Agronomic performance of Conkesta E3® soybean to increasing doses of 2,4-D herbicide

Soybean (Glycine max (L.)) is a dicotyledonous plant from the Fabaceae family, originally from East Asia, and today, Brazil is the largest global producer of this legume. However, over the past few decades, various challenges in weed control have led to significant economic losses for soybean producers. As a response, new technologies have been introduced to address this issue. Among these innovations, multiple resistance biotechnology stands out, enabling producers to use glyphosate, 2,4-D, and glufosinate-ammonium in soybean crop. The present study, conducted at IFSULDEMINAS Campus Inconfidentes, aimed to evaluate the performance of soybean cultivars carrying this new technology when subjected to increasing doses of 2,4-D, commercially known as Enlist® Colex-D. The experiment utilized two commercial soybean cultivars (B5710 CE and 98R30 CE), with a randomized complete block design (RCBD) in a 2x9 factorial scheme, involving 2 cultivars and 9 different herbicide dosages per cultivar, totaling 18 treatments and 4 replications. The herbicide doses ranged from 0 g a.i. ha-1 to elevated levels, with the highest dose being 3648 g a.i. ha-1. The variables assessed included phytotoxicity, chlorophyll index, plant height, thousand-grain weight, and grain yield. Increasing herbicide doses gradually induced phytotoxicity, but statistically, there was no significant impact on the final grain yield of the crop in both cultivars.