ABSTRACT:
With the possibility of using ammonium glufosinate in corn, studies on its association with other herbicides are essential. The aim of this study was to assess weed control and herbicide selectivity in association with ammonium glufosinate in corn containing the pat and cp4-epsps genes. The experiment was carried out under field conditions in two sites in a randomized block design with four replications. Treatments consisted of ammonium glufosinate, glyphosate, ammonium glufosinate + glyphosate, ammonium glufosinate + nicosulfuron, ammonium glufosinate + atrazine, ammonium glufosinate + tembotrione, ammonium glufosinate + mesotrione, ammonium glufosinate + carfentrazone ethyl, ammonium glufosinate + bentazon, ammonium glufosinate + 2,4-D, control without weeding, and hand-weeded control. Visual assessments were performed regarding damage, electron transport rate in photosystem II (ETR), ammonia quantification, height, and grain yield of corn plants, as well as weed control at both sites. The application of ammonium glufosinate and its associations did not provide a reduction in productivity when compared to the hand-weeded control. Some treatments presented higher levels of visual damage and ammonia accumulation, but without a yield reduction. Therefore, herbicide mixture with ammonium glufosinate may be an alternative to weed control without damaging corn crop, which presents in its genetic constitution the cp4-epsps and pat genes.
Keywords:
ammonia accumulation; phosphinothricin; electron transport rate; herbicide resistance; Zea mays
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Source: Brazilian National Institute of Meteorology (INMET).
Means followed by equal lowercase letters in columns of the same color do not differ significantly from each other by the Tukey’s test (p≤0.05). 1 - ammonium glufosinate; 2 - glyphosate; 3 - ammonium glufosinate + glyphosate; 4 - ammonium glufosinate + nicosulfuron; 5 - ammonium glufosinate + atrazine; 6 - ammonium glufosinate + tembotrione; 7 - ammonium glufosinate + mesotrione; 8 - ammonium glufosinate + carfentrazone ethyl; 9 - ammonium glufosinate + bentazon; 10 - ammonium glufosinate + 2,4-D; 11 - control without weeding; and 12 - hand-weeded control.
Means followed by equal lowercase letters in columns of the same color do not differ significantly from each other by the Tukey’s test (p≤0.05). Graphs without letters were not significant. 1 - ammonium glufosinate; 2 - glyphosate; 3 - ammonium glufosinate + glyphosate; 4 - ammonium glufosinate + nicosulfuron; 5 - ammonium glufosinate + atrazine; 6 - ammonium glufosinate + tembotrione; 7 - ammonium glufosinate + mesotrione; 8 - ammonium glufosinate + carfentrazone ethyl; 9 - ammonium glufosinate + bentazon; 10 - ammonium glufosinate + 2,4-D; 11 - control without weeding; and 12 - hand-weeded control.
Means ± confidence interval. Means followed by equal lowercase letters in columns of the same color do not differ significantly from each other by the Tobey test (p≤0.05). Graphs without letters were not significant. 1 - ammonium glufosinate; 2 - glyphosate; 3 - ammonium glufosinate + glyphosate; 4 - ammonium glufosinate + nicosulfuron; 5 - ammonium glufosinate + atrazine; 6 - ammonium glufosinate + tembotrione; 7 - ammonium glufosinate + mesotrione; 8 - ammonium glufosinate + carfentrazone ethyl; 9 - ammonium glufosinate + bentazon; 10 - ammonium glufosinate + 2,4-D; 11 - control without weeding; and 12 - hand-weeded control.
Means followed by equal lowercase letters in columns of the same color do not differ significantly from each other by the Tukey’s test (p≤0.05). 1 - ammonium glufosinate; 2 - glyphosate; 3 - ammonium glufosinate + glyphosate; 4 - ammonium glufosinate + nicosulfuron; 5 - ammonium glufosinate + atrazine; 6 - ammonium glufosinate + tembotrione; 7 - ammonium glufosinate + mesotrione; 8 - ammonium glufosinate + carfentrazone ethyl; 9 - ammonium glufosinate + bentazon; 10 - ammonium glufosinate + 2,4-D; 11 - control without weeding; and 12 - hand-weeded control.