Direct pollination efficiency of Apis mellifera on the flowers of the Allium cepa L. 1753 (Liliaceae), Chagari variety in Mokong (Mayo-Tsanaga, Far North Region; Cameroon)

The aim of this work was to study the foraging activity of Apis mellifera (Apidae) and to evaluate its direct pollination efficiency on fruit and seed yields of Chagari variety of Allium cepa (Liliaceae). The observations were carried out from November 2020 to September 2021 in Mokong (Far-North Region of Cameroon). Each year, 40 umbels were isolated at the flower bud stage and the activity of A. mellifera was noted on the 40 free umbels. During the flowering period, each isolated umbel was reopened and closed again after a single visit from A. mellifera. The numbers of fruits per umbel and seeds per fruit were counted. A. mellifera was the most frequent insect (29.94% of total visits) of the 40 visitors. During the flowering period, there was a high daily and seasonal frequency of visits of this Apidae which collected very largely the nectar and weakly the pollen. The direct pollination efficiency of A. mellifera on fruiting rate, the average number of seeds per fruit and the percentage of normal seeds were 74.61, 33.96 and 66.13%, respectively. A single visit of A. mellifera significantly increased the fruit and seed yields.