Enhance Fruit Quality Research Articles

Foliar applications of calcium and potassium increase cracking resistance and enhance fruit quality in sweet cherries

Sweet cherry production represents a competitive sector with important economic prospects but faces many challenges. Rain-induced cracking stands out as a particular issue, as it has been linked to yield losses of up to 90%. To address this concern and meet consumer demand, foliar treatments, involving a mixture of commercial products rich in calcium and potassium salts, have been tested in sweet cherry commercial orchards. This study was a randomized block experiment consisting of three blocks (ten plants each), five of which were treated and five were controls. The treatments were applied in addition to the standard cultivation practice throughout the season. Observations were made on the SPAD index and shoot elongation, and in post-harvest, cherries were analyzed for qualitative characteristics (skin color, caliber, firmness, total soluble content, titratable acidity and cracking index) and nutraceutical parameters (total anthocyanin content, total phenols content and antioxidant activity). Results indicate that foliar salt application can facilitate the maturation process, indicated by a higher soluble solid content (TSS), softening, and darker pigmentation in treated fruits. The applied formulations also provided increased shoot growth and enhanced SPAD index. Furthermore, the treated fruits exhibited a significantly lower incidence of cracking compared to the control treatment and showed improved nutraceutical properties

Machine Vision System for Early-stage Apple Flowers and Flower Clusters Detection for Precision Thinning and Pollination

Early-stage identification of fruit flowers that are in both opened and unopened condition in an orchard environment is significant information to perform crop load management operations such as flower thinning and pollination using automated and robotic platforms. These operations are important in tree-fruit agriculture to enhance fruit quality, manage crop load, and enhance the overall profit. The recent development in agricultural automation suggests that this can be done using robotics which includes machine vision technology. In this article, we proposed a vision system that detects early-stage flowers in an unstructured orchard environment using YOLOv5 object detection algorithm. For the robotics implementation, the position of a cluster of the flower blossom is important to navigate the robot and the end effector. The centroid of individual flowers (both open and unopen) was identified and associated with flower clusters via K-means clustering. The accuracy of the opened and unopened flower detection is achieved up to mAP of 81.9% in commercial orchard images.

Machine vision system for real-time debris detection on mechanical wild blueberry harvesters

Improving fruit quality is important to wild blueberry producers. Plant debris like leaves and stems caused a reduction in fruit quality during mechanical harvesting. A debris detection system was developed using two Logitech C920 webcam cameras mounted before and after the blower fan on a commercial mechanical wild blueberry harvester. Images were collected from two commercially managed wild blueberry fields located in central Nova Scotia to develop a dataset of 1000 images. Two convolutional neural networks (CNNs), YOLOv3 and YOLOv3-SPP, were used and compared for performance analysis. The CNNs were trained using no augmented images, images with five augmentations (sharpening, brightness, contrast, gamma correction, and saturation), and images with five augmentations that were more heavily weighted towards gamma. Four different computer hardware packages (Hewlett-Packard, Shuttle XPC, Jetson TX2, and GPU-based Desktop) were used to determine the appropriate hardware and CNN model combination for real-time performance. YOLOv3 and YOLOv3-SPP were trained to mAP scores of 72.87 and 74.38% using the dataset with more gamma-augmented images. This was an improvement over the dataset with no augmentation (67.75; 68.49%) and equally numbered augmentations (71.26%; 73.03%). YOLOv3-SPP combined with an Intel® Core™ i9-7900X CPU and Nvidia GeForce RTX™ 2080 Ti GPU in a desktop computer achieved the fastest detection rate of 33.30 ms. The detection speed on all other hardware configurations exceeded 33.30 ms, indicating that a powerful desktop GPU is required for real-time performance of this task. With adequate processing hardware, the developed technology could be integrated into a control system to automatically adjust brushes based on conveyor information from mechanical wild blueberry harvesters to make cleaning berries easier and enhance fruit quality.

