scholarly journals Higher bee abundance, but not pest abundance, in landscapes with more agriculture on a late-flowering legume crop in tropical smallholder farms

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10732
Author(s):  
Cassandra Vogel ◽  
Timothy L. Chunga ◽  
Xiaoxuan Sun ◽  
Katja Poveda ◽  
Ingolf Steffan-Dewenter
Keyword(s):  
Fruit Set ◽  
Service Providers ◽  
Natural Habitat ◽  
Pigeon Pea ◽  
Landscape Composition ◽  
Agricultural Area ◽  
Important Food ◽  
Exclusion Experiment ◽  
Late Flowering ◽  
Bee Abundance

Background Landscape composition is known to affect both beneficial insect and pest communities on crop fields. Landscape composition therefore can impact ecosystem (dis)services provided by insects to crops. Though landscape effects on ecosystem service providers have been studied in large-scale agriculture in temperate regions, there is a lack of representation of tropical smallholder agriculture within this field of study, especially in sub-Sahara Africa. Legume crops can provide important food security and soil improvement benefits to vulnerable agriculturalists. However, legumes are dependent on pollinating insects, particularly bees (Hymenoptera: Apiformes) for production and are vulnerable to pests. We selected 10 pigeon pea (Fabaceae: Cajunus cajan (L.)) fields in Malawi with varying proportions of semi-natural habitat and agricultural area within a 1 km radius to study: (1) how the proportion of semi-natural habitat and agricultural area affects the abundance and richness of bees and abundance of florivorous blister beetles (Coleoptera: Melloidae), (2) if the proportion of flowers damaged and fruit set difference between open and bagged flowers are correlated with the proportion of semi-natural habitat or agricultural area and (3) if pigeon pea fruit set difference between open and bagged flowers in these landscapes was constrained by pest damage or improved by bee visitation. Methods We performed three, ten-minute, 15 m, transects per field to assess blister beetle abundance and bee abundance and richness. Bees were captured and identified to (morpho)species. We assessed the proportion of flowers damaged by beetles during the flowering period. We performed a pollinator and pest exclusion experiment on 15 plants per field to assess whether fruit set was pollinator limited or constrained by pests. Results In our study, bee abundance was higher in areas with proportionally more agricultural area surrounding the fields. This effect was mostly driven by an increase in honeybees. Bee richness and beetle abundances were not affected by landscape characteristics, nor was flower damage or fruit set difference between bagged and open flowers. We did not observe a positive effect of bee density or richness, nor a negative effect of florivory, on fruit set difference. Discussion In our study area, pigeon pea flowers relatively late—well into the dry season. This could explain why we observe higher densities of bees in areas dominated by agriculture rather than in areas with more semi-natural habitat where resources for bees during this time of the year are scarce. Therefore, late flowering legumes may be an important food resource for bees during a period of scarcity in the seasonal tropics. The differences in patterns between our study and those conducted in temperate regions highlight the need for landscape-scale studies in areas outside the temperate region.

scholarly journals Complex landscapes partially mitigate negative pesticide effects on tropical pollinator communities

2021 ◽  
Author(s):  
Diana Obregon ◽  
Olger R. Guerrero ◽  
Elena Stashenko ◽  
Katja Poveda
Keyword(s):  
Pesticide Residues ◽  
Fruit Set ◽  
Natural Habitat ◽  
Landscape Composition ◽  
List Type ◽  
Buffer Effect ◽  
Pollination Services ◽  
Pollinator Decline ◽  
Bee Diversity ◽  
Bee Communities

