrient solution was studied 21 days after transplanting. The results showed that there was a significant quadratic correlation between the potassium supply in the nutrient solution and plant height and biomass accumulation, respectively. The most suitable level of potassium supply via the nutrient solution was deemed to be 10~13 mmol/L. However, if irreversible damage or severe stress to tomato plants has occurred because of potassium deficiency, there will be serious differences in the growth status of plants, and the diagnosis results will deviate greatly. In addition, the photosynthetic induction characteristics responding to the dark–light conversion of tomato leaves with potassium contents of 0.9%, 2.1%, 3.1%, and 3.3% cultivated with potassium supply amounts of 1, 4, 8, and 16 mmol/L in the nutrient solution were investigated. The results showed that tomato leaves with potassium contents of 3.1% and 3.3% had a more rapid response to dark–light conversion and higher first-order derivatives of net photosynthetic rate compared to those with potassium contents of 0.9% and 2.1%, but the first-order derivative of intercellular CO2 concentration showed an opposite trend. Additionally, a quadratic correlation between leaf potassium content and CO2 assimilation during 5 min of photosynthetic induction was established (R2 > 0.99). According to this correlation, the suitable leaf potassium content was estimated to be 2.3~2.7%, similar to that of tomatoes cultured in the nutrient solution with a 4~8 mmol/L potassium supply. Therefore, this method can realize the rapid, non-destructive, and real-time detection of potassium content in tomato leaves based on a portable photosynthetic measurement system by establishing the relationship between leaf potassium content and net CO2 assimilation during the photosynthetic induction period, therefore helping to avoid the irreversible damage caused by potassium deficiency at the later stages of plant cultivation and providing technical support for the precise fertilization of potassium in actual cultivation. Full article
(This article belongs to the Special Issue Advances in Ecophysiology of Horticultural Crops)
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18 pages, 3035 KiB  
Article
European Grapevine Cultivars and Rootstocks Show Differential Resistance to Xylella fastidiosa Subsp. fastidiosa
Horticulturae 2023, 9(11), 1224; https://doi.org/10.3390/horticulturae9111224 - 12 Nov 2023
Viewed by 851
Abstract
Several Xylella fastidiosa subsp. fastidiosa (ST1) strains that cause Pierce’s disease were isolated from grapevine in Spain. In this study, we applied an approach to assess PD susceptibility among 24 different well-known Vitis vinifera subsp. vinifera cultivars and five rootstocks belonging to different [...] Read more.
Several Xylella fastidiosa subsp. fastidiosa (ST1) strains that cause Pierce’s disease were isolated from grapevine in Spain. In this study, we applied an approach to assess PD susceptibility among 24 different well-known Vitis vinifera subsp. vinifera cultivars and five rootstocks belonging to different species of the genus Vitis. Both were commonly commercialized, representing about 75% of the cultivated area in Spain. This method incorporated disease severity, disease progression, and water potential from the stem xylem. The trials were carried out under field and greenhouse conditions. The virulence of the Xff strain XYL 2055/17 was significantly higher than that of strain XYL 2177/18. However, while this difference in strain virulence did not seem to modify the susceptibility profiles of the cultivars, disease severity could be climate dependent. This work established two significantly different groups of European cultivars of grapevine characterized by high and low susceptibility to Xff ST1: cultivars with high susceptibility, including reference cultivars such as Tempranillo and Tempranillo Blanco, and cultivars with high resistance, such as Hondarrabi Zuri and Cabernet Sauvignon. Cultivar susceptibility was independent of the rootstock on which they were grafted. No conclusive data were found regarding the potential of water loss as an early detection test prior to symptom onset. This study provides a framework with which to advance cultivar susceptibility studies under different environmental conditions. Full article
(This article belongs to the Special Issue Genetic Resources for Viticulture)
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19 pages, 1421 KiB  
Article
Macronutrient Fertilization and Cadmium Absorption in Two Cocoa Clones
Horticulturae 2023, 9(11), 1223; https://doi.org/10.3390/horticulturae9111223 - 12 Nov 2023
Viewed by 692
Abstract
Soil Cd is absorbed by roots and accumulated in cocoa plants, which represents a problem in the commercialization of beans. In order to evaluate whether the exogenous application of macronutrients (N, N-P, N-P-K, N-P-K-S, N-P-K-S-Mg, and N-P-K-S-Mg-Ca) mitigates the absorption, translocation, and accumulation [...] Read more.
