Influence of Certain Agrochemicals, Oils and Foliar Fertilizers Against Citrus Leaf miner, Phyllocnistis citrella Stainton (Lepidoptera:Gracillariidae) on Lime Trees

Abstract

Field trials were conducted on a private farm cultivated with lime trees, Citrus aurantifolia Frank, 4 years old, in Kom Hamada, Behaira governorate. The influence of certain insecticides, oils, and foliar fertilizers was studied against citrus leafminer Phyllocnistis citrella on lime trees. The insecticides included abamectin, spinetoram, thiocyclam, azadirachtin, lambda-cyhalothrin, and profenofos; two oils (mineral and vegetable oils); and two foliar fertilizers (calcium nitrate and potassium nitrate). The results indicated that abamectin consistently showed the highest efficacy in eliminating the citrus leaf miner, on lime trees. This effectiveness was observed over five consecutive administrations conducted during the 2021 growing season. The treatment with abamectin exhibited the highest level of efficacy among the several treatments that were evaluated. It yielded reduction percentages of 79.60%, 85.90%, 81.20%, 89.40%, and 92.10%, respectively, and a grand reduction of 85.64%. The application of mineral oil came in the second order and resulted in a decrease in infestation levels by 64.90%, 63.10%, 65.70%, 70.90%, and 70.50% after five consecutive applications, with a grand reduction of 67.03%. Meanwhile, the treatments of vegetable oil, spinetoram, and lambda-cyhalothrin produced medium-significant reductions in infestation (̰50%), revealing grand reductions of 52.50, 52.04, and 49.92%, respectively, among the five consecutive applications. Based on the results of our research, it is evident that abamectin as well as mineral oil remain viable and advantageous options for effectively controlling the citrus leaf miner infestation in juvenile lime trees.