Culturing¬ of Chick pea as a Trap Crop for Damage Decrease of Helicoverpa armigera in Cotton
2013
Heravi, Parisa | Sarkolaee, Akbar | Tavasoli, Esmaeel
To determine the effect of trap crop in reducing the population of American bollworm Helicoverpa armigera(Hub.) chick pea was planted in 0.5 hac. In two geographical places , Gorgan and kordkooy in early March of 2011. Samplings in chick pea were started with the beginning of the pest activity and continued every 5-7 days.The trap crop was ploughed in mid June to eliminate the existed larvae and pupae of H. armigera. four plots of cotton inside the both place in distances 5, 100, 200 and 300 meters from trap crop were selected. The results showed that in chick pea the mean larval density of H. armigera per plant in Gorgan and Kordkooy were 0.31 and 0.33 respectively . The maximum larval number of H. armigera in this two places were 0.47 and 0.58 respectively. The number of eliminated larvae of H. armigera in chick pea in kordkoy and gorgan were 40000 and 59000 respectively, which is a considerable number for the tested regions because H. armigera female has high fecundity and its population increases sharply. In cotton mean larval density were 15.6, 11, 5 and 13 times in gorgan and 10.8, 7.8, 8.1 and 5 times were less than the density of the pest in chick pea in the same year in distances 5, 100, 200 and 300 meters from trap crop respectively .In cotton insecticide was used only one time in some plots for H. armigera control in both years which was less than the average annual amount of insecticide usage against this pest in the region (between 2-3 times). Overall it is concluded that planting chick pea as trap crop and killing the attracted population of H. armigera could be a suitable method in Integrated Management of H. armigera in cotton.
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