Investigating how the production of insulin is regulated in fruit flies reveals surprising insights that may help to better understand how this process unfolds in humans.

Heatwaves are a risk to fruit tree yield and production. In this study, a dynamic agrivoltaic system was tested as a solution to protect trees from high temperatures by shading the fruits when irradiance and air temperature peak at their maximum values. The study was completed in an apple dynamic agrivoltaic system in France in 2022 and 2023. The agrivoltaic system was compared to a control without solar panels. The study was initiated in 2022 with measurements of microclimate (incident solar radiation and air temperature) and sunburn damage. In 2023, these measures were complemented with detailed measurements of fruit surface temperature and fruit growth. In 2023, fruit surface temperature was continuously measured for two control and two agrivoltaic trees using type T thermocouples (12 apples per treatment). Fruit diameter of 18 tagged fruit per treatment was monitored weekly. Air temperature at the agrivoltaic trees was lower compared to control trees due to a reduction of 50% in daily incident radiation. Sunburn damage was reduced for agrivoltaic apples in 2022 (control 13% vs. agrivoltaics 2%). In 2023, although there were low sunburn values for both the control and agrivoltaic apples, it was found that agrivoltaic apples were cooler than control apples. The maximal fruit surface temperature reduction during the study was 3.3 °C. Fruit diameter was the same across treatments. Dynamic agrivoltaic systems can be used to reduce apple fruit surface temperature and minimize the risk of sunburn when trees are shaded during periods of high irradiance and temperature.

1-Methylcyclopropene (1-MCP) and Ascorbic Acid (AsA) inhibit the ethylene effect in horticultural products. Mostly 1-MCP and AsA are used as individual treatments to extend the fruit shelf life and maintain the quality of horticultural products. In this study, we elucidate the influences of the combination effect of 1-MCP and AsA on the postharvest fruit shelf life and quality of tomato. 1-MCP at 0, 1, and 2 μL L−1 combined with AsA at 0, 2, and 4 % was treated to Br + 4 of tomato fruit. The postharvest fruit quality and shelf life were evaluated during 21 d of postharvest storage. The result showed that a combination of 1-MCP 2 μL L−1 + AsA 4 % significantly improved tomato fruit shelf-life by 6 d longer than control (untreated fruits), whereas the individual treatment of 1-MCP improved only 4 d longer than control, also improved fruit firmness 37.01 % harder than control, and reducing fruit loss 10.37 % lower than control at 21 d of storage. In the nutritional parameeters, it affects in the reducing the total sugars 20.97 %, lycopene 23.45 %, β-carotene 25.32 % lower than control, but did not affect on the change of total polyphenol and flavonoid. These results indicate that the effectiveness of 1-MCP in improving tomato fruit shelf-life was enhanced by its combination with AsA, which will be useful for practical application in postharvest handling.

[Objective] Litchi (Litchi chinensis Sonn.) is a hermaphroditic plant which possesses unisexual flowers formed by selective abortion of the floral sexual organs after meiosis. Too many flowers and low rate of females of panicles often lead to low fruit setting rate in litchi. This study aimed to develop new plant growth regulators that could be applied on litchi panicles to improve the yield and fruit quality. Exogenous auxin application on litchi panicles can decrease the rate of female flowers and reduce the amount of fruit set, so we wonder if auxin inhibitors have the opposite effects on flowering and fruit setting. [Methods] This study utilized litchi cultivar Feizixiao as the experimental material and applied naphthylacetic acid (NAA) along with varying concentrations of auxin inhibitors, namely 4-phenoxyphenylboronic acid (PPBo) and 2, 3, 5-triiodobenzoic acid (TIBA), by a spray on litchi flower spikes. The water treatment served as the control group. Astudy was performed to analyze the impacts of different treatments on the quantities of male and female flowers, the flowering duration of male and female flower, the quantity of fruit set, and the quality of litchi fruits. In terms of fruit quality, we tested the vertical diameter, transverse diameter, single fruit weight, peel weight, pericarp thickness, seed weight, edible rate and total soluble solid. In addition, the correlation between different flowering characters and fruit setting quantity of litchi were investigated. [Results] In the flowering aspect, the amount of female flowers and the rate of female flowers in litchi panicles were reduced by NAA treatment, as previously reported. Accordingly, the number of male flowers in litchi was decreased by PPBo and TIBA treatment at different concentrations, and TIBA treatment showed significantly difference compared with the control. However, the number of female flowers was not significantly altered between different auxin inhibitor treatments and the control group. The concentration of 100 mg·L-1 of TIBA (TIBA-2) had a notable impact on boosting the proportion of female flowers to 30.29%, but not other auxin inhibitor treatments. When compared with the control, all of the treatments had no impact on the duration of male and female flowering, as well as the overlap period between the males and females, however, the panicles of TIBA treatment had significantly longer flowering period of female flowers than the panicles of the NAA treatment. In terms of fruit setting quantity, both PPBo and TIBA treatments resulted in an increase in the average number of first and final fruit setting, which were calculated 1 and 7 weeks after female flowers withering, respectively. However, only the TIBA-2 treatment exhibited a considerable increase of the first and final fruit setting compared with the control, with an average of 59.17 and 15.00 per panicle, respectively. The correlation analysis of flowering traits and fruit setting quantity revealed significantly positive correlations between the initial fruit setting quantity and the ratio of female flowers as well as the number of female flowers, with the correlation coefficient of 0.70 and 0.51, respectively. On the contrary, the initial fruit setting quantity was negatively correlated with the number of male flowers and the total flowers, with significant correlation coefficients of-0.57 and-0.43, respectively. It is worth mentioning that the final and initial fruit setting amounts were correlated similarly with the flowering characteristics, however the correlation coefficients were larger in the initial fruit setting amount. Besides, the final and initial fruit setting amount showed a significantly positive correlation with the correlation coefficient of 0.73. From the perspective of fruit quality, there were no significant variations in fruit longitudinal diameter between the various treatments and the control. TIBA-2 had a considerably larger transverse diameter than the control, but there was no significant difference between the other treatments. Furthermore, the proper concentration of PPBo or TIBA could significantly boost the weight of individual fruits. The peel thickness of NAA and different concentrations of TIBA treatments was significantly lower than that of the control. There was no significant difference in the seed weight or total soluble solid (TSS) between the different treatments and controls. NAA and TIBA-2 treatment had the significantly higher edible rate than the control, reaching more than 80%, but the other treatment did not differ significantly from the control. [Conclusion] The auxin inhibitor TIBA treatments showed remarkable effects in reducing the number of male flowers, while increasing the proportion of female flowers and fruit setting quantity. Additionally, TIBA treatments reduced peel thickness and increased fruit weight and overall edibility. TIBA-2 with the concentration of 100 mg·L-1 was the most effective treatment that could enhance both the fruit quantity and fruit quality.

