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1.
Ecological intensification of agriculture implies managing ecological processes to improve performance of agricultural systems. However, impacts on relevant ecological functions such as insect pollination from other crop management factors are poorly explored. Pest insects and crop resources such as water availability can directly affect crop yields, but it is unknown if there are indirect effects through effects on insect pollination. With a factorial experiment, we examined how irrigation and control of pollen beetles affected crop attractiveness and pollinator visitation in an open-pollinated spring oilseed rape cultivar. We studied how irrigation and pest control modified the production of flowers and nectar in oilseed rape, and if this in turn affected the flower-visitation of honey bees and bumble bees. Pest control increased the number of oilseed rape flowers by 69%, and the amount of nectar per flower with 36%, but for the latter only in non-irrigated plots. Furthermore, we found higher pollinator densities in plots with reduced pollen beetle densities. Pest control also reduced the number of non-legitimate flower visits, suggesting higher pollination efficiency in plots with reduced pollen beetle densities. We show that crop management affects the value of mass-flowering crops as a resource for pollinating insects. Development of pest control tools that are harmless to pollinators could increase the value of flowering crops as food resources for pollinating insects.  相似文献   

2.
1. Global pollinator declines have led to concern that crop yields might fall as a result of a pollination deficit. Companion planting is a traditional practice thought to increase yield of insect pollinated crops by planting a co-flowering species next to the crop. 2. Using a combination of conventional researcher-led experiments and observational citizen scientist data, we tested the effectiveness of bee-friendly borage (Borago officinalis) as a companion plant to strawberry (Fragaria x ananassa). Insect visitors to the ‘Test’ (strawberry + borage) versus ‘Control’ (strawberry only) plants were observed, and strawberry fruit collected. Strawberries collected during the researcher-led experiment were also subject to fruit measurements and assessments of market quality. 3. Companion plants were found to significantly increase both yield and market quality of strawberries, suggesting an increase in insect pollination per plant. Test strawberries companion planted with borage produced an average of 35% more fruits, and 32% increased yield by weight. Test strawberry plants produced significantly more fruit of higher aesthetic quality when assessed by Marketing Standards for Strawberries. 4. Although there was no significant difference in the overall insect visits, when broken down by broad insect group there were significantly more flies visiting the test strawberries than controls. 5. These results could have implications for both gardeners and commercial growers. As consumers prefer a cosmetically perfect fruit, the production of fruit with increased aesthetics aids food waste reduction.  相似文献   

3.
Global pollinator declines and land-use change can lead to pollination limitation with implications for agricultural productivity. Hand pollination is used in agricultural production as a technique to manually pollinate crops. But the prevalence of hand pollination, as well as benefits and costs, remain unknown. We systematically reviewed the literature for examples, methods, drivers, and economic motivations of hand pollination. Furthermore, we discuss the risks, constraints, and opportunities of hand pollination. We found evidence for 20 hand-pollinated crops, including minor but also economically important crops (e.g. apple, oil palm, cacao). The lack of pollinators was the most important reason for the application of hand pollination (50% of crops), while insufficient proportion or proximity of pollinizers (8% of crops) and skewed sex ratio or dichogamy (8% of crops) were second most important. The main economic motivations for practicing or recommending hand pollination were to increase fruit set, and/or fruit quality (78% of crops). Hand pollination is practiced in large- and small-scale farming, home gardens, and greenhouses. Opportunities of hand pollination are the control of pollen origin and quantity, pollination timing and frequency as well as independence from environmental fluctuations. Farmers can increase yields, improve fruit quality, avoid fruit abortion, increase employment, and secure subsistence food. The main constraints of hand pollination are high labor inputs, high material costs, and required skills. Major risks of hand pollination include management ignoring pollinator conservation, high food prices, over-pollination, labor accidents, and unfair labor. We conclude that in the face of global change, hand pollination allows improved control of pollination and is likely to increase in importance. The benefits of hand pollination need to outweigh the costs and fair labor is essential. Altogether, hand pollination can be a valuable tool for crop systems where pollinators are absent or are not reliable for sustaining high-quality crop production.  相似文献   

