Fruit Size Research Articles

A Multi-Year Study of Forchlorfenuron’s Effects on Physical Fruit Quality Parameters in A. chinensis var. chinensis

CPPU, N-(2-Chloro-4-pyridyl)-N-phenylurea, is a synthetic cytokinin extensively used to enhance fruit size and overall quality in several crops, including kiwifruit. This study aimed to investigate the effects of three different CPPU application strategies (2.3, 3.0, and 4.6 ppm) and two crop load levels on key fruit quality parameters at harvest, as well as on post-harvest storage performance. Our results demonstrate that two applications of CPPU (4.6 ppm) significantly increased fruit weight, especially under standard crop-load conditions, likely due to more efficient resource allocation. Additionally, fruit firmness improved with two or three CPPU applications, probably because of enhanced cell wall development. Crop load consistently influenced fruit firmness, with lower loads resulting in softer fruits. The soluble solids content was not significantly affected by the two CPPU applications; however, it was notably influenced by crop load, with fruits from the standard crop load showing higher sugar accumulation. A similar trend was observed in fruit dry weight, where CPPU had a greater impact under standard crop loads. Regarding post-harvest performance, CPPU applications showed a limited effect on maintaining fruit firmness during the first five months of storage. Overall, CPPU can be a potential strategy to enhance fruit quality, but its effectiveness depends heavily on field management practices. Therefore, controlling field variables is essential to fully realize the benefits of CPPU and to avoid interference with the plant’s physiological responses.

Time–Course Analysis of the Onset and Progression of Cuticle Cracking in Fruits of Cherry Tomato Cultivar ‘Nene’

Cuticle cracking in tomatoes, characterized by fine cracks on the cuticular membrane, significantly reduces their shelf life. In this study, we collected basic information about the onset and progression of cuticular cracks in cherry tomatoes by observing the time–course of cuticular cracks incidence and severity during three cultivation periods. Several fruit characteristics—including the fruit weight, cuticular membrane deposition, and epidermal cell morphology—were analyzed alongside environmental factors to identify the conditions under which cuticular crack occurs. In the spring–summer season, cuticular cracks’ onset occurred at 30 days after anthesis, whereas in the summer–autumn, it occurred at 20 days after anthesis. The severity of cuticular cracks at harvest was higher in the summer–autumn cultivation than in the spring–summer. These results indicate that the period during which susceptibility to cuticular cracks increases may vary by season, contributing to seasonal differences in the final severity. However, no consistent relationship was observed between the incidence or severity of cuticular cracks and the fruit size, temperature, or humidity throughout the study. In both seasons, the onset of cuticular cracks coincided with the peaking of the cuticular membrane deposition. Thickening of the cuticular membrane, resulting in decreased elasticity may contribute to the cuticular cracks’ onset.

Effects of Chemical Thinning Agents on the Growth, Fruit Set, Yield and Quality of the Nectarine Cultivar 'Silver King'

The investigation was conducted at the Research Farm of the Division of Fruit Science, SKUAST-Kashmir, Shalimar campus, during 2016 and 2017 to evaluate the effects of chemical thinning agents on vegetative growth, fruit set, yield, and fruit quality of the nectarine cultivar 'Silver King.' The chemicals tested, were Naphthalene Acetic Acid (NAA), Urea, and Ethephon and were applied after petal fall. The findings revealed that NAA (30 ppm) significantly enhanced vegetative parameters such as plant height, shoot elongation, and leaf area. Both NAA and ethephon effectively reduced fruit set and overall yield while improving fruit quality traits, including fruit size, weight, and coloration. Additionally, ethephon (150 ppm) accelerated fruit maturation by 7–8 days. These results indicate that chemical thinning, particularly with NAA and ethephon, holds potential for optimizing fruit quality and marketability in the 'Silver King' nectarine cultivar.

