Fruit Firmness Research Articles

Impact of Dropping on Postharvest Physiology of Tomato Fruits Harvested at Green and Red Ripeness Stages.

Dropping during transportation is a critical issue for tomato fruits, as it triggers ethylene production and affects quality parameters, leading to lower quality and a reduced storage life. Thus, this study was conducted to assess the physiological alterations in tomato fruits subjected to dropping. This study involved tomatoes harvested at green and red stages, subjected to the following five dropping treatments: 0 cm, 10 cm, 30 cm, 50 cm, and 100 cm. The results revealed that dropping from 100 cm induced the highest ethylene production, particularly in green fruits, where production began within one hour and peaked within 48 h. Red fruits exhibited a dose-dependent response to mechanical stress, with a notable decrease in ethylene production starting from the second week post-dropping, suggesting a regulatory mechanism. CO2 production peaked at 350.1 µL g-1 h-1 in green fruits and 338.2 µL g-1 h-1 in red fruits one day after dropping from 100 cm. Dropping also significantly influenced fruit color, firmness, electrolyte leakage, and vitamin C content. Principal component analysis (PCA) revealed distinct changes in metabolite profiles, with methionine and ACC (1-aminocyclopropane-1-carboxylate), key ethylene precursors, increasing in response to dropping, particularly in red fruits. These findings underscore the critical role of mechanical stress in modulating fruit physiology, with implications for post-harvest handling practices aimed at enhancing fruit quality and shelf life.

The Effect of the Foliar Application of Biostimulants in a Strawberry Field Plantation on the Yield and Quality of Fruit, and on the Content of Health-Beneficial Substances

In modern horticulture, biostimulants can be an effective alternative to traditional, industrial means of production. The aim of the study was to assess the effect of three biostimulants (Calgreen, Erathis, Greit VG) containing selected macronutrients (N, Ca), organic matter, and amino acids on the yield and quality of strawberries and their content of health-beneficial substances. In the comparative variant, the plants were treated with mineral fertilisers applied into the soil. In 2021, an experiment was conducted on a two-year-old strawberry plantation of the ‘Rumba’ cultivar located on a horticultural farm in northwestern Poland. The following parameters were assessed: the yield, weight, and firmness of fruits as well as their content of soluble substances, sugars, organic acids, phenolic compounds, and anthocyanins. The use of biostimulants caused a decrease in soil acidity and salinity. In comparison with the soil fertilisation variant, the number of flowers and fruits on the plants increased by 50% to over 100%, which translated into a significant increase in the yield. The fruits from the plants treated with the biostimulants several times were of better quality. Their average weight, firmness, and the content of soluble substances (also after being stored for several days) increased significantly. However, the total content of sugars and ascorbic and malic acids, as well as the content of phenolic compounds and anthocyanins, did not change.

Influence of Fruit Load Regulation on Harvest and Postharvest Fruit Quality and Antioxidant-Related Parameters in Sweet Cherry (Prunus avium L.) cv. Regina Cultivated under Plastic Covers in Southern Chile.

Plastic covers have been used to prevent environmental constraints negatively affecting sweet cherry production in Southern Chile. However, less information is available on agronomic practices and their effects on fruit quality in sweet cherry covered orchards. Thus, in this study, we evaluated the impact of fruit load regulation on cherries' antioxidant-related parameters and the quality and condition at harvest and postharvest in sweet cherry (Prunus avium) cv. Regina that was cultivated under a plastic cover in Southern Chile. For this, four fruit load treatments were manually applied-(i) 100% fruit load (the control), (ii) 80% fruit load, (iii) 60% fruit load, and (iv) 40% fruit load-in a commercial sweet cherry orchard for two seasons (2021/2022 and 2022/2023). The results revealed that the yield and fruit load were not significantly different between the treatments. Interestingly, the 60% and 40% fruit loads increased the fresh weight, fruit size, and firmness (20.3%) compared to the control (the 100% fruit load) during both seasons. Likewise, the 60% and 40% fruit load treatments exhibited the highest fruit size distribution of 30 mm, while the 100 and 80% fruit load treatments showed the highest fruit distribution with fruit sizes between 28 mm and 24 mm. The total soluble solids (TSSs) did not vary among the fruit load treatments, while a significant increase was found in the titratable acidity (TA) in the 60 and 40% fruit load treatments during both seasons. No significant differences in antioxidant activity (AA) and total phenols (TPHs) among the treatments were observed during both seasons. Overall, the results revealed that the fruit load treatments, mainly 40%, increased the fruit weight and firmness and reduced pitting in fruits by 39.4% at postharvest. Thus, fruit thinning might be an important agronomical practice to regulate fruit load, positively affecting fruit quality at harvest and during postharvest storage in sweet cherry cv. Regina cultivated under a plastic cover. However, more biochemical and molecular studies are needed to elucidate the mechanism involved in this improvement.