4.
The global decline in insect diversity threatens pollination services, potentially impacting crop production and food security. Here, we argue that this looming pollination crisis is generally approached from an ecological standpoint, and that consideration of evolutionary principles offers a novel perspective. First, we outline that wild plant species have overcome ‘pollination crises’ throughout evolutionary history, and show how associated principles can be applied to crop pollination. We then highlight technological advances that can be used to adapt crop flowers for optimal pollination by local wild pollinators, especially by increasing generalization in pollination systems. Thus, synergies among fundamental evolutionary research, genetic engineering, and agro-ecological science provide a promising template for addressing a potential pollination crisis, complementing much-needed strategies focused on pollinator conservation.  相似文献   

5.
Pollination limitation and its impact on agricultural production is a serious concern of recent time. Assessment of the extent of dependency of various pollinator dependent crops on insect pollination assumes importance in this context. On the other hand, measures for restoring the pollination service needs to be explored for sustainable production of economically important crops particularly for the benefit of the small and marginal farmers. The present study aimed to assess the extent of insect pollinator dependency of brinjal (eggplant) fruit production and impact of honey bee (Apis cerana F) box introduction on the production in vegetable farms of North 24 Parganas, West Bengal, India. Through a pollinator exclusion experiment using enclosures it was found that brinjal fruit production reduces by 54.5 % when they are pollinator limited. This finding is in contrast with earlier report of 25 % dependency. The flower density in a pollinator limited environment was observed to increase by 31 %. This might be plant’s response to pollinator limitation where the plant invests more on reproductive structure than vegetative structures. However, this requires further exploration. Introduction of bee boxes in brinjal, pumpkin and pointed gourd farms showed significant increase in fruit production. This indicates both pollination limitation as well as the need for increasing the pollinators in the crop field for sustainable crop production.  相似文献   

6.
Bees are in decline potentially leading to reduced pollination and hence production of insect-pollinated crops in many countries. It is however still unclear whether the consequences of pollinator shortages differ among countries with different environmental and societal conditions. Here, we calculated economic gains attributed to insect (particularly bee) pollination (EVIP) as well as their contribution to the total value of crop production (vulnerability), and analyzed their temporal trends and inter-annual variability from 1991 to 2009 for each country of the European Union (EU). To understand which factors drive country-specific differences in pollinator dependency and stability of insect-dependent crop yields, we further asked whether EVIP, vulnerability and stability of yields were influenced by a country's climate, the number of wild bee species and/or managed honeybee hives per country, and (agricultural) gross domestic product (GDP).Across Europe, crop pollination by insects accounted for 14.6 [±3.3] billion EUR annually (EVIP), which equaled 12 (±0.8)% of the total economic value of annual crop production. Gains strongly varied among countries. Both EVIP and vulnerability increased (and the inter-annual variation of vulnerability decreased) significantly from the colder northern to the warmer Mediterranean EU countries, in parallel with increases in the number of wild bee species. Across years, economic importance of pollination increased in all but three EU countries. Apples were the most important insect-pollinated crop in the EU, accounting for 16% of the EU's total EVIP. Our results show that whereas dependency on insect pollination increased from the colder north to the warmer south, variation in economic gain from insect pollination decreased, indicating that Mediterranean countries had more stable yields of pollinator-dependent crops across years and thus more reliable gains from pollination services.  相似文献   

7.
Wild animals substantially support crop production by providing ecosystem services, such as pollination and natural pest control. However, the strengths of synergies between ecosystem services and their dependencies on land-use management are largely unknown. Here, we took an experimental approach to test the impact of land-use intensification on both individual and combined pollination and pest control services in coffee production systems at Mount Kilimanjaro. We established a full-factorial pollinator and vertebrate exclosure experiment along a land-use gradient from traditional homegardens (agroforestry systems), shaded coffee plantations to sun coffee plantations (total sample size = 180 coffee bushes). The exclusion of vertebrates led to a reduction in fruit set of ca 9%. Pollinators did not affect fruit set, but significantly increased fruit weight of coffee by an average of 7.4%. We found no significant decline of these ecosystem services along the land-use gradient. Pest control and pollination service were thus complementary, contributing to coffee production by affecting the quantity and quality of a major tropical cash crop across different coffee production systems at Mount Kilimanjaro.  相似文献   