Effects of Colchicine and 60Co-γ Radiation Treatments on the Leaf Size and Fruit Quality of Kiwifruit ‘Donghong’

Colchicine and 60Co-γ radiation are commonly used breeding techniques for kiwifruit, offering advantages such as low cost, rapid execution, and high efficiency. The buds of red-fleshed kiwifruit (Actinidia chinensis) cv. ‘Donghong’ were used as experimental material and subjected to different concentrations of colchicine and different doses of 60Co-γ radiation, respectively. Then, the buds were grafted on rootstock, and the ploidy, leaf size, and fruit quality of mutant fruit were evaluated, and principal component analysis (PCA) and simple sequence repeat markers were used to comprehensively assess and detect genetic variations, respectively. The results indicated that a total of 19 buds successfully germinated, with 13 branches successfully bearing fruit. Significant changes were observed in both leaf and fruit morphology following the mutation treatments. Most of the mutant materials showed significant increases in fruit weight, flesh firmness, and soluble sugar content, while titratable acidity and ascorbic acid content significantly decreased. Notably, the 25Gy 60Co-γ radiation (25d) treatment demonstrated outstanding results, with fruit weight increasing by 256.10%, soluble sugar content rising by 88.29%, titratable acidity decreasing by 29.86%, and ascorbic acid content increasing by 35.60%. PCA results showed that the 25d mutant had the best comprehensive traits. And, except for the 0.4c mutant, all other mutant materials exhibited significant genetic changes at the DNA level.

Unraveling the genetic architecture of blueberry fruit quality traits: major loci control organic acid content while more complex genetic mechanisms control texture and sugar content

BackgroundFruit quality traits, including taste, flavor, texture, and shelf-life, have emerged as important breeding priorities in blueberry (Vaccinium corymbosum). Organic acids and sugars play crucial roles in the perception of blueberry taste/flavor, where low and high consumer liking are correlated with high organic acids and high sugars, respectively. Blueberry texture and appearance are also critical for shelf-life quality and consumers’ willingness-to-pay. As the genetic mechanisms that determine these fruit quality traits remain largely unknown, in this study, an F1 mapping population was used to perform quantitative trait loci (QTL) mapping for pH, titratable acidity (TA), organic acids, total soluble solids (TSS), sugars, fruit size, and texture at harvest and/or post-storage and weight loss.ResultsTwenty-eight QTLs were detected for acidity-related parameters (pH, TA, and organic acid content). Six QTLs for pH, TA, and citric acid, two for quinic acid, and two for shikimic acid with major effects were consistently detected across two years on the same genomic regions on chromosomes 3, 4, and 5, respectively. Putative candidate genes for these QTLs were also identified using comparative transcriptomic analysis. No QTL was detected for malic acid content, TSS, or individual sugar content. A total of 146 QTLs with minor effects were identified for texture- and size-related parameters. With a few exceptions, these QTLs were generally inconsistent over years and post-storage, indicating a highly quantitative nature.ConclusionsOur findings enhance the understanding of the genetic basis underlying fruit quality traits in blueberry and guide future work to exploit DNA-informed selection strategies in blueberry breeding programs. The major-effect QTLs identified for acidity-related fruit characteristics could be potential targets to develop DNA markers for marker-assisted selection (MAS). On the other hand, genomic selection may be a more suitable approach than MAS when targeting fruit texture, sugars, or size.

Pré-melhoramento de um acesso de Capsicum annuum para uso ornamental

ABSTRACT Capsicum annuum is a domesticated pepper species that exhibits a wide range of fruit size, color, and shape, as well as plant characteristics important for ornamental pepper cultivars, including plant architecture and leaf size and color. This variability can be found in Capsicum accessions from germplasm banks and used in breeding programs to develop new ornamental pepper cultivars. The objective of this study was to develop the ornamental characterization and pre-breeding of a segregating Capsicum annuum accession from the Active Germplasm Bank of Capsicum of the Brazilian Agricultural Research Corporation (Embrapa Temperate Climate). Sixty-seven F1-generation and sixty-two F2-generation plants were characterized based on 16 morphological descriptors: stem color, nodal anthocyanin, plant growth habit, branching density, leaf density, leaf color, number of leaves per axil, flower position, corolla color, calix pigment, immature fruit color, fruit position, mature fruit color, fruit shape, fruit apex shape, and fruit brightness. The relative contribution of each trait to the genetic divergence was determined using the method proposed by Singh (1981). A principal component analysis was carried out. Almost all evaluated variables showed segregation, except for flower position and immature fruit color. Genetic variability was found in both F1 and F2 generations, indicating their potential for developing ornamental Capsicum annuum varieties.

Phytochemical Compositions and Antioxidant Activities of Different Cultivars of Prunus salicina Lindl. in Southern China.

