Fruit Quality Research Articles

Mechanism of Exogenous Silicon in Enhancing Cold Stress Tolerance in Solanum lycopersicum L. Seedlings: Insights from Resistance and Quality Indicators

Environmental stress, notably the exposure to low temperatures during the early developmental stages of seedlings, has been identified as a critical determinant impacting the yield and quality of tomato crops cultivated in greenhouses. Silicon (Si), recognized as a beneficial element, is posited to mitigate the adverse effects of such stress on plant physiology. This study explores whether exogenous Si fertilizer can effectively alleviate the stress of low temperature and cold damage on tomato plant growth, fruit yield, and quality. Tomato plants were placed under low temperature conditions (6 °C at night, daily average temperature 15 °C), with normal temperature conditions as the control (below 16 °C at night, daily average temperature 28 °C), and two different concentrations of nano Si and ionic Si (50 mg·L−1 and 200 mg·L−1) were sprayed on the leaves, with an equivalent amount of deionized water as the control, for a total of 10 treatments. Relevant indexes were measured to investigate the effects of exogenous Si on tomato resistance, yield, and quality under low-temperature stress. The results show that compared with the control treatment, the plant height, stem diameter, and fresh weight of above-ground and underground parts of tomato seedlings decreased significantly by 46.52%, 42.53%, 28.81%, and 28.97%, respectively, after 15 days of low-temperature stress (p < 0.05), and in order to resist low temperature, the activity of antioxidant enzymes and the content of osmotic adjustment substances were up-regulated in seedlings. Ultimately, low-temperature stress inhibited the morphological growth, nutritional quality, and yield of fruits. Both concentrations of Si application can promote the growth and biomass accumulation of tomato plants under low temperature conditions. Moreover, it significantly ameliorated the osmotic adjustment and antioxidant capacity of the plants, thereby alleviating the low-temperature stress. Under low-temperature stress, 50 mg L−1 ionic Si was the most effective for increasing tomato yield per plant, which was significantly increased by 22.44% compared with the control treatment (p < 0.05). Consequently, the study advocates for the application of 50 mg·L−1 ionic Si fertilizer as a strategy to mitigate the impact of low-temperature stress on tomato plants. Furthermore, the use of nano Si fertilizer has been demonstrated to exert a significant influence on enhancing both the yield and quality of tomatoes, with a 50 mg·L−1 concentration of nano Si fertilizer leading to a notable increase in yield by 20.15% under normal temperature conditions (p < 0.05). These findings are intended to furnish a theoretical foundation and practical direction for advancing research aimed at combating the detrimental effects of low-temperature stress in the context of protected vegetable cultivation.

Effects of different rootstocks on the essential oil composition in the peel and leaf of rio red grapefruit

TThe use of rootstocks in citrus production is an increasingly common in practice. The selection of the appropriate rootstock is important in many aspects such as the adaptation of the variety to environmental conditions, growth, fruit set, flowering, fruit yield and fruit quality. In the present study, essential oil yields and components determined in the peels and leaves of Rio Red grapefruit grafted onto 7 different citrus rootstocks were compared. While essential oil yields from the peels of rootstocks were identified ranged between 0.5% and 1.5%, measurements could not be made due to trace amounts in the leaves. The essential oil composition was characterized using GC-MS, with limonene being the main identified compound in all the peels with 93.39 and 95.44% in Carrizo citrange and Volkameriana, respectively. However, in the leaves of rootstocks, besides limonene, major compounds were changed. In the leaves of Brazilian sour orange, β-sinensal was detected at significantly higher ratio (33.53%), sabinene was found at high ratios in Smooth Flat Seville sour orange (27.62%).

