The effects of gibberellic acid (GA 3 ) on cluster and fruit quality were evaluated in the table grape cultivar Concord Seedless under two training systems, Munson and vertical shoot positioning (VSP), over two growing seasons (2023 and 2024). GA 3 was applied at three prebloom rates (21, 42, and 63 mg/L) and one postbloom rate (50 mg/L) in all combinations alongside water as a control. Cluster weight and the frequency of shot berries and berry thinning were all influenced by both training system and GA 3 treatment. Munson-trained vines produced heavier clusters than VSP-trained vines, possibly because of higher light exposure during fruit set. Prebloom GA 3 alone generally reduced or did not affect cluster weight and consistently caused cluster curling and excessive berry thinning. In contrast, postbloom GA 3 alone increased cluster weight, reduced shot berry frequency, and minimized negative effects on cluster appearance through excessive thinning or cluster curling. In 2024, the combination of prebloom and postbloom GA 3 produced the greatest cluster weight, suggesting a synergistic effect, but cluster curling and berry thinning were still observed. Overall, findings from our study indicate that a single postbloom GA 3 application may be an effective strategy for improving cluster quality in ‘Concord Seedless’.

Trichomes, the hair-like outgrowths of the plant epidermis, are critical for defence, reproduction and development. However, the underlying molecular mechanisms governing their initiation remain elusive. Here, we identified CsGL2, an AP2/ERF transcription factor, as a key integrator controlling trichome initiation and fruit development in cucumber. Genetic and molecular studies indicate that CsGL2 activates CsGL1/Mict, subsequently triggering the morphogenesis of multicellular trichomes. Beyond epidermal fate, CsGL2 upregulates the tubercle regulator Tu together with the cytokinin rate-limiting enzyme gene IPT1, thereby initiating fruit tubercles through cytokinin-linked pathways. Notably, we found that ovule-specific CsGL2 activates the parthenocarpy gene CsNPF1, and CsGL2 overexpression markedly increases the frequency of seedless fruit set. Thus, our findings establish a switch-based mechanism for progressive cell-fate specification in multicellular epidermal organs. This reveals how a single transcription factor integrates transcriptional and hormonal pathways to coordinate distinct developmental programmes.

Historically, angiosperm seed production has been considered to be either pollen or resource limited. However, seed production involves more than pollen and seed resources and typically involves multiple ovules in multiple flowers. Therefore, various constraints may act simultaneously. Proportional components of seed production were assessed for rapid-cycling Brassica rapa plants on which 25, 50, 75, or 100% of flowers were hand outcrossed. Fruit set increased in a decelerating manner with the percentage of pollinated flowers. For all treatments, only flowers pollinated early on plants produced fruit, although the transition to complete fruiting failure was delayed on poorly pollinated plants. Despite stigmas receiving abundant pollen, only 61% of ovules in pollinated flowers were fertilized, on average. Fertilization success varied within ovaries, with more fertilization of apical ovules in flowers on plants with 75% of pollinated flowers, but more fertilization of basal ovules with 25% pollination. Per-flower fertilization also varied positively with ovule number and the number of basal fruits and negatively with flower position. Almost all fertilized ovules developed into seeds, so variation in seed set depended primarily on the effects on ovule fertilization. Regardless of pollination treatment, seed production by all plants was jointly limited by both pollen and availability of seed resources and possibly by ovule infertility/receptivity. A simple model demonstrates that such co-limitation can be adaptive if plants produce excess flowers. Interacting effects of the proportion of pollinated flowers and anthesis day on fruit set are consistent with hormonal mediation of resource distribution among fruits.