Mango is a tropical fruit of great economic importance in Brazil. However, as a highly perishable climacteric fruit, mango ripens quickly after harvest, limiting its transport to distant markets. Technologies such as modified atmosphere packaging (MAP) and ethylene absorption can delay ripening and thereby offer high quality fruit in more distant markets. The objective of this study was to evaluate the efficiency of new modified atmosphere packages (MAPs), with or without ethylene absorption, to maintain the postharvest quality of ‘Palmer’ mangos harvested at more advanced ripeness. The experiment followed a completely randomized design with four replications and eight fruit per replication. The treatments were unpacked fruit (control), fruit packed in polyethylene bags with BreathWay (BW) membranes presenting low (BWA 50%), medium (BWA) or high (BWB) permeability to O2, with or without an It’s Fresh ethylene absorption filter, and fruit packed in perforated polyethylene bags with It’s Fresh ethylene absorption technology. Advanced ripeness (i.e., low peel chlorophyll content) fruit were selected in the packinghouse with a DA-meter. The fruit were stored for 28 days at 9°C with 90-95% relative humidity. Then, all MAPs were opened and the fruit kept for another 4 days at 20 °C to simulate the shelf life conditions. All MAPs, without ethylene absorption, were able to delay ripening and mass loss, compared to control fruit. The ripening index at harvest was 2.3. The control fruit reached ripeness indices of about 1.4 and 1.0 after 28 days of storage and 4 days of shelf life, respectively. Ethylene absorption had no effect on delaying ‘Palmer´ mango ripening. | Resumo 212.

A field experiment was conducted in 2023 and 2024 in Beijing, China, to investigate effects of soil water stress, applied before the fruit ripening stage, on the fruit total soluble solid accumulation and cracking of jujube trees. The experiment consisted of two variation factors: (a) irrigation levels (MDI and SDI, applied 80% and 50% of the irrigation volume, respectively) and (b) growth stages (stage 1, before the fruit enlargement stage, and 2, before the fruit ripening stage). The two irrigation levels were applied at each growth stage in a 2 × 2 factorial arrangement, plus a control treatment receiving 100% irrigation volume, resulting in five treatments per replicate. The findings indicated that pre-enlargement stage water stress enhanced the accumulation of total soluble solid content within fruits, which subsequently promoted faster fruit growth in from the early- to mid-August period. However, by late August, both the total soluble solid content and fruit growth rates had declined, thereby mitigating the risk of fruit cracking. During the fruit enlargement stage, the fruit total soluble solid content in SDI-2 increased by approximately 24% by the end of August compared to the control, leading to lower osmotic potential and higher turgor pressure during the following ripening stage. As skin growth ceased, high turgor pressure caused fruit cracking at the following ripening stage. The SDI-2 treatment demonstrated a fruit cracking rate approximately 1.5 times higher than that of the control. Pearson correlation analysis also indicated that fruit cracking was positively correlated with total soluble solids accumulated in August. Meanwhile, the yield of SDI-2 was reduced about 18%. Therefore, the adequate soil moisture during the fruit enlargement stage was crucial to minimize jujube fruit cracking and economic losses. Meanwhile, the deficit irrigation applied during the pre-enlargement stage could effectively conserve water resources and mitigate the occurrence of extensive jujube fruit cracking.

