CONTROL OF ERGOT IN KENTUCKY BLUEGRASS SEED PRODUCTION USING FUNGICIDES

Foliar applications of sterol demethylation inhibiting fungicides were evaluated for control of ergot (Claviceps purpurea) in a Kentucky blu egrass (Poa pratensis) seed production field near Post Falls, Idaho, d uring 1990 and 1991. Flusilazole, propiconazole, tebuconazole, and tri adimefon were applied at several rates and plant growth stages. Single applications of all fungicides except triadimefon significantly reduc ed ergot compared with nontreated controls. Sclerotia and panicle exud ate (honeydew) were reduced to zero, or near zero, with single applica tions of flusilazole alone or with flusilazole, propiconazole, and teb uconazole combined with a wetting agent. Application of fungicides at preanthesis controlled disease more than midanthesis or late-anthesis applications. Seed weight per panicle was reduced when high rates of f lusilazole or fungicide-wetting agent combinations were used. Seed ger mination was not reduced by preanthesis applications except by the hig hest rates of flusilazole. Most fungicides applied at mid- and late an thesis reduced germination.