Fruit Set Research Articles

Effect of Seaweed Extract and Humic Acid Treatment on the Phenological and Yield Characteristics of Guava (Psidium guajava L.)

Aim: The main aim of this study was to evaluate the impact of seaweed and humic acid treatment at different doses on the phenological characteristics and yield of guava. Study Design: Randomized block design. Place and Duration of Study: A field experiment was conducted from December 2023 to July 2024 to assess the impact of bio-stimulants on the phenological and yield traits of guava (var. Arka Kiran) in the Poongunam village, Chengalpattu Dist, Tamil Nadu, India. Methodology: The experiment followed a Randomized Block Design with eight treatments: T₁ - Absolute control, T₂ - Water Spray, T₃ - 1% Seaweed Extract, T₄ - 1.5% Seaweed Extract, T₅ - 2% Seaweed Extract, T₆ - 1% Humic Acid, T₇ - 1.5% Humic Acid, and T₈ - 2% Humic Acid, each replicated three times. Results: Results showed that 2% Seaweed Extract (T₅) significantly improved flower retention (7.55 flowers per shoot), reduced the duration from flowering to fruit set (12.47 days), and shortened the time from fruit set to harvest (121.56 days). T₅ also led to the highest fruit set (68.65%), lowest fruit drop (48.72%), largest fruit weight (150.02 g), and greatest yield (13.35 kg/tree). Humic Acid at 2% (T₈) also improved fruit set (64.32%), fruit drop (49.54%), and yield (12.34 kg/tree), but was less effective than Seaweed Extract. Conclusion: This study demonstrates the potential of Seaweed Extract as a powerful bio-stimulant to enhance guava production, offering a sustainable alternative to traditional chemical treatments.

Impacts of Climate Change-Induced Temperature Rise on Phenology, Physiology, and Yield in Three Red Grape Cultivars: Malbec, Bonarda, and Syrah

Climate change has significant implications for agriculture, especially in viticulture, where temperature plays a crucial role in grapevine (Vitis vinifera) growth. Mendoza’s climate is ideal for producing high-quality wines, but 21st-century climate change is expected to have negative impacts. This study aimed to evaluate the effects of increased temperature on the phenology, physiology, and yield of Malbec, Bonarda, and Syrah. A field trial was conducted over two seasons (2019–2020 and 2020–2021) in an experimental vineyard with an active canopy heating system (+2–4 °C). Phenological stages (budburst, flowering, fruit set, veraison, harvest), shoot growth (SG), number of shoots (NS), stomatal conductance (gs), chlorophyll content (CC), chlorophyll fluorescence (CF), and water potential (ψa) were measured. Additionally, temperature, relative humidity, light intensity, and canopy temperature were recorded. Heat treatment advanced all phenological stages by approximately two weeks, increased SG and NS, and reduced gs and ψa during the hottest months. CC and CF remained unaffected. The treatment also resulted in lower yields, reduced acidity, and increased °Brix in both seasons. Overall, rising temperatures due to climate change advance the phenological phases of Malbec, Syrah, and Bonarda, leading to lower yields, higher °Brix, and lower acidity, although physiological variables remained largely unchanged.

Improving Performance and Yield of Solanum Melongena L. through Growth Regulator Applications

This study was conducted in an agricultural area located in Dharmabad, Nanded district, Maharashtra. The experiment followed a randomized design with three replications and involved the application of ten different growth regulator treatments. The findings indicated that foliar treatment significantly influenced the vigor of Brinjal plants and their yield-contributing features when compared to the control group. Specifically, the foliar application of Tricontanol and Gibberellic acid during the flowering and bud stages resulted in notable improvements in plant height, plant spread, number of branches, and number of fruits per plant. These treatments also demonstrated positive effects on various yield-contributing characteristics such as days to 25% flowering, fruit set, fruit length, and fruit diameter, as compared to the control group.

