Poor Fruit Quality Research Articles

An evaluation rule to manage productivity properties performance of male date palms

ABSTRACT Male palm trees almost prominently display minute morphological variations; however, date palm growers rely on readily available pollen from unproven male genotypes without giving correct type selection any thought, which may result in low productivity and/or poor fruit quality. This study sought to develop an evaluation rule by calculating an evaluation index for managing the productivity characteristics performance of nine male date palms, which were examined for their pollen productivity, nutritional status and morphological traits from their leaves, pinnae and spathes. The findings showed that the evaluation rule for a male date palm should depend on pollen grains productivity and germination percentage traits with a weight of 5, spathe morphological traits with a weight of 4, pinnae morphological traits with a weight of 3, leaf morphological traits with a weight of 2 and leaf nutritional status with a weight of 1. The best productivity characteristics performance of male date palms was male No. 8 ‘M8’ due to its high evaluation index. The proposed evaluation index criterion will contribute to better information and analytical support for management of the date palm industry to maximise the effectiveness of germplasm conservation and exploitation, as well as procedural and methodological aspects of the analysis.

The Biological and Genetic Mechanisms of Fruit Drop in Apple Tree (Malus × domestica Borkh.)

The apple tree (Malus × domestica Borkh.) belongs to the Rosaceae. Due to its adaptability and tolerance to different soil and climatic conditions, it is cultivated worldwide for fresh consumption. The priorities of apple growers are high-quality fruits and stable yield for high production. About 90 to 95 percent of fruits should fall or be eliminated from apple trees to avoid overcropping and poor-quality fruits. Apple trees engage in a complex biological process known as yield self-regulation, which is influenced by several internal and external factors. Apple buds develop in different stages along the branches, and they can potentially give rise to new shoots, leaves, flowers, or fruit clusters. The apple genotype determines how many buds will develop into fruit-bearing structures and the capacity for yield self-regulation. Plant hormones such as ethylene, cytokinins, auxins, and gibberellins play a crucial role in regulating the fruit set, growth, and development, and the balance of these hormones influences the flowering intensity, fruit size, and fruit number on the apple tree. Apple growers often interfere in the self-regulation process by manually thinning fruit clusters. Different thinning methods, such as by hand, mechanical thinning, or applying chemical substances, are used for flower and fruit thinning. The most profitable in commercial orchards is the use of chemicals for elimination, but more environmentally sustainable solutions are required due to the European Green Deal. This review focuses on the biological factors and genetic mechanisms in apple yield self-regulation for a better understanding of the regulatory mechanism of fruitlet abscission for future breeding programs targeted at self-regulating yield apple varieties.

Regulation of crop load and quality in sweet cherry cv. ‘Sweet Heart’ using blossom thinning

ABSTRACT Self-fertile cultivars of sweet cherry (Prunus avium) produce heavy crop load that is often associated with small and poor-quality fruits. Therefore, a crop load-management strategy is required to improve the quality of the fruit. In this study, the effect of blossom thinners on fruit set, yield and quality of the fruits was evaluated. Three types of blossom thinners were used at three different concentrations viz., ammonium thiosulphate (ATS) (1, 1.5 and 2%), naphthaleneacetic acid (NAA) (20, 40 and 60 ppm) and corn oil emulsion (1, 2 and 3%). These were sprayed at 80% of the bloom stage. The vegetative, flowering, fruit set and yield parameters were observed and recorded. Fruit quality was evaluated by measuring the physical and chemical characteristics of the fruits at the harvest stage. Negative correlation was found between fruit set and quality of fruit. The reduction in the crop load was associated with enhanced vegetative growth, including higher leaf:fruit ratio, higher supply and availability of photosynthates to the remaining fruitlets and reduced fruit firmness and titratable acidity. Fruit size, weight, volume, hue value, chroma value, soluble solid content (SSC), total sugars, SSC/acid ratio, anthocyanin and ascorbic acid content were enhanced as a result of thinning. The foliar spray of ATS at 2% and NAA at 60 ppm, at 80% bloom proved to be the most effective in reducing crop load and enhancing the fruit quality.