Fresh passion fruit is sensitive to chilling injury (CI) during storage at improper low temperature of 5 °C, which lowers the fruit quality and limits its shelf life. The present study aimed to determine the impacts of melatonin on CI development of passion fruit in relation to antioxidant ability and membrane lipid metabolism during refrigeration. In present study, passion fruit was treated with 0.50 mmol L−1 melatonin and distilled water (control) for 20 min, hereafter stockpiled at 5 °C. The results indicated that, in storage, melatonin-treated passion fruit showed the lower CI index and cell membrane permeability, lower superoxide anion production rate and malondialdehyde level, greater activities of catalase, superoxide dismutase and ascorbate peroxidase, higher levels of ascorbic acid and glutathione, and higher 1, 1-diphenyl-2-picrylhydrazyl radical scavenging capacity than control passion fruit. Besides, lower membrane lipid-degrading enzyme activities, lower contents of phosphatidic acid and saturated fatty acids (SFAs), higher levels of phosphatidylcholine, phosphatidylinositol and unsaturated fatty acids (USFAs), and greater ratio of USFAs to SFAs and index of USFAs were revealed in melatonin-treated passions than control passions. Thus, these results indicated that melatonin retained cell membrane structure via boosting antioxidant capacity and restricting membrane lipid degradation, accordingly increased the chilling resistance and delayed the CI development in fresh passion fruit.

Uneven fruit ripening (UFR) is currently causing a decrease in the quality and value of “Ri 6” durian fruit. The soil moisture and nutrient (K, Ca, and Mg) levels present during the fruit development stage are the two main factors affecting UFR in durian fruit. However, measurements that can be used to determine the decrease in the UFR rate of durian remain unknown. Therefore, this study sought to evaluate the impact of plastic mulching (PM) and polyhalite fertilizer (PH) on improving the UFR rate and quality of durian fruit. A field study was conducted at three different durian orchards in the Vietnamese Mekong Delta (VMD) throughout two seasons (2022–2023 and 2023–2024). We used PM a month before fruit harvesting, combined with PH applied during the fruit development stage. Four treatments were used: (T1) control; (T2) PM, plastic mulching a month before durian fruit harvesting; (T3) PH, polyhalite fertilizer application (3 kg tree⁻¹ year⁻¹); and (T4) PM + PH, polyhalite fertilizer application (3 kg tree⁻¹ year⁻¹) and plastic mulching a month before durian fruit harvesting. The farmer’s fertilization practice (450 g N–450 g P–450 g K per tree⁻¹ during the fruit development period) was used in all treatments. Parameters such as soil physicochemical properties, fruit quality, and leaf mineral nutrient concentration were investigated at the harvesting stage. The results show that using PM + PH decreased soil moisture (>15%) but increased the concentrations of K, Mg, and Ca in both soil and durian leaves, thereby reducing the UFR rate (>80%) compared with the control. Additionally, applying PM + PH increased the aril proportion (>18%) and total soluble solids (approximately 5%) in durian fruit in comparison with the control. In conclusion, combining PM and PH improved the UFR rate and durian fruit quality. Therefore, we recommend that farmers apply these methods to their durian orchards to decrease physiological disorders and enhance fruit quality, thus contributing to achieving sustainable durian production in the VMD.

Brown rot caused by Monilinia spp. is the most important postharvest disease of stone fruit. Currently, no chemical fungicides are allowed in the European Union to be applied to stone fruit after harvest. In previous work, radio frequency (RF) treatment for 4.5 min applied with fruit immersed in water at 40 °C was very promising for the control brown rot on peaches and nectarines. In the present study, the efficacy of this radio frequency treatment was studied employing different infection times, inoculum concentrations, fruit maturity levels and in naturally infected fruit. Generally, infection time and maturity level of fruit did not have a significant effect on the RF treatment efficacy and brown rot incidence was significantly reduced in fruit inoculated 0, 24 or 48 h before treatment and at all maturity levels evaluated in both peaches and nectarines. RF treatment significantly reduced brown rot incidence at all inoculum concentrations evaluated (103, 104, 105 and 106 conidia mL−1). However, in peaches, the treatment efficacy was slightly less when the inoculum concentration was increased to 105 or 106 conidia mL−1. In naturally infected fruit, brown rot incidence was significantly reduced from 92% among control fruit to less than 26% in peaches and complete brown rot control was achieved in nectarines. RF treatment did not have an effect on fruit firmness in the varieties tested, and even a delay of fruit softening was observed. Moreover, both external and internal fruit appearance was not affected by the treatment. | Authors are grateful to REDBIO Project, to the University of Lleida for their financial support by and organic production research project and to Spanish Government for their financial support by a national project AGL2011-30472-C02-01 from Ministry of Science and Innovation and for the grant AP2008-01223 from Ministry of Education. Authors also are grateful to Maria Helena Borralho, Isabel Alonso and Celia Sanchez for their technical support.