Comparison of the Morphological Characteristics, Yield, and Quality Traits of Fruits of Two Papaya Cultivars Grown Under Protected Cultivation

This study aimed to investigate the morphological characteristics and performance of Formosa and Sunrise Solo papaya cultivars under protected cultivation in subtropical climate conditions as well as the relationships between the yield and factors affecting the yield. The Formosa cultivars had higher values in terms of plant height (519.4 cm), stem diameter (238.4 mm), first flowering height (138.2 cm), and duration from flowering to harvest (141 days) compared to the Sunrise Solo cultivars. The yield per plant was higher in the Formosa cultivars (52.5 kg/plant/year) than in the Sunrise Solo cultivars (27.4 kg/plant/year). The values of fruit peel color parameters were highest in the spring, the fruit flesh firmness was highest in the autumn, and the soluble solid content was higher in fruits harvested in the summer. Medium to high positive phenotypic correlations were found between the first flowering height and fruit set, fruit weight, yield, fruit width, fruit length, and fruit flesh firmness (0.371–0.595) and between the fruit set (number/plant) and fruit weight, yield, fruit width, fruit length, and fruit flesh firmness (0.388–0.819) (p ≤ 0.01). The papaya can be commercially cultivated under protected cultivation in extreme subtropical conditions, and the Formosa cultivars generally performed better than the Sunrise Solo cultivars across many parameters.

Strategic honey bee hive placement improves honey bee visitation but not pollination in northern highbush blueberry.

Commercial blueberry Vaccinium spp. (Ericales: Ericaceae) production relies on insect-mediated pollination. Pollination is mostly provided by rented honey bees, Apis mellifera L. (Hymenoptera: Apidae), but blueberry crop yields can be limited due to pollination deficits. Various hive placement strategies have been recommended to mitigate pollination shortfalls, but the effect of hive placement has received limited formal investigation. This study explores the effects of clumped and dispersed hive placement strategies on honey bee visitation and pollination outcomes in "Bluecrop" and "Duke" fields over 2 years (2021 and 2022) within 2 economically important regions of production in the United States-the Midwest (Michigan) and Pacific Northwest (Oregon and Washington). Clumping hives consistently increased honey bee visitation rate but did not result in higher fruit set, fruit weight, or seed count. Increases in honey bee visitation through clumping could perhaps improve pollination outcomes in more pollination-limited blueberry cultivars and other pollination-dependent crops. Clumping hives is substantially more efficient and cost-effective for beekeepers due to fewer drop locations and could lead to cost savings for both beekeepers and blueberry growers without growers sacrificing pollination levels and crop yields.

Climate Change as an Existential Threat to Tropical Fruit Crop Production—A Review

Climate change is an emerging threat to global food and nutritional security. The tropical fruits such as mango, bananas, passionfruit, custard apples, and papaya are highly sensitive to weather changes especially; changes of monsoon onset and elevated temperature are influencing crop growth and production. There is a need for more specific studies concerning individual crops and regional variations. Long-term effects and interactions of weather parameters and increased concentration of greenhouse gases, especially carbon dioxide, with phenological stages of the plant, pests, and diseases remain understudied, while adaptation strategies require further exploration for comprehensive understanding and effective mitigation. Few researchers have addressed the issues on the effect of climate change on tropical fruits. This paper focuses on the impact of abiotic (temperature, rainfall, humidity, wind speed, evaporation, carbon dioxide concentration) and biotic (pest and pathogens dynamics) factors affecting the fruit crop ecosystem. These factors influence flowering, pollination, fruit set, fruit yield and quality. This review paper will help develop adaptive strategies, policy interventions and technological innovations aimed at mitigating the adverse effects of climate change on tropical fruit production and safeguarding global food and nutritional security.

Comparative Analysis of Photosynthetic Traits, Yield, and Fruit Quality Among Different Chestnut Cultivars