Influence of plant growth regulators on fruit set, yield and quality of mango varieties under HDP

Plant hormones are signal molecules produced within the plant, and occur in extremely low concentrations. Phytohormones determine the formation of flowers, fruit set, stems, leaves, shedding of leaves, and development and ripening of fruits. They shape the plant, affecting seed growth, time of flowering, sex of flowers, senescence of leaves and fruits. Hormones are vital for plant growth and lacking them, plants would be mostly a mass of undifferentiated cells. Plant growth regulators include salicylic acid, CPPU, tricontanol and brassinosteroid. The production of poor quality fruits is a matter of common experience. It would be therefore worth while to improve the yield and quality of fruit crops by foliar application of plant growth regulators. The use of growth regulators has become an important component of agro-technical procedures for most of the cultivated plants and especially for fruit plants. In this review, we focus on the role of plant growth regulators on fruit production.

Simultaneous Detection of Grapevine Viruses via Multiplex Reverse Transcription Polymerase Chain Reaction: An Academic Approach

Grapevine viruses pose a significant threat to the viticulture industry, resulting in reduced grape yield, poor fruit quality, and economic loss. Accurate and timely detection of multiple viruses are essential for effective disease management and the implementation of appropriate control measures. The aim of this study was to assess the presence of grapevine fanleaf virus (GFLV), grapevine fleck virus (GFkV), grapevine leafroll-associated virus‑1 (GLRaV-1), arabis mosaic virus (ArMV), and grapevine virus A (GVA) in 320 plant samples collected from the Aegean region of Turkey using the powerful technique of multiplex reverse transcription-polymerase chain reaction (RT-PCR). Through comprehensive analysis, 119 of the 320 infected samples were identified using PCR. The distribution of the detected viruses revealed the presence of 28 GFLV, 31 GLRaV‑1, 12 GFkV, 21 GVA, and 27 ArMV. By comprehensively analyzing the samples, the researchers were able to simultaneously detect and identify the target viruses using a single, cost-effective assay. These results reveal the prevalence and distribution of these viruses in the Aegean region, providing valuable insights into the viral landscape of grapevines in this important viticultural area. The high detection rates of these viruses highlight the urgent need for improved disease management strategies to safeguard vine health and productivity.

Canopy Manipulation for Production of Winter Guava (Psidium guajava L.) in the Eastern Himalayan Region of India

Elimination of rainy-season crops is pivotal to encourage winter crops in guava. In general, rainy-season guava fruits are of poor fruit quality, insipid in taste, have poor shelf life, and mostly affected by many insect pests. Pruning is also considered one of the most eco-friendly methods for crop regulation. To fully comprehend the impact of pruning time and severity on flowering, fruit quality, and crop production, a field experiment was carried out. Three alternative pruning times (mid-April, mid-May, and mid-June) at different pruning levels (low, moderate and heavy pruning) were employed in the experiment, which was designed as two-factor factorial RBD. For obtaining optimal fruiting, size of fruit and quality of fruit attributes, mid-May pruning has proven to be the best time for guava pruning. Whereas, concerning pruning severity, moderate pruning (pruning 1/2 of the current season’s shoot length) showed a good response to yield and fruit quality parameters. Therefore, the present study concluded that moderate pruning of guava trees during the month of mid-May proved to be the most effective for producing winter-season guava with good yield and superior quality.

Comprehensive evaluation of fruit quality for premium Wangmo Castanea mollissima plants

In this study, the fruit phenotype and quality of 32 superior Wangmo Castanea mollissima plants (designated GM1 to GM32) were examined to identify the trait characteristics of different cluster groups and germplasms with excellent comprehensive performance. The goal was to provide a theoretical basis and research foundation for collecting high-quality germplasm resources and breeding superior cultivars of Wangmo C. mollissima. Ten fruit phenotypic traits and 13 quality traits were measured and analyzed in these 32 superior Wangmo C. mollissima plants. Cluster analysis and principal component analysis (PCA) were used to perform a comprehensive evaluation. Extremely significant positive correlations (P<0.01) were observed for 15 pairs of fruit phenotypic and quality traits, and significant positive correlations (P<0.05) were observed for 16 pairs of traits. Highly significant negative correlations (P<0.01) were observed for 4 pairs of fruit phenotypic and quality traits, and significant negative correlations (P<0.05) were observed for 15 pairs. The plants were divided into three groups by cluster analysis: the first group had large fruits and good fruit quality, the second group had small fruits and poor fruit quality, and the third group had medium-sized fruits with a high starch content. Four principal components were extracted from the 23 traits by PCA, contributing 76.23% of the variance. The ten plants with the highest comprehensive quality were GM32, GM31, GM29, GM1, GM8, GM17, GM10, GM30, GM3 and GM28. The results of this study provide a reference for the development and utilization of Wangmo C. mollissima germplasm resources.