Comparative analysis of physical traits, mineral compositions, antioxidant contents, and metabolite profiles in five cherry tomato cultivars

Cherry tomatoes (Solanum lycopersicum var. cerasiforme) are cultivated and consumed worldwide. While numerous cultivars have been bred to enhance fruit quality, few studies have comprehensively evaluated the fruit quality of cherry tomato cultivars. In this study, we assessed fruits of five cherry tomato cultivars (Qianxi, Fengjingling, Fushan88, Yanyu, and Qiyu) at the red ripe stage through detailed analysis of their physical traits, mineral compositions, antioxidant contents, and metabolite profiles. Significant variations were observed among the cultivars in terms of fruit size, shape, firmness, weight, glossiness, and sepal length, with each cultivar displaying unique attributes. Mineral analysis revealed distinct patterns of essential and trace element accumulation, with notable differences in calcium, sodium, manganese, and selenium concentrations. Fenjingling was identified as a selenium enriched cultivar. Analysis of antioxidant contents highlighted Yanyu as particularly rich in vitamin C and Fenjingling as having elevated antioxidant enzyme activities. Metabolomics analysis identified a total number of 3,396 annotated metabolites, and the five cultivars showed distinct metabolomics profiles. Amino acid analysis showed Fushan88 to possess a superior profile, while sweetness and tartness assessments indicated that Yanyu exhibited higher total soluble solids (TSS) and acidity. Notably, red cherry tomato cultivars (Fushan88, Yanyu, and Qiyu) accumulated significantly higher levels of eugenol and α-tomatine, compounds associated with undesirable flavors, compared to pink cultivars (Qianxi and Fengjingling). Taken together, our results provide novel insights into the physical traits, nutritional value, and flavor-associated metabolites of cherry tomatoes, offering knowledge that could be implemented for the breeding, cultivation, and marketing of cherry tomato cultivars.

Comparative Analysis of the Characteristics of Two Hardy Kiwifruit Cultivars (Actinidia arguta cv. Cheongsan and Daebo) Stored at Low Temperatures.

A cold storage system is useful for maintaining the quality of hardy kiwifruit. However, extended cold storage periods inevitably result in cold stress, leading to lower fruit marketability; the severity of chilling injury depends on fruit types and cultivars. In this study, the impact of cold storage conditions on the physicochemical properties and antioxidant capacity of two phenotypically different hardy kiwifruit cultivars-'Cheongsan' (large type) and 'Daebo' (small type)-stored at low (L; 3 °C, relative humidity [RH]; 85-90%) and moderate-low (ML; 5 °C, RH; 85-90%) temperatures was determined. Significant differences in fruit firmness and titratable acidity between treatments L and ML were observed in both cultivars during the experimental storage period. Meanwhile, the browning and pitting rates of the 'Cheongsan' fruits in treatment L increased for 8 weeks compared with those of the 'Daebo' fruits in treatments L and ML; nonetheless, fruit decay was observed in the 'Daebo' fruits in treatment ML after 6 weeks. The total chlorophyll, carotenoid, flavonoid, and ascorbic acid concentrations as well as the antioxidant activities of both the cultivars significantly differed between treatments L and ML. After 2 weeks of storage, the 'Cheongsan' fruits in treatment L had lower antioxidant activities and ascorbic acid content than those in treatment ML. These results demonstrate that the quality attributes and antioxidant activity of hardy kiwifruit are influenced by the low-temperature storage conditions and the specific kiwifruit cultivars. Our findings suggest that optimal cold storage conditions, specific to each hardy kiwifruit cultivar, promise to maintain fruit quality, including their health-promoting compounds, during long-term storage.

