Bee pollination increases fruit weight and antioxidants in pumpkins

Bee pollination of strawberries on different spatial scales – from crop varieties and fields to landscapes

The augmentation of pollination success in lemon (Citrus limon Eureka) flowers remains contingent on the involvement of bee pollinators. With wild bee pollinator populations declining in agroecosystems, meliponiculture has emerged as a potential option in Indonesia. This study aimed to investigate the effects of meliponicultural use of Tetragonula laeviceps on diversity, foraging behavior, and monthly population of bee pollinators, as well as lemon pollination efficacy with and without meliponiculture treatment during two periods. Using scan and focal sampling methods in first and second periods, the study found that the diversity of wild bee pollinators was six species (Apis cerana, Lasioglossum albescens, Megachile laticeps, Xylocopa confusa, Xylocopa latipes, and Xylocopa caerulea), and T. laeviceps when using meliponiculture. The relative abundance and daily foraging activity of wild bee pollinators were initially reduced in the first period (March-June) and then maintained in the second period (July-October). T. laeviceps foraged on the flowers, involving specific sequences for 72 s with highest visitation rate of 0.25 flowers/h from 10:00-13:00. Light intensity was observed to be the most influential factor for bee pollinator density. Pollination efficacy results showed that meliponiculture usage has greater benefit compared to meliponiculture absence across various parameters, including fruit sets, fruit weight, yield, and estimated productivity. The effects of meliponicultural use of T. laeviceps can enhance lemon pollination efficacy while preserving the diversity of wild insect pollinators. This suggests that meliponiculture stingless bees could be a beneficial practice in agroecosystems, especially in tropical regions where wild bee populations and diversity are declining.

Pollination is essential for achieving high yields and enhancing the quality of kiwifruit cultivation, both of which significantly influence growers' interests and consumers' preferences. However, compared to studies on yield, there are fewer studies exploring the impact of pollination methods on the flavor of kiwifruit Actinidia chinensis Planchon. This study examined the effects of bee (Apis mellifera L.) pollination and artificial pollination on the yield and flavor of kiwifruit in the main producing areas of China. Compared with those pollinated artificially, bee-pollinated kiwifruit exhibited a greater fruit set rate, heavier fruit weight, and greater number of seeds. Notably, the number of seeds was positively correlated with fruit weight in bee-pollinated kiwifruit, whereas no such correlation was detected in artificially pollinated fruit. Bee pollination not only enhanced the yield but also improved the flavor of kiwifruit. Specifically, bee-pollinated kiwifruit contained higher levels of sucrose and lower concentrations of glucose and fructose, while the acid content was less affected by pollination methods. Furthermore, significant differences were observed in the volatile organic compound (VOC) levels in kiwifruit subjected to different pollination treatments, with bee-pollinated fruit exhibiting a superior flavor. Our findings provide new insights into the beneficial role of bee pollination in enhancing kiwifruit yield and quality, underscoring the crucial importance of bees in kiwifruit pollination.

Effect of modes of pollination on yield parameters of cucumber under polyhouse conditions when evaluated it was observed that fruit set under bee + hand pollinated (84.29%) condition was at par with bee pollinated (82.45%) or hand pollinated condition (79.99%), irrespective of hybrids. The fruit length under bee pollination (13.31cm) was at par with bee pollination + hand pollination (13.30cm) and significantly higher than hand pollination (13.19cm). Mean Fruit weight (135.25gm) observed under bee pollination + hand pollination, was at par with (134.91gm) under bee pollination and significantly higher than (132.83gm) under hand pollination. While mean fruit diameter under bee pollination and bee pollination + hand pollination was observed maximum (3.51cm), which was significantly higher than hand pollination (3.49cm). Hybrid Pusa Sanyog and Pant Sankar Khira recorded with maximum fruit set and fruit diameter, whereas hybrid Rani shows highest mean fruit weight and fruit length. While, minimum fruit set, fruit weight and fruit length were recorded on hybrid Sheetal and minimum fruit diameter was observed in Pusa Sanyog.