Background and Aim: Guava (Psidium guajava L.), often referred to as the ‘Apple of Tropics,’ is a vital fruit crop in tropical and sub-tropical regions worldwide. This study focused on a sub-mountainous, undulating terrain with high cultivation costs and no permanent water sources, aiming to optimize fertilizer efficiency, enhance fruit yield and quality, and conserve water for future generations. Drip irrigation recognized as effective method for delivering water and nutrients, results in reduced water usage while, improving fruit quality. The research investigated the effects of fertigation on the phenological and physico-chemical responses of guava cv. Allahabad Safeda in the lower Shiwalik belt of Punjab. Study Design: The experimental trial utilized a simple randomized block design with ten different treatments replicated thrice. Place and Duration of Study: The research was conducted at Fruit Research Fram, Dr D R Bhumbla Regional Research Station, Ballowal Saunkhri, Balachaur, SBS Nagar, Punjab. The trial was conducted for duration of nine months. Methodology: The experiment comprised of 10 different treatment viz. T1 - I1F1 (100% of PE + 100% RDF), T2 – I1F2 (100% of PE + 75% RDF), T3 – I1F3 (100% of PE + 50% RDF), T4 – I2F1 (80% of PE + 100% RDF), T5 - I2F2 (80% of PE + 75% RDF), T6 - I2F3 (80% of PE + 50% RDF), T7 – I3F1 (60% of PE + 100% RDF), T8 - I3F2 (60% of PE + 75% RDF), T9 - I3F3 (60% of PE + 50% RDF) and T0 - control (no fertigation) and replicated thrice. The data were recorded and analyzed as per standard procedures. Results: The results showed significant improvements in phenological traits viz., date of initiation & period of vegetative bud emergence, date of initiation & period of flower bud initiation, date of initiation & period of peak flowering, date of initiation & period of fruit set; and date of initiation & period of fruit maturity. Additionally, the fruit's physico-chemical properties were also enhanced, yielding higher Vitamin C and pectin content, along with lower titratable acidity. Conclusion: This work underscores the importance of efficient water and nutrient management for sustainable guava production and improved nutritional security in agriculturally challenged areas.

Introduced flowering plants often encounter novel pollinator assemblages in their non-native ranges, potentially reshaping plant-pollinator interactions and driving evolutionary change. We tested whether variation in pollinator assemblages mediates local adaptation of introduced Mimulus guttatus (Phrymaceae). Using a reciprocal transplant experiment between the southern and northern extremes of the British Isles, we combined pollinator censuses with measurements of floral traits and fruit production to assess pollinator assemblages, phenotypic differentiation and selection. Pollinator assemblages differed between sites, with more abundant bumblebees in the northern garden. Pollinator visitation rate was positively associated with fruit set, indicating that pollinators remain essential for sexual reproduction in the introduced range. Plants from northern populations received more visits in the northern than in the southern garden, and more visits than southern populations in the northern garden. This pattern paralleled a previously reported local and home advantage in fruit production. Corolla width was under positive and stabilizing selection mediated by bumblebees in the north, suggesting that pollinator-driven selection contributes to floral differentiation between regions. Our findings demonstrate that M. guttatus has undergone pollinator-mediated adaptive differentiation within two centuries in the British Isles, highlighting how strong biotic pressures can generate rapid ecological diversification during plant introductions.

Biological invasions are strongly shaped by biotic interactions in recipient communities, which can either facilitate or constrain the establishment and spread of alien species. Among these interactions, antagonistic relationships with native consumers may act as mechanisms of biotic resistance, yet their role in plant invasions remains insufficiently explored. In this study, we analyzed the effect of nectar robbing (measured both as the intensity and frequency of robbing) by native floral visitors on the fruit set of the introduced plant, Kalanchoe pinnata, in the Galápagos Islands. The results showed that two generalist native species, robbed K. pinnata nectar, and significantly decreased fruit production. In addition, nectar robbing was more frequent in flowers with longer corolla tubes and in plants with larger floral displays, suggesting that pervasive robbing may impose selective pressures opposing floral trait patterns typically associated with legitimate pollination. These findings document a previously undescribed antagonistic interaction between native animals and an introduced plant, highlighting nectar robbing as a mechanism of biotic resistance that can constrain the sexual component of reproduction and potentially influence the evolutionary trajectory of invasive plants on oceanic islands.

