PERFORMANCE OF CERTAIN GROUND AND AERIAL APPLICATION TECHNIQUES AGAINST PIERCING AND SUCKING INSECTS IN COTTON CULTIVATIONS

Eleven techniques represented almost spraying and dusting appli‌cation methods common in Egypt were tested to control sucking insects on cotton cultivations by using certain insecticides recommended from Ministry of Agriculutre in Egypt. These insecticides were Deltanet, Prem‌pet, catabron and Sulfur during seasons 1993, 1994. In the early sea‌son, three types of ground spraying equipment were used. These spray‌ers are semco, Tapa, CP-3 sprayed as target and drift spraying technique by using Deltanet against aphid. The target spray revealed 98-100% reduction in number of insects with the comprarison of drift spray technique which caused 75% reduction. The season remain, the used techniques were categorized into three groups according to their capabilities in the mentioned respects as good, moderate and improper techniques for controlling sucking insects in cotton plantations. A. The first group (Good techniques): Deltante and prempet caused 80% reduction from population insects by using semco sprayer and CP-3 sprayer as target spraying techniques. The droplet spectrum ranged between 15-58 droplets/cm2 with diameter 65-100 pm (VMD). The percentage of spray lost on ground was 25% from the total spray vol‌ume. B. The second group (Moderate techniques): Deltanet caused 77% re‌duction from population insects by using semco, CP-3 and convention‌al sprayer. Although there was not droplets on lower surfaces of cot‌ton plants could be observed, but might be settling droplets less than 25 pm. Produced by conventional sprayer which could not be counted through measuring technique used. Catabron insecticide (unrecommended against sucking insects) revealed 50% reduction from insect populations by using semco sprayer, while the same insecticide revealed 60% reduction from insect popula‌tion by using helicopter. The percentage of spray lost on ground was 44% for ground equipment as target spraying technique and helicopter. C. The third group (Improper techniques): Three insecticides caused 12‌47% reduction from insect population by using conventonal sprayer, and 43% was lost spray on ground from the total spray of the men‌tioned sprayer, but in case of sulfer dust by ground equipment or heli‌copter a 32% reduction from population insects was done with the same level mentioned for spray lost on ground. Generally, it was rec‌ommended to apply Deltanet insecticide which has a spectrum of droplets within 65-100 micrometers (VMD) in numbers not less than 15 droplets/cm2 on the lower sides of leaves with enough distribu-tional homongenity.