8.
The pollination effectiveness of the commercially reared bumble bee Bombus impatiens Cresson, was compared in field studies to the honey bee, Apis mellifera L., for lowbush blueberry, Vaccinium angustifolium Ait. A preliminary study indicated that B. impatiens had potential as an alternative pollinator. In a 3-yr study, percentage fruit set, percentage harvested berries, berry weight, and seeds per berry were compared in blueberry fields stocked at 7.5 A. mellifera hives per hectare to 5, 7.5, or 10 B. impatiens colonies per hectare. Percentage of harvested berries (yield) was significantly higher in fields stocked with B. impatiens at 10 colonies per hectare. No other parameters measuring pollinator effectiveness were significantly different at 5, 7.5, or 10 colonies per hectare. Flower handling time was significantly faster for B. impatiens and it more frequently collected blueberry pollen. All parameters of pollinator effectiveness were similar for B. impatiens, A. mellifera, and native wild bees in a follow-up study. Overall, B. impatiens was a suitable alternative to A. mellifera.  相似文献   

9.
Insect pollination plays a vital role for the yield of many crops, such as apples, strawberries and coffee, which are economically significant commodities on the global market. Yet, knowledge about the role of insect pollination is lacking for many cash crops that support the livelihoods of small-scale farmers in developing countries.To assess if yields of watermelon are pollen limited, we conducted a supplemental hand-pollinated experiment (using a pollen mixture of cross and self-pollen) in 13 small-scale farms in an agricultural landscape in the Kilimanjaro and Arusha regions in northern Tanzania. We assessed fruit set, fruit abortion and weight of the mature fruits stemming from hand pollinated and control flowers. To check if differences in yield responses between hand-pollinated and control treatments depended on resource availability, we also accounted for local soil conditions.We found that hand pollination (i) increased the probability of fruit initiation by 30%, (ii) reduced the probability of fruit abortion by 13%, (iii) increased the probability of flowers developing into mature fruits by 42% and (iv) increased average fruit weight by 1.3 kg (±0.15 SE). Our results indicate that our system is pollen limited, due to insufficient visitor frequency and/or inefficient pollinator species.Fruit initiation and fruit weight were positively related to soil carbon, irrespective of treatment. The influence of soil moisture was not consistent across the measured responses, and differed between hand-pollinated and the control treatments.We suggest that farmers in our focal area should focus on improving the quality of the landscape to sustain and enhance healthy pollinator communities ultimately improving yields. We also suggest that farmers should continue current practices with respect to fertilization. The role of soil moisture on fruit initiation and maturation should be investigated to ensure that the positive effects of pollen is not hindered by soil moisture conditions.  相似文献   

10.
The yield of many agricultural crops depends on pollination services provided by wild and managed bees, many of which are experiencing declines due to factors such as reductions in floral resources. Thus, improving pollinator habitat on farmlands using management strategies like planting wildflower strips is vital for wild bee conservation and sustainable crop pollination. Yet, few studies have examined whether and at what spatial scales wildflower strips enhance crop pollination and yields, and most research has been conducted in large-scale commercial agriculture. Therefore, we investigated the effects of wildflower strips on crop pollination on small, diversified farms (i.e., those growing a variety of crop species) where wild bee diversity and abundance is predicted to be comparatively high. Over three years, on four diversified farms in Montana USA, we tested the hypothesis that distance (20, 60, and 180 m) of crops from native perennial wildflower strips planted alongside crop fields affected wild bee visitation, pollination, and yields of squash and sunflower crop plants. We found that distance to wildflower strips did not affect bee visitation or pollination in crops. Squash yield was pollen-limited in the growing season prior to wildflower strip establishment, and in one of the two years after wildflower strip establishment, but proximity to wildflower strips did not influence the magnitude of pollen limitation. Sunflower seed production was not pollen-limited in any year. Our findings demonstrate that even on diverse farms with wildflower strips and a demonstrated high diversity of bees, some crops do not necessarily receive maximum pollination, regardless of distance from the wildflower strips. However, the value of wildflower strips for supporting wild bee diversity, and other ecological or economic benefits, needs consideration for a full understanding of this pollinator habitat management strategy.  相似文献   