Pollination efficiency of artificial and bee pollination practices in kiwifruit

Current approaches to determining the value of insect pollinators to crop yield assume that plants are primarily pollen limited. This is particularly relevant in a crop such as lowbush blueberry, Vaccinium angustifolium, where no fruit will set without insect‐mediated cross‐pollination. However, such valuations usually ignore other factors that are necessary to maximise crop yields. We conducted an experiment to test whether yields of lowbush blueberry attributed to pollinator activity increased independently of pest management. The experiment was a 2 × 2 factorial design, incorporating two intensities of pollination (25% or 100% of flowers), and two levels of insect and disease management with recommended fungicide and insecticide sprays (‘full inputs’ or ‘no inputs’). We demonstrated an interaction between these two factors, such that increased fruit set at harvest was only possible if 100% pollination was combined with the ‘full input’ treatment. Furthermore, increases in fruit weight among the remaining treatments were only realised in the ‘full input’ plots. These results suggest that the value accorded to pollinator activity in blueberries is strongly dependent upon pest and disease management of the crop.

The acclimation, foraging behavior, and pollination efficiency of stingless bees of the species Nannotrigona perilampoides Cresson were evaluated in tomato (Lycopersicon esculentum Mill.) plants cultivated in two greenhouses. The greenhouses were divided into three areas of 16 m2, and one of the following treatments was used for pollination: stingless bees (SB), mechanical vibration (MV), and no pollination (NP). Observations were conducted once a week from 0800 to 1600 hours during 2 mo. The acclimation of the bees to the greenhouses was estimated by the number of bees that did not return to the hive (lost bees) and by comparing the population of the colonies (brood and adults). The foraging activity of the bees across the day was evaluated by comparing the number of foragers per hour. The influence of environmental variables on the foraging activity was also analyzed. The pollination efficiency was compared among treatments through the percentage of fruit set, weight of individual fruit, kilograms of fruit produced per square meter, and the number of seed per fruit. The bees started foraging on the flowers approximately 7 d after the colonies were introduced to the greenhouse. There was a decline in the population of the colonies across the experiment, but colonies did not die out. Correlations of environmental variables with the foraging activity of the bees showed that none of them had a significant influence on pollen foraging. However, water collection was positively correlated with the temperature and negatively correlated with the humidity inside the greenhouse. The estimation of the pollination efficiency per treatment showed that there were significant differences in fruit set in SB (83 +/- 4.2) and MV (78.5 +/- 6.4) compared with NP (52.6 +/- 7.6). However, the average weight of the fruit was similar for the three treatments (65 g). There were significant differences for seed number in SB (200 +/- 15.3) and MV (232 +/- 21.4) compared with NP (120 +/- 16.6). The productivity in kilograms of fruit per square meter was higher in SB (5.72 +/- 0.61) and MV (5.66 +/- 0.58 kg) compared with NP (3.34 +/- 0.72). The number of seed was positively correlated with the weight of the fruit. We conclude that the use of Nannotrigona testaceicornis Rondani, for pollinating greenhouse tomatoes in tropical climates, could be an alternative to the use of highly defensive African-derived Apis mellifera or non-native bumble bees (Bombus spp.). However, more research is needed to evaluate the cost/benefit on large-scale greenhouse pollination using N. perilampoides Cresson against other bee species and pollination methods.

In modern agriculture, many high-value cash crops that were formerly cultivated in open fields are now grown in greenhouses and net-houses. While changing the cultivation environment, attention is needed to ensure adequate pollen transfer to the stigma due to absence of wind, isolation from wild pollinators and low viability of reproductive organs due to the extreme temperature under those conditions. This study explores the effects of honeybee (Apis mellifera L.) pollination on various fruit characteristics of several different cultivars of sweet pepper (Capsicum annuum L.) under enclosed conditions. In all 16 cultivars examined during two growing seasons, bee pollination increased numbers of seeds per fruit, and had a significantly positive effect on fruit placenta weight, fruit weight, fruit width and fruit-wall thickness. While fruit diameter consistently correlated with bee pollination, fruit-length response alternated between seasons. It may be concluded that although bee pollination is a powerful tool for affecting fruit characteristics in sweet pepper, each cultivar exhibits different levels of response. Cultivars need to be evaluated separately, relative to market demand, when considering the use of bees for pollination.

Sweet orange which bears highly attractive flowers having high sugar concentration of nectar, with heavy pollens is not adapted for wind pollination. Therefore cross-pollination is accomplished by pollinators. The highest fruit retention % (1.67± 0.08%), fruit weight (118.93± 0.36 g) and yield (8.93± 0.17 kg/plant) were recorded from open pollination and it is significantly superior over both exclusive stingless bee pollination and pollinator exclusion. All the treatments were at par as regards fruit TSS, dry matter and ash %. Diverse pollinators influence fruit retention, fruit weight and productivity in comparison to single pollinator and pollinator exclusion. Nevertheless, single pollinator also enhances the productivity in comparison to pollinator exclusion.