AbstractLand-use change and pesticides have been identified as two of the main causes behind pollinator decline. Understanding how these factors affect crop pollinator communities is crucial to inform practices that generate optimal pollination and ensure sustainable food production. In this study, we investigated the effects of landscape composition and pesticide residues on bee communities and their pollination services in Solanum quitoense “lulo” crops in Colombia. On 10 farms, located along a gradient of landscape complexity that varied from 0.15 to 0.62 in their natural habitat proportion, we characterized the bee community visiting the crop, and carried out pollination experiments with bagged and open inflorescences to later estimate fruit set, weight, and diameter at every site. Additionally, we performed pesticide analysis on collected anthers through liquid chromatography to estimate pesticide risk coming from the crop fields using hazard quotients (HQ). Bee abundance and species richness decreased with increased HQ, but these negative pesticide effects were less detrimental in farms with higher natural habitat proportions. However, this buffer effect was lost at sites with very high HQs. Imidacloprid was frequently found in the anthers and there were extremely high concentrations in some farms (0.6 to 13063 μg/kg), representing the molecule of greater risk for bees in this context. Pollinator’s importance to crop yield was demonstrated in the exclusion experiments, where we found a reduction in fruit set (51%), weight (39%), and diameter (25%). We found a significant effect of bee richness on fruit set, while landscape composition and HQ had no significant effect on fruit set, suggesting that the last two factors do not affect yield directly, but indirectly through a decrease in pollinator diversity. Our results provide novel evidence that the natural habitat loss due to the expansion of pastures for cattle ranching and pesticide residues in anthers reduce bee diversity and abundance in this Andean cropping system, but strategies to protect and restore natural habitat can help to buffer, until certain levels, these negative effects.Highlights- We explored how landscape composition and pesticide residues impact bee communities and pollination services in Solanum quitoense crops.- As the proportion of natural habitat in the landscape increased, bee richness also increased. While as pesticide hazard quotients in S. quitoense anthers increased, bee diversity and abundance decreased.- The natural habitat surrounding farms mitigates the negative pesticide effects on bees when hazard quotients are low/medium, but not when they are high.- S. quitoense crops are highly dependent on bees for optimum yield.

scholarly journals Time of flowering and fertilisation of quince varieties

1999 ◽  
Vol 5 (1-2) ◽  
Author(s):  
T. Szabó ◽  
J. Nyéki ◽  
M. Soltész ◽  
Z. Szabó ◽  
T. Tóth
Keyword(s):  
Fruit Set ◽  
Fruit Size ◽  
Late Flowering ◽  
Cross Pollination ◽  
Self Pollination ◽  
The Individual ◽  
Contradictory Data

Literature dealing with flowering and fertilisation of quince is scarce. Most controversial and scanty are informations on observations of self- and cross-pollination. According to our observations, differences in blooming time are few (2-3) days only, thus flowering of most varieties is synchronous. The varieties observed are grouped as early, intermediate and late flowering ones. Self fertility of the individual varieties, however, was not assessed unequivocally, therefore it is recommended, by safety reasons, to consider quince actually as a whole to be auto-incompatible. Artificial self-pollination (or rather geitonogamy) as well as cross pollination with other varieties increased substantially fruit set if compared with the results of natural self-pollination (autogamy). According to the fruit set of their open pollinated flowers, varieties have been classified according to fertility as low (below 10 %), medium (between 10 and 20 %) and high (more than 20 %). Cross fertility of varieties is highly variable depending on combination and on season. Contradictory data are probably due to the sensitivity of quince to conditions of search. Better fruit set was coincident with higher number of stout seeds per fruit. Well developed seeds are definitely a prerequisite of larger fruit size.  

scholarly journals Reproductive biology of Ophiorrhiza caudata C.E.C.Fisch. (Rubiaceae), an endemic and endangered creeping perennial herb of the Western Ghats, India

2021 ◽  
Vol 13 (13) ◽  
pp. 20056-20065
Author(s):  
Maria Theresa ◽  
Appukuttan Kamalabai Sreekala ◽  
Jayalakshmi Mohanlal
Keyword(s):  
Seedling Establishment ◽  
Fruit Set ◽  
Floral Morphology ◽  
Climatic Factors ◽  
Monsoon Season ◽  
Natural Habitat ◽  
Flowering Phenology ◽  
Perennial Herb ◽  
In The Wild ◽  
The Western Ghats

Ophiorrhiza caudata is a creeping, perennial herb distributed along wet and shady areas. The species is distylous with two distinct floral morphs: pin and thrum. Flowering usually occurs during the monsoon season. No particular difference was noticed in the flowering phenology of the two morphs. Presently the species is self-incompatible, however, it shows a tendency towards intramorph compatibility. Fruit set is above 60% in open pollination and intermorph pollination. Bees and butterflies are the major pollinators. The pollen flow between the two floral morphs varies depending upon floral morphology and pollinators. Fruit is a bi-valved capsule which dehisces by a splashing drop mechanism. The seeds are very minute. The rate of seed germination and seedling establishment in the wild condition is very poor due to adverse climatic factors. Ophiorrhiza caudata is struggling for survival in its natural habitat, where habitat fragmentation, climatic factors and poor seedling establishment could account for its narrow distribution.

scholarly journals Flowering phenology, fruiting success and progressive deterioration of pollination in an early-flowering geophyte