Assessment of<i> in vitro alpha</i>-glucosidase inhibitory activity, phenolics, flavonoidsand antioxidant potential of jamun (<i>Syzygium cumini)</i> seeds

Jamun (Syzygium cumini Linn. Syn. Eugenia jambolana) genotypes collected from different parts of the country were evaluated for in vitro alpha-glucosidase inhibitory activity, polyphenolic content and antioxidant potential along with fruit characters. Results indicated significant variation among genotypes for fruit characters, phenolics, flavonoids, antioxidant potential, and alpha-glucosidase inhibitory potential. Total phenolics and flavonoids in seeds varied between 15.5 mg to 98.7 mg GAE/g and 0.79 mg to 9.03 mg CE/g seeds, respectively. The seeds with a high content of polyphenolic compounds required a very less amount of sample to inhibit alpha-glucosidase enzyme. The genotype Selection 45 recorded the highest alpha-glucosidase inhibitory activity, and required only 50.3 µg of sample to inhibit 50 % of the enzyme activity. Both phenolics and flavonoids content positively correlated with antioxidant potential and negatively correlated with enzyme inhibitory potential. From cluster analysis, the genotypes AJG-85, Kaithanal, Selection-45, Collection-2, and Konkan Bahdoli were identified as superior genotypes having a considerable amount of seeds with alpha glucosidase inhibitory compounds. These genotypes/collections may be effectively utilized for further studies to isolate and characterize the bioactive constituents with alpha-glucosidase inhibitory potential.

Effect of insect pollinators on quantitative yield parameters of okra (Abelmoschus esculentus) in mid-Himalayan region

Okra [Abelmoschus esculentus (L.) Moench] is an often cross-pollinated crop with up to 19–42% of cross pollination assisted by insects and planned pollination may improve the economic fruit yield and biological parameters. The present study was carried out during rainy (kharif) seasons of 2021 and 2022 at Research Farm of ICAR-Vivekananda Parvatiya Krishi Anusandhan Sansthan, Hawalbagh, Almora, Uttarakhand to assess the pollinator diversity and possible results (both biological and economical) of planned bee pollination. The study on floral visitors of okra recorded 28 insect spp. belonging to four insect orders, among which five spp., viz. Apis cerana indica (Fabricius) 1798, Apis mellifera (Linnaeus) 1758, Bombus haemorrhoidalis (Smith) 1852, Lithurgus atratus (Smith) 1853 and Xylocopa latipes (Drury) 1773 were predominant. The foraging activity and pollination behaviour showed that two non-Apis bee species (X. latipes and B. haemorrhoidalis) were swift flyers and visited more numbers of flowers per unit time. It was noticed that, peak period of pollinator’s visitation was between 9.00–11.00 h accounting to 113.76±7.65 insects/m2/10 min, during which stigma receptivity and pollen germination were at its peak. Assessment of yield related parameters of insect pollinated flowers showed superior quality fruits with better capsule length (17.4–20.9 cm), capsule girth (6.56–7.84 cm), seeds/capsule (51.4–60.6), test weight of 100-seeds (7.05–8.38 g) and even the seed yield (1.86–3.04 tonnes/hectare) than closed control and hand pollination (emasculated and cross pollinated). In conclusion, ecological engineering of okra fields enhances the pollination rate and ultimately the yield and seed quality.

Identification and characterization of thorny and high temperature tolerant brinjal (Solanum melongena) genotype for hot arid environment

Brinjal (Solanum melongena L.) is one of the most common vegetable which is generally cultivated as rainy (kharif) season crop to get the fruits during autumn-winter season. However, the summer season crop has more potential than the kharif season as the fruits harvested during summer gets premium price in the market. But, getting high quality fruit yield during summer due to high temperature stress (>45°C) is a challenge particularly in hot arid agro-climate as the day and night temperature above 35°C reduces the pollen viability, fruit set, number of fruits/plant and colour retention to a great extent. The present study was carried out during 2020 and 2021 at ICAR-Central Institute of Arid Horticulture, Bikaner, Rajasthan to develop varieties with better quality fruit yield under high temperature conditions. The experiments were conducted in split plot design (SPD) considering environments as main plots and replicates within environment as subplots with three replications. As a result, CIAH-22 has been identified and characterized as a trait specific high temperature tolerant (up to 45°C) thorny brinjal genotype suitable for hot arid region. Fruit weight at marketable stage varied from 144.56–155.84 g that indicates bigger sized fruits with thorns on calyx which are preferred most by the local growers and consumers of this region. It has the yield potential of 2.18–3.72 kg fruits/plant and 447.78–471.74 q/ha. The identified genotype CIAH-22 was able to set fruits at temperature as high as 45°C which was also evidenced by its pollen viability i.e. 83.71%. High pollen viability significantly enhanced fruit set, fruit weight and number of fruits per plant and thereby yield under high temperature stress. Thus, this identified genotype can be a potential source for brinjal improvement for high temperature tolerance and regional preference of big-sized thorny fruits with attractive colour retention.

