Insects in cotton as affected by irrigation and fertilization practices

Cotton research personnel and growers have often observed that some insect pests are more abundant in parts of a cotton field or in, entire fields where plant growth is rank and succulent. The research reported here was initiated to test this observation. Three different regimes of irrigation water and nitrogen, tested in factorial combinations brought about distinct differences in growth patterns between various plots. Throughout the course of the study the lygus bug, Lygus hesperus Knight, was found significantly more abundant in plots with high irrigation and nitrogen levels, than in plots receiving minimum applications of either variable. A complex relationship was found to exist between cotton lint production, vegetative plant growth, insect numbers, and water and nutritional management. The implication of these tests is that cotton growers may reduce the threat from insect pests through management of their irrigation and fertilization practices.