Soil Cd is absorbed by roots and accumulated in cocoa plants, which represents a problem in the commercialization of beans. In order to evaluate whether the exogenous application of macronutrients (N, N-P, N-P-K, N-P-K-S, N-P-K-S-Mg, and N-P-K-S-Mg-Ca) mitigates the absorption, translocation, and accumulation of Cd in plants, soil pH and electric conductivity, dry root and shoot biomass, leaf gas exchange, chlorophyll content, and macronutrient bioaccumulation were evaluated in two cocoa clones (CCN-51 and EET-103) grown in a greenhouse. An increase in macronutrients gradually increased the extraction capacity of Cd in both clones, with the highest Cd values being obtained with the application of N-P-K-S-Mg-Ca. Macronutrient fertilization did not affect leaf gas exchange; however, it caused significant reductions of 30, 40, and 60% in chlorophyll content, shoot, and root dry biomass, respectively. The greatest translocation of Cd from the root to the shoot was obtained with treatments that included N in clone EET-103 and Ca in clone CCN-51. Fertilization with macronutrients did not decrease the absorption and accumulation of Cd in the cocoa seedlings, because a greater removal force of Cd from the adsorption complex towards the soil solution was caused by the exogenous application of Ca and Mg and an increase in soil acidity. Full article
(This article belongs to the Special Issue Sustainable Fertilization and Irrigation Management in Horticulture)
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20 pages, 2244 KiB  
Article
Melatonin Enhanced Drought Stress Tolerance and Productivity of Pelargonium graveolens L. (Herit) by Regulating Physiological and Biochemical Responses
Horticulturae 2023, 9(11), 1222; https://doi.org/10.3390/horticulturae9111222 - 11 Nov 2023
Viewed by 853
Abstract
As a type of abiotic stress, drought limits plant growth and productivity. The increased demand for the valuable essential oil extracted from geranium (Pelargonium graveolens L.) is mainly regulated by plant growth, which is adversely affected by drought. Melatonin (MT) has been [...] Read more.
As a type of abiotic stress, drought limits plant growth and productivity. The increased demand for the valuable essential oil extracted from geranium (Pelargonium graveolens L.) is mainly regulated by plant growth, which is adversely affected by drought. Melatonin (MT) has been used to enhance plant growth under various abiotic stresses, although its impact on overcoming drought stress in aromatic plants, including geranium, has not yet been investigated. In the current investigation, MT at 100 µM was applied at 100% (well-watered) or 50% (drought stress) field capacity to verify the role of MT in geranium under drought stress. Drought stress markedly reduced growth parameters, herb yield, and total chlorophyll content; however, MT alleviated these effects. The herb yield of the stressed plants was reduced by 59.91% compared to the unstressed plants, while this reduction was only 14.38% when MT was applied. In contrast, drought enhanced the essential oil percentage in geranium leaves. Despite the reduction in oil yield caused by drought, MT application mitigated this reduction and improved both oil yield and oil components. Moreover, the MT treatment enhanced the accumulation of total phenols, glutathione, and proline and improved the activity of ascorbate peroxidase, catalase, and glutathione reductase, resulting in the alleviation of drought-induced oxidative damage. Consequently, MT reduced both hydrogen peroxide and malondialdehyde accumulation by 71.11 and 48.30%, respectively, under drought, thereby maintaining the cellular structures’ integrity. Overall, this is the first report that reveals the ability of MT application to improve geranium oil yield and resistance to drought by enhancing the antioxidant defense system. The results enrich awareness regarding the potential benefits of the external application of MT and its roles that can help researchers to improve aromatic plants’ performance and productivity under drought stress. Full article
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16 pages, 1254 KiB  
Article
Quantification and Comparison of Nutritional Components in Oni Walnut (Juglans ailanthifolia Carr.), Hime Walnut (Juglans subcordiformis Dode.), and Cultivars
Horticulturae 2023, 9(11), 1221; https://doi.org/10.3390/horticulturae9111221 - 11 Nov 2023
Viewed by 928
Abstract
Walnuts are rich sources of lipids and polyunsaturated fatty acids and are expected to promote health. There are two Japanese native walnut species: Oni walnut (Juglans ailanthifolia Carr.) and Hime walnut (Juglans subcordiformis Dode.). However, despite the fact that these Japanese [...] Read more.