Plant Growth, Yield, and Quality of Containerized Heirloom Chile Pepper Cultivars Affected by Three Types of Biostimulants

Peppers (Capsicum annuum) are one of the most widely cultivated vegetable crops, with per capita consumption of bell and chile peppers being 11.4 and 7.7 pounds in 2017. Biostimulants are an emerging sustainable alternative to enhance plant health by increasing photosynthetic activity, stress tolerance, and nutrient uptake through various modes of action. The effects of different biostimulant applications largely remain unknown in containerized heirloom pepper production. This study evaluated plant growth, yield, and fruit quality of nine heirloom chile pepper cultivars, including ‘Anaheim Chili,’ ‘Ancho or Poblano,’ ‘Big Jim,’ ‘Cayenne Purple,’ ‘Chile de Arbol,’ ‘Jamaica Hot Red,’ ‘Mulato Isleno,’ ‘Padron,’ and ‘Pasilla Bajio’ in a container production system throughout the years of 2020 and 2021. Each cultivar was treated with three types of biostimulants, including Tribus® Original (a mixture of Bacillus bacterias), Vitazyme (containing plant growth regulators and B vitamins), C-Bio CPS (seaweed extract of Ascophyllum Nodosum), and water as control. Pepper cultivars varied in yield and quality, including fruit length, diameter, single fruit weight, and fruit color in both years. ‘Anaheim Chili,’ ‘Big Jim,’ and ‘Jamaica Hot Red’ produced highest marketable yields similarly, with ‘Chile de Arbol’ and ‘Pasilla de Bajio’ producing the lowest marketable yields in both years. Biostimulant application did not affect marketable yield either in 2020 or 2021 but enhanced fruit quality, including fruit length, diameter, and green coloration.

Enhancing fruit set, yield and quality of LeConte pear trees by preharvest foliar spray of some plant growth regulators

Enhancing fruit set, yield and quality of LeConte pear trees by preharvest foliar spray of some plant growth regulators

Controlled Atmosphere Improves the Quality, Antioxidant Activity and Phenolic Content of Yellow Peach during the Shelf Life

Controlled atmosphere (CA) has been demonstrated to maintain the shelf-life quality of fruits, but its effect on the antioxidant activities and phenolic content of yellow peach is not comprehensive. This study analyzed the role of CA on the quality of shelf period, phenolic content and antioxidant activity of "Jinxiu" yellow peach. Yellow peach was left under specific aeration conditions (3.5-4% CO2, 2-3% O2, 92-95.5% N2, 1 ± 0.5 °C) and the control (1 ± 0.5 °C) for 21 d, to observe changes in physiological parameters of the fruit during 10 d of the shelf life (25 ± 1 °C). The result showed that CA reduced the weight loss rate (WLR), decay rate (DR), and browning index (BI) of yellow peaches. Furthermore, the CA held a high level of total flavonoid content (TFC), total phenol content (TPC) and phenolic content in the fruit. Antioxidant analysis showed that polyphenol oxidase (PPO) enzyme activity was lower and free radical scavenging capacity (DPPH, ABTS, and FRAP) and antioxidant enzyme activities (POD and PAL) were higher in the CA group. Combining the results of significance analysis, correlation analysis, principal component analysis (PCA) and hierarchical cluster analysis (HCA) clearly identified the differences between the CA group and the control group. The results showed that the CA could maintain higher phenolic content and reduce the oxidation of yellow peach fruit and enhance fruit quality by affecting the antioxidant activities of yellow peach.

