Control of weeds in wheat under no-till using reduced herbicide doses and application volumes

Abstract

The aim of the present work was to assess the effect of lower doses than recommended by the manufacturer of the herbicide diclofopmethyl + fenoxaprop – p - ethyl + mefenpyr – diethyl and different application volumes to control the grass weeds Avena sterilis L. and Lolium rigidum G. in post-emergence in no-till wheat and the consequent effect on crop yield.

Therefore lower herbicide doses than recommended (1; 1.5 and 2 l ha^-1) were combined with lower application volumes (100; 200 and 300 l ha^-1) at two different weed development stages (beginning of tillering and complete tillering). The recommended herbicide doses to control these weeds vary between 2.5 and 3 l ha^-1 and the application volumes should vary between 350 and 600 l ha^-1 .

The results show that the anticipation of the herbicide application (beginning of tillering) leads to a better weed control even using herbicide doses and application volumes lower than recommended. The lower efficiency to control more developed grass weeds and a longer period of competition between crop and weeds for the second application timing (complete tillering) were responsible for the lower crop yields for this application date.