Response of peanut to low rates of MSMA

Abstract

The response of peanut to low rates of MSMA under weed-free conditions was studied in 1992 and 1994 near Tifton, GA. MSMA was applied 40, 70, 100, or 130 days after emergence (DAE). At each application timing, MSMA was applied at 0, 90, 168, and 336 g ai ha−1. MSMA application timing did not affect peanut yield. Increasing rates of MSMA caused minor reduction in peanut yield. Analysis using atomic absorption spectroscopy showed elemental arsenic accumulation of ≤ 0.7 ppm in peanut kernels from MSMA applied 70 and 100 DAE. This approximates the time interval of peanut pod and kernel formation. MSMA applied 40 and 130 DAE resulted in little detectable arsenic in kernels. Low rates of MSMA, originating as drift from aerial applications to cotton or illegal and unsound applications to peanut for Florida beggarweed control, are not likely to reduce peanut yields. The greatest hazard from peanut exposure to MSMA is accumulation of arsenic in kernels, which would adversely affect peanut marketability and consumer demand.