Silicon application improves strawberry plant antioxidation ability and fruit nutrition under both full and deficit irrigation

Deficit irrigation has been widely studied on fruit quality improvement, but it also leads to yield losses, especially, fruit size reduction. The objective of this study was to investigate if the silicon application could offset the negative influence brought by deficit irrigation while enhancing fruit quality. A two-factor-three-level split plot greenhouse experiment was conducted where the Fragaria × ananassa cv. Kaorino plants were subjected to full irrigation (FI) or deficit irrigation (DI), and within each irrigation regime the plants were subjected to no silicon application (N), silicon foliar application (L) or silicon root application (R), resulting in 6 treatments in total, viz., FIN, FIL, FIR, DIN, FIL and DIR. The results showed that DI increased the fruit sugars and anthocyanins concentrations without reducing the fruit size. Compared to foliar application, silicon root application was more favorable for fruit quality improvement, especially under full irrigation, by which the anthocyanins, ascorbate and glutamate concentration were significantly increased. Under deficit irrigation, silicon root application also altered the leaf photosynthetic pigments composition, increasing carotenoids and reducing membrane peroxidation to protect the photosynthetic complexes. Also, only when plants were under deficit irrigation, the silicon foliar application could perform better on the improvement of antioxidant capacity and nitrogen assimilation, enhancing the ROS scavenging and amino acids synthesis. Collectively, exogenous silicon application is promising in alleviating the negative effects of DI on fruit yield while improving fruit quality of strawberry.

Shade Screen and Citriculture

Sustain citriculture faces various environmental challenges like rising temperature, increase solar radiation, and warm nights during flower bud induction, particularly in arid and semi-arid regions. Shading net represents an intermediate solution to maintain the growth and productivity of citrus trees under fluctuation in climate conditions. Shading techniques protect plants from different biotic and abiotic stresses, by modifying the microclimate around the trees. Numerous benefits of shading net include reducing leaves temperature and decreasing light intensity, particularly at midday in the summer season, improving tree vigor, reduce physiological disorder and enhancing fruit quality.

The Effect of Electrical Conductivity on Fruit Growth Pattern in Hydroponically Grown Tomatoes

Osmotic stress enhances fruit quality, including the dry matter content, in tomatoes (Solanum lycopersicum L.). This study aimed at providing further insight into the precision control of fruit yield and quality on the long-term moderate osmotic stress conditions in tomato fruit production. We compared the growth pattern between fruits of two cultivars, typical Japanese and Dutch cultivars, under two different nutrient concentrations (2.3 and 5.0 dS·m−1) to understand the effect of electrical conductivity (EC) on dry mass and water content of fruits. The experiment was performed with a rockwool bag culture system in a controlled greenhouse. Increasing EC resulted in an approximately 20% decrease in fruit yield and a 0.5–1% increase in fruit dry matter content in both cultivars. This yield reduction was not caused by the fruit number, but by an approximately 25% decrease in individual fresh fruit weight. Non-linear models were used to describe the changes in dry matter content, water content, and dry weight of tomato fruit as a function of cumulative temperature. The decay rate of dry matter content in the fruit decreased with high EC treatments in the Japanese cultivar. The points at which the rates of changes in water and dry weight increased the in fruit were around 585 and 480 °C-days after anthesis, respectively, under the low EC condition. Rates of water increase in the fruit were changed by high EC treatment, while the shifts were opposite with respect to the cultivars. Dry weight increase in the fruit was not affected by EC treatment. Collectively, our findings clarify the effect of EC on the fruit growth characteristics of Japanese and Dutch tomato cultivars, and provide new insights into the yield of high-Brix tomato cultivation.

Perception of Mango Growers towards Enhanced Freshness Formulation (EFF) Technology- A Study in Krishnagiri District of Tamil Nadu

Mango fruits are perishable, and as a result, they are prone to significant post-harvest losses. However, mango fruits lost roughly 35% of their value at several phases from farm to consumer level. Enhanced Freshness Formulation (EFF) is a relatively new technology that has been proven to help prolong shelf life, minimize insect problems, and improve fruit quality. The objective of the study was analyze the perception of mango growers towards EFF technology. Ex-post facto research design was adopted for the study. Krishnagiri district was selected purposively since it possessed the maximum number of farmers who had adopted EFF technology. The duration of the study was about 1 month, June 2022. Based on simple random sampling, the data has been collected from 120 mango growers by using pre-testing and a well-structured interview schedule. The statistical tool used was descriptive statistics. EFF users placed a higher value on shelf life (4.608) followed by uniform ripening (4.375), fruit freshness (4.083), and finally environmental repercussions (1.8) and minimal adverse health (1.7). EFF technology is considered vital in enhancing fruit quality and prolonging shelf life. These twin benefits can allow farmers to sell fruits in niche and high-value markets, reduce postharvest losses and improve economic returns for the farmers.

