Greenhouse studies were conducted to evaluate shoot number, shoot weight, and root weight reduction of yellow and purple nutsedge to three placement levels (soil, foliar, and soil foliar applied) and four herbicide treatments (CGA-362622, imazaquin, MSMA, and imazaquin MSMA). Soil-applied CGA-362622 reduced shoot number, shoot weight, and root weight greater than foliar-applied CGA-362622. Foliar-applied imazaquin and soil-applied MSMA achieved little reduction in measured variables compared with the nontreated control. Foliar-applied imazaquin and soil-applied MSMA reduced shoot number, shoot weight, and root weight less than imazaquin MSMA applied in a similar manner. Averaged over placement levels, imazaquin reduced shoot weight of yellow nutsedge greater than purple nutsedge. Averaged over herbicide treatments, soil-applied treatments were more effective in reducing purple nutsedge shoot number, whereas foliar-applied treatments were more effective in reducing yellow nutsedge shoot number.
Nomenclature: CGA-362622, N-[(4,6-dimethoxy-2-pyrimidinyl)carbamoyl]-3-(2,2,2-trifluroethoxy)-pyridin-2-sulfonamide sodium salt; imazaquin; MSMA; purple nutsedge, Cyperus rotundus L. #3 CYPRO; yellow nutsedge, Cyperus esculentus L. # CYPES.
Additional index words: Foliar absorption, root absorption.
Abbreviations: DAP, days after planting; DAT, days after treatment; NIS, nonionic surfactant; POST, postemergence.