Efeito do níquel na mitigação da fitotoxidez de glufosinato aplicado em pós-emergência da soja IPRO RR2

Abstract

New soybean cultivars tolerant to glufosinate ammonium enable more efficient weed management. However, herbicide drift can adversely affect susceptible crops. Nickel (Ni) nutrition has been studied as a potential strategy to mitigate herbicide-induced phytotoxicity, as several studies highlight its role in enhancing tolerance to environmental stresses, including toxicity in annual crops. This study evaluated the effect of foliar Ni application in mitigating phytotoxicity induced by glufosinate ammonium in the susceptible soybean cultivar Intacta RR2 PRO® (IPRO). The experiment was conducted in two locations: Area 1 (LRV) in the municipality of Lucas do Rio Verde and Area 2 (NMT) in the municipality of Nova Mutum. Herbicide applications were performed at the V6 phenological stage (sixth node of the main stem with fully developed leaves), followed by Ni application 120 hours later. Five doses of glufosinate ammonium (0%, 15%, 25%, 50%, and 100% of the maximum recommended dose) and two Ni doses (0% and 100%, equivalent to 60.0 g ha⁻¹) were tested. Phytotoxicity symptoms were assessed through visual observation at 7, 14, and 21 days after application using a standardized phytotoxicity rating scale. At the R8 stage, plant height and yield components were evaluated, including grain yield, thousand-grain weight (TGW), and total pod number (TPN). The results suggest that foliar Ni application partially mitigated the phytotoxic effects of glufosinate ammonium. This mitigating effect was evidenced by its influence on plant height, pod number, and grain yield, as well as by a reduction in visual phytotoxicity symptoms. Therefore, Ni supplementation may represent a promising strategy for alleviating glufosinate ammonium-induced phytotoxicity in soybean cultivation.