Investigation of Effects of Cushioning Packaging on the Physiological and Quality Changes in Chinese Olive Fruits During Cold Chain Transportation.

To gain a deeper understanding of the mechanisms by which cushioning packaging preserves the quality of Chinese olive fruits during cold chain transportation and extends their shelf life, this study simulated cold chain conditions and investigated the effects of cushioning packaging on the physiology, antioxidant capacity, and secondary metabolites of fruits during a 20-day shelf life. The results indicated that the decay rate in cushioning-packaging-treated fruit was 75% lower than that in the unbuffered packaging fruit at day 20 of shelf life. Simultaneously, cushioning packaging treatment mitigated the damage severity of the cell membrane structure and kept the cell membrane permeability at a low level, which was 15.34% lower than that in the unbuffered packaging fruit at day 20 of shelf life. Additionally, cushioning packaging effectively restrained the increases in malondialdehyde (MDA) content and alleviated the decline in chlorophyll and total flavonoid contents. It kept a balance among reactive oxygen species (ROS), antioxidant levels, and antioxidant enzyme activities, thereby reducing mechanical-damage-induced decay rates in Chinese olive fruits during the shelf life. Furthermore, metabolome analysis of Chinese olives during the shelf life was performed comparing those without buffered packaging to those with buffered packaging. The metabolome analysis found that the flavonoid biosynthetic pathway exhibited a higher accumulation of chrysin, neohesperidin, naringenin chalcone, sakuranetin, quercetin, catechin, and naringenin metabolites in cushion-packaging treatment compared to those without cushioning treatment. Furthermore, within the phenylalanine metabolic pathway, the accumulation of phenylalanine, p-coumaraldehyde, p-coumaric acid, coniferin and caffeoyl quinic acid metabolites was significantly higher in buffered-packaging groups compared to those without buffering. Together, these findings suggest that cushioning packaging can effectively sustain the integrity of cell membranes and enhance the shelf-life quality of Chinese olive fruits by regulating the balance of ROS and mitigating oxidative stress during cold chain transportation.

Elevated CO2 in dynamic controlled atmosphere storage: Impact on anaerobic metabolism and overall quality of 'Maxi Gala' apples.

The present study investigated the effects of high CO2 partial pressures (pCO2) in dynamic controlled atmosphere monitored by respiratory quotient (DCA-RQ 1.3) on the anaerobic metabolism compounds, physiological disorders and overall quality of 'Maxi Gala' apples after 9 months of storage (2.0 °C), plus 7 days of shelf life (20 °C). Two experiments were conducted over 2 years. In the first year, 'Maxi Gala' apples were stored under controlled atmosphere (CA - 1.2 kPa O2 + 2.0 kPa CO2), CA + 1-methylcyclopropene (1-MCP), DCA by chlorophyll fluorescence (DCA-CF + 1.2 kPa CO2) and DCA-RQ 1.3 with different pCO2 (0.4, 1.2, and 1.6). The same treatments were evaluated in the second year, with addition of DCA-RQ 1.3 + 2.0 kPa CO2. 'Maxi Gala' apple stored under DCA-RQ 1.3 + 0.4 kPa CO2 and DCA-CF maintained healthy fruit amount similar to DCA-RQ 1.3 + 1.2 and 1.6 kPa CO2, but with lower flesh firmness. DCA-RQ 1.3 with higher pCO2 (1.6 or 2.0) increases the production of ethyl acetate, but did not impact physiological disorders compared to DCA-CF. CA + 1-MCP maintained high flesh firmness, but reduced healthy fruit amount. The present study has demonstrated that DCA-RQ 1.3 with 1.6 or 2.0 pCO2 can be adopted for 'Maxi Gala' apples storage, resulting in similar or better fruit quality than DCA-RQ 1.3 + 1.2 kPa CO2. Additionally, the adoption of high pCO2 in the DCA-RQ storage system can result in cost reductions related to CO2 adsorption. © 2024 Society of Chemical Industry.

