Evaluation of a potato leafhopper (PLH) resistant alfalfa cultivar effects on PLH injury in alfalfa: grass mixed stands with and without insecticide.

Abstract

The combination of a resistant cultivar and a grass resulted in significantly better PLH control than did the resistant cultivar alone or the grass alone. The resistant cultivar had 36% fewer PLH than the susceptible cultivar; however, the number of PLH was significantly higher than for the plots that were sprayed with insecticide (average less than 1 PLH per sub-plot). The untreated plot with the lowest PLH damage score was the resistant alfalfa/grass mixture (score = 1.8), whereas the resistant cultivar alone scored 2.4 and the susceptible cultivar alone and with grass averaged 3.5.