Whitefly-Transmitted Viruses Threatening Tomato Production in Oman

Tomato (Solanum lycopersicum) is a vital crop in Oman, contributing significantly to the country's agricultural economy and food security. However, the tomato industry faces a critical threat from whitefly-transmitted viruses that have emerged as a major concern for tomato growers in the region. This abstract summarizes the pressing issue of whitefly-transmitted viruses and their impact on tomato production in Oman. Whiteflies (Bemisia tabaci), small sap-feeding insects, have become notorious for their role in transmitting various devastating viruses to tomato plants. These viruses, including Tomato yellow leaf curl virus (TYLCV), Tomato leaf curl virus (ToLCV), and Tomato chlorosis virus (ToCV), can cause severe damage to tomato crops, leading to reduced yields, poor fruit quality, and substantial economic losses for farmers. This abstract emphasizes the urgent need for a comprehensive approach to mitigate the impact of whitefly-transmitted viruses on tomato production in Oman. Such an approach may include integrated pest management strategies, breeding programs for resistant tomato varieties, and education and awareness campaigns for farmers. Additionally, collaborative efforts between researchers, farmers, and policymakers are essential to develop sustainable solutions and ensure the continued viability of the tomato industry in Oman. Whitefly-transmitted viruses pose a significant threat to tomato production in Oman, jeopardizing food security and economic stability. Addressing this issue requires immediate attention and a concerted effort to protect the tomato industry, safeguard livelihoods, and ensure a sustainable future for agriculture in the country.

Postharvest Melatonin Application Preserves Quality and Imparts Chilling Tolerance in Peaches

Peach being a climacteric fruit has a limited shelf life. Cold storage of peaches is an essential measure to maintain their quality. However, prolonged exposure to cold temperatures causes chilling injury in peaches, resulting in significant economic losses. Approximately, 40% of the produced commodity is lost in postharvest handling in which chilling injury contributes to about 25%. Melatonin can be a green solution and plays a key role in protecting peaches from chilling injury. Therefore, this experiment aimed to determine the effect of melatonin on the “Silver King” peaches by dipping them in 100 μM melatonin for 2 hours followed by storing them at chilling temperatures of 2 ± 1°C and 90–95% relative humidity for 21 d. The results showed that while control fruit experienced chilling injury and poor fruit quality, increased respiration rate, and enhanced senescence, 100 μM melatonin treatment was successful in preserving the fruit quality at chilling temperatures and was associated with the delayed respiration rate and lower malondialdehyde levels, along with the preservation of certain physicochemical parameters, namely, total soluble solids, pH, fruit firmness, and titratable acidity. Moreover, a 1.5 times higher proline concentration was observed in melatonin-treated peaches when compared to that of nontreated peaches. This rise was linked to the enhanced activity of Δ1-pyrroline-5-carboxylate synthetase and ornithine-δ-aminotransferase along with a decrease in the activity of proline dehydrogenase during 21 d of storage.

Monitoring the distribution and development of apple scab (Venturia inaequalis) and powdery mildew (Podosphaera leucotricha) disease in the southern and southeast regions of Kazakhstan