2010 ◽  
Vol 365 (1555) ◽  
pp. 3187-3199 ◽  
Author(s):  
James D. Thomson
Keyword(s):  
Fruit Set ◽  
Flowering Phenology ◽  
Bumble Bee ◽  
Late Flowering ◽  
Progressive Deterioration ◽  
Pollination Limitation ◽  
Hand Pollination ◽  
Western Colorado ◽  
Spatio Temporal ◽  
Erythronium Grandiflorum

Spatio-temporal patterns of snowmelt and flowering times affect fruiting success in Erythronium grandiflorum Pursh (Liliaceae) in subalpine western Colorado, USA. From 1990 to 1995, I measured the consistency across years of snowmelt patterns and flowering times along a permanent transect. In most years since 1993, I have monitored fruit set in temporal cohorts (early- to late-flowering groups of plants) at one site. To assess ‘pollination limitation’, I have also conducted supplemental hand-pollination experiments at various times through the blooming season. The onset of blooming is determined by snowmelt, with the earliest years starting a month before the latest years owing to variation in winter snowpack accumulation. Fruit set is diminished or prevented entirely by killing frosts in some years, most frequently but not exclusively for the earlier cohorts. When frosts do not limit fruit set, pollination limitation is frequent, especially in the earlier cohorts. Pollination limitation is strongest for middle cohorts: it tends to be negated by frost in early cohorts and ameliorated by continuing emergence of bumble-bee queens in later cohorts. This lily appears to be poorly synchronized with its pollinators. Across the years of the study, pollination limitation appears to be increasing, perhaps because the synchronization is getting worse.

scholarly journals Ehretia pubescens Benth. with differential germinability patterns due to climate change

2017 ◽  
Vol 6 (06) ◽  
pp. 1630
Author(s):  
Amalaurpava Mary Michael* ◽  
Gopal G.V.
Keyword(s):  
Climate Change ◽  
Fruit Set ◽  
Pollen Viability ◽  
Natural Habitat ◽  
Flowering Phenology ◽  
Flowering Pattern ◽  
Floral Phenology ◽  
The Impact

Climate change may influence the composition of plant communities by affecting the reproduction, growth, establishment and local extinction of plant species. Predicting the effect of climate change may provide insight into the impact and relationship between weather pattern and flowering phenology in long term studies. Pollen viability is one important factor of reproduction. Pollen viability is essential for a good fruit set. The study is undertaken to evaluate the influence of temperature and rainfall fluctuation pattern on floral phenology and pollen viability in the restricted distribution of the plant Ehretia pubescens Benth. Field observation on floral phenology has revealed changes occurring in the pollen viability with the change of temperature and rainfall. The plants show drought resistant; however, it is observed that it blooms immediately after the rainfall. Change in the rainfall pattern results in change in flowering pattern. On the natural habitat fruit set is a good indicating of good germinability of pollen grain in vivo. In vitro pollen germinability is less efficient for this species as supported by the data.

scholarly journals ADOPTION AND IMPACT OF IMPROVED PIGEON PEAS ON FARMING HOUSEHOLD POVERTY IN SEMI-ARID SOUTH EAST KENYA

2020 ◽  
Vol 5 (1) ◽  
pp. 36-48
Author(s):  
S J Matere ◽  
J R Busienei ◽  
O.L E Mbatia
Keyword(s):  
Service Providers ◽  
Rural Poverty ◽  
Household Survey ◽  
Pigeon Pea ◽  
Farm Income ◽  
Market Information ◽  
Cross Sectional ◽  
Factors Influencing ◽  
The Impact ◽  
Semi Arid

Purpose: The purpose of the study was to assess the factors influencing adoption of improved pigeon peas in semi-arid South Eastern Kenya and to evaluate the impact of adoption on households’ poverty. Methodology: The study used cross sectional data gathered through household survey to establish the factors influencing improved pigeon pea adoption. Propensity score matching approach was further used to assess the impact of adoption on households’ poverty. Findings: The results show that farmers’ access to improved pigeon pea seed, contact with agricultural extension service providers and access to market information significantly influenced adoption (p< 0.001). Adopters and non-adopters got an average net farm income of Kenya shillings (KES) 29,570 and 21, 490 per acre per year respectively. Adoption of improved pigeon peas resulted in a decrease of head count poverty by 0.24% and a reduction of poverty gap and poverty severity by 0.30% and 0.20 % respectively. Contribution to theory, practice and policy:  The study recommends that both National and County Government make policies that create enabling environment for private sector participation in production of certified seed to improve farmers’ access to improved seed to augment production. Facilitating farmers’ improved access to reliable and timely market information will increase production of marketable surplus of the peas that are adaptable to semi-arid areas, increase fall income and contribute to reduction of rural poverty.