11.
Honey bees, Apis mellifera L., probe for nectar from robbery slits previously made by male carpenter bees, Xylocopa virginica (L.), at the flowers of rabbiteye blueberry, Vaccinium ashei Reade. This relationship between primary nectar robbers (carpenter bees) and secondary nectar thieves (honey bees) is poorly understood but seemingly unfavorable for V. ashei pollination. We designed two studies to measure the impact of nectar robbers on V. ashei pollination. First, counting the amount of pollen on stigmas (stigmatic pollen loading) showed that nectar robbers delivered fewer blueberry tetrads per stigma after single floral visits than did our benchmark pollinator, the southeastern blueberry bee, Habropoda laboriosa (F.), a recognized effective pollinator of blueberries. Increasing numbers of floral visits by carpenter bee and honey bee robbers yielded larger stigmatic loads. As few as three robbery visits were equivalent to one legitimate visit by a pollen-collecting H. laboriosa female. More than three robbery visits per flower slightly depressed stigmatic pollen loads. In our second study, a survey of 10 commercial blueberry farms demonstrated that corolla slitting by carpenter bees (i.e., robbery) has no appreciable affect on overall V. ashei fruit set. Our observations demonstrate male carpenter bees are benign or even potentially beneficial floral visitors of V ashei. Their robbery of blueberry flowers in the southeast may attract more honey bee pollinators to the crop.  相似文献   

12.
Pollinators are beneficial for many wild and crop plants. As a mass-flowering crop, oilseed rape has received much focus in terms of its pollination requirements but despite a threefold increase in area of cultivation of this crop in Ireland over the past 5 years, little is known about its pollination here. We surveyed the flower visiting insects found in commercial winter oilseed rape fields and evaluated the importance of different pollinator groups, investigated the contribution of insect pollination to oilseed rape seed production, and estimated the economic value of insect pollination to the crop at a national level. Our data showed that winter oilseed rape is visited by a wide variety of insect species, including the honeybee, bumblebees, solitary bees, and hoverflies. The honeybee, Eristalis hoverflies and bumblebees (especially Bombus sensu stricto and B. lapidarius) were the best pollinators of winter oilseed rape based on the number of pollen grains they carry, visitation rates per flower and their relative abundance per field. Exclusion of pollinators resulted in a 27 % decrease in the number of seeds produced, and a 30 % decrease in seed weight per pod in winter crops, with comparable values from a spring oilseed rape field also. The economic value of insect pollination to winter oilseed rape was estimated as €2.6 million per annum, while the contribution to spring oilseed rape was €1.3 million, resulting in an overall value of €3.9 million per annum. We can suggest the appropriate conservation and management of both honeybees and wild pollinators in agricultural areas to ensure continued provision of pollination services to oilseed rape, as a decrease in insect numbers has the potential to negatively influence crop yields.  相似文献   

13.
Value estimates of ecosystem goods and services are useful to justify the allocation of resources towards conservation, but inconclusive estimates risk unsustainable resource allocations. Here we present replacement costs as a more accurate value estimate of insect pollination as an ecosystem service, although this method could also be applied to other services. The importance of insect pollination to agriculture is unequivocal. However, whether this service is largely provided by wild pollinators (genuine ecosystem service) or managed pollinators (commercial service), and which of these requires immediate action amidst reports of pollinator decline, remains contested. If crop pollination is used to argue for biodiversity conservation, clear distinction should be made between values of managed- and wild pollination services. Current methods either under-estimate or over-estimate the pollination service value, and make use of criticised general insect and managed pollinator dependence factors. We apply the theoretical concept of ascribing a value to a service by calculating the cost to replace it, as a novel way of valuing wild and managed pollination services. Adjusted insect and managed pollinator dependence factors were used to estimate the cost of replacing insect- and managed pollination services for the Western Cape deciduous fruit industry of South Africa. Using pollen dusting and hand pollination as suitable replacements, we value pollination services significantly higher than current market prices for commercial pollination, although lower than traditional proportional estimates. The complexity associated with inclusive value estimation of pollination services required several defendable assumptions, but made estimates more inclusive than previous attempts. Consequently this study provides the basis for continued improvement in context specific pollination service value estimates.  相似文献   