Apple (Malus domestica) is a very important fruit tree that is widely cultivated in different climatic regions of the world. Scab (Venturia inaequalis (Cooke) G.) and powdery mildew (Podosphaera leucotricha) are common fungal diseases in apple orchards. The harmful impact of these disease results in poor fruit size and quality, premature fruit fall, peeling, less fruit bud development in the next year's fruit buds. When the patho-gen is present under favorable environmental conditions, disease develops highly, and the crop losses of up to70 %. Phytosanitary monitoring for the spread and development of the scab and powdery mildew pathogen was carried out the main fruit tree-growing regions of Kazakhstan, namely, Almaty, Turkestan and Zhambyl regions apple-growing farms in 2022. Research was conducted on apple orchards on the territory of 14 ha in Almaty region, 288 ha in Turkestan region and 40 ha in Zhambyl region. We carried out a phytopathological assessment of fungal disease for folowing commercial varieties Starkgrimson, Zolotoy presvesov, Aydaret, Americanka, Samured, Gala, Fuji and Golden Delicious grown in these regions. According to the results of the study, there were no symptoms of powdery mildew in Almaty and Zhambyl regions. Furthermore, pow-dery mildew distribution was 18.05 % in the Aidaret, while its development was at a lower level of 3.06 % in the apple orchards where Tulkibas district of Turkestan region. Scab pathogen is present in all orchards of the studied regions. The pathogen Venturia inaequalis was spread at an average level with 23 -31 % in Starkgrim-son, Zolotoy presvesov and Aidaret varieties, while its development was at a low level with 1-2.84 % in the Almaty region. The disease distribution is with 30-37 % of orchards where Starcrimson, Golden Delicious and Red Delicious varieties are grown in the Zhambyl region. As well as the development of the disease was 2-4.12 %. In the Turkestan region, in Samured and Starkrimson varieties, scab ditribution was at a low levelwith 3-3.71 %, while the development of the disease was with 0.50-0.81 %. In Idared and Gala varieties, thedisease distribution in the range about 16-17 %, while the development developed at a lower level with 0.13-1.25 %. The Fuji was recognized as resistant variety to scab, for the reason of no disease symptoms.

Silver Nanochito Oligomer Hybrid Solution for the Treatment of Citrus Greening Disease (CGD) and Biostimulants in Citrus Horticulture

Citrus greening disease (CGD), or Huanglongbing (HLB), is principal in Citrus farming because of its severe damage, decreased yield, poor quality of fruit, and frequent disappearance before harvest. Present research blended silver nanoparticles (AgNPs) colloid with chitooligomers and monomers (COAMs) to create the composites referred to as a “hybrid solution”. The hybrid solution has been synthesized for antimicrobial effects and plant growth stimulation. The hybrid solution was applied to cure the CGD, which was then tested using the results of the iodine test kit. Study results revealed that the mechanism for antibacterial properties is efficient and leads to cell death by silver ions (positive charge) attached to the cell wall of pathogens (negative charge). COAMs increase AgNPs’ ability to adhere to negatively charged bacterial cytoplasmic membranes and amplify their electrostatic interaction. There are synergistic antibacterial effects of AgNPs–COAMs. The findings reveal a notable increase in the shoot length of leaves which may be the reason for the growth stimulation function of the hybrid solution due to the properties of COAMs as a biostimulant. The hybrid solution-treated trees yielded around 104.50 ± 4.56 kg of fruits by the trunk or foliar application. Citrus fruits did not show the presence of any silver residues, as displayed by the results of the accumulation test. Compared to conventional ampicillin, the hybrid treatment of CGD was significantly more cost-effective, increased productivity, and had minor accumulation. The acquired results may also be applied to further plant disease treatment.

Micronutrients spray to combat granulation and improve fruit quality of sweet orange [Citrus sinensis (L.) Osbeck] cv. Mosambi under nontraditional citrus growing track

Calcareous and alkaline soil is the major drawback for low yield and poor fruit quality of sweet orange cv. Mosambi with increased granulation problem because such types of soil hinders the smooth micronutrient uptake from the soil. Therefore, the impact of micronutrients spray for three times at one month intervals from May to July on granulation and fruit quality of Mosambi was initiated for two consecutive years (2018–19 and 2019–20). Combined application of Zn @0.5% + Fe @0.2% + B @0.3% + Cu @0.1% followed by B @0.3% + Fe @0.2% and Zn @0.5% + B @0.3% were found effective for improving growth of Mosambi plants. Yield was also obtained maximum in foliar spray of Zn @0.5% + Fe @0.2% + B @0.3% + Cu @0.1% (19.92 t ha−1). Maximum fruit weight and volume was obtained in B @0.3% + Fe @0.2% treatment (173.80 g and 190.53 cc, respectively). Fruit quality attributes in terms of total soluble solids (TSS): acid ratio, sugar, and phenol content were recorded maximum in Zn @0.5% + Fe @0.2% + B @0.3% + Cu @0.1% spray. Minimum incidence of granulation was observed in Cu @0.1% spray (1.96%) with par result in Zn @0.5% + Fe @ 0.2% + B @0.3% + Cu @0.1% (2.33%). Hence, it can be concluded that three foliar spray of Zn @0.5% + Fe @0.2% + B @0.3% + Cu @0.1% from May to July is very effective to get maximum yield of better quality, granulation free fruits from Mosambi orchard under non-conventional citrus growing track having calcareous and alkaline nature of soil.

