Injury and yield of leafhopper-infested dry beans

Differences in potato leafhopper (Empoasca fabae Harris) injury symptoms were noted in 22 cultivars or lines of dry beans (Phaseolus vulgaris L.) in a 1991 field trial at North Platte, Neb. Seed yield, biomass, and plant injury symptoms were recorded. The same 22 dry bean cultivars or lines were planted in a split-plot design, with main plots protected (sprayed with insecticide) vs. unprotected (not sprayed) and cultivars or lines as subplots in 1992 and 1993. Significant differences were observed between cultivars/lines for leafhopper injury and yield in all 3 years. 'Tacaragua' (black-seeded) and pinto 'Sierra' were highly resistant to leafhoppers, with no visual leafhopper injury symptoms in all 3 years. Significant negative correlation coefficients between leafhopper injury symptoms and yield were recorded in the protected (-0.50) and unprotected (-0.33) plots in 1993 but only in the unprotected (-0.46) plots in 1992. A cultivar X spray interaction response to leafhoppers occurred in 1992 but not in 1993. The degree of leafhopper injury symptoms varied between years