Cu-Doped MnO2 Catalysts for Effective Fruit Preservation via Ozone Synergistic Catalytic Oxidation.

Developing and implementing technologies that can significantly reduce food loss during storage and transport are of paramount importance. Ozone synergistic catalytic oxidation (OSCO) technology has been developed, which sterilizes bacteria and viruses on the surface of food and degrades ethylene released during fruit storage through the active oxygen produced by the catalytic decomposition of ozone. Herein, we report the hydrothermal synthesis of MnO2 with distinct phase compositions and nanostructures through simply varying the reaction temperatures. Optimized copper-doped α-MnO2 nanorods exhibited remarkable efficacy in activating ozone at a concentration of 40 ppb, and this activation resulted in the complete eradication of indicator bacteria on food surfaces within a 24 h period. Moreover, these nanorods demonstrated high effectiveness in decomposing more than 80% of the ethylene molecules emitted by apples and bananas during the preservation period. The high concentration of surface oxygen vacancies is believed to contribute to the enhanced catalytic activity of the Cu-doped α-MnO2 catalyst in the OSCO procedure by reducing ethylene production and maintaining the fruit quality during the preservation period.

Effects of Cyclic Aeration Subsurface Drip Irrigation on Greenhouse Tomato Quality and Water and Fertilizer Use Efficiency.

Tomato (Jinglu 6335) was selected for assessing the impact of varying fertilizer (F:N-P2O5-K2O) and aeration rates on crop quality, as well as water and fertilizer utilization efficiency during the cyclic aeration subsurface drip irrigation process. Four aeration treatments (O1, O2, O3, and S, representing aeration ratios of 16.25%, 14.58%, 11.79%, and non-aerated treatment, respectively) and three fertilizer applications (F1: 240-120-150 kg/hm2, F2: 180-90-112.5 kg/hm2, F3: 120-60-75 kg/hm2) were compared in a total of 12 treatments in this study. This study revealed that cyclic aerated drip irrigation improved the fruit quality. The aerated treatment resulted in increased accumulation of nitrogen, phosphorus, and potassium, with the level of aeration positively correlating with the increase in nutrient accumulation, reaching the highest values in the high aeration irrigation treatment. The highest nitrogen, phosphorus, potassium, and water use efficiency occurred under the medium fertilizer with high aeration treatment. The maximum partial productivity of the fertilizer occurred under the low fertilizer with high aeration treatment, while the minimum occurred in the high fertilizer with non-aerated treatment. Taking all factors into consideration, the high-aeration and medium-fertilizer treatment was the most effective combination for greenhouse tomatoes under the conditions in this experiment.

Mechanism of induced soluble sugar accumulation and organic acid reduction in plum fruits by application of melatonin