14.
Worldwide, human appropriation of ecosystems is disrupting plant–pollinator communities and pollination function through habitat conversion and landscape homogenisation. Conversion to agriculture is destroying and degrading semi‐natural ecosystems while conventional land‐use intensification (e.g. industrial management of large‐scale monocultures with high chemical inputs) homogenises landscape structure and quality. Together, these anthropogenic processes reduce the connectivity of populations and erode floral and nesting resources to undermine pollinator abundance and diversity, and ultimately pollination services. Ecological intensification of agriculture represents a strategic alternative to ameliorate these drivers of pollinator decline while supporting sustainable food production, by promoting biodiversity beneficial to agricultural production through management practices such as intercropping, crop rotations, farm‐level diversification and reduced agrochemical use. We critically evaluate its potential to address and reverse the land use and management trends currently degrading pollinator communities and potentially causing widespread pollination deficits. We find that many of the practices that constitute ecological intensification can contribute to mitigating the drivers of pollinator decline. Our findings support ecological intensification as a solution to pollinator declines, and we discuss ways to promote it in agricultural policy and practice.  相似文献   

15.
《Journal of Asia》2022,25(1):101844
Brassica rapa L., is a crop grown globally and studies have indicated that insect pollination can improve yields. However, the importance of insect pollination in this crop depends on cultivar reproductive biology, insect pollinator species and their abundances. In Bangladesh, the acreage of B. rapa for oilseed production has been expanding, but little is known about whether insects contribute to yield improvements. Using the commonly grown variety Tori-7, we found that plants with inflorescences left exposed to flower visiting insects (body width > 1.5 mm) had a 30.8% greater seed yield compared to those where insect flower visitors were excluded. Of 794 insect flower visiting individuals recorded from observation and trapping surveys conducted across four separate fields, Apis bees (four spp.) were the most abundant (66.1%), followed by flies Musca domestica (14.7%), Sepsis fulgens (6.3%) and hoverflies (3.0%; 3 spp; Syrphidae). Other flower visitors included ants, wasps, beetles, butterflies and moths. For the cultivar assessed, we calculated the economic value of oilseed rape was $US 87.5 million per annum in Bangladesh, of which the economic value of insect pollination was $US 26.92 million per annum. Thus, one in every four dollars earned by our Bangladeshi growers resulted from insect crop pollination. This demonstrates to growers the need to promote and protect insect pollination to optimize their economic returns.  相似文献   

16.
Understanding the relative contributions of wild and managed pollinators, and the functional contributions made by a diverse pollinator community, is essential to the maintenance of yields in the 75% of our crops that benefit from insect pollination. We describe a field study and pollinator exclusion experiments conducted on two soft-fruit crops in a system with both wild and managed pollinators. We test whether fruit quality and quantity is limited by pollination, and whether different pollinating insects respond differently to varying weather conditions. Both strawberries and raspberries produced fewer marketable fruits when insects were excluded, demonstrating dependence on insect pollinators. Raspberries had a short flowering season which coincided with peak abundance of bees, and attracted many bees per flower. In contrast, strawberries had a much longer flowering season and appeared to be much less attractive to pollinators, so that ensuring adequate pollination is likely to be more challenging. The proportion of high-quality strawberries was positively related to pollinator abundance, suggesting that yield was limited by inadequate pollination on some farms. The relative abundance of different pollinator taxa visiting strawberries changed markedly through the season, demonstrating seasonal complementarity. Insect visitors responded differently to changing weather conditions suggesting that diversity can reduce the risk of pollination service shortfalls. For example, flies visited the crop flowers in poor weather and at the end of the flowering season when other pollinators were scarce, and so may provide a unique functional contribution. Understanding how differences between pollinator groups can enhance pollination services to crops strengthens the case for multiple species management. We provide evidence for the link between increased diversity and function in real crop systems, highlighting the risks of replacing all pollinators with managed alternatives.  相似文献   