Applications of Calcium Boron or Potassium Phosphite Combined with Different Fruit Thinning Styles to Enhance Fruit Quality of Barhee date palm

Applications of Calcium Boron or Potassium Phosphite Combined with Different Fruit Thinning Styles to Enhance Fruit Quality of Barhee date palm

The Foraging Activity and Pollination Services of Three Stingless Bee Species to Enhance Fruit Quality and Quantity of Okra (Abelmoschus Esculentus L.)

Insect pollination has been reported to have a better yield quality and quantity than artificial pollination. Wild bees, including stingless bees contribute to effective and efficient pollination on okra (Abelmoschus esculentus L.: Malvaceae). However, previously no report about okra pollination by native Indonesian stingless bees, which can be potential as pollinators. Therefore, this research aims to compare foraging activities of three species of stingless bees (Heterotrigona itama, Tetragonula laeviceps, and T. clypearis) on okra plants and fruits quality and quantity parameters among four pollination treatments (three stingless bee species and without pollinator). Four cages with 50 okra plants were used for pollination treatments. The foraging observation of different stingless bee species on okra was conducted in the cages, and the okra yield from each treatment was compared. Our results showed the foraging activities of three stingless bee species were higher in the morning than those in the afternoon. In the morning, the number of visits of T. clypearis and T. laeviceps were negatively correlated with visit duration. The current study also showed that size and weight of pod, the number of seeds, and the percentage of fruit set of okra were enhanced by pollination of three stingless bee species. Unfortunately, the pollination of stingless bee species did not affect the seed germination and flavonoid content of fruits. The native of Indonesian stingless bees are good pollinators to improve pod quality and quantity.

Enhancing fruit quality of three Physalis sp. throughout foliar nutrition

Foliar nutrients containing macronutrients, micronutrients and a combination of both were applied to Physalis peruviana, P. alkekengi and P. ixocarpa to determine their effect on fruit quality. A randomised complete block design study was conducted in a greenhouse on Madura Island, Indonesia. This study showed significant interactions between Physalis species and foliar nutrition to the physicochemical character of the fruit. Each species responded differently to the given nutrients. The combination of 1 g/L macronutrient (P and K) and 0.0625 g/L micronutrients (Zn, Fe, Cu, B, Mo and Mn) resulted in the highest fruit antioxidant activity, vitamin C, total soluble solids and redness of the three Physalis species. Generally, macronutrients and micronutrients in combination can be recommended to increase the quality of Physalis fruit.

Comparison of Metabolome and Functional Properties of Three Korean Cucumber Cultivars.

Cucumber (Cucumis sativus L.) is consumed worldwide and various cultivars have been developed to enhance fruit quality. However, few studies have comprehensively evaluated the quality of various cultivars. We carried out a metabolomics approach to study the three different cucumber cultivars (Chuichung, White Dadagi, and Mini) and their parts (peel and flesh) coupled with antioxidant activities. The amino acids, sugars, flavonoids, carotenoids, and chlorophylls were upregulated in Mini flesh; however, in the case of peel, they were highly expressed in Chuichung. The highest antioxidant activity was observed in the peel of Chuichung and flesh of Mini. Through correlation analysis between metabolites and antioxidant activity, apigenin and quercetin derivatives, chlorophyll a, chlorophyll b, lutein, α-carotene, and β-carotene were found to be significantly positively correlated with antioxidant activity. To understand the metabolism of these compounds, we performed a comprehensive pathway analysis using a metabolomics approach and analysis of associated gene expression. In secondary metabolism, the expression levels of carotenoid-related genes (15-cis-phytoene synthase and ζ-carotene desaturase) and chlorophyll-related genes (protochlorophyllide reductase and glutamyl-tRNA reductase) were consistent with the metabolome analysis data. Collectively, carotenoid and chlorophyll metabolism were upregulated in Chuichung peel and Mini flesh, which had the highest antioxidant activity in each part. These bioactive compounds can be used as biomarkers of commercial cucumber fruit quality. Accordingly, this study offers integrative insights into the quality of different cucumber cultivars and explores valuable metabolites and genes that are helpful in improving quality with functional properties.