This study aimed to compare the photosynthetic physiological traits, fruiting characteristics, and fruit quality of four different chestnut cultivars. The cultivars studied were ‘Yanshanzaofeng’ (YS), ‘Guangdedahongpao’ (GD), ‘Chang’anhuijianli’ (CA), and ‘Guizhouyouli’ (GZ). Leaf functional traits, photosynthetic activity, fruit setting characteristics, and both external and internal fruit quality indicators were measured. The results indicated significant differences in leaf traits among cultivars. Cultivar GD exhibited the largest leaf area and dry matter content, while cultivar GZ had the smallest. The photosynthetic rate (Pn) followed a bimodal curve, with an obvious ‘lunch break’ caused by stomatal limitations. Cultivar GD had the highest Pn, followed by CA, YS, and GZ. The water use efficiency (WUE) and CO2 utilization of cultivar CA were notably superior, indicating its suitability for arid conditions. In terms of yield, cultivar GD had the highest bur, nut weight, and plant yield, followed by CA, YS, and GZ. The phenotypic quality of the fruit was also superior in cultivar GD. However, cultivar YS had the highest amylopectin and soluble sugar content, and cultivar GD had the greatest amylose, total starch, and fat content. Cultivars CA and YS exhibited better overall fruit quality than GZ. Correlation analysis revealed that single bur weight, single nut weight, and single plant yield all exhibited highly significant or significant positive correlations with Pn, stomatal conductance (Gs), intercellular CO2 concentration (Ci), and the transpiration rate (Tr). The longitudinal diameter of burs showed a significant positive correlation with vitamin C (Vc), Pn, and Gs, with a correlation coefficient of 0.99. Additionally, both the transverse and longitudinal diameters of nuts were significantly positively associated with Pn and Ci. Furthermore, the total starch content and water content of nuts demonstrated a significant positive correlation with Pn. In conclusion, cultivar GD was found to be ideal for high-yield starch production, while cultivar YS offers superior sweet and waxy nut qualities. Cultivar CA presents a balance of photosynthetic capacity, yield, and quality, making it the second-best candidate. Cultivar GZ is unsuitable for large-scale cultivation.

Flower scent, pollinators, and effects of proximity between plants on fruit set of the rare, threatened, and endemic Daphne rodriguezii

AbstractThis study focuses on Daphne rodriguezii, a threatened plant species that is endemic to Menorca in the Balearic Islands of the Western Mediterranean. The main objective was to investigate the volatile organic compounds (VOCs) in the floral aroma, as well as the timing and chemical variations in scent production. The primary pollinators were identified, and the relationship between their behavior and the chemical profile of the floral scent was investigated. Furthermore, the impact of plant density on fruit set rates was evaluated to obtain valuable insights for conservation and habitat‐management initiatives. The findings reveal that D. rodriguezii emits a distinct sweet floral aroma that primarily consists of benzenoids and linalool derivatives. Scent emission occurs during the evening and night, coinciding with the activity period of moths (Autographa gamma), which were identified as the primary pollen vectors for this self‐incompatible species. The fruit set values exhibit a positive correlation with the proximity between plants. These results emphasize the importance of moths and plant proximity as crucial factors to consider in the conservation management of this species.

The reproductive strategy of a typical distylous Ophiorrhiza alatiflora (Rubiaceae), in fragmented habitat

IntroductionHeterostyly is a genetically controlled style polymorphism, that plays an important role in promoting outcrossing and improving reproductive fitness. Although distyly is often studied in plants of the Rubiaceae family, little attention has been paid to the reproductive strategies of distylous species in fragmented habitats. Here, We report for the first time the growth of Ophiorrhiza alatiflora, a type distylous species, in karst areas and evaluate its reciprocity between long styled morph and short one. We analyze the two distyly morph differences in the ancillary polymorphic of flowers and explore their reproductive strategy in fragmented habitats.MethodsIn this study, we measured the floral characteristics of different morphs and performed differential secondary metabolite analysis on different morphs and tissue organs; Different pollination treatments were carried out to observe the fruit set, pollen germination, and pollen tube elongation of O. alatiflora.Results and discussionOur research indicates that O. alatiflora is a typical distylous plant for the distyly has high reciprocity. Both morphs exhibit the highest fruit set of intermorph outcrossing; The pollen germination and pollen tube elongation experiments have also demonstrated that the affinity of pollen from intermorph outcrossing is highest, regardless of whether it is the long or short morph as the maternal parent; Meanwhile, O. alatiflora is an incompletely self-incompatible plant that exhibits a certain degree of self-pollination and intramorph outcrossing, which may be one of the important means to ensure sustainable reproduction in severely disturbed habitats. In the ancillary polymorphic of flowers, L-morphs flowers produce more pollen, and S-morph flowers produce more ovules to improve their male-female fitness and compensate for the asymmetry of pollen flow; Compared with S-morphs, L-morphs contain significantly higher levels of several kinds of terpenoids. S-morphs produce more flavonoids than L-morphs. The differences in secondary metabolites between L-morphs and S-morphs are mainly reflected in the different nutritional organs (including stems and leaves). Overall, our work has revealed the unique reproductive strategy of O. alatiflora in fragmented habitats based on the characteristics of distyly, verifying the hypothesis that the distyly of O. alatiflora promotes outcrossing and avoids male-female interference, improving male-female fitness and this is the first time in the Ophiorrhiza genus.

