EFFECT OF SEQUENTIAL PROGRAMS OF INSECTICIDES ALTERNATIVES AGAINST COTTON BOLL WORMS AND IT,S SIDE EFFECTS ON THE QUANTITY AND QUALITY OF COTTON CROP IN MIDDLE EGYPT

Abstract

The effect of sequential control sprays on cotton bollworms P. gossypiella and spiny bollworm, E. insulana on the average percent of infestation, the % reduction of bollworms population, economic losses in cotton yields and average of actual yield was studied. The 3 rd program was the most effective one against cotton bollworms, the seasonal percentages of reduction for spiny and pink bollworms were 92.85 and 94.86 % as compared with the Recommended Ministry Program (RMP), (87.65 and 81.67 % for both insects, respectively). The 1 st , 2 nd and 3rd programs didn't significantly affect the total common predators in cotton fields while the 4th and 5th programs didn't significantly affect the total common predators as compared with the untreated check, while ministry program effect highly significant on the total common predators on the cotton fields, showing the average percentage of reduction was 65.0%. The % economic losses in cotton yields and average actual yield were 4.76 % and 8.45 kentar / fed. as compared with the (RMP), (5.95 % and 8.55 kentar / fed.) , respectively. The seasonal percentage of reduction for pink and spiny bollworms were 86.62, 82.22 , 80.19, 83.90 % and 86.67,79.44, 79.44, 70.42 % for the 1st, 2nd, 4th and 5th programs applied to control both insects as compared with the Ministry program (87.65 and 81.67 %), respectively. The % economic losses in cotton yields and average actual yield were (5.37, 7.89, 10.32, 8.35 %) and 8.1, 8.05, 7.14, 7.95) kentar / fed. for the 1st, 2nd, 4th and 5th programs applied to control both insects as compared with the ministry program (5.95% and 8.55 kentar / fed.) respectively. Concerning the effect of these programs on the chemical properties, oil and protein , it proved no effect .The difference in fiber length at 2.5 % SL affected by these programs. The differences in fiber length (Pressley index) did not affected by these programs. The highest value of micronaire reading (4.53 micronaire unit) resulted from 5 th program as a compared with the Ministry Program (4.37 miconaire unit).