Unveiling Breeding Tools for Improving Fruit Set in Oil Palm through Biotechnological Approaches: A Systematic Review

Durian (Durio zibethinus) requires cross-pollination for optimal fruit set, yet natural pollination rates remain below 10% due to declining pollinator populations. This study evaluates the efficiency and economic feasibility of mechanized pollination methods, focusing on their impact on fruit set and quality. A randomized complete block design (RCBD) was implemented in a commercial Mon Thong durian orchard to compare four pollination treatments, namely natural pollination (control), hand pollination, drone-assisted pollination using a DJI Agras T20P operated at an altitude of 7-8 meters above the canopy and air blower-assisted pollination using a KAWA BL5202 positioned 30-50 cm from the flowers. Each treatment was applied to 50 female flowers per tree under controlled conditions to assess fruit set and operational costs. Results showed that drone-assisted pollination achieved a 75% fruit set rate, surpassing air blower pollination (63%), hand pollination (58%), and natural pollination (9%). Economic analysis indicated that drone-assisted pollination reduced labor costs by 40% compared to hand pollination while maintaining comparable fruit quality in terms of size, weight, and seed abortion rates. Statistical analysis confirmed significant differences among methods (p < 0.05), with regression analysis demonstrating a strong correlation between pollination efficiency and yield profitability. To further optimize drone-assisted pollination, future studies should integrate Pollen Tracking Camera Systems for real-time pollen dispersion monitoring, Anemometer Sensors to adjust airflow based on wind conditions and sugar-based pollen adhesives to enhance pollen adhesion and fertilization efficiency. These innovations could refine drone-based pollination, ensuring higher consistency and maximizing fruit set in commercial durian production.

The Cucurbitaceae family encompasses some of the world's most economically significant vegetable and fruit crops, including cucumber, melon, watermelon, pumpkin, squash, and bitter gourd. Plant growth regulators (PGRs)—naturally occurring or synthetically applied compounds that modulate plant developmental processes—exert a profound and multifaceted influence on virtually every aspect of cucurbit crop physiology. This review synthesises current knowledge of how major PGR classes, namely auxins, gibberellins, cytokinins, ethylene and ethylene-releasing agents, abscisic acid, and brassinosteroids, regulate vegetative growth, sex expression, flowering, yield, and fruit quality across Cucurbitaceae. The central role of ethylene in determining floral sexuality through the ACC synthase gene network—CsACS2 in cucumber, CmACS7 in melon, CpACO1A in squash, and CitACS4 in watermelon—is examined alongside the promotive role of gibberellins in inducing male flower formation. The practical applications of exogenous ethephon for feminisation, silver compounds for masculinisation, and plant growth retardants for manipulating vegetative architecture are discussed with reference to their agronomic relevance. Parthenocarpy, mediated primarily by auxins, cytokinins, gibberellins, and brassinosteroids, emerges as a key strategy for improving fruit set under suboptimal pollination conditions. The contribution of abscisic acid to non-climacteric fruit ripening in watermelon and the complex hormonal crosstalk governing postharvest quality are also addressed. This review reveals both the scientific advances and the remaining knowledge gaps, and highlights the potential of integrating molecular and applied PGR research to improve cucurbit productivity and quality in the face of climate variability and changing agricultural demands.

Date palm is a vital fruit crop widely cultivated in developing regions, contributing significantly to food security, nutrition, and economic sustainability due to its rich content of carbohydrates, minerals, dietary fiber, and bioactive compounds. This study evaluated the combined effects of vermicompost (VC) and micronutrients with amino acids (Trace-amino, TA) on the yield and fruit quality of Barhi date palm under the agro-climatic conditions of Qena Governorate, Southern Egypt. Seven treatments were applied, including three levels of VC (50, 75, and 100 mL L⁻¹) as a soil application combined with two foliar levels of TA (2 and 4 g L⁻¹), in addition to a control treatment (water spray). The results showed that all treatments significantly improved yield components, including fruit set, fruit retention, bunch weight, and yield per palm, as well as fruit physical and chemical characteristics compared to the control. The highest yield and best fruit quality were recorded with the application of VC at 100 mL L⁻¹ combined with TA at 4 g L⁻¹, followed by VC at 100 mL L⁻¹ with TA at 2 g L⁻¹ during both seasons.

