Resistance and Reflective Foil Mulch as Control Measures for the Potato Leafhopper (Homoptera: Cicadellidae) on Phaseolus Species

Abstract

Nine genotypes of the common bean, Phaseolus vulgaris L., were evaluated in the field for resistance to the potato leafhopper, Empoasca fabae (Harris). Genotypes were also tested in combination with carbaryl and reflective foil mulch. In laboratory tests the same genotypes, plus five other genotypes, were evaluated for resistance to leafhopper adults and nymphs. Field yields of G3950 and G3947 were least affected by leafhopper activity. Genotype G4786 expressed a high level of resistance to damage symptoms but yield was reduced. Generally, resistance to nymphal infestation had a greater impact on yield than resistance to damage. Reflective foil mulch treatments resulted in greater yields than treatments without foil. The foil plus carbaryl treatments were additive and produced the highest yields. A significant genotype × treatment interaction resulted. The foil mulch was effective in repelling leafhoppers early in the season and accelerated plant growth and maturity. However, later in the season, because of the increased attractiveness of plants grown on foil mulch, higher leafhopper populations were observed. In laboratory tests, differences for plant damage by adult feeding were exhibited after 9 days of exposure to the plants. Differences were correlated with field results. Damage was lowest on G4786, ‘Cuilapa,’ CSW643, and G3947. However, no differences among genotypes for percentage of nymphal survival were found.