Changes in hemicellulose metabolism in banana peel during fruit development and ripening

Hemicellulose is key in determining the fate of plant cell wall in almost all growth and developmental stages. Nevertheless, there is limited knowledge regarding its involvement in the development and ripening of banana fruit. This study investigated changes in the temporal-spatial distribution of various hemicellulose components, hemicellulose content, activities of the main hydrolysis enzymes, and transcription level of the main hemicellulose-related gene families in banana peels. Both hemicellulose and xylan contents were positively correlated to the fruit firmness observed in our previous study. On the contrary, the xylanase activity was negatively correlated to xylan content and the fruit firmness. The vascular bundle cells, phloem, and cortex of bananas are abundant in xyloglucan, xylan, and mannan contents. Interestingly, the changes in the signal intensity of the CCRC-M104 antibody recognizing non-XXXG type xyloglucan are positively correlated to hemicellulose content. According to RNA-Seq analysis, xyloglucan and xylan-related genes were highly active in the early stages of growth, and the expression of MaMANs and MaXYNs increased as the fruit ripened. The abundance of plant hormonal and growth-responsive cis-acting elements was detected in the 2 kb upstream region of hemicellulose-related gene families. Interaction between hemicellulose and cell wall-specific proteins and MaKCBP1/2, MaCKG1, and MaHKL1 was found. The findings shed light on cell wall hemicellulose's role in banana fruit development and ripening, which could improve nutrition, flavor, and reduce postharvest fruit losses.

Improvement of post-harvest quality of Balady lime fruit with Aloe vera gel and tea tree oil against green mold disease caused by Penicillium digitatum

Penicillium digitatum Sacc is a common postharvest pathogen affecting lime fruits. It causes significant losses in postharvest lime production. An emerging alternative to chemical control is the use of environmentally friendly such as edible and biodegradable films and packaging. The goal of the current study was to test different concentrations of Aloe vera gel (5, 15, 25, 50, 75, and 100% v/v), tea tree oil coating (0.5, 1, 2.5, 5, and 10% v/v), and their combination for controlling P. digitatum in vitro. The results revealed that specific concentrations of Aloe vera gel (75% and 100% v/v), tea tree oil (2.5, 5, and 10% v/v), and Aloe vera gel (25%) + tea tree oil (1%) v/v showed the highest inhibitory effect against the pathogen. The most effective concentrations of Aloe vera gel (75%), tea tree oil (2.5%), and Aloe vera gel (25%) + tea tree oil (1%) were evaluated against the green mold disease of lime under natural infection through storage period (0, 7, 14, 21, and 28 days). Compared to the control group, all edible layers demonstrated a significant delay and reduced in disease severity percentage throughout the storage periods. However, coating lime fruits with a combination of Aloe vera gel (25%) + tea tree oil (1%) successfully prevented the green mold disease of lime fruits over 28 days. The impact of these coatings was evaluated on lime fruit quality maintenance (weight loss, firmness, juice weight, total soluble solids, total acidity, pH, vitamin C, lipid peroxidation content, total phenols, total flavonoid, and total protein) over 28 days of storage during the 2021 and 2022 seasons. All treatments improved fruit quality through the storage period compared with untreated fruits. Treated lime fruits with Aloe vera gel (25%) + tea tree oil (1%) exhibited slight reductions in weight loss and juice weight compared to alternative treatments as an average of the two successive seasons. Simultaneously, this treatment improved fruit firmness, vitamin C levels, total phenols, total flavonoid, and total protein when contrasted with other treatments as an average of the two studied seasons. These findings show that the combination of Aloe vera gel and tea tree oil coatings enhances the shelf life and maintains the quality of lime fruits. They can also be used as an environmentally acceptable, chemical-free alternative treatment to preserve the postharvest quality of lime fruit.