Melatonin (MT) can improve plant resistance and fruit quality. The mechanism by which MT affects soluble sugar and organic acids accumulation in drupe fruits is not clear. In this study, 100 µmol/L MT was sprayed on the leaves of plum trees at the second stage of rapid fruit expansion (90 and 97 d after flowering), and the effects of MT on plum fruit quality and its effects on the soluble sugar-organic acid metabolism were investigated. At 28 d after MT treatment (at maturity), the longitudinal diameter, fruit weight, and vitamin C content of plum fruits were increased by 5.05%, 12.93%, and 56.09%, respectively, compared to the control. MT caused significant increase in the total soluble solids content and decreased the titratable acid content. MT increased the contents of total soluble sugar, sucrose, sorbitol, and citric acid after 21 and 28 days of treatment, while decreasing the contents of fructose, malic acid, quinic acid, and tartaric acid after 28 days of treatment. Additionally, MT increased the activities of sucrose synthase (catabolism direction), sucrose phosphate synthase, glucokinase, fructokinase, sorbitol oxidase, and NADP+-malic enzyme, and decreased the activities of soluble acid converting enzyme, cell wall insoluble converting enzyme, NAD+-sorbitol dehydrogenase, and NAD+-malic dehydrogenase after 21 or 28 days of treatment. Moreover, the differentially expressed genes (DEGs) after 21 and 28 days of treatment were accelerated starch and sucrose metabolism, galactose metabolism, fructose and mannose metabolism, as well as glycolysis, gluconeogenesis, and pentose phosphate metabolism pathways. In conclusion, exogenous MT increases soluble sugar content and decreases organic acid content in plum fruits by regulating various soluble sugar-organic acid metabolic pathways, thereby improving the fruit quality.

Characterization of a tomato chlh mis-sense mutant reveals a new function of ChlH in fruit ripening.

Tomato fruit ripening is a complex developmental process that is important for fruit quality and shelf life. Many factors, including ethylene and several key transcription factors, have been shown to play important roles in the regulation of tomato fruit ripening. However, our understanding of the regulation of tomato fruit ripening is still limited. Here, we describe mut26, an EMS-induced tomato (Solanum lycopersicum) mutant that exhibits chlorophyll-deficient phenotypes in various organs, including fruits. Genetic mapping and functional analyses revealed that a single-nucleotide substitution and a corresponding Pro398->Ser mis-sense mutation in SlChlH (GENOMES UNCOUPLED 5, GUN5), which encodes the H subunit of magnesium chelatase, are responsible for the defects in the mut26 strain. Transcript analyses towards the expression of many SlPhANGs revealed that mut26 is defective in plastid retrograde signalling during tomato fruit ripening initiation, namely the transition from mature green to breaker stage. mut26 exhibits delayed progression of fruit ripening characterized by reduced fruit ethylene emission, increased fruit firmness, reduced carotenoid content and delayed plastid conversion from chloroplast to chromoplast. Given that fruit ripening requires signalling from plastids to nucleus, these data support the hypothesis that GUN5-mediated plastid retrograde signalling promotes tomato fruit ripening. We further showed that the delayed fruit ripening of mut26 is not likely caused by reduced chlorophyll content. Taken together, we identified a new function of SlChlH in the promotion of tomato fruit ripening and ethylene biosynthesis, suggesting that GUN5-mediated plastid retrograde signalling plays a promotive role in tomato fruit ripening.

Exogenous phenylalanine application effects on phytochemicals, antioxidant activity, HPLC profiling, and PAL and CHS genes expression in table grapes (Vitis vinifera cv. ‘Qzl Ouzum’)

