Document Type : Original Article
Authors
Plant Protection Research Institute, Agricultural Research Center, Dokki, Giza
Abstract
Different control agents were carried out in Baltiem District, Kafrel-sheikh Governorate during October and November, 2016. Two applications were implemented at interval of 15-days between each. The potency of the tested control methods was recorded at 3, 5, 10 and 15-days from each application as reduction percentages in the larval infestation caused by tomato leaf miner, Tuta absoluta larvae on tomato vegetable plants. Nowadays, finding a safe control program is the objective of all researchers. The goal of this work is to investigate the effect of gamma radiation on the entomopathogenic nematodes, Steinernema carpocapsae BA2, the egg parasitoid, Trichogramma evanescens in comparable with the insecticidal applications for controlling the pest infesting tomato fruits under field conditions. Results showed that 2 Gy irradiated S. carpocapsae BA2 was substantially more effective in controlling the insect larvae compared with normal nematodes. Based on the general mean reduction in infestation rates caused by the larvae of the pest as mean average of two successive applications, the efficiency of these agents could be decendingly arranged in order as follows: irradiated nematode at rate of 80IJ's+2Gy /ml, irradiated nematode at rate of 40 IJ's+2Gy/ml, normal nematode at rate of 80 IJ's /ml, , The insecticide proclaim, irradiated nematode at rate of 20 IJ's+2Gy/ml, normal nematode at rate of 40IJ's/ml,the insecticide, match, irradiated nematode at rate of 10IJ's+2Gy/ml, the egg parasitoid, T. evanescens, normal nematodes at rates of 20 IJ's/ml, 10IJ's/ml and the insecticide, chlorfan. The corresponding general mean reduction in the larval infestation rates were 89.20, 85.81, 83.73, 83.17, 82.38, 80.67, 79.66, 78.70, 77.64, 77.12, 74.77 and 74.74 %; respectively. The highest healthy yield production recorded 13.40 tons/feddan in case of treatment with irradiated nematode at rate of 80 IJ's +2Gy/ml; whereas the lowest healthy yield production reached 9.75 tons/feddan for the insecticide, chlorfan. The corresponding relative price benefit percentages recorded 230.86 and 140.74%; respectively as compared with the untreated plot.
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