Improving the quality of ‘Keitt’ Mango using pre-harvest calcium lactate treatment and post-harvest applications of kojic and ascorbic acids

ABSTRACT This study intended to enhance fruit quality, extend shelf life and maintain quality of ‘Keitt’ mango (Mangifera indica L.) by using edible compounds without affecting quality or taste. Pre-harvest foliar treatment using calcium lactate (CaL) was applied at 1 and 2% alone or in combination with one of the post-harvest dipping treatments of 2% ascorbic acid (AsA) or 0.3% kojic acid (KA), before storage at 4°C for 12 days during two successive seasons. Pre-harvest treatment with calcium lactate at 2% significantly enhanced the quality of ‘Keitt’ mango fruits at harvest. It was observed that all the conducted treatments were effective in maintaining the quality of the pre-prepared ‘Keitt’ mango as compared to the untreated ones. Pre-harvest application of 2% CaL + post-harvest 2% AsA was the most effective treatment under experimental conditions in terms of total phenols, ascorbic acid, TSS/acid ratio, overall appearance, colour purity, browning incidence, and decay percentage. CaL at 2% showed the lowest significant values of CPLW and it maintained the highest significant firmness compared with control.

Application of Aloe vera gel and olive oil coatings to enhance fruit quality and shelf-life of ber (Ziziphus mauritiana L.)

Application of Aloe vera gel and olive oil coatings to enhance fruit quality and shelf-life of ber (Ziziphus mauritiana L.)

Deciphering the influence of Bacillus subtilis strain Ydj3 colonization on the vitamin C contents and rhizosphere microbiomes of sweet peppers.

Bacillus subtilis strain Ydj3 was applied to sweet peppers to understand the influence of this bacterium on the growth, fruit quality, and rhizosphere microbial composition of sweet pepper. The promotion of seed germination was observed for sweet pepper seeds treated with the Ydj3 strain, indicating that Ydj3 promoted seed germination and daily germination speed (131.5 ± 10.8 seeds/day) compared with the control (73.8 ± 2.5 seeds/day). Strain Ydj3 displayed chemotaxis toward root exudates from sweet pepper and could colonize the roots, which enhanced root hair growth. Following the one-per-month application of strain Ydj3 to sweet pepper grown in a commercial greenhouse, the yield, fruit weight, and vitamin C content significantly increased compared with those of the control. Additionally, the composition of the rhizosphere bacterial community of sweet pepper changed considerably, with the Bacillus genus becoming the most dominant bacterial genus in the treated group. These results suggested that B. subtilis Ydj3 promotes seed germination and enhances fruit quality, particularly the vitamin C content, of sweet pepper. These effects may be partly attributed to the B. subtilis Ydj3 colonization of sweet pepper roots due to Ydj3 chemotaxis toward root exudates, resulting in the modulation of the rhizosphere bacterial community.