There are representative Prunus salicina Lindl. (plum) cultivars in the different provinces of Southern China. However, little data are available on the physiochemical characteristics of those plums. In this study, the fruit weight and size, edible rate, rate of juice, color, moisture, total soluble solids, total acids, ascorbic acid (AA), reducing sugar, polysaccharide, total polyphenols, total tannins, total anthocyanins, antioxidant activity, and phenolic composition of 11 plum varieties in Southern China were analyzed. The results showed that the content of reducing sugar, AA, polysaccharide, total polyphenols, total tannins, and total anthocyanins in different cultivars was in the range of 3.09-10.48g/100g, 2.30-14.75mg/100g dry weight (DW), 0.78-2.20g/100g, 20.73-41.18mg/g DW, 0.42-1.09mg/g DW, and 1.80-8.95mg/g DW, respectively. A total of 11 phenolic compounds were identified in plums by ultra high pressure liquid chromatography (UPLC)-QqQ-MS/MS. Cultivar "Da Pao" showed the highest level of total polyphenols, and ferric ion reducing antioxidant power values, whereas cultivar "San Hua" had the highest content of total anthocyanins, 1,1-diphenyl-2-picrylhydrazyl, and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt values. Principal component analysis separated cultivars according to their physiochemical characteristics. This study provides reference information for consumers and the further deep processing of those plums.

Comparative transcriptome analysis and heterologous overexpression indicate that the ZjZOG gene may positively regulate the size of jujube fruit

BackgroundFruit size is a crucial economic trait that impacts the quality of jujube (Ziziphus jujuba), however, research in this area remains limited. This study utilized two jujube cultivars with similar genetic backgrounds but differing fruit sizes to investigate the regulatory mechanisms affecting fruit size through cytological observations, transcriptome sequencing, and heterologous overexpression.ResultsThe findings reveal that variations in mesocarp cell numbers during early fruit development significantly influence final fruit size. Comparative transcriptome sequencing identified 16,778 differentially expressed genes across five developmental stages. Co-expression network analysis identified 16 co-expression modules. KEGG enrichment analysis of these modules indicated the significant role of plant hormone-related pathways in fruit development. A detailed analysis of the ‘sky blue’ module revealed candidate genes associated with the regulation of mesocarp cells, leading to the construction of a regulatory network. Heterologous overexpression of the candidate gene ZjZOG in tomato confirmed its positive role in fruit size enhancement. Transcriptomic analysis of these overexpression lines further validated the regulatory network and identified reliable candidate genes for fruit size control.ConclusionThis study provides valuable insights into the regulatory mechanisms of fruit size, which may facilitate the breeding of larger jujube cultivars.

Assessment of phenological and physicochemical characteristics of peach (Prunus persica L.) varieties in Mustang, Nepal

This research was conducted at the Temperate Horticulture Development Center (THDC), Mustang, Nepal, to study flowering phenology and evaluate the physicochemical characteristics of five peach varieties (Surprise, Benedict, Peregrine, Local Khallya and Early Red) from February to September 2023. This research was conducted on a randomized complete block design with four replications and five treatments (fruit trees of a particular variety were replicated four times). The flowering phenology of varieties was studied by dividing the developmental stages of a flower into eight different stages: first swelling, calyx green, calyx red, first pink, first bloom, full bloom, petal fall and fruit set. The completion of each phenological stage was marked from a reference date. Physicochemical analysis of fruits was performed following UPOV guidelines of peach. Physical characteristics were encompassed in individual fruit weight, fruit length, fruit volume, fruit size (length and width), stone weight, stone size (length and width) and mesocarp thickness and in chemical characteristics, pH, total soluble solids (TSS), titratable acidity (TA) and TSS/TA ratio were included. The study of flowering phenology revealed that Early Red was found to be the earliest (60.50 DARD) to reach the fruit-set stage. The highest and lowest fruit weights were measured in Benedict (153.85 g) and Early Red (46.5 g), respectively. Finally, chemical analysis revealed that TSS/TA was found to be maximum in Benedict (12.38) and minimum in Early Red (6.03). It can be concluded that Early Red was the earliest maturing variety among the varieties. Also, Benedict was found to be the superior in terms of sweetness and size.

