Response of Sugarbeets and Weeds to Cycloate, Propachlor, and Pyrazon

Abstract

Cycloate (S-ethylN-ethylthiocyclohexanecarbamate) at 3 lb/A, 2-chloro-N-isopropylacetanilide (propachlor) at 4 lb/A, and 5-amino-4-chloro-2-phenyl-3(2H)-pyridazinone (pyrazon) at 4 lb/A were applied by 10 different procedures to moist and dry soil in 2 years. When cycloate was incorporated 3 inches deep in either moist or dry soil, it consistently controlled barnyardgrass (Echinochloa crusgalli(L.) Beauv.) and certain broadleaf weeds and caused only temporary injury to the sugarbeets (Beta vulgarisL.). No method of applying pyrazon and propachlor consistently controlled weeds selectively in sugarbeets. Activity of all herbicides was increased by some means of soil incorporation. Activity was frequently extreme when any of the herbicides was applied as a subsurface layer 1 or 2 inches deep; and sugarbeets, as well as weeds, were killed.