Chemical Control of Aphid Populations in Cotton Using Hydraulic and Electrostatic Sprayers and Aphid Alarm Pheromone
Mar 8, 2019
In experimental cotton fields in Lianoverghi, Imathia, Greece in 1995 (cultivar Zeta-2) and Velestino, Magnesia in 1996 (cultivar Corina), experiments comparisons were made between different application methods for chemical control of aphids. There were five treatments in a randomized complete block design in four replications. The treatments were: control, cyhalothrin sprayed with hydraulic or electrostatic sprayer and cyhalothrin with pheromone sprayed with hydraulic or electrostatic sprayer. Observations of the presence of aphids were taken 1-2 days before and 7-8 and 20 days after the applications. The predominant aphid species in both regions was Aphis gossypii Glover. The electrostatic sprayer was more effective than the hydraulic. The presence of the pheromone did not change the efficiency of the insecticide with either method. Both methods were less effective when aphid populations were high. Aphid populations were high in untreated plots 7 days after spraying, but later declined below populations in the treated plots, possibly because of the activity of natural enemies. The electrostatic sprayer was less efficient than the hydraulic when aphid populations were very high and full grown plants formed a continuous canopy.