The twenty-seven identical peach trees were exposed to different levels of a Nano Chelated fertilizer contain 12% Zn and Spirulina platensis liquid extract in a factorial experiment based on RCD, in order to enhance fruit yield and quality. The maximum values of leaf area (35.9 cm2), SPAD (51.2 value), fruit set (28.2%), fruit firmness (26.3 lb. inch-2), fruit diameter (137 mm), individual fruit weight (116.3 g), flesh weight of fruit (106.7 g), seed weight (9.6 g), fruit number per tree (534.7 n), fruit yield per tree (62.2 kg), fruit yield (31.5-ton ha-1), TSS (13.15°Brix), and vitamin C content (12.90 mg/100 mg FW) were obtained under application of Spirulina platensis at 2500 ppm plus Zn NPs at 6 mL L-1. Furthermore, the lowest fruit decay (33.33%) was observed under this combined treatment. Application of this treatment significantly improved leaf area (8.2%), SPAD (58.3%), fruit set (32.8%), fruit number (46.5%), fruit diameter (30.5%), fruit weight (41.7%), flesh weight (42.0), seed weight (37.9%), fruit yield per tree (107.5%), fruit yield ha-1 (107.5%), fruit firmness (62.9%), fruit decay (-44.5%), TSS (83.7%), and total phenol (6.6%ns) compared to control. Principal component analysis (PCA) confirmed results of means comparison and recognized 2500 ppm Spirulina platensis extract +6 mL L-1 Zn NPs as the optimal treatment to maximize yield and growth traits while maintaining low decay and high biochemical quality. Furthermore, Pearson's correlations and regression analysis revealed the strong positive relations between physical, morpho-physiological, and yield variables. Based on the results of univariate analysis and confirmation with multivariate analysis, Foliar application of 2500 ppm seaweed in combination with 6 mL L-1 Zn NPs has been recommended for the improvement of fruit quantity and quality in peach trees.

Climate impacts apple pollination, yield and economic outcomes of farmers.

Pawpaw ( Asimina triloba ), a North American native tree fruit, produces tropical-flavored fruit for fresh-market sales, and its extracted pulp is widely used in value-added products such as wine, beer, brandy, and jam. However, pawpaw can exhibit poor fruit set as a result of self-incompatibility and a lack of effective pollinators during flowering. We identified, categorized, and quantified the insect species that were potential pollinators visiting the flowering and nonflowering branches of two pawpaw cultivars. Three sampling methods were used: sticky traps, field observations during the flowering period, and insect collections from flowers at peak bloom. In 2023 and 2024, sticky traps were deployed in a completely randomized design. Field observations were conducted on male- and female-stage flowers in 2024 to record visitation rates, and insects were collected from flowers for identification to order and taxa. Across both years, Diptera and Coleoptera were the most abundant insects captured in traps, followed by Hemiptera, Hymenoptera, and Lepidoptera in lower numbers. During flowering observations and collections, male-stage flowers attracted significantly more insects than female-stage flowers, particularly flies and click beetles. Lady beetles were most abundant overall. Many insects were observed carrying pollen, indicating their potential contribution to pollination. Enhancing the attraction of key beetle and fly species may improve pawpaw pollination efficiency and fruit set in commercial orchards.

Chinese jujube (Ziziphus jujuba Mill., 2n = 2x = 24) is a drought-tolerant, nutrient-rich fruit crop. However, its genetic improvement is constrained by protandry, low fruit set, and severe embryo abortion. Interspecies hybridization between Chinese jujube and Indian jujube (Ziziphus mauritiana Lam., 2n = 4x = 48) is further hindered by asynchronous flowering. We developed a dual-regime protocol combining temperature control and strategic heavy pruning to advance the flowering time of Indian jujube (cultivar 'Niunaidaqingzao', N) by 2months, thereby synchronizing its anthesis with that of Chinese jujube ('Dongzao', D) and wild Chinese jujube ('Suanzao', S). In vitro artificial self-pollination (AS) and in vitro artificial cross-pollination (AC) were conducted to assess pollen tube elongation and ovary expansion. Triple AS (TAS) boosted pollen tube emergence to 59%-87% across the three genotypes, more than doubling in vitro spontaneous self-pollination (SSP) rates and outperforming single AS 1.4 to 2.7 times (P < 0.05). Ovary-swelling frequencies of TAS reached 68.52% in wild Chinese jujube S and 27.78% in Indian jujube N, indicating 2.85 and 2.14 times increases over SSP and 1.88-4.11 times increases over single AS. In ♀S × ♂D, ♀D × ♂S, and ♀S × ♂N crosses, triple AC (TAC) raised pollen tube emergence to 54%-72% (1.3-2.2 times of single AC) and ovary expansion to 26%-39% (1.4-1.9 times of single AC) (P < 0.05). These findings provide a practical and efficient strategy for overcoming asynchronous flowering and reproductive barriers of interspecies hybridization in genus Ziziphus, enabling the establishment of interspecies hybrid populations for downstream breeding programs.

