Influence of Honey Bee (Hymenoptera: Apidae) Density on the Production of Canola (Crucifera: Brassicacae)

Abstract

Pollination is an essential step in the seed production of canola, Brassica napus L. It is achieved with the assistance of various pollen vectors, but particularly by the honey bee, Apis mellifera L. Although the importance of pollination has been shown for the production of seed crops, the need to introduce bee hives in canola fields during flowering to increase oil seed yield has not yet been proven. With the purpose of showing this, hives of A. mellifera were grouped and placed in various canola fields in the Chaudière-Appalaches and Capitale-Nationale regions (nine fields; three blocks with three treatments; 0, 1.5, and 3 hives per hectare). A cage was used to exclude pollinators and bee visitations were observed in each field. After the harvest, yield analyses were done in relation to the bee density gradient created, by using pod set, number of seeds per plant, and weight of 1000 seeds. Results showed an improvement in seed yield of 46% in the presence of three honey bee hives per hectare, compared with the absence of hives. The introduction of honey bees contributed to production and consequently, these pollinators represented a beneficial and important pollen vector for the optimal yield of canola.

Agricultural Policies Exacerbate Honeybee Pollination Service Supply-Demand Mismatches Across Europe

“…These RSR estimates are inconsistently estimated and unlikely to be broadly applicable; for instance the lowest RSR for oilseed rape (1 colony/ha) is taken from a field study in Australia [36] where feral honeybees among other wild pollinators are widespread and thus greater “ambient” services are available. By contrast a more comprehensive study from Canada, where climates are similar to much of Europe, demonstrates that 3 colonies/ha provide significantly greater yield than 1.5 colonies/ha [37]. Furthermore, for some crops, existing RSR values are very limited, such as soybean for which only a single estimate is available [18].…”

Diesel exhaust rapidly degrades floral odours used by honeybees

“…3a)2627 however, to forage effectively, honeybees need to be capable of learning and recognizing the plants floral odour blend228. Our results infer that a constituent of airborne pollutants, NO x gases, may be capable of disrupting the odour recognition process that odour guided pollinating insects rely on for location of floral food resources.…”

In search of the best pollinators for canola (Brassica napus L.) production in Pakistan

“…Much work has been conducted on the pollination biology and the ecology of B. napus. With few exceptions (Williams et al 1986), most pollination biologists have favored insect pollination in terms of quantitative and qualitative yields, i.e., greater seed yield, higher seed set, high seed-meal lipid, more seeds per pod and more pods, earlier pod formation, earlier cessation of flowering, faster and more uniform seed maturation, and increased germination of seeds (Langridge and Goodman 1975;Fries and Stark 1983;Korpela 1988;Mesquida et al 1988;Kevan and Eisikowitch 1990;Sabbahi et al 2005). The flower of B. napus has a generalized open structure (Faegri and van der Pijl 1971) that almost every group of pollinating insects can feed from.…”