Control of Johnsongrass on Drainage Ditchbanks in Sugarcane

Abstract

Several herbicides were applied to drainage ditchbanks in sugarcane (Saccharum officinarum L.) to control johnsongrass (Sorghum halepense (L.) Pers.) from rhizomes and seed. Five post-emergence applications of monosodium methanearsonate (MSMA) at 3.6 lb/A or 2,2-dichloropropionic acid (dalapon) at 7.4 lb/A controlled rhizome johnsongrass as effectively as 600 lb/A of sodium chlorate, the standard treatment. Johnsongrass seedlings infested ditchbanks 1 year after applying sodium chlorate. But preemergence treatments with mixtures of (2,3,6-trichlorophenyl)acetic acid (fenac), 5-bromo-3-sec-butyl-6-methyluracil (bromacil), or trichloroacetic acid (TCA) with MSMA, or postemergence applications of MSMA, dalapon, and sodium chlorate controlled these seedlings. Bermudagrass (Cynodon dactylon (L.) Pers.) rapidly vegetated ditchbanks treated with MSMA, but other herbicide treatments suppressed vegetation with desirable species to the point where erosion could become a problem.