Title: COTTON PRODUCTION UNDER CONSERVATION TILLAGE IN SUBTROPICAL AREAS OF TEXAS:III. WEED MANAGEMENT
Submitted to: International Cotton Pest Management Committee
Publication Type: Proceedings
Publication Acceptance Date: December 22, 1995
Publication Date: N/A
Interpretive Summary: Cotton weed control in south Texas has traditionally consisted of applying trifluralin pre-plant incorporated and planting into the treated soil followed by a second herbicide treatment at layby when the cotton canopy is almost to close. No-till cotton production leaves the previous crop residue on the soil surface, and incorporation of a herbicide prior to planting would bury much of this residue and also encourage weed seed germination and growth. Sixteen herbicides or combinations of herbicides were evaluated at five locations in corn and grain sorghum crop residue ranging from 4,500 to over 11,000 kg/ha on the soil surface. Banded applications of coteran plus pendimethalin or coteran plus clomazone provided the most consistent weed control with the least amount of crop injury or effect on crop yield when compared to handweeded controls.
Crop residue on the soil surface interferes with traditional methods of incorporating soil applied herbicides prior to planting cotton. In conservation tillage systems, pre-plant weeds are chemically controlled with a burn down herbicide, thus leaving the crop residue on the soil surface. Conservation tillage has several production advantages over conventional tillage systems such as reduced wind and water erosion, reduced time, labor, fuel, equipment, trips over the field, and increased net returns. The primary objective of this study was to determine weed management strategies for no-tillage cotton production. Weeds were controlled adequately by two mechanical cultivations plus pre-emergence banding of the herbicide combinations of pendimethalin plus coteran, or coteran plus clomazone. Several other combinations worked well to control weeds but cause reductions in lint yield or were cost prohibitive.