Dicamba-Based Herbicide Programs, Cropping Sequences, Tillage Types in Cotton – Profitability and Risk Efficiency Analysis

Abstract

Herbicide-resistant weeds threaten cotton production, and herbicides alone are not a sustainable remedy. Field trials at two locations, College Station and Thrall, Texas (2019-21), assessed dicamba-based herbicide programs in various crop sequences and tillage systems to identify sustainable weed management recommendations based on weed control and partial net returns. The study showed no-till cover cropping and conventional tillage had the highest aggregate partial net returns at College Station and Thrall, respectively. A cotton:sorghum:cotton rotation provided significantly higher partial net returns (>$450 ha-1) compared to continuous cotton only at Thrall. Partial net returns were significantly higher in a low input herbicide program (LI) compared to a high input herbicide program (HI) from 2019-21 only at Thrall. Herbicide programs showed a high degree of overlap and were indistinct in all tillage types at College Station based on CDFs graphs. Low input under cotton:sorghum:cotton rotation showed 100% probability of higher partial net returns compared to continuous cotton in all tillage types at Thrall. Stoplight charts showed LI provided greater than 50% probability of partial net returns greater than $1,066 ha-1 across tillage types at College Station. In Thrall, LI under cotton:sorghum:cotton rotation offered 88% and 26% probability of partial net returns above $1,066 ha-1 in conventional and strip tillage, respectively. Higher partial net returns for LI were mostly attributed to cost savings from using inexpensive herbicides rather than higher yields. Therefore, using less expensive herbicide programs and crop rotation appeared to be the most risk efficient strategy for managing weeds in irrigated and dryland cotton production.