BackgroundGrape (Vitis vinifera L.) is one of the most important fruit products globally and has a high nutritional value with potent antioxidant and anti-cancer activities. In current years, phenylalanine application has been particularly noticed for enhancing the nutritional quality of horticultural crops. With the aim of quality improvement, the effects of foliar application of phenylalanine at 5 concentrations (0, 100, 500, 1000, and 2000 μM) on Vitis vinifera cv. ‘Qzl Ouzum’ berry compositions were studied. The studied parameters included antioxidant activity, phenolics, flavonoids, anthocyanin, catalase and phenylalanine ammonia-lyase enzyme activity, and phenolic compounds content based on HPLC analyses (myricetin, quercetin, kaempferol, syringetin, catechin, gallic acid, caffeic acid, p-coumaric acid, resveratrol).ResultsPhenylalanine at 1000 μM increased total phenols, flavonoids, anthocyanins, and PAL enzyme activity. In addition, HPLC analysis revealed a significant accumulation of individual phenolic compounds by phenylalanine treatment. The highest values were recorded in the treatments with 100 and 500 μM phenylalanine for most of the phenolic components. Real-time quantitative RT-PCR results showed that the expression of PAL and CHS genes was induced by phenylalanine. The highest PAL and CHS gene expression was observed at 500 μM and then at 1000 μM phenylalanine treatment.ConclusionsWith the use of phenylalanine, the activity of the PAL and CHS enzyme and PAL and CHS gene expression were significantly increased and led to a greater accumulation of phenolic compounds and antioxidant activiety. This study suggests that the use of phenylalanine as a main precursor for the synthesis of phenolic compounds, can improve the phenolic composition of grapes and could be a practical approach to advance fruit quality in the production of grape cv. ‘Qzl Ouzum’.

Assessment of antimicrobial edible coatings derived from coffee husk pectin and clove oil for extending grapes shelf life

Grapes are rich in phenolic compounds with potent antioxidant properties that mitigate risks associated with cardiovascular and neurodegenerative diseases. However, postharvest storage often leads to microbial infestations, significantly deteriorating fruit quality. This study investigated the effects of two composite edible coatings i.e., Coffee Husk Pectin-Clove Oil (CHP-CO) and Freeze-Dried Coffee Husk Pectin-Clove Oil (FD-CHP-CO) on prolonging the shelf life of grapes. Coated and uncoated grapes were evaluated for their physicochemical (weight loss, colour, pH, total soluble solids and titratable acidity), bioactive compounds (total phenolics and total flavonoids), in vitro antioxidant and antimicrobial properties during 14 d of storage at ambient (RT, 25 ± 1 °C) and cold (4 ± 1 °C) storage conditions. Coated grapes maintained better quality compared to uncoated grapes, with FD-CHP-CO reducing weight loss by up to 76 % at ambient conditions (0.92 ± 0.26 % vs. 3.89 ± 1.63 % in uncoated grapes). The FD-CHP-CO coating also resulted in a significant inhibition zone increase against Staphylococcus aureus MTCC 96 from 11 to 15 mm. Additionally, the coated grapes showed higher retention of bioactive compounds, with total phenolics and total flavonoids retention of 86.9 % and 83.7 %, respectively. These results suggest that CHP-CO and FD-CHP-CO coatings effectively extend the shelf life of grapes, maintaining their quality and safety during storage, and highlight the potential of these coatings in reducing food waste and improving consumer satisfaction.Graphical

Relationships between the number of nuts per cluster and fruit characteristics in the Foşa hazelnut cultivar

This research aimed to determine the effect of the number of nuts per cluster on the fruit characteristics of the Foşa hazelnut cultivar grown in the Arsin district of Trabzon province, Türkiye. Hazelnuts are divided into groups of 1 to 7 according to the number of nuts in cluster. Nut weight, nut length, nut width, nut depth, kernel weight, kernel length, kernel width, kernel depth, shell thickness, kernel ratio, husk length, husk width, and husk opening of the hazelnuts in each group were examined. Principal component analyses (PCA) was used to determine the relationship between the number of nuts in cluster and fruit characteristics. Nut weight, shell thickness, husk length, and husk width values were the highest values in single nut clusters. If the number of nuts in the cluster exceeds four, nut and kernel weights decrease. There was a negative relationship between the nut weight and nut length when the number of nuts in the cluster was above four. A strong relationship were observed in clusters 1, 2, 3, and 4, but a weaker relationship, was seen especially in clusters 5 and 7. A negative relationship was determined between the nut weight and nut length. This study clarified that increasing nut numbers shifts quality characteristics, particularly in a negative trend.