Phytolacca acinosa Roxb., a perennial herb native to East Asia, is increasingly naturalizing in Europe, yet its reproductive ecology in the secondary range remains poorly understood. This study evaluated seed productivity across central and edge populations in the secondary range, fruit and seed morphometrics, and germination responses to cold storage, acid scarification (simulating bird endozoochory), and light exposure. Fruit production per raceme was influenced by an interaction between insolation and range position: reduced insolation increased fruit set in central populations but decreased it at the range edge. Raceme number per shoot was lower in spontaneous plants compared to cultivated ones. Fresh seeds exhibited strong dormancy with no germination without scarification. Acid scarification significantly enhanced germination, particularly with light exposure, reaching up to 55%. Cold storage did not increase germination percentage but accelerated germination of scarified seeds under light, reducing median germination time from 24 to 21 days. Compared to the congeneric P. americana, P. acinosa shows more stringent dormancy requirements. We conclude that P. acinosa retains deep seed dormancy in its secondary range and relies on bird-mediated endozoochory for both dispersal and dormancy release. At the northern range edge, reduced plant vigor and lower raceme numbers are partially offset by increased flower production per raceme, though fruit set remains constrained. The species does not exhibit the simplified germination requirements often associated with successful invaders; instead, its invasion success appears driven by a bet-hedging strategy combining persistent seed banks with specific dormancy-breaking cues.

Determination of the effects of bumblebee (Bombus terrestris), hand, and natural pollination on fruit set, yield, and quality in pitaya (Hylocereus spp.) cultivation under subtropical conditions.

Successful hybrid seed production in pepper depends strongly on the stress sensitivity of reproductive processes, particularly pollen function and flower retention. Integrating physiological understanding of pollen biology, hormonal regulation of abscission, and targeted environmental and genetic interventions is essential to stabilize fruit set and improve hybrid seed yield under increasing climatic variability. Hybrid pepper (Capsicum annuum L.) F1 seed production relies largely on controlled (manual) emasculation and pollination, while seed set at commercial scale is often unstable due to the pronounced environmental sensitivity of the reproductive phase. The present review discusses, within an integrated framework, the main constraints of manual pollination and hybrid seed yield as well as the possible solutions, with particular emphasis on (i) abiotic stressors (temperature, light intensity and light spectrum, water and nutrient supply, relative humidity), (ii) pollen biological and progamic processes, (iii) the hormonal regulation of flower and young fruit abscission, and (iv) genetic/male-sterility systems supporting hybrid purity. Based on the literature, pollen is the most stress-sensitive "weak link": consistently high temperatures (above 32°C) and unfavorable light regimes impair pollen development, viability, and pollen tube growth, while shifts in the auxin-ethylene balance in the abscission zone increase flower and fruit drop. Reduced assimilate availability (source-sink competition) and the hormonal dominance of developing fruits further intensify abortion, in protected cultivation potentially leading to cyclic fruit-set patterns. Although CMS/CGMS (cytoplasmic and cytoplasmic-genic male sterility) and GMS (genic male sterility) systems can reduce labor costs and improve genetic purity, their application is not suitable in all breeding and hybrid seed production scenarios; therefore, controlled pollination performed with manual emasculation remains of key importance. The review proposes a physiology-based, decision-support approach that integrates microclimate optimization (thermal and spectral management), pollen-based rapid phenotyping, and marker-based male-sterility identification to improve successful fertilization, seed formation, and hybrid seed quality. In this review, the most critical research gap is the lack of an empirically validated relationship between in vitro pollen stress assays and in vivo fertilization and seed-set success, as this could establish the predictive foundations of stress-tolerant, scalable hybrid seed production.

