Nine soil-applied herbicides were evaluated in the field in cotton (Gossypium hirsutum L.) and soybeans [Glycine max (L.) Merr.] and in the greenhouse without crops to determine their effects on the control, regrowth, and tuber production of yellow nutsedge (Cyperus esculentus L.). Fluridone {1-methyl-3-phenyl-5-[3-(trifluoromethyl) phenyl]-4(1H)-pyridinone} and norflurazon [4-chloro-5-(methylamino)-2-(α,α,α-trifluoro-m-tolyl)-3(2H)-pyridazinone] provided the best (100%) control in the greenhouse. Tubers exposed to herbicide-treated soil in the greenhouse for 4 or 8 weeks produced fewer new tubers when transplanted into nontreated soil than nontreated tubers did. Yellow nutsedge shoot and tuber populations in the field were significantly reduced by all herbicides, except for alachlor [2-chloro-2′,6′-diethyl-N-(methoxymethyl)acetanilide], after 2 yr of treatment in cotton and soybeans.