Insecticidal potential of botanical extracts for management of, the oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae)

BackgroundBactrocera dorsalis (Hendel) poses a significant threat to global fruit production and quality, including in Pakistan, where it causes substantial losses. Traditional control methods have heavily relied on the indiscriminate and imprudent use of insecticides, leading to challenges such as insecticide resistance, environmental pollution, fruit contamination, and health risks. This study explores the insecticidal potential of seven selected botanicals: Artemisia vulgaris L., Capparis spinosa L., Mentha longifolia, Mentha piperita, Peganum harmala, Eucalyptus globulus, and Callistemon viminalis, each at three different concentrations (10mL, 20mL, and 30mL), against Bactrocera dorsalis (B. dorsalis). Two in vitro experiments involving the application of plant extracts mixed with protein bait and direct spray were conducted.ResultsBoth experimental results demonstrated a direct correlation between the concentration of plant extract and the mortality of B. dorsalis. In the plant extract mixed with protein bait, results recorded after 96 h at 10 mL ranged from 8.667 ± 1.52–47.000 ± 3.00, at 20 mL from 18.667 ± 1.52–53.667 ± 6.02, and 30 mL from 26.000 ± 5.29- 67.667 ± 2.08. Meanwhile, for direct spray, mortality ranged from 2.333 ± 1.15–32.333 ± 6.80 at 10 mL, 1.000 ± 1.00–42.667 ± 7.02 at 20 mL, and 9.667 ± 2.30–61.333 ± 8.50 at 30 mL, respectively. The plant species exhibiting the highest toxic potential against the respective pests was C. viminalis, followed by A. vulgaris L. In contrast, the least toxic effect was observed in Eucalyptus globulus at all concentrations. The highest mean mortality and repellence % were recorded in C. viminalis and E. globulus in both experimental trials. The results revealed the highest efficacy of C. viminalis with an LC50 value of 9685.15 and 19,909.11 ppm, for the extract mixed with protein bait and sprayed, was obtained, respectively, the most toxic to the pest followed by the extracts E. globulus and C. spinosa L.ConclusionBased on our experimental results, it is concluded that C. viminalis and A. vulgaris L. are an effective alternative for the management of B. dorsalis.

Optimal Harvest Maturity Changes Depending on the Season Throughout the Year in Papaya Grown in Mediterranean Climate-Improved Greenhouses

Papaya is a tropical fruit that is highly appreciated worldwide for its organoleptic properties and its nutritional and medicinal value. The optimal fruit quality for market requirements is determined by genotype, environmental conditions, and crop management, as well as fruit handling at harvest and adequate postharvest conservation. The aim of this work was to determine the optimal maturity stage, based on skin color, at which to harvest papayas grown in Mediterranean greenhouses with active climate control in south-east Spain, depending on the harvest season. We confirm that it is possible to produce high-quality papayas in our conditions, but the optimal harvest maturity stage in each season, along with the postharvest storage capacity, vary throughout the year, even with active climate control. Thus, 10% yellow skin color (S0) is the optimal for harvesting in autumn, mainly due to its better conservation capacity and firmness, having a high TSS content (>11 °Brix). In summer and spring, the lower TSS content discourages harvesting at S0, with S1 (30–40% yellow skin color) or S2 (50–60% yellow skin color) being the optimal stages for harvest to ensure the minimum TSS content required for papaya commercialization (10 °Brix). In any case, papayas produced under our conditions are generally well rated by consumers.

How multi-species pollination boosts strawberry yield, quality, and nutritional value

