Entomophilous pollination in rape (Brassica napus L var oleifera) in BrazilJ.E.B. Adegasa and R.H. Nogueira Coutob
a Zootecnista Graduado pela Faculdade de Ciências Agrárias e Veterinárias, UNESP, São Paulo, Brazil
b Bióloga, Depto de Zootecnia de Não Ruminantes da Faculdade de Ciências Agrárias e Veterinárias, UNESP, Rodovia Carlos Tonanni, 14870, Jaboticabal, São Paulo, Brazil
Abstract - The present experiment was performed to study the development of rape flowers (Brassica napus var oleifera, cv CTC 4), volume and concentration of nectar produced, insects involved in the pollination and their behaviour in the flower (nectar or pollen collection), and the effects of this pollination on the production of pods and seeds, and germination and oil content in the seeds. The most frequent insect visitors to the flower were: Apis mellifera, 80.6%; Trigona spinipes, 12.8% and Dialictus sp, 6.6%. The sugar content averaged of 16.3 μg, and the percentage of sugar in the nectar collected from workers (Apis mellifera) was 37 ± 18%. Total protein content and ether extract in the pollen were 17.5 and 6.7%, respectively. The visits of A mellifera collecting nectar and pollen contributed to pollination and to an increased production of pods per square meter and individual seed weight. No influence was registered on total number of seeds per pod, normal seeds (fully formed) or abnormal seeds (shrivelled and undersized) per pod, percentage of seed germination and oil content.
Key words: Brassica napus var oleifera / pollination / nectar / foraging behaviour / Apis / Trigona / Dialictus / seed production