Morphological characterization and ecotypic classification of olive varie-ties in Bordj Bou Arreridj, Algeria

The aim of this research is to establish the phenotypic variation that exists in the olive varieties of Olea europaea L. in the Bordj Bou Arreridj region of Algeria. The study examined 18 olive varieties from 20 farms, focusing on the morphological characterisation of fruits, leaves, and endocarps using standard descriptors and precise measurement tools. Significant coefficients of variation were ob-served for the traits studied, indicating substantial differences among the varieties. The highest variability was found in fruit weight, with a coefficient of variation (CV) of 48.60%, while leaf length demonstrated the lowest CV at 9.77%. Principal Component Analysis (PCA) primarily distinguished three different ecotypic groups based on fruit and endocarp size and shape parameters. The Bray-Curtis similarity analysis revealed compositional similarities among some of the local variants, providing insights into their po-tential genetic relationships. Notably, the study reports the presence of the rare Leucocarpa variety, which had not been previously doc-umented in Algeria. This discovery highlights the importance of thorough regional surveys in uncovering hidden biodiversity. The findings reveal a rich agro-morphological genetic variation in olive ecotypes in the region, which is valuable for genetic conservation efforts and breeding research. This diversity could potentially be exploited to develop cultivars with improved traits such as disease resistance, oil quality, or adaptation to specific environmental condi-tions. Our classification enables targeted breeding, prioritized conser-vation, and optimized cultivation practices, supporting the devel-opment of resilient, locally-adapted varieties and the preservation of valuable genetic resources in the region's olive industry.

High extinction risk of the endemic tree flora in a hyper‐diverse region of the Amazon

Societal Impact StatementThe rapid global loss of biodiversity, especially in the Neotropics, underscores the need to understand how deforestation impacts endemic plant species' extinction risk and conservation status. Due to limited ranges and habitat specialization, endemics are particularly vulnerable. Our study reveals that around 14% and 47% of Ecuadorian Amazon endemic trees are Critically Endangered and Endangered, respectively, with 41% facing high extinction risk. Traits like life‐form, fruit size, and height relate to extinction vulnerability. These findings highlight the factors driving Amazonian tree flora endangerment, providing crucial insights for conservation efforts of this fundamental component of Amazon hyper‐diverse forests.Summary Comprehensive analyses of the global conservation statuses of endemic tree species are scarce, especially for species‐rich forests. Endemic trees arguably suffer a higher extinction risk than other plant species due to their restricted geographic range and habitat specialization. Here, we present an updated assessment of the conservation status and extinction risk estimates for the endemic tree flora of the Ecuadorian Amazon, a darkspot of biodiversity. We combined an extensively verified taxonomic database of Amazon tree species abundance and occurrence with the most updated data of deforestation for this region. We found that approximately one sixth of the Ecuadorian Amazon endemic tree flora is Critically Endangered. A few clades, including Myrtaceae, Elaeocarpaceae, Fabaceae s.l., and Lauraceae, harbor one third of the Critically Endangered endemic tree species. According to our analysis, the extinction risk for endemic trees is associated not only with extrinsic factors such as deforestation but also with their ecology. Life‐form, fruit size, and maximum height are significantly related to extinction risk. Thus, endemic understory and canopy trees with small fruits are more prone to suffer extinction than emergent tree species. We argue that assessment programs should also include biological trait information in addition to geographic ranges and habitat specialization for the establishment of effective conservation strategies of this hyper‐diverse region of the Amazon.

Profiling of agronomic traits and folic acid in five dessert bananas (Musa spp.)

