Murdannia nudiflora control in soybean postharvest

Abstract

The species of Murdannia nudiflora belongs to the family Commelinaceae is known as doveweed. Because of competitive capacity and tolerance to glyphosate this species growing during the soybean crop cycle, presenting rapid growth when the leaf senescence of soybean occurs difficulting weed management in others cultures. The objective of this study was to evaluate the efficiency of different active ingredients of herbicides in combination or separately, and verify the best dosage of the active ingredient, which provided the best control of M. nudiflora. Two field experiments were arranged in randomized block design. The first experiment consisted of eight herbicide treatments being glyphosate 972 g a.e. ha^-1, atrazine 1500 a.i. g ha^-1, carfentrazone 12 g a.i. ha^-1, imazethapyr 100 g a.i. ha^-1, glyphosate + imazethapyr 972 + 30 g ha^-1, imazethapyr + atrazine 30 + 1500 g ha^-1, carfentrazone + atrazine 8 + 1500 g ha^-1 and check. The second experiment used the herbicide atrazine in different dosages 0, 880, 1100, 1320 e 1540 g a.i. ha^-1. In the experiments all herbicide was applied in post emergence. In the results of the first experiment, only treatments with atrazine presented efficient control (> 80%). Glyphosate at the dose of 972 g a.e. ha^-1 showed low control (< 20%) even when mixed with imazethapyr. In the second experiment, doses starting 880 g a.i. ha^-1 of atrazine were sufficient for control in post-emergence of M. nudiflora