The Effect of Pollinators and Pollination on Fruit Set and Fruit Yield of Okra (Abelmoschus esculentus (L.) Moench) in the Forest Region of Ghana

Abstract

Aims: To determine the effect of pollinators and how they affect the reproductive performance of okra cultivated in the forest region of Ghana. Study Design: The experiment was conducted in a randomized complete block design (RCBD) with three treatment and three replications. Place and Duration of Study: The experiment was conducted on an experimental farm of the Department of Horticulture of the Kwame Nkrumah University of Science and Technology, Kumasi, Ghana during the minor rainy season of 2011 and repeated during the major rainy season of 2012. Methodology: Nine subplots, each measuring 4 m × 6 m were raised with an alley of 2 m between the plots and blocks. Okra seeds were sown at two seeds per hole at a spacing of 80cm × 60cm and thinned to one plant per stand one week after germination. The three treatments were insecticide application, net-covered plants and a control which was neither sprayed nor covered. Basal NPK fertilizer was applied to all the plots at a rate of 10 g per plant. Data were collected on insects that visited the flowers for pollination, numbers of flower sets and numbers of aborted flowers, fruit set, numbers of fruits and number of seeds per pod in ten randomly selected plants on each plot. Results: Honeybees were the main pollinators of okra flower. Many of the other insects found on the plant were not involved in pollination of the flowers. There were no significant differences (P>0.05) in the numbers of flowers per plant and numbers of aborted flowers, but significant differences (P<0.05) were recorded in the numbers of pods per plant, yield per plant and the numbers of seed per pod. Honeybee numbers were significantly different on the different treatments. Conclusion: It was observed that even though the net-covered plant recorded some yield, insect pollinated flower recorded better yield, therefore conservation of honeybees as pollinators of okra flowers will improve the yield of this crop