Competitive network of polyamines metabolic and ethylene biosynthesis pathways during gibberellin-induced parthenocarpic grape fruit setting

Polyamines (PAs) and ethylene are involved in the modulation of plant growth and development. However, their roles in fruit-set, especially in exogenous gibberellin (GA3)-induced grape parthenocarpic berries, and the related competitive action mode are poorly understood. For this, we, here performed their content determination, bioinformatics and expression pattern analysis of genes to identify the key ones in the competitive network of polyamines metabolic and ethylene biosynthesis (PMEB) pathways. The content of putrescine (Put) significantly increased; while 1-aminocyclopropanecarboxylic acid (ACC) sharply decreased during the fruit-set process of GA3-induced grape parthenocarpic seedless berries. Totally, twenty-five genes in PMEB pathways, including 20 polyamines metabolic (PM) genes and 5 ethylene biosynthesis (EB) ones were identified in grape, of which 8 PM and 2 EB genes possessed the motifs responsive to phytohormone GA. The expression levels of most PMEB genes kept changing during grape fruit-set generating a competitive action mode of GA3-mediated two metabolic fluxes toward PAs and ethylene synthesis. Exogenous GA3 might enhance grape fruit-set of parthenocarpic berries via up-regulation of VvSAMS4, VvSAMDC1/2, VvODC1, VvSPDS1, and VvPAO1 to promote PAs accumulation, whereby repressing the ethylene synthesis by down-regulation of VvACS1 and VvACO2. Our findings provide novel insights into GA3-mediated competitive inhibition of ethylene by PAs to promote the fruit-set of parthenocarpic berries in grape, which has important implications for molecular breeding of seedless grape with high fruit-setting rate.

Effect of weather on panicle development, flower morphogenesis and fruit set in litchi cv. Shahi

Effect of weather on panicle development, flower morphogenesis and fruit set in litchi cv. Shahi

Effect of plant bio regulators on fruit set and yield of cashew (Anacardium occidentale L.) cv. BPP-9

Effect of plant bio regulators on fruit set and yield of cashew (Anacardium occidentale L.) cv. BPP-9

Melatonin and Gibberellin Employing to Mitigate Heat Stress Effects on “Canino” Apricot

The fruit yield of apricot trees may decrease as a result of temperature stress. Through improving growth, productivity, and fruit quality, some compounds may play a significant part in resolving that issue. Therefore, this study was conducted during two successive growing seasons (2017 and 2018) in order to lessen the effects of heat stress on the production and fruit quality of Canino apricot trees cultivated on the farm of the Horticulture Research Station at El Kanater El Khayreia, Egypt, by foliar spray of hormonal substances and antioxidants i.e. (melatonin “MEL” or gibberellic acid” GA3 “each at concentration (25 mg/L) at pre-dormancy stage. It could be concluded that spraying Canino apricot trees at pre-dormancy stage (August) with both of GA3 and MEL enhanced the vegetative growth, as well as it improved flower quality compared with untreated control during the two cultivated seasons, also, melatonin improved growth and fruit set, yield, and fruit quality, followed by gibberellic acid compared with Control.

Optimizing Olive Production: The Role of Foliar Fertilizers in Boosting Yield and Quality

To enhance yield and produce high-quality olive products, it is crucial to implement accurate and balanced fertilization programs. Like other crops, olive trees require the application of specific macro and micronutrients in addition to basic fertilization. This study aimed to evaluate the effects of foliar fertilizer applications containing K as well as N, K, Ca, and B, in addition to basic fertilization, on the yield and quality parameters of the Gemlik olive (Olea europaea L. cv. Gemlik) variety, known for its high economic value and use in black table olives and oil production, during two consecutive seasons in 2021–2022. The research evaluated the effects on olive fruit yield, fruit nutrient content (N, Ca, P, Na, K, Mg, Zn, Fe, Cu, and Mn), oil yield, and quality. In addition to traditional basic fertilization (NPK fertilizer), foliar fertilizers containing K as well as N, K, Ca, and B nutrients were applied before flowering and after fruit set. These applications were organized using a randomized block design with three replicates, each consisting of three trees. The results showed that foliar fertilizer applications, in addition to basic fertilization, had a significant impact on the yield and quality parameters. Specifically, foliar K applications positively affected olive yield in the second year. Moreover, foliar fertilizer applications improved the fruit nutrient content, oil quality (K-232, K-270, peroxide, acidity, and total phenol), and oil composition (%). Therefore, it is recommended that foliar fertilizers are applied during similar periods under similar conditions. However, ensuring the continuity of an optimal fertilization management plan is crucial for olive, as it is a perennial plant.

