Abstract:
The purpose of the study was to investigate the influence of pesticide application
on the abundance and diversity of watermelon flower visitors as well as its effect
on the crop yield. This was to help identify the most beneficial insecticide
application regime to ensure pollinator health and the control of insect pests
whiles ensuring maximum yield. Insects that visited watermelon flowers were
collected weekly with the use of sweep nets and pan traps from plots with
pesticide application twice a week, once a week and no application.
Phenologically the plants promoted male fitness by producing more male flowers
than female flowers. The plot with no pesticide application had the highest
diversity of flower visitors present with a value of 1.50 on the Shannon Weiner
index, and the highest species richness of eight. The most abundant and most
efficient pollinator of the watermelon plant according to this study was the honey
bee Apis mellifera L. There was a significant difference between the number of
insect flower visitors collected from the different treatments used in the study (p<
0.05). It was also established from the study that there was no significant
difference (p> 0.05) in fruit yield from plots with different pesticide application
regimes. In effect, the application of pesticides once a week after flowering is best
to achieve protection of pollinators and still ensure maximum fruit yield.