The transcription factor EjNAC5 regulates loquat fruit chilling lignification.

Changes in both lignin biosynthesis and DNA methylation have been reported to be associated with chilling stress in plants. When stored at low temperatures, red-fleshed loquat is prone to lignification, with increased lignin content and fruit firmness, which has deleterious effects on taste and eating quality. Here, we found that 5 °C storage mitigated the increasing firmness and lignin content of red-fleshed 'Dahongpao' ('DHP') loquat fruit that occurred during 0 °C storage. EjNAC5 was identified by integrating RNA sequencing with whole-genome bisulfite sequencing analysis of 'DHP' loquat fruit. The transcript levels of EjNAC5 were positively correlated with changes in firmness and negatively correlated with changes in DNA methylation level of a differentially methylated region in the EjNAC5 promoter. In white-fleshed 'Baisha' ('BS') loquat fruit, which do not undergo chilling-induced lignification at 0 °C, the transcripts of EjNAC5 remained low and the methylation level of the differentially methylated region in the EjNAC5 promoter was higher, compared with 'DHP' loquat fruit. Transient overexpression of EjNAC5 in loquat fruit and stable overexpression in Arabidopsis and liverwort led to an increase in lignin content. Furthermore, EjNAC5 interacts with EjERF39 and EjHB1 and activates the transcription of Ej4CL1 and EjPRX12 genes involved in lignin biosynthesis. This regulatory network involves different transcription factors from those involved in the lignification pathway. Our study indicates that EjNAC5 promoter methylation modulates EjNAC5 transcript levels and identifies novel EjNAC5-EjERF39-Ej4CL1 and EjNAC5-EjHB1-EjPRX12 regulatory modules involved in chilling induced-lignification.

Postharvest Quality of ‘Keepsake’ Apple Fruit

Storage information regarding ‘Keepsake’ apple fruit is lacking. The objective of this research was to investigate the postharvest characteristics of ‘Keepsake’ apple (Malus ×domestica Borkh.), which is a parent of ‘Honeycrisp’. Apples were obtained from three orchards in Minnesota in 2022 and 2023, assessed for quality, and stored at 0 to 1 °C or 4 to 5 °C in air. Fruit were tested for firmness, soluble solids content (SSC), and titratable acidity (TA) for up to 6 months in storage. At harvest, fruit from different orchards differed in ground color, firmness, SSC, and titratable acidity. The starch pattern index did not differ among the orchards within a year, but it was greater during the 2023 harvest than during the 2022 harvest. Fruit firmness decreased less rapidly at 0 to 1 °C than at 4 to 5 °C. Changes in SSC with storage varied by orchard, storage temperature, and year. In 2022 to 2023, SSC changes were highly variable, remained the same during storage for fruit from one orchard, increased and then decreased for fruit from another orchard, increased after 1 month of storage, and then remained unchanged thereafter for fruit from the third orchard. In 2023 to 2024, SSC was generally unchanged during storage at 0 to 1 °C, and it increased slightly over time during storage at 4 to 5 °C. Titratable acidity decreased during storage, but there was no difference between storage temperatures. These findings demonstrate the difficulty determining when to harvest ‘Keepsake’ fruit because neither starch pattern index nor ground color is a reliable indicator of ripeness. Growers must rely on experience and fruit redness to determine when to harvest this late-season cultivar. To prolong fruit firmness, growers should store ‘Keepsake’ fruit at 0 to 1 °C rather than at 4 to 5 °C.

Non-contact measurement of firmness properties of fruits and vegetables using a parabolic-reflector airborne ultrasonic transducer and laser Doppler velocimeter

The requirement for high-quality fruits and vegetables have been increased. The sorting and grading of them in a non-contact way is important, and firmness is an important criterion. In this study, we developed a non-contact measurement system for the firmness of fruits and vegetables by using airborne ultrasonic waves and a parabolic reflector. Focused airborne ultrasound produced vibration on the surfaces of samples and the vibrations were detected by a laser Doppler velocimeter to characterize the elastic properties. First, we designed and fabricated an offset-type parabolic reflector. Then, the elastic parameters (maximum displacements, center frequencies, and damping factors) were determined based on the Kelvin⎯Voigt model. Finally, individual differences in the elastic properties of twelve kinds of samples and temporal changes in the maturity state and elastic properties of three kinds of samples were observed. From the results, we confirm the developed system could be potentially used as an evaluation system for the firmness of fruits and vegetables.