Many varieties of Musa spp. have been used as edible fruits around the world. Bananas belong to the genus Musa, whose fruits contain high calories and nutritional values. There is little data on agronomic traits and folic acid (FA) concentrations of different types of dessert bananas in Vietnam. This study aimed to determine such information in the fruits of five banana varieties, including Cau, Xiem, Gia Huong, Com, and Dole. Agronomic characteristics were considered, including fruit size and weight, peel colour and pulp firmness, while FA concentrations were quantified by high-performance liquid chromatography. The results showed significant differences among agronomic values and FA contents. Dole had the heaviest weight (175.48 g), followed by Xiem (123.71 g), Gia Huong (121.77 g), Com (103.12 g) and Cau (52.07 g). The size (length × width) of 5 cultivars has significant differences, including Dole (16.22 × 4.17 cm), Xiem (11.78 × 4.44 cm), Gia Huong (15.44 × 4.22 cm), Com (11.59 × 3.88 cm) and Cau (9.00 × 3.79 cm). For the colour results, most banana cultivars had yellow peels, except Gia Huong which remained green colour at ripening stages (b/a<0). The pulp firmness is expressed with the hardest value from Xiem (0.59 N), then Dole (0.36 N), Com (0.32 N), Cau and Gia Huong (0.29 N). The FA concentrations ranged 3-12 μg /100 g fresh weight. The cultivar Cau had the highest level of FA per 100 g fresh weight (12.04 μg), followed by Gia Huong (8.76 μg), Dole (6.00 μg), Xiem (4.62 μg), and Com (3.14 μg). The FA contents were positively correlated with the colour brightness L, performed by Pearson value, with r = 0.755 (p<0.001). On the other hand, an inverse correlation was found between FA concentration and the fruit weight (r = -0.542, p<0.001) and the pulp firmness (r = -0.337, p<0.05). In conclusion on 5 varieties of dessert bananas, measured values of agronomic traits and FA have been recorded, and Pearson analysis shows a positive relation between FA and colour brightness and a negative one between FA and fruit weight/firmness.

The hexose transporters CsHT3 and CsHT16 regulate postphloem transport and fruit development in cucumber.

Hexoses are essential for plant growth and fruit development. However, the precise roles of hexose/H+ symporters in postphloem sugar transport and cellular sugar homeostasis in rapidly growing fruits remain elusive. To elucidate the functions of hexose/H+ symporters in cucumber (Cucumis sativus L.) fruits, we conducted comprehensive analyses of their tissue-specific expression, localization, transport characteristics, and physiological functions. Our results demonstrate that CsHT3 (C. sativus hexose transporter), CsHT12, and CsHT16 are the primary hexose/H+ symporters expressed in cucumber fruits. CsHT3 and CsHT16 are localized in the sieve element-companion cell during the ovary and early fruit development stages. As the fruit develops and expands, the expression of both symporters shifts to phloem parenchyma cells. The CsHT16 knockout mutant produces shorter fruits with a larger circumference, likely due to impaired sugar and phytohormone homeostasis. Concurrent reduction of CsHT3, CsHT12, and CsHT16 expression leads to decreased fruit size. Conversely, CsHT3 overexpression results in increased fruit size and higher fruit sugar levels. These findings suggest that CsHT16 plays an important role in maintaining sugar homeostasis, which shapes the fruit, while CsHT3, CsHT12, and CsHT16 collectively regulate the supply of carbohydrates required for cucumber fruit enlargement.

Influence of Vermicompost and Biofertilizers on Growth and Yield of Strawberry (Fragaria х ananassa Duch.) cv. Camarosa

The present investigation was carried out during 2023-2024 to find out the effect of vermicompost and biofertilizers on the growth and yield of strawberry (Fragaria × ananassa Duch.) cv. Camarosa at the Horticultural Research Farm of Doon (P.G.) College of Agriculture Science and Technology, Dehradun, Uttarakhand. The growth and yield parameters of strawberry were significantly influenced by different treatments of vermicompost and biofertilizers. The maximum plant height (23.10 cm) and plant spread (24.99 cm) was observed in the treatment T6 [Vermicompost (50%) + Azotobacter (25%) + Arbuscular Mycorrhiza (25%)]. Maximum number of leaves per plant (67.11) and leaf area (96.67 cm2) were observed in the treatment T2 [Vermicompost (75%) + Azotobacter (50%)]. Treatment T6 [Vermicompost (50%) + Azotobacter (25%) + Arbuscular Mycorrhiza (25%)] exhibited superiority in yield attributing characters like number of runners per plant (7.38), fruit size (15.52cm2), fruit weight (21.12 g), fruit volume (5.79 ml), number of fruits per plant (27.99) and yield per plant (569.86 g).