Analisis Produktifitas Pada Mesin Empty Bunch Press Untuk Menaikkan Jumlah Oil Extraction Rendemen (OER) Minyak Kelapa Sawit

Empty Palm Oil Bunches (TTKS) or empty fruit bunches are one of the solid wastes produced by palm oil mills. Judging from the oil content, TTKS has the potential to be re-quoted. Empty Bunch Press machine, so as to produce oil before being pressed (oil before press) and oil after being pressed (oil after press) produced using this machine and knowing the factors that cause OER or low oil yields. The analysis of this calculation can result in an average % OER empty bunch press of 0.16% and a total % OER from the addition of an empty bunch press machine of 21.91% where in this case there is an additional OER using an empty bunch press machine. Without the use of an empty bunch press machine,%OER 21.17%. The results of the analysis show that extracting oil obtained from TTKS using an empty bunch press machine can increase the factory's OER of about 0.16% to processed FFB. The results of the analysis from June 14 to June 27 2022 OER of palm oil has decreased or is low due to factors such as the maturity level of the fruit, processing at the factory, and poor fruit quality

240 Community Participant-based Study Design: Use of Virtual Focus Groups to Explore Acceptability of a Cooking Intervention among African-American Women Living in Washington, D.C.

OBJECTIVES/GOALS: African-Americans are at increased risk for nutrition disparities; home cooking is a strategy to optimize dietary quality. to develop a cooking intervention, a mixed-methods community-based participatory, acceptability study was conducted to understand cooking behaviors, options for intervention content, and implementation factors. METHODS/STUDY POPULATION: Self-identified African-American adults were recruited from a larger community-based study within Washington, D.C. Five moderated virtual focus groups with four participants in each group were conducted in March and April of 2021. A semi-structured moderator’s guide focused on cooking, meal habits, food choices, and the proposed cooking intervention was utilized. Qualitative data collected were verbatim transcriptions and notes from research team members. Thematic analysis was conducted using an iterative process among research team members. Participant validation interviews were conducted following the research team analysis. Electronic self-administered surveys were used to measure demographic, food environment, cooking behavior, health behavior, and psychosocial variables. RESULTS/ANTICIPATED RESULTS: Study participants (n=20 females, mean age 60.1 years) lived in low-food resource neighborhoods but reported high food security (n=14). Barriers to the intervention included traveling distances to other neighborhoods for produce, poor quality of vegetables and fruit within neighborhood stores, lack of trustworthiness from neighborhood store experiences, perception of decreased cooking skills, and competing priorities related to time and weekday schedules. Motivators included health promotion for self, family, community, and enjoyment from cooking. Virtual or in-person sessions were suggested. Intervention options included costs of recipe ingredients, using recipes with ingredient flexibility, nutrition information, and provisioning of or compensation for ingredients used in virtual classes. DISCUSSION/SIGNIFICANCE: Use of virtual focus groups for a participant-based design of a cooking intervention among African American adults living in low-food access neighborhoods provided acceptability results that were food and home environments contextual and provided barriers and motivators to participation and implementation of behavior from the intervention.

Evaluating the Combined Effects of Water and Fertilizer Coupling Schemes on Pear Vegetative Growth and Quality in North China

Unreasonable fertilizer and irrigation applications and dosages in orchards in northern China result in poor vegetative growth and fruit quality. To reveal the combined effect of water and fertilizer coupling on vegetative growth and fruit quality, this study used pear as a field experiment material, considering: (1) irrigation lower limits (55%, 65%, 75%θf, θf is field capacity) and (2) nitrogen fertilizer application (162, 324, 486 kg·ha−1). Nine coupling schemes and a control treatment (C) were set up in the orthogonal combination. The results showed that, under the higher irrigation rate and nitrogen dose, the spring shoot length, base diameter, and leaves relative chlorophyll content values were increased by 36.77%, 31.86% and 12.91%, respectively. The response of each coupling scheme was different. However, selected water and nitrogen coupling schemes improved the fruit quality. The evaluation results indicated that medium irrigation and high fertilizer scheme were optimal. In conclusion, integrating the vegetative growth and fruit quality, it is recommended that the water and fertilizer coupling scheme for pear in the northern China is as follows: a lower irrigation limit of 65%θf and a nitrogen fertilizer amount of 486.00 kg·ha−1.

