ANBAR JOURNAL OF AGRICULTURAL SCIENCES

Abstract

Field experiments were conducted to evaluate the effect of planting date on some agricultural pests on four cotton cultivars in the region of Karkok during the growing seasons of 2000 and 2001.Results showed that planting date and cotton cultivar had an obvious influence on pest infestation which was too low except for whitefly Bemisia tabaci Gen and the leafhopper Asymmytrasca decedents (Boali) during both seasons. The lowest population density was 8 individuals/5 leaves recorded on Lashata cultivars planted in 1/4/2000. The highest number of insects was16 idividuals/ 5 leave on Kocker cultivar . The lowest and highest general means were recorded for1/4 and 15/4/2001 planting dates respectively. As for the second growing season , the number of whiteflies and leafhoppers showed no significant differences in most cases. The general means were 7.1 and 1.0 individuals/5 leaves respectively recorded on Lshata cultivar.. The spiny bollworm Erias insulana Boisd was almost absent during both seasons except for the last reading of September for the growing season of 2001. The lowest percentages of infestation was about 9% on Kocker and Marsumi cultivars planted in 1/4/2001 and the highest percentages was 20% recorded for the same cultivars planted in 15/4/2001. The feasibility of utilizing these results in the management and production practices of cotton in Iraq was discussed.