Impacts of gibberellin application on citrus: An overview from seed germination to fruit quality enhancement

Gibberellins are key plant hormones, and their application in citrus plants is frequently reported. This review aims to provide an overview of the application of gibberellic acid (GA3) in citrus cultivation, emphasizing their effects on growth, flowering, fruit quality, and ripening. Citrus fruits often face challenges like irregular fruit set, size inconsistency, and environmental stress, impacting yield and profitability, with exogenous gibberellin application as a potential solution. Applying gibberellins can accelerate citrus seed germination and seedling growth, enhance vegetative growth, inhibit flowering, delay fruit ripening, and improve fruit quality. However, the efficacy of gibberellins varies across species and conditions, highlighting the need for reference studies. This work presents an alternative option for optimizing gibberellin use to support sustainable citrus production practices.

The effect of the microponic mixture and the female cultivar on some physical characteristics of date palm Phoenix dactylifera L., produced from tissue culture and grown in Thi Qar Governorate.

This study was conducted during the 2023 growing season at the palms Akkad station in Shatrah District, affiliated with the General Authority for Palms - Ministry of Agriculture, to study the effect of spraying with Microponic at four concentrations (0, 0.5 , 1, and 1.5 ) ml L-1 and the female cultivar resulting from tissue culture (Barhi and Hilali) and the interaction between them in some physical characteristics of date palms. The results showed the following: Spraying with different concentrations of Microponic and the female cultivar had a significant effect in improving the physical characteristics of the fruits during the khalal stage, and the spraying treatment with Microponic at a concentration of 1 ml L-1 significantly achieved the highest averages for: (fruit weight, core , fruit size and diameter) reaching (14.42 and 13.51) g fruit-1 , 13.19 cm3 fruit-1 and 2.650 cm.fruit-1, respectively, for the khalal stage. The Hilali cultivar was significantly superior in giving the highest averages of fruit weight, core , fruit size, and diameter reaching (16.16 and 15.24) gm fruit-1, 15.08 cm3 fruit-1, and 2.835 gm fruit-1), respectively, in the Khalal stage. As for the effect of the interference treatments, it was significantly superior to the interference treatment between Microponic at a concentration of 1 ml L-1 and the Al-Hilali cultivar gave the highest averages for (fruit weight, core, fruit size and diameter) reaching ( 17.36 and 16.40 ) g. fruit-1 and 16.27 cm3 fruit-1 and 2.927 cm , respectively.

Impact of Irrigation and Fertigation Schedules on Physical and Biochemical Properties of Apple Under High-Density Plantation

ABSTRACT Over the 2-year period of study (2019–2020), the impact of different irrigation and fertigation schedules on the physical and biochemical properties of apple under high-density plantation was investigated. The quality of fruits is considerably influenced by irrigation and fertigation. Drip fertigation levels unveiled significant effect on fruit length (65.43 mm), fruit breadth (72.32 mm), and fruit weight (187.53 g). The application of 100% ETc with 100% AD (NPK) during fertigation enhanced both fruit size and weight. Under uniform application of water, photosynthesis increased, which improved the assimilate partitioning. Growth hormones, including cytokinins, gibberellins, and auxins, are generated at optimal and uniform nutrient distribution, which promotes nutrients uptake and assimilates water translocation, resulting in increased fruit size and weight. Drip irrigation and fertigation treatments produced fruits with better color. A higher dose of NPK applied via drip fertigation system produced higher levels of anthocyanin and ascorbic acid content in fruits over conventional approaches. Merging new orchard designs with a high-coloring strain of an apple cultivar and more efficient irrigation and fertigation systems results in higher productivity with better fruit quality and less water consumption.

An interplay of salt and Ni stress on contrasting tomato (Solanum lycopersicum L.) genotypes: a physiological and biochemical insight