Walnuts are rich sources of lipids and polyunsaturated fatty acids and are expected to promote health. There are two Japanese native walnut species: Oni walnut (Juglans ailanthifolia Carr.) and Hime walnut (Juglans subcordiformis Dode.). However, despite the fact that these Japanese native walnuts have long been consumed in local cuisine, their nutritional composition is largely unknown. This study aimed to assess the concentrations of total lipids, and fatty acid composition including polyunsaturated fatty acids, in the kernels of Oni walnut and Hime walnut. In addition, we assessed various aspects related to their nutritional and functional values, by measuring the total protein, amino acids, minerals, and total polyphenols. The concentrations of the measured compounds in the two native species were compared with those in the English walnut (Juglans regia L.), a globally recognized cultivar, and its counterpart cultivated in Japan, Shinano walnut (Juglans regia L.). The results showed that Oni walnut and Hime walnut contained significantly higher protein and minerals and lower lipid content than conventional cultivars. However, both Oni and Hime walnuts contained higher ratios of unsaturated fatty acids in total fatty acids. This study offers novel insights into the nutritional components of Oni and Hime walnuts, contributing to a deeper understanding of their nutritional value and potential applications as unique native walnut species. The findings of this study highlight the relationship between the different types of walnut species and their nutritional composition, and the value of native walnuts used in local cuisine, and will lead to new developments in functional foods from walnut species consumed around the world. It will contribute to the development of functional and processed foods by increasing the production of native walnut species, which are rich in protein, unsaturated fatty acids and minerals and by using them in local cuisines and health-promoting foods. Full article
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16 pages, 317 KiB  
Review
Basic Substances and Potential Basic Substances: Key Compounds for a Sustainable Management of Seedborne Pathogens
Horticulturae 2023, 9(11), 1220; https://doi.org/10.3390/horticulturae9111220 - 11 Nov 2023
Cited by 1 | Viewed by 990
Abstract
Seedborne pathogens represent a critical issue for successful agricultural production worldwide. Seed treatment with plant protection products constitutes one of the first options useful for reducing seed infection or contamination and preventing disease spread. Basic substances are active, non-toxic substances already approved and [...] Read more.
Seedborne pathogens represent a critical issue for successful agricultural production worldwide. Seed treatment with plant protection products constitutes one of the first options useful for reducing seed infection or contamination and preventing disease spread. Basic substances are active, non-toxic substances already approved and sold in the EU for other purposes, e.g., as foodstuff or cosmetics, but they can also have a significant role in plant protection as ecofriendly, safe, and ecological alternatives to synthetic pesticides. Basic substances are regulated in the EU according to criteria presented in Article 23 of Regulation (EC) No 1107/2009. Twenty-four basic substances are currently approved in the EU and some of them such as chitosan, chitosan hydrochloride, vinegar, mustard seed powder, and hydrogen peroxide have been investigated as seed treatment products due to their proven activity against fungal, bacterial, and viral seedborne pathogens. Another basic substance, sodium hypochlorite, is under evaluation and may be approved soon for seed decontamination. Potential basic substances such as essential oils, plant extracts, and ozone were currently found effective as a seed treatment for disease management, although they are not yet approved as basic substances. The aim of this review, run within the Euphresco BasicS project, is to collect the recent information on the applications of basic substances and potential basic substances for seed treatment and describe the latest advanced research to find the best application methods for seed coating and make this large amount of published research results more manageable for consultation and use. Full article
(This article belongs to the Special Issue Sustainable Control Strategies of Plant Pathogens in Horticulture)
14 pages, 310 KiB  
Article
A Cost–Benefit Analysis of Novel IPM-Based Approaches to Onion Thrips Management in US Dry Bulb Onions
Horticulturae 2023, 9(11), 1219; https://doi.org/10.3390/horticulturae9111219 - 10 Nov 2023
Viewed by 584
Abstract
Onion thrips, Thrips tabaci (Lindeman), is a major pest of dry bulb onion throughout the US and across the world. Yield and quality damage from thrips feeding and the expense of insecticides used for thrips management have jeopardized profitable and sustainable onion production. [...] Read more.
Onion thrips, Thrips tabaci (Lindeman), is a major pest of dry bulb onion throughout the US and across the world. Yield and quality damage from thrips feeding and the expense of insecticides used for thrips management have jeopardized profitable and sustainable onion production. To improve approaches to thrips management, researchers in multiple US onion-producing regions developed novel, integrated pest management (IPM)-based strategies employing threshold-based insecticide treatments and reduced fertilization practices. The purpose of this study was to estimate the benefits from public investment in research to develop IPM-based onion thrips management techniques using a cost–benefit analysis. Benefits were extended over a 20-year timespan and were measured by reduced insecticide and fertilizer costs. The estimated net present value of benefits from improved pest management tactics will depend on the adoption and use of novel approaches to management. Using a scenario that assumes a maximum adoption rate of 58%, the estimated net present value of the research is $15.91 million, the benefit–cost ratio is 4.00, and the internal rate of return is 32%. Assuming a scenario with a maximum adoption rate of 29%, the estimated net present value of the research is $8.3 million, the benefit–cost ratio is 3.34, and the internal rate of return is 24%. Even when estimated assuming conservative adoption scenarios, results indicate a healthy return on investment in research to develop and refine new approaches to manage onion thrips and optimize dry bulb onion production. Full article
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