Manual thinning increases fruit size and sugar content of Citrus reticulata Blanco and affects hormone synthesis and sugar transporter activity

Manual fruit thinning (MFT) in fruit trees has been previously shown to increase fruit size and enhance fruit quality, but the effect of MFT on Ponkan (Citrus reticulata Blanco) and the underlying mechanisms remain poorly understood. In this study, efforts were made to elucidate how MFT influences the fruit quality of Ponkan. The results showed that MFT substantially increased fruit size and elevated fruit total soluble solids in comparison with the fruit from the unthinned trees (used as control). Expression analyses demonstrated that mRNA abundance of three important sugar transporter genes, including CrSUT1, CrSTP1 and CrTMT1, was evidently elevated in the flesh of thinned fruit when compared with those of the control. In addition, MFT prominently up-regulated the transcript levels of various auxin and gibberellin (GA) biosynthesis and signaling genes, including CrYUC6, CrAUX/IAA, CrGA20ox1 and CrGA3ox1. Concurrently, the contents of endogenous IAA and GA3, measured at 90 d after fruit thinning, were notably elevated in the fruit from trees with the thinning treatment relative to the control, although no difference was detected in the two groups before the thinning manipulation. Taken together, these results indicate that manual fruit thinning could greatly improve fruit quality, which may be attributed to promoting fruit expansion due to the increased auxin levels and expediting sugar accumulation through the up-regulation of sugar transporter genes.

Ammonium to Total Nitrogen Ratio Interactive Effects with Salinity Application on Solanum lycopersicum Growth, Physiology, and Fruit Storage in a Closed Hydroponic System

Using high-salinity water for plant fertigation may have negative consequences for plant growth, overall yield and crop quality. In the present study, the effects of NaCl-salinity in conjunction with three different ammonium to nitrate ratios (Nr) on tomato (Solanum lycopersicum Mill.) plant growth, nutritional status, yield, fruit quality and postharvest storage were examined. The electrical conductivity (EC) was increased by adding NaCl into the nutrient solution and three different Nr ratios were applied, Nr0.05, Nr0.10 and Nr0.15, while the other macronutrient and micronutrient concentrations were constant in all treatments. The EC of the nutrient solution supplied to the plants was 2.2 mS cm−1 at the low salinity treatments and 7.5 mS cm−1 at the high salinity treatments. Increased salinity resulted in decreased plant growth factors and fruit yield, despite the Nr. An increased Nr reduced the pH value of the nutrient solution, while the fruits of the plants cultivated under high salinity obtained reduced Ca, K, Mg, P and N content. Reduced Ca content can lead to blossom end rot disorder and this was evidenced on tomato cultivation under high salinity. However, in the present study, this disorder appeared at the very late stages and did not affect the marketability of the fruits. On the other hand, both salinity and Nr0.15 increased fruit firmness at harvest or following storage, while citric acid, total soluble solid and vitamin C contents were also increased by salinity. Total phenols were increased by salinity at harvest, and lycopene and β-carotene content were increased by salinity at harvest and/or following storage at 12 °C or 25 °C. Salinity enhances fruit quality and improves the organoleptic characteristics of the crop, while an appropriate Nr ratio may restrict the detrimental effects of salinity on the nutritional status of plants by regulating the pH in hydroponic systems.

Italian Tomato Cultivars under Drought Stress Show Different Content of Bioactives in Pulp and Peel of Fruits.

Background: This study aims to evaluate the performance, in terms of accumulation of antioxidant compounds in fruits, of nine local and three commercial Italian tomato cultivars subjected to drought stress. The same local cultivars had been previously studied at morpho-physiological level. Methods: The present manuscript analyzes drought stress as a tool to increase the amount of secondary metabolites that can enhance fruit quality. Nutraceutical characterization of the fruits was performed by analyzing the content of antioxidants, phenols, flavonoids, lycopene, ascorbic acid (vitamin C), rutin, caffeic acid, and naringenin. At the same time, plant sensitivity to stress during the reproductive phase was monitored in terms of flower abscission, fruit drop, and seed germination. Results: Perina turns out to be the tomato cultivar with the best nutraceutical properties in the absence of stress while the Quarantino cultivar is so for flavonoid content (control plants) and lycopene and vitamin C content (stressed plants). Perina and Quarantino are the cultivars with the best response to drought and Perina has the highest concentrations of bioactives. Quarantino responds most effectively to stress in the reproductive phase. Conclusions: data confirm that drought stress increases bioactive production in some local cultivars of tomato, which produce higher quality fruits.