Computer vision-based prototype robotic picking cum grading system for fruits

Huge harvest and post-harvest losses in conventional processes and methods demands precise applications of agricultural inputs. Computer vision based robotic picking is one of such systems that reduces time consumption, labor requirement; and enhances fruits picking and grading efficiency. In this study, an all-in-one prototype robotic picking cum grading system is developed that integrates robotic picking and fruit quality recognition based grading processes. Therein, computer vision algorithms are used for fruit detection followed by picking and placing through controlled robotic arm. For fruit detection, the steps includes color scheme conversion, masking of normal/fresh skin, masking of defects, and morpological dilation operations; and opencv library is used for implementation in Python Language on Anaconda Spyder Integrated Development Environment (IDE). The detection information is then communicated to robotic arm through microcontroller. The fabricated arm is of 4 Degrees of Freedom (4-DOF) and therein, four servo motors aid the robotic arm. The time taken by proposed computer vision algotihms scheme is as follows: 0.0035136 s, 0.0081954 s, 0.0005433 s, and 0.0002408 s for color scheme conversion, segmentation, morphological operations, and bitwise operations respectively; and total time for complete scheme is 0.0125 s. Overall, the developed system took average time of 15 s for one grading cycle in case of poor quality fruits. For this case, no action is carried out and the fruit passes the conveyor directly to storage bin. However, the time required for good quality fruits is high i.e. 21 s as the robotic arm picks and places the fruits for this case.

Efficiency of exogenous zinc sulfate application reduced fruit drop and improved antioxidant activity of 'Kinnow' mandarin fruit.

Kinnow' mandarin (Citrus nobilis L.× Citrus deliciosa T.) is an important marketable fruit of the world. It is mainstay of citrus industry in Pakistan, having great export potential. But out of total production of the country only 10% of the produce meets the international quality standard for export. Pre-harvest fruit drop and poor fruit quality could be associated with various issues including the plant nutrition. Most of the farmers do not pay attention to the supply of micro nutrients which are already deficient in the soil. Furthermore, their mobility within plants is also a question. Zinc (Zn) is amongst those micronutrients which affect the quality and postharvest life of the fruit and its deficiency in Pakistani soils is already reported by many researchers. Therefore, this study was carried out to evaluate the influence of pre-harvest applications of zinc sulfate (ZnSO4; 0, 0.4%, 0.6% or 0.8%) on pre-harvest fruit drop, yield and fruit quality of 'Kinnow' mandarin at harvest. The treatments were applied during the month of October i.e. 4 months prior to harvest. The applied Zn sprays had significant effect on yield and quality of the "Kinnow" fruit. Amongst different foliar applications of ZnSO4applied four months before harvest, 0.6% ZnSO4 significantly reduced pre-harvest fruit drop (10.08%) as compared to untreated control trees (46.45%). Similarly, the maximum number of fruits harvested per tree (627), fruit weight (192.9 g), juice percentage (42.2%), total soluble solids (9.5 °Brix), ascorbic acid content (35.5 mg 100 g-1) and sugar contents (17.4) were also found significantly higher with 0.6% ZnSO4 treatment as compared to rest of treatments and control. Foliar application of 0.6% ZnSO4 also significantly improved total antioxidants (TAO) and total phenolic contents (TPC) in fruit. In conclusion, foliar spray of ZnSO4 (0.6%) four months prior to harvest reduced pre-harvest fruit drop, increase yield with improved quality of 'Kinnow' mandarin fruit.