Influence of organic manures on yield parameters of guava (Psidium guajava) cv. Lucknow 49

The present investigation on “Influence of organic manures on yield parameters of guava (Psidium guajava) cv. Lucknow 49” was conducted in a farmer’s field located at Suthamalli village under Ariyalur District, Tamil Nadu during 2023-24. The study aimed to evaluate the application of organic manures, specifically combinations of farmyard manure, vermicompost, poultry manure, and neem cake significantly enhanced the yield parameters of guava cv. Lucknow 49 compared to untreated control conditions. The field experiment was laid out in randomized block design in three replications with fourteen treatments. The treatments were designed by combination of FYM, vermicompost, poultry manure and neem cake at different levels. The results of the present study indicated that the yield parameters viz., number of flowers/tree (162.16 and 173.36), number of fruits/tree (151.97 and 163.52), fruit set percentage (93.71 % and 94.32%), fruit length (6.71 and 6.98 cm), fruit diameter (6.89 and 7.10 cm), fruit weight (189.22 and 193.27 g) and yield/tree (29.83 and 34.18 kg) was found to be the highest in two successive crops, the treatment which received soil application of FYM 10 kg + vermicompost 5 kg + poultry manure 2.5 kg + neem cake 5 kg/tree followed by vermicompost 5 kg + poultry manure 2.5 kg + neem cake 5 kg/tree. The least values for all the yield parameters were noticed in the untreated control.

Characterization of Some Leading Mango (Mangifera indica L.) Cultivars in Bihar Condition Based on Yield and Chemical Quality Parameters

A conventional and simple technique to determine the ideal genotype for a breeding program is to characterize various genotypes of mangos according to their yield and chemical quality parameters. In light of this, an inquiry was carried out in the experimental area of BAU, Sabour, with the aim of characterizing a few elite mango cultivars in the agro-climatic conditions of Bihar based on factors related to yield and chemical quality. Using yield and chemical quality characteristics, twenty mango cultivars were characterized in 2008–2009. Fruit set per panicle (12.66 to 72.58 fruits per panicle), number of fruits per tree (284.15 to 784.41 fruits per tree), fruit weight (105.45 to 488.15g), fruit yield (39.67 to 343.68 kg), TSS (15.60 to 21.96 0Brix), total sugar (13.25 to 24.15 percent), reducing sugar (2.20 to 6.92 percent), acidity (0.23 to 0.43 percent), and ascorbic acid (11.49 to 55.22 mg) were among the cultivars that differed most significantly. In the Bihar agro- climatic conditions, Langra surpassed Mallika in terms of fruit quality criterion and Mallika produced a greater yield among the cultivars described below.

Vanilla planifolia: Artificial and Insect Pollination, Floral Guides and Volatiles.

The natural pollinator of the major species of commercially-grown vanilla, Vanilla planifolia, is unknown, and the crop requires hand pollination to achieve significant levels of fruit set; however, the traditional technique (using a toothpick) is costly, as it requires skilled personnel. To overcome this problem, two native Australian bees, Tetragonula carbonaria and Austroplebeia australis, and the blowfly, Lucilia cuprina, were trialled as pollinators. Three alternatives to the toothpick method were also trialled. The appearance of vanilla flowers under ultraviolet radiation was examined to determine the presence of cryptic pollination guides, and the chemical composition of nectar from extrafloral nectaries and aroma volatiles from the flowers were characterised. None of the three insects effected pollination due to their small size and behaviour; other insect pollinators need to be identified. The alternative mechanical methods of pollination trialled resulted in fruit set; however, the percentages of fruit set were lower than the traditional toothpick method, and the fruit were of inferior quality. The nectar produced predominantly consisted of sucrose and melezitose. Melezitose is a strong attractant of various ant species, which may explain the concentration of ants around the nectaries and the apparent lack of nectar production in part of this study. The aroma volatiles included monoterpenoids, terpenes, sesquiterpenoids, aromatics, nitrogen-containing compounds and fatty acids, the most abundant being a-pinene and eucalyptol. Illumination of the flowers with UV-A radiation revealed fluorescence from the stamens, the column and the callus, which is located on the labellum. These observations may aid the identification and use of potential pollinators.