Willingness to Pay for Blueberries: Sensory Attributes, Fruit Quality Traits, and Consumers’ Characteristics

Understanding consumers’ preferences for fruit quality attributes is key to informing breeding efforts, meeting consumer preferences, and promoting increased market demand. The objective of this study was to assess the effect of fruit quality traits and hedonic sensory evaluation on consumers’ willingness to pay (WTP) for a selection of fresh northern and southern highbush blueberry cultivars. The WTP was elicited by using a double-bounded contingent valuation conducted in conjunction with a consumer sensory test. Two types of models were estimated using either sensory evaluations (i.e., consumer preference and consumer intensity) or instrumental measurement data (i.e., measures of soluble solids, titratable acidity, sugars, acids, and firmness) as explanatory variables to model WTP. Results using sensory evaluations indicated that flavor liking, flavor intensity, and sweetness intensity are key factors that influence consumers’ acceptance and WTP for blueberries. A regression analysis using instrumental measurements indicated that measures related to sweetness and acidity traits are important factors that determine WTP. Higher WTP was associated with higher total sugar content across different levels of total organic acid. The WTP increases with organic acid content, because this is needed for enhanced flavor; however, WTP declines at high concentrations of organic acid. Except for extreme values of firmness, the WTP increased as measures of fruit firmness increased, indicating a consumer preference for firmer blueberries. Overall, the results provided new insights into the relationships between consumer preference and WTP and fruit quality benchmarks to select for improved quality.

Impact of harvest time on cold storage performance in Kiwifruit

In the present study the fruits of the cultivar 'Hayward' kiwifruit were harvested at a total soluble solid content of 5–6 % (Harvest I, H1), 6.1–7.0 % (Harvest II, H2), 7.1–8.0 % (Harvest III, H3) and 8.1–9.0 % (Harvest IV, H4) and stored at 0±1°C temperature and 85–90 % relative humidity (RH) conditions for 6 months. Changes in fruit flesh color, flesh firmness, soluble solids content (%), titratable acidity (TA), individual sugars (sucrose, glucose, fructose), ascorbic acid content, antioxidant activity (DPPH, FRAP), total phenolic content, weight loss and marketable fruit were observed at one month intervals. In kiwifruits, an increase was observed in health benefit compounds such as ascorbic acid and total phenolic content, antioxidant capacity by progressing of harvest times. However, early (H1) and late (H4) harvest times led to faster loss in fruit firmness, significant loss in titratable acidity and soluble solid content, higher weight loss rates in fruit. The results show that the second and third harvest times, when the soluble solids content of the fruit is 6.1–7.0 % (H2) and 7.1–8.0 %(H3), seem to be optimum in terms of quality preservation for 'Hayward' kiwis grown in the Black Sea Coast and provides health benefits with a higher marketable fruit rate after 180 days of cold storage. Finally, there was a positive correlation between SCC and sucrose, glucose, fructose. There was a negative relationship between fruit SSC and flesh firmness, TA, L*, C*, h° after 6 months of storage. And also there was a negative correlation between weight loss and marketable product quantity, fruit flesh firmness.

Chlorogenic Acid as a Promising Tool for Mitigating Chilling Injury: Cold Tolerance and the Ripening Effect on Tomato Fruit (Solanum lycopersicum L.).