Influence of Preharvest Bagging on Maturity Indices and Postharvest Quality of Cherry Tomato (Solanum lycopersicum var. cerasiforme)

The production of cherry tomato (Solanum lycopersicum var. cerasiforme) is negatively affected by harsh environmental conditions such as extremely high and low temperatures, wind and hail damage, and pest and disease infestation. These factors delay maturity and cause uneven ripening, fruit abrasion, and blemishes, which consequently result in poor fruit quality and reduced shelf life. Preharvest bagging is an environmentally friendly alternative technique for enhancement of fruit quality and hence alleviates the stated problems. The study evaluated the physico-chemical quality of ‘Tinker’ and ‘Roma VF’ cherry tomato as influenced by preharvest bagging (transparent and blue plastics) during 8 days of shelf life at ambient conditions. Five clusters of fruit per plant per cultivar with a diameter of 1.5 to 2.0 cm were bagged after 16 days of fruit set and harvested at the green maturity stage, 12 days after preharvest bagging for the assessment of postharvest quality. Preharvest bagging effectively accelerated fruit maturity and ripening as indicated by enhanced fruit size, uniform color development, high pH, dry matter (DM) content, soluble solid content (SSC), and low titratable acidity (TA) during shelf life. Bagged fruit had higher loss of firmness and weight mainly due to ripening and showed very slight incidence of diseases during shelf life of 8 days. Unbagged cherry tomato had delayed maturity and ripening; small-sized fruit; uneven color development; low pH, SSC, and DM; and high TA. Although unbagged cherry tomato had lower firmness and weight loss due to delayed ripening, fruit showed moderate to severe incidence of tomato bacterial canker disease (Clavibacter michiganensis subsp. michiganensis) during shelf life. These results indicated that preharvest bagging accelerated fruit maturity and ripening, improved physico-chemical quality, and reduced disease infestation on cherry tomato during shelf life.

Advancing fruiting season in Annona cv. Arka Sahan through pruning

Annona cultivar ‘Arka Sahan’, an inter-specific hybrid of Annona atemoya × A. squamosacomes to harvest during August-September under mild tropical climate, which coincides with monsoon rains resulting in poor fruit quality and high susceptibility to anthracnose and fruit fly. An attempt was made to advance the fruiting in this hybrid through pruning during 2016- 17 and 2017-18. The effect of three pruning levels (25, 50 and 75% of previous season’s growth) at five different times (60, 75, 90, 105 and 120 days after final harvest of previous crop) on flowering and fruiting were compared. Early sprouting, flowering and fruit harvest were recorded in trees pruned to 75% of the past season’s growth in both the years. Earliest fruits were harvested 271 (3rd week of June) and 268 (2nd week of June) days after pruning in trees pruned during first week of October in 2016-17 and 2017-18 respectively (P<0.05).Bigger fruits with lesser seeds per 100 g of pulp (P<0.05) were harvested from trees pruned to 75% and 25% levels in the first and second year, respectively, irrespective of pruning time. Tree canopy following pruning at 75%level recorded higher light interception and photosynthetic rate (P<0.05). Pruning time and levels significantly influenced the biochemical constituents of leaf and shoot. The fruiting in cultivar ‘Arka Sahan’ could be thus advanced by 8-9 weeks to June from the normal season of August-September with comparable or better fruit quality by pruning 75% of the last season’s growth during October.

Effect of Nano-TiO2 Composite on the Fertilization and Fruit-Setting of Litchi.

Titanium dioxide nanoparticles (nTiO2) are widely used as fertilizers in agricultural production because they promote photosynthesis and strong adhesion. Low pollination and fertilization due to rainy weather during the litchi plant's flowering phase result in poor fruit quality and output. nTiO2 would affect litchi during the flowering and fruiting stages. This study considers how nTiO2 affects litchi's fruit quality and pollen viability during the flowering stage. The effects of nTiO2 treatment on pollen vigor, yield, and fruit quality were investigated. nTiO2 effectively improved the pollen germination rate and pollen tube length of litchi male flowers. The germination rate reached 22.31 ± 1.70%, and the pollen tube reached 237.66 μm in the 450 mg/L reagent-treated group. Spraying with 150 mg/L of nTiO2 increased the germination rate of pollen by 2.67% and 3.67% for two types of male flowers (M1 and M2) of anthesis, respectively. After nTiO2 spraying, the fruit set rates of 'Guiwei' and 'Nomici' were 46.68% and 30.33%, respectively, higher than those of the boric acid treatment group and the control group. The edibility rate, titration calculation, and vitamin C of nTiO2 treatment were significantly higher than those of the control. The nTiO2-treated litchi fruit was more vividly colored. Meanwhile, the adhesion of nTiO2 to leaves was effectively optimized by using ATP and BCS to form nTiO2 carriers and configuring nTiO2 complex reagents. These results set the foundation for future applications of titanium dioxide nanoparticles as fertilizers for agriculture and guide their application to flowers and fruits.