Apis mellifera pollination improves agronomic productivity of anemophilous castor bean (Ricinus communis)

Abstract

Castor bean (Ricinus communis L.) is cultivated mainly for biodiesel production because of its oil-rich seeds; it is assumed to be an anemophylous species. But pollination deficit can lead to low productivity often attributed to other reasons. In this paper, we investigated pollination requirements, pollination mechanism, occurrence of pollination deficit, and the role of biotic pollinators in a large commercial plantation of castor bean. Our results show that r. communis bears a mixed breeding system favoring selfing by geitonogamy, although the wind promotes mostly outcrossing. We also found that the honey bee (Apis mellifera L.) foraging on castor bean can both transfer pollen from male to female flowers within the same raceme and boost the release of airborne pollen by male flowers. Both situations increase geitonogamy rates, raising significantly fruit set and seed yield. This is the first report of an animal foraging activity increasing seed yield in an anemophilous and geitonogamous crop and elucidates the role of biotic pollinators in castor bean reproduction.

Honey bees ( Apis mellifera ) visiting flowers of yellow melon ( Cucumis melo ) using different number of hives

“…Other studies using honeybee for pollination of melon and other crops (cashew, guava, cotton and castor beans) observed similar foraging behavior (HOLANDA- NETO & FREITAS, 2000;SOUSA, 2003;ALVES & FREITAS, 2006;SILVA, 2007;RIZZARDO et al, 2012).…”

Biologia reprodutiva de L. leucocephala (Lam.) R. de Wit (Fabaceae: Mimosoideae): sucesso de uma espécie invasora

“…Já mamoneira (Ricinus communis L.), muito utilizada para produção de biodiesel, também apresenta comportamento de espécie invasora. Mesmo sendo uma espécie considerada anemófila, tem sua produção de sementes aumentada com a visitação de abelhas (especialmente Apis mellifera), assim como L. leucocephala, o que aumenta o sucesso de suas populações (Rizzardo et al, 2012). A alta taxa de produção de frutos observada neste estudo, onde houve polinização através dos visitantes florais, realça essa influência dos polinizadores no sucesso reprodutivo de plantas invasoras, pelo aumento de sua abundân-cia e auxílio na colonização de novas áreas, através da alta produção de frutos e sementes.…”

Explosive pollen release, stigma receptivity, and pollen dispersal pattern ofBoehmeria caudataSw. (Urticaceae) in a Brazilian rain forest

“…We cannot exclude the possibility that flower visitors feeding on pollen and so touching the anthers also contribute to the explosive mechanism, as for example occurs in R. communis (Rizzardo et al 2012). At the start of our study we experimentally touched the filaments with a needle and caused explosions (Fig.1).…”