抄録
A five-crop system over two years has recently been studied for the higher yield of forage crops in Kyushu, Japan. In this cropping system, barley Hordeum vulgare, oats Avena sativa and Italian ryegrass Lolium multiflorum are cultivated as summer crops in the second year. In this study, we investigated the effects of infestation by the maize orange leafhopper Cicadulina bipunctata, which is a serious pest of maize, causing maize wallaby ear symptom (MWES), on these three gramineous crops. A laboratory experiment revealed that all tested barley varieties showed stunted growth but did not show any deformation on leaves infested by C. bipunctata. Both oats and Italian ryegrass showed stunted growth together with abnormal leaf growth. A significant varietal difference in the degree of MWES tolerance was detected in oats. A cropping experiment in a field where C. bipunctata is heavily present resulted in the highest yield of barley, followed by oats, and the lowest yield of Italian ryegrass. The yield of oats varied markedly among varieties. These results indicate that barley and some oat varieties are appropriate for summer cropping in areas where C. bipunctata is distributed.