17.
The role of many insect species in crop pollination has been widely studied. The use of entomophilous pollination, commonly adopted for other crops, may be of key importance in order to improve seed yields in seed-propagated globe artichoke (Cynara cardunculus var. scolymus) cultivars. In this regard, in a 2-year field experiment, the role of two honeybees (Apis mellifera ligustica and A. mellifera siciliana) and one bumblebee (Bombus terrestris) was evaluated on the seed production of two globe artichoke cultivars in caged-protected environments. Overall, the number and weight of seeds plant−1 and head−1, 1,000 seed weight and fruit setting were higher in caged plants with imposed pollination than open field plants. The pollination efficiency was both insect and cultivar dependent. Both honeybee species performed better on the Mediterranean cultivar ‘Violetto di Sicilia’, while the bumblebee performed better on the Brazilian cultivar ‘NP4’. These results could be very useful to modernise the agronomic management of globe artichoke and reduce the costs of cultivation. In addition, such knowledge can be used to improve the seed production in globe artichoke seed-propagated cultivars and cardoon. This will benefit the bioenergy, nutraceutical, cosmetic and ornamental applications.  相似文献   

18.
Insect pollination and pest control are pivotal functions sustaining global food production. However, they have mostly been studied in isolation and how they interactively shape crop yield remains largely unexplored. Using controlled field experiments, we found strong synergistic effects of insect pollination and simulated pest control on yield quantity and quality. Their joint effect increased yield by 23%, with synergistic effects contributing 10%, while their single contributions were 7% and 6%, respectively. The potential economic benefit for a farmer from the synergistic effects (12%) was 1.8 times greater than their individual contributions (7% each). We show that the principal underlying mechanism was a pronounced pest-induced reduction in flower lifetime, resulting in a strong reduction in the number of pollinator visits a flower receives during its lifetime. Our findings highlight the importance of non-additive interactions among ecosystem services (ES) when valuating, mapping or predicting them and reveal fundamental implications for ecosystem management and policy aimed at maximizing ES for sustainable agriculture.  相似文献   

19.
Insect pollination improves the yield and quality of many crops, yet there is increasing evidence of insufficient insect pollinators limiting crop production. Effective Integrated Crop Pollination (ICP) involves adaptable, targeted and cost-effective management of crop pollination and encourages the use of both wild and managed pollinators where appropriate. In this study we investigate how the addition of honeybee hives affects the community of insects visiting oilseed rape, and if hive number and location affect pollinator foraging and oilseed rape pollination in order to provide evidence for effective ICP. We found that introducing hives increased overall flower visitor numbers and altered the pollinator community, which became dominated by honeybees. Furthermore a greater number of hives did not increase bee numbers significantly but did result in honeybees foraging further into fields. The timing of surveys and proximity to the field edge influenced different pollinators in different ways and represents an example of spatial and temporal complementarity. For example dipteran flower visitor numbers declined away from the field edge whereas honeybees peaked at intermediate distances into the field. Furthermore, no significant effects of survey round on wild bees overall was observed but honeybee numbers were relatively lower during peak flowering and dipteran abundance was greater in later survey rounds. Thus combining diverse wild pollinators and managed species for crop pollination buffers spatial and temporal variation in flower visitation. However we found no effect of insect pollination on seed set or yield of oilseed rape in our trial, highlighting the critical need to understand crop demand for insect pollination before investments are made in managing pollination services.  相似文献   

20.
Pollination is critical to fruit production, but the interactions of pollination with plant resources on a plant's reproductive and vegetative features are largely overlooked. We examined the influences of pollination, irrigation and fertilisation on the performance of almond, Prunus dulcis, in northern California. We used a full‐factorial design to test for the effects of pollination limitation on fruit production and foliage variables of whole trees experiencing four resource treatments: (i) normal water and nutrients, (ii) reduced water, (iii) no nutrients, and (iv) reduced water and no nutrients. In each of these combinations, we applied three pollination treatments: hand‐cross pollination, open‐pollination and pollinator exclusion. Pollination strongly affected yield even under reduced water and no nutrient applications. Hand‐cross pollination resulted in over 50% fruit set with small kernels, while open‐pollinated flowers showed over 30% fruit set with moderate‐sized kernels. Pollinator‐excluded flowers had a maximum fruit set of 5%, with big and heavy kernels. Reduced water interacted with the open‐ and hand‐cross pollination treatments, reducing yield more than in the pollinator exclusion treatment. The number of kernels negatively influenced the number of leaves, and reduced water and no nutrient applications interacted with the pollination treatments. Overall, our results indicate that the influences of pollination on fruit tree yield interact with the plant availability of nutrients and water and that excess pollination can reduce fruit quality and the production of leaves for photosynthesis. Such information is critical to understand how pollination influences fruit tree performance.  相似文献   

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