Tomato fruit (Solanum lycopersicum L.) has a very brief storability, displaying chilling injury (CI) when stored in cold conditions used to delay ripening. For this reason, in this study, different concentrations (10, 50, and 100 mg L-1) of chlorogenic acid (ChA) were assayed to evaluate its effectiveness in maintaining fruit quality traits and mitigating CI symptoms in tomatoes. Our results showed that ChA treatments effectively delayed weight loss and maintained fruit firmness, with optimal results observed at 50 mg L-1. In general, higher concentrations did not result in significant quality improvements. Additionally, ChA-treated tomatoes exhibited reduced values in malondialdehyde (MDA) content and electrolyte leakage (EL), indicating improved membrane integrity and reduced oxidative damage. ChA treatments also maintained a higher total phenolic content (TPC) during storage, with significant levels of individual polyphenols such as rutin, neochlorogenic acid, and p-coumaric acid, suggesting enhanced antioxidant capacity and better preservation of fruit quality. This is the first time the potential of ChA to reduce CI has been evaluated in any fruit species, and its impact in tomato ripening is shown to uphold fruit quality during cold storage, prolonging the storability of tomatoes. In particular, we highlight its natural origin and effectiveness as a postharvest treatment.

Melatonin extends shelf life in postharvest okra via delaying fruit softening and reducing weight loss.

Melatonin, a hormone present in animals and some plants, has garnered attention for its potential in preserving harvested produce. Softening due to changes in cell wall composition and wilting caused by weight loss are the major reasons for the loss of commercial value in postharvest okra. This study aimed to evaluate the impact of melatonin on the softening and weight loss of postharvest okra. The results revealed that the application of melatonin had a significant influence on the maintenance of fruit firmness by inhibiting the breakdown and dissolution of cell wall polysaccharides by suppressing the expression of specific genes responsible for cell wall degradation in okra. Conversely, melatonin treatment positively influenced the expression of genes involved in the synthesis of cell wall components. Furthermore, the treatment exhibited notable benefits in reducing weight loss in okra, which was accomplished by promoting the closure of stomata - the tiny pores on the surface of the fruit. Melatonin could serve as a novel approach to reduce water loss, delay fruit softening and extend the shelf life of okra. © 2024 Society of Chemical Industry.

Impact of Storage Conditions on Fruit Color, Firmness and Total Soluble Solids of Hydroponic Tomatoes Grown at Different Salinity Levels

Tomatoes are delicate and prone to damage quickly, which ultimately leads to lower quality and increased post-harvest losses. Hence, an ideal storage environment is very important to maintain the quality of tomato fruits after harvest. Therefore, this study was conducted to determine the effect of storage conditions on the quality parameters of tomato fruits. Experiments were de-signed for six storage periods (4, 8, 12, 16, 20, and 24 days) and two temperatures (12 °C and room air temperature “22 °C”). Three tomato fruit quality parameters (Brix, color, and firmness) have been selected and measured for three tomato varieties (Ghandowra-F1, Forester-F1, and Feisty-Red) grown hydroponically at three salinity levels (2.5, 6.0, and 9.5 dS m−1) of the nutrient solution. Results showed that the highest mean Brix values, for all varieties, were recorded at the highest salinity (9.5 dS m−1), and were significantly (Pr < 0.0001) higher than those at medium (6.0 dS m−1) and low (2.5 dS m−1) salinity levels. In addition, the highest fruit firmness was recorded at high salinity level (9.5 dS m−1), but there was no significant difference to that recorded at medium salinity (6.0 dS m−1). Regarding tomato fruit color, the highest average values were recorded for the Ghandowra-F1 (2.51) and Forester-F1 (2.69) varieties at medium salinity (6.0 dS m−1), while the highest average color value for the Feisty-Red variety (1.54) was obtained at high salinity (9.5 dS m−1). On the other hand, the Brix, color, and firmness of tomato fruits were significantly affected by the storage temperature. Moreover, the mean Brix values (7.66%) were slightly higher at 12 °C storage temperature compared to those at 22 °C (7.38%). In general, the fruit color values gradually increased with the storage period, especially under 22 °C storage temperature, with peak color values of 2.73, 2.70, and 1.66 recorded on the 12th day of the storage period for Ghandowra-F1, Forester-F1, and Feisty-Red, respectively. Tomato fruit firmness decreased faster with the storage period at 22 °C compared to the storage temperature of 12 °C. However, the highest average values of fruit firmness for Ghandowra-F1 (9.37 N cm−1) and Forester-F1 (9.41 N cm−1) recorded at control condition were not significantly different those recorded on the 8th day of storage at 12 °C storage temperature. By contrast, the highest average value of fruit firmness for Feisty-Red (8.85 N cm−1) recorded at control condition was not significant than that recorded on the 4th day of the storage period at 12 °C storage temperature (8.82 N cm−1). Overall, tomato fruits can be stored at 12 °C temperature for up to 20–24 days, without negative effects on fruit quality.

