Submitted to: Entomological Society of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 6, 2000
Publication Date: N/A
Technical Abstract: Conservation tillage cotton production is gaining popularity in south Texas due to the many benefits which include reduced wind and water erosion, decreased fuel, equipment, labor, input costs and increased net returns. The objective of this study was 1) to determine the effects of conservation tillage on soil temperature, soil moisture, plant canopy structure, light interception, and timing of fruit set, and 2) how these factors affect bol weevil (Anthonomus grandis Boheman.) populations, cotton crop damage, lint yield, and net returns when compared with a conventional moldboard plow and disk tillage system. The soil moisture in the no-tillage was greater early in the growing season because tillage had not dried out the soil. No-tillage cotton set squares and bolls early in the season and averaged 5 bolls per plant at 80 days after planting. The conventional moldboard tillage cotton had less moisture and greater plant stress due to lack of soil moisture early in the growing season causing plants to shed squares and bolls. The no-tillage cotton quickly went into a reproductive fruiting mode while the conventional tillage cotton was putting most of its resources into vegetative growth of stalks and leaves. Increased plant height and leaf number in the conventional tillage provided more light interception and shading of the soil surface, and the no-tillage had greater soil temperatures between the rows. Boll weevil populations in plants were from 1.3 to 5 times greater in the conventional tillage compared with the no-tillage. Trap counts of weevil populations followed a similar trend with 1.9 to 4.9 times more weevils in the conventional tillage compared to no-tillage. No-tillage cotton produced more bolls and lint and had fewer boll weevils than the conventional tillage cotton.