Adoption of Best Management Practices for Herbicide-Resistant Weeds in Midsouthern United States Cotton, Rice, and Soybean

Abstract

In fall 2011, cotton and soybean consultants from Arkansas, Louisiana, Mississippi, and Tennessee were surveyed through direct mail and on-farm visits, and rice consultants from Arkansas and Mississippi were surveyed through direct mail to assess the importance and level of implementation of herbicide resistance best management practices (HR-BMPs) for herbicide-resistant weeds. Proper herbicide timing, clean start with no weeds at planting, application of multiple effective herbicide modes of action, use of full labeled herbicide rates, and prevention of crop weed seed production with importance rating of ≥ 4.6 out of 5.0 were perceived as the most important HR-BMPs in all crops. Purchase of certified rice seed was on 90% of scouted hectares. In contrast, least important HR-BMPs as perceived by consultants with importance ratings of ≤ 4.0 in cotton, ≤ 3.7 in rice, and ≤ 3.8 in soybean were cultural practices such as manual removal of weeds; tillage including disking, cultivation, or deep tillage; narrow (≤ 50 cm)-row crops, cover crops, and altered planting dates. Narrow crop rows and cover crops in cotton; altered planting dates in cotton and soybean; and cleaning of farm equipment and manual weeding in rice and soybean is currently employed on ≤ 20% of scouted hectares. Extra costs, time constraints, adverse weather conditions, lack of labor and equipment, profitability, herbicide-related concerns, and complacency were perceived as key obstacles for adoption of most HR-BMPs. With limited adoption of most cultural practices that reduce risks of herbicide-resistant weeds, there are opportunities to educate growers concerning the proactive need and long-term benefits of adopting HR-BMPs to ensure sustainable weed management and profitable crop production.

Seletividade de herbicidas isolados e em associações para milho RR2/LL®

“…(Osório et al, 2015). Soltani et al (2010) A associação e rotação de herbicidas tratam-se de importantes ferramentas no manejo de plantas daninhas e também na prevenção de seleção de biótipos resistentes a herbicidas (Green, 2007;Riar et al 2013). Nesse contexto a tecnologia LL ® ganha destaque, devido à possibilidade do uso do herbicida glufosinate.…”

Assessment of Roundup Ready 2 (RR2) corn subjected to application of isolated and associated herbicides

“…Results from Shaner (2000) warned that although the crops tolerant to glyphosate are important tools in weed control, intensive use of glyphosate in RR crops would cause problems, especially in the selection of resistant biotypes. In this sense, focusing on a better control of weeds and preventing the selection of resistant weed biotypes, the use of two or more mechanisms of action are advisable measures (Riar et al, 2013;Barroso et al, 2015). A recent survey by Gazziero (2015) found that for 97% of rural and technical producers, tank-mixing is a common practice in 95% of the times ranging from two to five products and that 72% of the interviewed producers said they did not know anything or have used insufficient amount of information about tank mixtures.…”

Application of Post-Emergence ALS Inhibitor Herbicides Associated or Not to Glyphosate in RR/STS Soybean

“…In this context, new technologies and cultivars tolerant to herbicides, such as soybean imidazolinone tolerant, 2.4-D, sulfonylureas, among other molecules, deserve highlights (Riar et al, 2013).…”