THE IMPACT OF INTERCROPPING COTTON AND COWPEA ON PEST INFESTATION

Field trials were conducted at Etay El-Baroud Experimental Sta­tion during the two seasons 1989 and 1990. The effect of the two in­tercropping systems of cotton and cowpea on the population density of target pests; aphid, Aphis gossypii Glover; jassid, Empoasca decipiens Paoli; whitefly, Bemisia tabaci (Genn.); spider mite, Tetranychus arabicus Attiah and bollworm, pectinophora gossypiella (Saunders) was studied. The intensity of attack to cotton and cowpea differed during the two seasons. Cowpea as a monocrop was more attractive than cotton to pests infestation. The two intercropping patterns (1:1) and (1:2) of cot­ton with cowpea significantly influenced the density of A. gossypii and E. decipiens suggesting that the presence of cowpea plant in the two crop­ping patterns had reduced the population build-up on cotton. Population reduction of the two insects was greater with the intercropping pattern (1:2) than the intercropping pattern (1:1). On the other hand, the pres­ence of cowpea as a preferable plant in the two cropping systems had resulted in a slight increase of B. tabaci and T. arabicus population on cotton. The population increase was higher at the intercropping pattern (1:2) than the intercropping pattern ( 1:1) . The cotton bollworm P. gossypiella did not follow any regular pattern in either system.