Phytotoxicity of Endothall on Peanut (Arachis hypogaea): Formulation, Rate, and Time of Application

Abstract

Field studies were conducted at Tifton, GA and Gainesville, FL to quantify the phytotoxicity of endothall formulation, rate, and time of application on peanut in a weed-free experiment. Peanut treated with mono (N,N-dimethylalkylamine) salt of endothall (DMAA endothall) were more necrotic than those treated with dipotassium salt of endothall (DP endothall), though necrosis was temporary. Injury from DMAA endothall at rates of 0.6 to 1.1 kg ai/ha was similar to the standard treatment of bentazon plus paraquat for most parameters. Peanut treated with the highest rate of DMAA endothall (4.5 kg/ha) were more necrotic and took longer to recover than lower rates. The highest rate of DP endothall (4.5 kg ai/ha) stunted peanut more than any DMAA endothall treatment. However, lower rates of DP endothall (0.6 to 2.2 kg/ha) were generally less injurious than DMAA endothall at equivalent rates. Peanut yields were not affected by either formulation of endothall at 0.6 to 1.1 kg/ha, applied from vegetative emergence through 4 wk after emergence.