Tofu liquid waste contains organic materials that can be utilized as liquid organic fertilizer (LOF). This study aims to determine the effect of dose and interval of LOF from tofu liquid waste on tomato plants (Lycopersicum esculentum. L). This study, conducted from April to July 2024 in Gajah Bendo Village, Pasuruan, examined the impact of tofu liquid waste-based Liquid Organic Fertilizer (LOF) on tomato plants (Lycopersicum esculentum. L). Utilizing a Completely Randomized Design (CRD) with two factors in triplicates, the researchers tested four dosage levels (0, 100, 200, and 300 ml/plant) and three application intervals (6, 10, and 14 days). The results of the study found that the combination of LOF tofu liquid waste dosage at a dose of 300 mL/plant with an application interval of 14 days resulted in the fastest flowering age compared to other treatment combinations. However, the combination of dosage and application interval treatments did not significantly affect the parameters of plant height, number of fruits, and fruit sets. The LOF application even tended to reduce the harvest weight of tomato fruit compared to the control treatment. Future research can focus on the optimal fermentation time of liquid waste to prepare LOF and apply the LOF on tomato plants under more controlled conditions such as in a greenhouse.

The hoverfly Episyrphus balteatus (Diptera: Syrphidae) contributes to crop pollination and biological control; however, these two essential ecosystem services are seldom jointly assessed. Here, we evaluate the pollination efficacy and aphid control performance of mass-reared E. balteatus in three greenhouse horticultural crops, i.e. tomato, eggplant, and muskmelon. In addition, fruit quality parameters were compared among crops subjected to hoverfly pollination and hormone treatment. Under E. balteatus treatments, fruit set in tomato, muskmelon, and eggplant was raised to rates above 97%. Hoverflies equally contributed to biological control of the aphid Aphis gossypii, achieving high control efficiency. The aphid biological control efficacy was 88% in muskmelon and 92% in eggplant under a hoverfly:aphid ratio of 1:200. Compared to hormone treatments, fruits pollinated by E. balteatus exhibited more symmetrical and rounded shapes along with enhanced nutrient content. Our study demonstrates that hoverfly-mediated pollination and biological control services bolster the yield and quality of crops, providing forward momentum for more sustainable forms of agri-food production in China and abroad. © 2026 Society of Chemical Industry.

ABSTRACT Revealing the linkages among camellia ( Camellia oleifera Abel.) growth, soil multifunctionality, and cow manure application rate might offer new light on the optimization of cow manure application rate and ecological and economic benefits in camellia plantations. However, studies have focused on the effect of cow manure application on soil multifunctionality and camellia growth, but the trade‐off between cow manure application rates and soil multifunctionality and camellia growth remains unclear. Thereby, we analyzed the linkages among fruit setting, soil nutrient availability and multifunctionality, and microbial communities with four different cow manure application rates (control without cow manure (CK); 10 kg plant −1 (CL); 20 kg plant −1 (CM); and 30 kg plant −1 (CH)). Soil multifunctionalities in the CL, CM, and CH treatments were increased by 39.74%, 66.57%, and 68.36%, respectively, compared to the CK treatment. The fruit setting rates in the CL, CM, and CH treatments were 2.00, 4.75, and 4.50 times of the CK treatment, respectively. Cow manure applications significantly enhanced soil total nitrogen (N), ammonium nitrogen (NH 4 + –N), nitrate nitrogen (NO 3 − –N), and microbial biomass nitrogen (MBN) contents, which had significant and positive effects on soil multifunctionality and fruit setting rate. Moreover, increases in soil mineral N contents stimulated soil Actinobacteria growth and activity, which also drove soil multifunctionality and fruit setting rate with cow manure amendment. Given the comprehensive balance among multifunctionality, fruit setting rate, cow manure input cost, microbial characteristic, and environmental impact, the 20 kg cow manure per plant might be appropriate for camellia plantations in this study. The comprehensive balances across yield, soil, and microbial properties should be further considered in the future.