CHEMIGATION AND GROUND-SPRAY APPLICATIONS OF CYPROCONAZOLE FOR CONTROL OF LATE LEAF-SPOT OF PEANUT

In field experiments conducted during 1990 and 1991, chemigation appli cations of the ergosterol biosynthesis inhibiting fungicide cyproconaz ole (0.112 kg a.i./ha) were equal to or better than ground-spray appli cations of cyproconazole or chlorothalonil (1.26 kg a.i./ha) for contr ol of late leaf spot, caused by Cercosporidium personatum, on peanut ( Arachis hypogaea) cultivars Florunner and Southern Runner. Late-season leaf spot epidemics and resulting defoliation were severe in nontreat ed plots in both years. All fungicide treatments provided similar leve ls of control in 1990. Leaf spot was less severe on plants treated wit h cyproconazole by chemigation than on those treated with chlorothalon il by ground sprays in 1991. Within cultivars, yields for all three fu ngicide treatments were similar and were higher than in nontreated plo ts in both years. Yield of Southern Runner was higher than that of Flo runner for all treatments in 1990 and in nontreated plots in 1991.