The influence of different fertigation levels on the functional quality characteristics of three different strawberry (Fragaria × ananassa Duch.) varieties cultivated under protected conditions

The strawberry, a member of the Rosaceae family, is one of the most significant fruit crops due to its widespread cultivation and the high appreciation it garners for its distinctive aroma, bright red colour, juicy texture and delightful sweetness. A field study was conducted during 2021-2022 to assess “the influence of different fertigation levels on the functional quality characteristics of 3different strawberry (Fragaria ×ananassaDuch.) varieties cultivated under protected conditions”. The study employed a Factorial Randomized Complete Block Design, encompassing 12 treatment combinations, replicated3times.The application of 100% RDF of NPK significantlyimpacted the functional quality characteristics of strawberries. The findings indicate that the highest values for total soluble solids (11.00 ºBrix), total sugars (7.70%), reducing sugars (5.40%), non-reducing sugars (2.31%), TSS: acidity ratio (14.28), juice content (45.32%), fruit pH (3.79%), antioxidants (0.19%), phenols (1.20%), fruit volume (12.89 cm3), fruit firmness (1.68 kg/cm2), specific gravity (1.04 g/cc)and shelf life (2.24 days) were observed under the fertigation level F3 (100% RDF of NPK).Additionally, minimum acidity (0.77%) and minimum physiological loss in weight (5.36 g) were also recorded at this fertigation level. The aim of this study is to enhance fruit production, increase yields and extend the shelf life of strawberries. By exploring factors such as fertigation levels and cultivars, this study provides valuable insights that promote sustainable and efficient practices. These findings hold promise for shaping the future of strawberry cultivation, facilitating increased yields and prolonged preservation.

Phenotypic and Gene Expression Analysis of Fruit Development of ‘Rojo Brillante’ and ‘Fuyu’ Persimmon (Diospyros kaki L.) Cultivars in Two Different Locations

Fruit development and maturation rely on intrinsic genetic programs involving hormone biosynthesis and signalling and environmental cues, integrating phenological cycles and climatic issues encompassing abiotic stresses and climate change. In persimmon trees, environmental inputs strongly influence fitness and agricultural performance, and fruit yield can be severely compromised by them. We have grown two persimmon accessions (‘Rojo Brillante’ and ‘Fuyu’) under contrasting meteorological conditions of two locations in Spain and Japan. Fruit size, colour change, and firmness parameters were followed during fruit development from 30 days after fruit set until commercial ripening, and the expression of genes related to ethylene production and signalling, gibberellin response, carotenoid biosynthesis, cell wall dynamics, and oxidative stress were reported. Genes depending on intrinsic developmental programs (ethylene and ripening variables, mostly) showed common expression trends in both cultivars and locations, whereas gibberellin and abiotic stress-related genes mimicked reduced fruit growth and abiotic stress associated with higher summer temperatures (>35 °C) and lower rainfall reported in the Spanish location. The expression pattern of these genes is consistent with a growth–defence trade-off that explains fruit differential growth through hormonal and stress tolerance mechanisms.

Effect of rabbit urine foliar spray on the yield and post-harvest quality of tomato (Solanum lycopersicum L.)

