Soybean tolerance to early preplant applications of 2,4-D ester, 2,4-D amine, and dicamba.

摘要

Preplant applications of two 2,4-D formulations and dicamba were evaluated for injury to no-till soybean. Herbicides applied 28 or 21 d before planting (DBP) at 0.56 kg ae/ha for the 2,4-D formulations and 0.28 kg ae/ha for dicamba did not injure soybean. At 14 DBP soyabean injury was lower (<6%) with applications of 2,4-D than with dicamba (13% to 17%). Injury increased when herbicides were applied at 7 DBP with soyabean injury from both 2,4-D (<11%) and dicamba (<38%). When the herbicides were applied at planting soyabean injury was <18% with the 2,4-D formulations and <73% with dicamba. Soyabean yields were unaffected by the injury from herbicides applied 21, 14, and 7 DBP. However, soyabean yield was decreased to 870 kg/ha in 2005 when dicamba was applied at planting compared to the nontreated check (1,950 kg/ha).