scholarly journals Phenology of Sclerocarya birrea (A. Rich.) Hochst. Provenances

2019 ◽  
Vol 3 (1) ◽  
pp. 10
Author(s):  
V. J. Msukwa ◽  
C. R. Y. Munthali ◽  
B. I. Nyoka ◽  
E. Missanjo
Keyword(s):  
Fruit Set ◽  
Fruit Yield ◽  
Early Flowering ◽  
Flower Opening ◽  
Late Flowering ◽  
Sclerocarya Birrea ◽  
Bud Set ◽  
Fruit Maturity ◽  
Maturity Period ◽  
Leaf Flush

Phenology study was conducted to assess 22 genotypes of Sclerocarya birrea (A. Rich.) Hochst, collected from West, Eastern and Southern Africa. Assessments were done on time for bud onset, flower opening, leaf flush, fruit set, fruit maturity period and fruit production.  Highly significant (P< 0.001) variations between provenances were obtained in all the phenological traits assessed including variations between sexes in time from flower bud set to anthesis. There was flowering overlaps and synchrony between provenances and sexes with males flowering earlier than females. So far two subpopulations have emerged within the trial referred to as early and late flowering genotypes. The early flowering included provenances from Mozambique, and Swaziland while the late flowering encompassed provenances from Malawi, Zimbabwe, Namibia, Tanzania and Zambia. Fruit maturity period ranged from 76±2 to 192±15days. The early flowering genotypes flowered, fruited and matured between August and January while the late genotypes flowered and fruited from September to May. There were highly significant (P≤0.001) variations in fruit yield of S. birrea provenances between 2016/2017 and 2017/2018 seasons with the former being more productive than the later confirming that S. birrea fruit yield is not constant across seasons due to seed mating effects. There were very strong positive relationship ranging r=0.81 to r=0.78 between leaf flush, bud set, flower opening and fruit set significant at (P<0.001). Some trees classified as females in the first year as based on flowers were found have male flowers which calls for more detailed investigations into this sex change behaviour.

scholarly journals Landscape-Level Effects of Forest on Pollinators and Fruit Set of Guava (Psidium guajava L.) in Orchards across Southern Thailand

Diversity ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 259 ◽  
Author(s):  
Katrine Hansen ◽  
Tuanjit Sritongchuay ◽  
Sara Bumrungsri ◽  
Benno I. Simmons ◽  
Niels Strange ◽  
...  
Keyword(s):  
Crop Yield ◽  
Fruit Set ◽  
Positive Impact ◽  
Natural Habitat ◽  
Apis Cerana ◽  
Psidium Guajava ◽  
Evergreen Forest ◽  
Visitation Rate ◽  
Southern Thailand ◽  
Landscape Level

Pollination by wild pollinators is a key ecosystem service threatened by anthropogenic-induced land-use change. The proximity to natural habitat has previously been shown to positively affect pollinator communities and improve crop yield and quality but empirical evidence is limited from most parts of the World. Here, across six farms in Southern Thailand, we investigated the significance of landscape-level effects of natural habitat (proportion of and distance to evergreen forest) on both visitation rate and richness of pollinators as well as fruit set of guava (Psidium guajava L.), a local economically-important crop in the tropics. Overall, the most abundant pollinator was the Asian honey bee Apis cerana (39% of all visits) and different species of stingless bees (37%). We found that pollinator richness was unrelated to the proportion and distance to evergreen forest, however, the proportion of forest within a 1, 5 and 10 km radius had a significant positive impact on visitation rate of wild pollinators. Still, neither the various forest parameters nor pollinator visitation rate showed a significant impact on fruit set of guava, perhaps because guava self-pollinates. This illustrates that landscape-level degradation of natural habitat may negatively impact pollinator communities without diminishing the crop yield of the farmers.

scholarly journals Relationships between wild bee abundance and fruit set of Camellia oleifera Abel

2020 ◽  
Author(s):  
Hongying Li ◽  
Michael C. Orr ◽  
Ancai Luo ◽  
Feiyue Dou ◽  
Ruomei Kou ◽  
...  
Keyword(s):  
Fruit Set ◽  
Camellia Oleifera ◽  
Wild Bee ◽  
Bee Abundance
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