A diverse assemblage of insect visitors can provide functional complementarity within plant pollination due to differences in characteristics such as their physical traits, visitation rate and foraging time of day or year. In a horticultural context, greater functional complementarity may play a crucial role in enhancing fruit yield and quality by improving pollination. We tested whether the identity of the crop pollinators (bumblebee Bombus terrestris and hoverfly Eupeodes corollae) independently and additively influenced commercial strawberry yield, quality, and nutritional parameters such as vitamin C and sugar concentration. Fragaria x ananassa “Malling Champion” plants received pollination treatments of either a) “control”: self-pollination where pollinators were excluded, b) “bee”: bumblebee Bombus terrestris, c) “hoverfly”: Eupeodes corollae, d) “combined”: both B. terrestris and E. corollae. Hoverflies and bumblebees exhibited distinct visitation patterns throughout the day, establishing a functional complementary relationship that enhances pollination success and crop output as well as vitamin C concentrations. Strawberries from plants receiving pollination by bumblebees, or bumblebees and hoverflies combined, had higher yields of higher marketable quality. They also had measurably higher vitamin C content than strawberries from plants pollinated by hoverflies alone, or the control (self-pollinating) plants. This study advances our understanding of niche complementarity and its impact on fruit yield and quality. By elucidating the behavioural and temporal dynamics of pollinators, we provide valuable insights for optimizing pollination strategies in agricultural contexts. Our findings highlight the significance of behavioural factors, such as handling time and number of visits, in determining fruit quality.

Training System Effect on Fruit Quality, Yield, Harvest Efficiency, Pruning Times and Growth in Sweet Cherries

Training System Effect on Fruit Quality, Yield, Harvest Efficiency, Pruning Times and Growth in Sweet Cherries

Assessment of Phenological and Yield Characteristics of Apple (Malus × domestica Borkh) Varieties

Phenology has gained recently a considerable emphasis as a method for assessing the impacts of changing climate on plant species. Shifting in phenological stages changes can have rippling impacts on environment. Quantifying the effects of these shifting changes on plants is therefore crucial. Knowledge of the dates and duration of particular phenological stages and their variations can be a valuable source of information for organizing, planning and implementation of some regular and special horticultural activities. The phenological study of apple is an essential component of the study as critical phenological stages of the apple are highly reliant on environment, they also have significant practical and scientific implications in the domain of selection. In particular, proper flowering and fruit ripening time are very critical to achieve optimum fruit yield and quality. Fruit yield is an important parameter that determines the acceptability of a cultivar by consumers. The present investigation was undertaken to evaluate the apple varieties for their phenology and yield under Kashmir conditions. Four varieties viz., Super Chief, Red Chief, Gala Redlum and Mitch Gala were used for study. Phenological characteristics revealed that Mitch Gala was earliest in all the phenological stages and Super Chief was late. The blooming period of the studied varieties indicated the synchronizing behaviour of the varieties, which is a prerequisite for effective pollination and adequate fruit set. As far as flowering is concerned, Mitch Gala was earliest to bloom and Gala Redlum was late. Fruit production characteristics revealed that Gala Redlum and Mitch Gala. In terms of yield characteristics, highest yield of 20.58 kg/tree was recorded in Gala Redlum followed by 19.40 kg/tree in Mitch Gala.

Mechanism of abscisic acid in promoting softening of postharvest 'Docteur Jules Guyot' pear (Pyrus communis L.).

Abscisic acid (ABA) is a key hormone in plant growth and development, playing a central role in responses to various biotic and abiotic stresses as well as in fruit ripening. The present study examined the impact of ABA and nordihydroguaiaretic acid (NDGA) on various postharvest 'Docteur Jules Guyot' pear fruit characteristics, including firmness, pectinase activity, pectin content, volatile aromatic substances, and the expression of correlated genes. The results showed that ABA quickly reduced fruit firmness, increasing the activity of pectin degradation-related enzymes. The contents of water-soluble pectin (WSP) and ionic-soluble pectin (ISP) increased, and covalent binding pectin (CBP) decreased under ABA treatment. Among the detected volatile aromatic substances, the highest-level substance of the fruit was ester, and the ABA treatment significantly promoted the amount of ester substances. The cell wall disassembly-related genes PcPME3, PcPG1, PcPG2, PcPL, PcARF2, and PcGAL1, as well as ABA biosynthesis-related genes PcNCED1 and PcNCED2, were also significantly induced by ABA. Conversely, all these genes were repressed in the NDGA treatment group. Therefore, it was speculated that ABA may promote the softening of postharvest European pear fruit by affecting the activity of pectin degradation enzymes in fruit cell walls.