Rotation of herbicides in wheat to prevent resistance weed under Mediterranean conditions

Abstract

Herbicide mixtures are widely recommended to prevent weed herbicide resistance. During a two-year period (2016/2017 and 2017/2018) two field trials were carried out on the Experimental farms of Passinho (Elvas) and Almocreva (Beja). The aim of these trials was to study the effect of herbicide mixtures with different sites of action or groups, in the weed control and grain yield of wheat (Triticum aestivum L.). In six different applications (treatments) the active ingredients studied were diflufenican, flufenacet and metribuzin applied in crop pre-emergence or early post-emergence and propoxycarbazone-sodium, mesosulfuron-methyl, iodosulfuron-methyl-sodium, bromoxynil octanoate and 2.4-DB - ethylhexyl ester, applied in crop post-emergence. There were no significant differences between the different treatments, nor to weed control efficiency, nor for grain yield. The control treatment obtained a significantly lower grain yield.