Foraging behavior and visit optimization of bumblebees for the pollination of greenhouse tomatoes

Bee pollination can affect tomato yield and quality. The mechanism of improving the yield and quality of tomatoes by bee pollination is not clear, and few studies have been conducted. To understand how bee pollination affects tomato quality, by using respectively weighing, vernier caliper, handheld refractometer, pH meter to measure single fruit weight, fruit size, the sugar content, and the pH value, enzyme linked immunosorbent assay (ELISA) to determine endogenous hormone content, and LC-MS to perform untargeted metabolomics analysis, we compared these physiological indicators, endogenous hormone levels, and metabolism of tomato fruits pollinated after honeybee, bumblebee, and plan growth regulator (PGR) pollination. Our results indicate that the tomatoes pollinated by bumblebees were heavier and larger than those pollinated by honeybees and PGR. The sugar content of tomatoes pollinated by honeybees and bumblebees significantly respectively increased by 7.96% and 10.18% than that of tomatoes pollinated by PGR. The pH value of tomatoes pollinated by honeybees (3.99 ± 0.02) and bumblebees (3.94 ± 0.03) was significantly lower than that of tomatoes pollinated by PGR (4.19 ± 0.04) (p < 0.05). Different pollination methods significantly affected the content of endogenous hormones in fruits. In five endogenous hormones, the highest content was gibberellin (GA) in honeybee pollination treatment, IAA in bumblebee treatment, and the highest contents were abscisic acid (ABA), zeatin (ZT), and N 6-(Δ2-isopentenyl) adenosine (iPA) in PGR treatment. It is speculated that different pollination methods may regulate the maturity and quality of tomatoes through different hormone levels. There were respectively five different metabolites (three upregulated and two downregulated), 95 different metabolites (59 upregulated and 36 downregulated), and 95 different metabolites (56 upregulated and 39 downregulated) in honeybee pollination vs. bumblebee pollination, honeybee pollination vs. PGR pollination, and bumblebee pollination vs. PGR pollination. Metabolites are mainly involved in phenylpropanoid biosynthesis, flavonoid biosynthesis pathway, and stilbenoid, diarylheptanoid and gingerol biosynthesis. Compared with PGR pollination, the metabolism of amino acids, vitamins, sugars, flavor substances, and organic acids with antioxidant physiological effects in honeybee pollination and bumblebee pollination groups was significantly higher. It can be inferred that the tomato fruit after bee pollination may have a better taste and is favorable to resisting diseases. These results provide valuable insight for uncovering the mechanism of how bee pollination enhances tomato fruit flavor and will enhance our understanding of interactions between bee pollinators and fruit development processes.

BackgroundPollination is crucial to obtaining optimal blueberry yield and fruit quality. Despite substantial investments in seasonal beekeeping services, blueberry producers consistently report suboptimal pollinator visitation and fruit set in some cultivars. Flower morphology and floral rewards are among the key factors that have shown to contribute to pollinator attraction, however little is known about their relative importance for improving yield in the context of plant breeding. Clarifying the relationships between flower morphology, nectar reward content, pollinator recruitment, and pollination outcomes, as well as their genetic components, can inform breeding priorities for enhancing blueberry production. In the present study, we measured ten flower and nectar traits and indices of successful pollination, including fruit set, seed count, and fruit weight in 38 southern highbush blueberry genotypes. Additionally, we assessed pollinator visitation frequency and foraging behavior over two growing seasons. Several statistical models were tested to optimize the prediction of pollinator visitation and pollination success, including partial least squares, BayesB, ridge-regression, and random forest.ResultsRandom forest models obtained high predictive abilities for pollinator visitation frequency, with values of 0.54, 0.52, and 0.66 for honey bee, bumble bee, and total pollinator visits, respectively. The BayesB model provided the most consistent prediction of fruit set, fruit weight, and seed set, with predictive abilities of 0.07, -0.08, and 0.42, respectively. Variable importance analysis revealed that genotypic differences in nectar volume had the greatest impact on honey bee and bumble bee visitation, although preferences for flower morphological traits varied depending on the foraging task. Flower density was a major driving factor attracting nectar-foraging honey bees and bumble bees, while pollen-foraging bumble bees were most influenced by flower accessibility, specifically corolla length and the length-to-width ratio.ConclusionsHoney bees comprised the majority of pollinator visits, and were primarily influenced by nectar volume and flower density. Corolla length and the length-to-width ratio were also identified as the main predictors of fruit set, fruit weight, seed count, as well as pollen-foraging bumble bee visits, suggesting that these bees and their foraging preferences may play a pivotal role in fruit production. Moderate to high narrow-sense heritability values (ranging from 0.30 to 0.77) were obtained for all floral traits, indicating that selective breeding efforts may enhance cultivar attractiveness to pollinators.