Viability fertility and SEM studies on cryopreserved pollen of cashew (Anacardium occidentale L.)

Abstract Cryopreservation can be utilized as an efficient and reliable tool for long-term conservation of cashew genetic diversity. This study aims at pollen germination in vitro, SEM studies, pollen cryopreservation and fruit set with cryostored pollen of cashew. Brewbaker’s and Kwack (1963) medium enriched with 30% sucrose and15% PEG elicited significant pollen germination in vitro. Madakkathara-2 recorded high viability profiles both with respect to fresh (90.32%) and cryopreserved (85.53%) pollen when compared to other genotypes and species. Anacardium othonianum recorded lower viability in fresh (40.97%) as well as cryopreserved (25.43%). The pollen grains were cryopreserved for six months and post viability assessment was carried out at regular intervals. Field pollination was carried and in vivo fertility was assessed using four month cryostored pollen. A fruit set range of13.17 to 30.67% and a seed germinability range from 37.75 to 63.64% was recorded. Both in vitro and in vivo results show the reliability of pollen cryopreservation, which can be effectively used in breeding and conservation of the cashew gene pool.

Sweet cherry response in absorption and mobility of 10B applied to soil and flowers under two soil boron conditions

AbstractBackgroundBoron (B) is an essential micronutrient for plants, and B deficiency reduces fruit set in sweet cherry trees. Several studies showed the advantages of foliar and soil B applications in fruit trees, but there is little information on the distribution of B in the plant, becoming an important issue when nutritional corrections are needed.AimsThe study aims to determine B mobility and distribution in sweet cherry trees, applying 10B to the flowers and soil, at different timings and under two levels of soil B availability.MethodsTwo experiments were conducted with sweet cherry trees. In the two previous seasons, the plants were managed in two soil B availability conditions (deficient and adequate). The experiments consisted of the applications of 10B solution to the flowers and the soil at different timings and under both soil B conditions.ResultsHigher 10B absorption occurred when the 10B was applied to the soil at full bloom than when it was applied before leaf senescence. Boron was mobilized to all the tissues, but mainly to the leaves. Nevertheless, the fruit presented no differences in 10B excess for both application timings. Irrespective of soil B conditions, the 10B applied to the soil at full bloom was absorbed and mobilized to different tissues, that is, roots + rootstock + trunk (39%–44%) and stems + leaves (53%–55%), showing no differences between them. A lower percentage of B was located in the fruit, with 1% and 8% at soil B‐deficient and B‐adequate conditions, respectively. The highest percentage of the 10B applied to the flowers remained in the fruit (∼70%), and nearly 20% and 10% were mobilized to stems + leaves and roots + rootstock + trunk, respectively, independent of the soil B condition.ConclusionsBoron applied to soil at full bloom or before leaf senescence, under B‐deficient soil condition, is absorbed and mobilized to all the plant tissues, enhancing the B status in sweet cherry trees particularly when it is applied at full bloom. However, B soil application before leaf senescence would improve the availability of B (reserves) to the flowers in the following season. Boron applied to the flowers, at full bloom, remains in a high proportion in the fruit, becoming an effective complementary method to meet the fruit demands of the growing season, independent of the soil B conditions.

The intermorph breeding system is responsible for reproductive success in heterostylous Nyctanthes arbor‐tristis L.

AbstractHeterostyly is a specialized reproductive system associated with self‐ and intramorph incompatibility. It reinforces the intermorph breeding system in heterostylous plant species. However, distyly has not been comprehensively studied in Nyctanthes arbor‐tristis. The present study demonstrates the floral traits, breeding system, fruit and seed set, and morph ratio in distylous N. arbor‐tristis. The length of style and filament showed reciprocal herkogamy between long style (L‐morph) and short style (S‐morph). Flower size, corolla tube size, stamen and anther length, ovary length, and pollen diameter were larger in S‐morph. However, the style was longer in L‐morph. Our results demonstrated strongly incompatible self‐ and intramorph pollination combinations. The intermorph pollination was compatible, showing normal pollen tube growth throughout the style and ovary. The embryo formation was also higher in intermorph interaction. Moreover, the fruit setting was higher when the intermorph plants grew in the vicinity of natural conditions. Collectively, all data indicate that N. arbor‐tristis is a distylous species with a self‐incompatible breeding system, resulting in less seed formation in nature.