Stewardship Practices in Xtendflex Cotton and Economic Analysis

Herbicide resistant weeds became a menace in cotton production systems in various parts of United States. To battle this menace, third generation herbicide tolerant cultivars with stacked resistance to multiple mode of action were introduced in cotton. The XtendFlex cropping system is a stacked trait system utilizing traits that confer resistance to the herbicides dicamba, glyphosate and glufosinate to improve weed control in soybean and cotton. XtendFlex cotton (DP 1646 B2XF) was introduced in 2015 and is currently 22.3% of 5.4 million hectares of total upland cotton grown throughout the United States. Going back in time, the exceptional success of the second generation herbicide tolerant cultivars at marketplace made the conservation tillage and no-till systems popular. Herbicides slowly replaced the use of different indigenous tillage practices and crop rotation systems for weed control. However, in recent times, weeds resistant to multiple modes of action especially glyphosate, were reported in different parts of the United States. This brought us to a point where the real world weed management practices have to be integrated and tested for their long-term efficacy in terms of weed control, cost effectiveness for market success and sustainability in terms of herbicide resistance management. Therefore, field level research is being carried out at three different locations in Texas for three years integrating three different tillage practices, rotating cotton with sorghum in each tillage and using two different herbicide programs with in-season residuals to provide growers with economic and long term weed control options. Sustainability of these grower recommendations is addressed using computer simulation models.