Chemical selector

Numerous formulations of 2,4-D are available. Weedar 64 contains 3.8 lb/gal dimethylamine salt. Savage is a dry soluble formulation containing 95% dimethylamine salt. Weedone 638, Weedone LV4, and Weedone LV6 contain 2.8 lb, 3.8 lb, and 5.7 lb/gal, respectively, of the butoxyethyl ester. Hi-Dep contains 3.8 lb/gal of the dimethylamine and diethanolamine (mixed amine) salts. Salvo and SEE 2,4-D LV4 contain 5 lb and 3.8 lb/ gal, respectively, of iso-octyl ester. Application rates, spray volumes, and timings differ with company and formulation. 2,4-D controls or suppresses annual and perennial broadleaf weeds. Most sorghum hybrids are injured by 2,4-D. High relative humidity and air temperature increase potential for sorghum injury. Sorghum is most tolerant to 2,4-D when 5 to 10 inches tall. Even then, expect crop response in the form of rolled leaves and brittle, spreading stems and tillers. When crop is more than 8 inches tall, use drop nozzles to reduce spray deposition on sorghum leaves. Do not apply during boot, flowering, or early dough stages. Very low rates of 2,4-D in combination with other postemergence herbicides are much safer to sorghum than higher rates of 2,4-D used alone. Yield-reducing sorghum injury can occur from over-the-top application rates as low as 0.125 lb and is common for rates of 0.25 lb and up. Producers should weigh potential sorghum injury from 2,4-D against potential loss of sorghum yield from weed competition.