Impact of the foraging activity of Apis mellifera (Hymenoptera: Apidae) on increasing yields of Gossypium hirsutum (Malvaceae) in Djoumassi (Garoua, Cameroon)

To evaluate the impact of the foraging behaviour of Apis mellifera in increasing boll and seed yields of Gossypium hirsutum, its pollination activities were studied in Garoua for two seasons, from September through October 2018 and 2019. Observations were made on 540 flowers divided into four treatments of which two were differentiated according to the presence or absence of flower protection regarding insect visits; the third was made of protected and opened flowers, to allow Apis mellifera visits and the fourth made of opened flowers then closed without any visit. The bee’s daily rhythm of activity, their foraging and pollination activities were evaluated. Results showed that, on Gossypium hirsutum flowers, Apis mellifera intensely collected pollen and nectar. Data obtained allow the classification of this Malvaceae as a highly polliniferous and nectariferous bee plant species. Through its pollination efficiency, Apis mellifera has increased the fruiting rate by 29.66% and 13.95%, the mean number of seeds per boll by 24.53% and 14.89% and the percentage of normal seeds by 3.89% and 8.87% in 2018 and 2019 respectively. Hence, the conservation of Apis mellifera colonies close to Gossypium hirsutum fields is recommended to improve its boll and seed yields.