Honeybees (Apis mellifera) are increasingly used in commercial crop production, while wild bees are also important pollinators. Few studies have investigated the relative importance of honeybees and wild bees for apple pollination and whether the contribution of wild bees is affected by increasing numbers of honeybees. Here, we conducted experiments in 52 commercially important Fuji apple orchards across three apple production areas in China, to investigate how wild bees, honeybees and their interaction influences apple quantity (fruit set, weight) and quality (seed number). Both honeybees and wild bees contributed to apples production, resulting in an overall 996%, 26% and 64% increase of apple fruit set, fruit weight and seed number, respectively. We found a hump‐shaped relationship between bee density and fruit set and fruit weight with the maximum fruit set at intermediate bee density, but honeybees reached the maximum only with one and a half times higher numbers than wild bees. Furthermore, when honeybee activity density was low, an increase in wild bee activity density and species richness led to enhanced pollination contribution. Conversely, when honeybee activity density was high, increased wild bee activity density and species richness were associated with reduced pollination contribution. Additionally, the highest fruit set was observed at high densities of wild bees and intermediate densities of honeybees. These results indicate that high honeybee activity density may interfere with the pollination services provided by wild bees in apple orchards. Synthesis and applications. Both honeybees and wild bees contribute to apple pollination and production, but wild bees evidenced much higher pollination efficiency than honeybees. Importantly, introducing high density of honeybee colonies appeared to enhance competition with wild bees, decreasing their contribution to pollination. As highest fruit set was found with high wild bee densities, but only intermediate levels of honeybee densities, it is important to carefully assess the number of honeybee colonies before possible introduction of hives for apple production, in particular when wild bee diversity and density are high. Conserving wild bee diversity is of priority to harness pollination services in apple production, given their high diversity and pollination efficiency.

Aonla is a nutrient-rich, underutilized fruit crop in which efficient pollination increases yield. The study was carried out at two different locations in 2023 to determine the abundance of insect visitation and the effect of bee pollination on the yield of Aonla. The relative abundance of insect visitor studies revealed 22 and 17 species of insects visiting the Aonla flowers at locations I and II, respectively. Insect visitors were abundant during the 1000 – 1200 h period of the study. At location I, 11 species were hymenoptera, four were diptera, one was coleoptera, and four were lepidoptera. In contrast, in location II, nine were hymenoptera, three were diptera, one was coleoptera, and five were lepidoptera. Among these insect visitors of the hymenopteran family Apidae, Apis cerana indica and Tetragonula iridipennis were recorded to be the most frequent. To evaluate the influence of bee pollination on fruit set and yield, A. cerana indica and T. iridipennis colonies were placed in two different Aonla ecosystems. A significant increase (p=0.05) in fruit set (8.53–19.59%), retention (39.86–58.46%), and an increase in fruit weight (8.93–34.57 g), yield per tree (9.79–37.13%) was observed in treated plots compared to control plots in both locations. It is concluded that four colonies of T. iridipennis/ acre can improve pollination in Aonla flowers to a great extent.

Tomato is one of the highest water-demanding crops, and the use of different irrigation systems and different water management strategies may affect crop yield. Despite the fact that tomato is a self-fertilizing (autogamous) plant, research has shown that bees (“buzz pollination”) improve yield and fruit quality. Here, we assess the effect of the irrigation method on bee visitation and pollination on flowers of the tomato crop. The study was conducted from Jul to Oct 2017 in Minas Gerais State, Brazil, using 6 plots with 150 tomato plants per plot. Three plots received water by sprinkler irrigation and the other 3 by drip irrigation, in a randomized complete block design. Bees were sampled from plants watered with both irrigation systems to evaluate visitation rate. Fruit set and fruit weight were compared between irrigation systems. Bee visitation rate was not affected by the irrigation method, and the mechanical impact of the sprinkler did not provide the same level of bee pollination. As pollination and pollinators were not negatively affected, the best irrigation method should take into account agronomic aspects, such as financial viability and water use efficiency. The drip irrigation system seems to be the most effective, because it exhibits these characteristics, even though it may have a higher cost.