The concurrently occurring multiple abiotic stresses like salinity and heavy metals (Nickel) pose a serious threat to plant survival and food security worldwide, especially in the face of climate change. Therefore, it is imperative to continuously test and study the plant’s physiological changes under combinations of abiotic stresses to ensure sustainability and food security. An experiment was conducted to study the interactive effects of salinity (0, 7.5, and 15 dS m−1) and Ni toxicity (0, 10, 20, and 40 mg kg−1) on a tolerant (Naqeeb) and a sensitive (Nadir) Solanum lycopersicum L. physiology and fruit quality in the soil. At maturity (50% fruit ripening), the plant growth and physiological characteristics were measured, revealing that the tolerant genotype exhibited the higher values for plant height, dry weight, potassium, membrane stability index (MSI), and antioxidant enzymes (superoxide dismutase; SOD, catalase; CAT, ascorbate peroxidase; APX, and glutathione reductase; GR). Additionally, it showed enhancement in fruit yield, size, and quality. Conversely, the tolerant genotypes showed a lower reduction in terms of plant height (25.4%) and plant dry weight (41.9%) compared to sensitive genotype (30.1 and 51.4%, respectively). Additionally, the tolerant genotype demonstrated lower values of Ni and Na+ concentration and MDA accumulation under the combined stress of salt and Ni, compared to the sensitive genotype. Furthermore, the study indicated that Ni at a concentration of 10 mg kg−1 significantly influenced tomato plant growth by enhancing its nutritional efficiency and competing with Na+. However, Ni at concentrations of 20 and 40 mg kg−1 had toxic effects on the plants, leading to a decrease in plant growth and physiological processes. Moreover, a negative relationship was observed between Ni uptake and Na+ uptake, while a positive relationship was observed between Ni and K+ uptake. Overall, this study provides valuable insights into the interaction between salinity, heavy metal toxicity, and tomato plant physiology, contributing to the development of sustainable agricultural practices.

D3-YOLOv10: Improved YOLOv10-BasedLightweight Tomato Detection Algorithm Under Facility Scenario

Accurate and efficient tomato detection is one of the key techniques for intelligent automatic picking in the area of precision agriculture. However, under the facility scenario, existing detection algorithms still have challenging problems such as weak feature extraction ability for occlusion conditions and different fruit sizes, low accuracy on edge location, and heavy model parameters. To address these problems, this paper proposed D3-YOLOv10, a lightweight YOLOv10-based detection framework. Initially, a compact dynamic faster network (DyFasterNet) was developed, where multiple adaptive convolution kernels are aggregated to extract local effective features for fruit size adaption. Additionally, the deformable large kernel attention mechanism (D-LKA) was designed for the terminal phase of the neck network by adaptively adjusting the receptive field to focus on irregular tomato deformations and occlusions. Then, to further improve detection boundary accuracy and convergence, a dynamic FM-WIoU regression loss with a scaling factor was proposed. Finally, a knowledge distillation scheme using semantic frequency prompts was developed to optimize the model for lightweight deployment in practical applications. We evaluated the proposed framework using a self-made tomato dataset and designed a two-stage category balancing method based on diffusion models to address the sample class-imbalanced issue. The experimental results demonstrated that the D3-YOLOv10 model achieved an mAP0.5 of 91.8%, with a substantial reduction of 54.0% in parameters and 64.9% in FLOPs, compared to the benchmark model. Meanwhile, the detection speed of 80.1 FPS more effectively meets the demand for real-time tomato detection. This study can effectively contribute to the advancement of smart agriculture research on the detection of fruit targets.

Tomato (Solanum lycopersicum L.) yield and quality depending on the osmotic potential and the number of stems

Objective: To evaluate the biochemical components, physical characteristics (number of stems and fruit), and yield of Saladette tomato (Solanum lycopersicum L.), Var. Cid F1, grown under greenhouse conditions and its response to a constant increase (from 1 to 2.5 dS m-1) of the osmotic potential of a nutrient solution, during three phenological stages (transplantation, 2nd cluster fruiting, and 6th cluster fruiting) of plants subjected to a single- and two-stem training system. Design/Methodology/Approach: A sampling was carried out in the 5th cluster to determine the physical characteristics (firmness, size, number, color) and biochemical components (total soluble solids, titratable acidity, vitamin C, lycopene, pH, electrical conductivity, and ripening index) of the fruits. The experiment was established in 2018, under a greenhouse hydroponic system at Colegio de Postgraduados. The experiment was set as randomized complete block design with four replicates. Results: The increase of osmotic potential and pruning had a positive effect on yield and number of fruits without affecting the biochemical components. Regarding the physical characteristics, T1 had 76% large fruits, 19% medium-sized fruits, 4% small fruits, and 1% tiny fruits. Study Limitations/Implications: This methodology should be evaluated to other tomato varieties using different substrate mixtures and rates of chemical and organic fertilizers to evaluate water response and crop yield. Findings/Conclusions: Increasing the osmotic potential of the nutrient solution, during phenological stages of maximum water and nutrient demand and the removal of old leaves had a positive response by increasing fruit number, size, and yield.