Amino acids for mitigation of phytopoisoning by herbicides inhibiting the enzyme acetolactate synthase (ALS) in sugar cane

Visual symptoms of phytotoxicity can be observed after the application of some herbicides, if they are applied outside of recommendations or if the environment provides great availability for the crop, and the exogenous supply of amino acids may be able to reverse these symptoms. The aim of the work was to evaluate the efficiency of exogenous application of amino acids to mitigate phytotoxicity induced with herbicides that inhibit the enzyme acetolactate synthase (ALS) in sugarcane. The experiment was conducted at the Engineering and Agricultural Sciences Campus of the Federal University of Alagoas. To evaluate the effect of herbicides, the trial was initially conducted in a completely randomized design, with the herbicides: imazapique, diclosulam, metsulfuron-methylic, imazapique + s-metolachlor, diclosulam + s-metolachlor, metsulfuron-methylyl + s-metolachlor applied in total pre-emergence, and the controls without herbicide. The application of the amino acid mix was carried out 65, 95 and 125 days after the application of the herbicide treatments, with the commercial product Kymon plus®. After application of the amino acid, the study was conducted in 2x7 factorial trials, consisting of 2 conditions (with amino acids and without amino acids) x 7 treatments. The variables evaluated were: height to leaf +1, number of green leaves, stem diameter and phytotoxicity scale. At the end of the experiment, the dry mass of leaves and stems was evaluated. After regrowth, the number of tillers and height up to leaf +1 were evaluated. The results demonstrated that the exogenous application of amino acids at 65, 95 and 125 days after application of the treatments does not attenuate phytointoxication by ALS-inhibiting herbicides in sugarcane.