Of all vegetable crops, tomato occupies the second-largest cultivated land after potato. However, its production is often lamed by insufficient nutrient supply and invasion by insect pests. Unlike inorganic fertilizers and synthetic pesticides commonly used, rabbit urine supplies nutrients to the crops, controls insect pests and has low mammalian toxicity. However, the most suitable rabbit urine foliar spray concentration for tomato production is currently unknown. The experiment was conducted in a randomized complete block design with six treatments and four blocks to evaluate the effect of different concentrations of rabbit urine foliar spray on the yield and post-harvest quality of tomato. The six treatments used include: five concentrations of rabbit urine (100%, 40%, 25%, 18.2% and 0%) and 0.1% Duduthrin 1.75EC. Results indicated that treatment 18.2% rabbit urine registered the highest marketable yield (129.14 t/ha) in trial 1. In trial 2, treatment 25% rabbit urine recorded the highest marketable yield (165.08 t/ha). These two treatments gave the highest marketable yields due to their sufficient nutrient supply, optimal pest control and zero foliage scorching. Unlike fruit firmness and sugar acid ratio, total soluble solids and titratable acidity increased with increase in rabbit urine concentration. Therefore, a rabbit urine foliar spray concentration of 25% optimally improves yield and post-harvest quality of tomato. More research work can be done to determine the effect of spraying intervals of rabbit urine on the yield and post-harvest quality of tomato.

Postharvest short-time partial dehydration extends shelf-life and improves the quality of Actinidia arguta during low temperature storage

Actinidia arguta is a type of kiwi fruit with a smooth glabrous shape, which provides high nutritional value, a sweet and sour taste, and excellent healthcare function. However, it is a typical climacteric fruit and decomposes quickly when stored. For delaying senescence, the effect of postharvest short-time partial dehydration (STPD) on the storage quality of A. arguta was investigated under dehydration rates of 2%, 4%, and 6% coupled with storage at (2.0 ± 0.5) °C, respectively. Results showed that appropriate dehydration treatment coupled with low temperature storage inhibited the pectinase activity and the decomposition of propectin, thus maintaining fruit firmness, reducing fruit decay rate, regulating the generation of abscisic acid (ABA) delaying ethylene production, and decreasing the peak level of respiration rate. It also inhibited the reduction of total soluble solid, titratable acid, and vitamin C, maintains catalase and peroxidase activity. Based on the present study, the 4% dehydration treatment was the most effective, which extended the storage period up to 60 days and reduced the decay rate to 33%. In conclusion, it was revealed that STPD could be an effective method for retarding the losses that occurred in the fruit quality of A. arguta during cold storage.

Effect of additional potassium and nickel on Hoagland solution combined with environmental condition for high antioxidants tomato production

Plant nutrient management and environmental conditions significantly affect plant growth, development and antioxidant contents. This research aims to identify the most effective plant nutrient management and environmental conditions for enhancing high-antioxidant tomato production. The Sweet Girl and Ranger tomato cultivars were evaluated for yield, fruit quality and antioxidant contents under 2 conditions: E1 (temperature ranging from 29 to 38 °C and relative humidity between 71–73 %) and E2 (temperature ranging from 32 to 36 °C and relative humidity between 75–80 %). These conditions were subjected to 6 different nutrient formulas, including Hoagland solution as control (H), H with 400 ppm potassium (H+K400), H with 300 ppm potassium (H+K300), H with 20 ppm nickel (H+Ni20), H with 10 ppm nickel (H+Ni10), H with 300 ppm potassium and 10 ppm nickel (H+K300+Ni10). The nutrient formulas did not yield significantly different results in terms of per-plant yields for the 2 cultivars. However, the H+K400 treatment showed notably higher lycopene contents, with increases of 1.2-fold for Ranger and 1.24-fold for Sweet Girl cultivars. Additionally, this treatment led to significant enhancements in total soluble solids (TSS) and ?-carotene content in the Sweet Girl cultivar, by 1.09-fold and 1.10-fold compared to the control respectively. Environment E2 provided more favorable conditions for achieving increased antioxidant tomato production, including improvements in fruit color index (red/yellow) by 1.11 to 1.18-fold, fruit firmness by 1.13 to 1.14-fold, TSS by 1.10 to 1.24-fold, lycopene by 1.98 to 2.45-fold and ?-carotene by 3.29 to 5.68-fold. Therefore, the H+K400 nutrient treatment and/or the E2 greenhouse conditions are recommended for producing high-antioxidant tomatoes, which have significant potential for fresh consumption or as materials for the nutraceutical or food industry.