A COMPARISON BETWEEN THE CAUSAL AGENTS OF CHERRY RASP LEAF AND FLAT APPLE DISEASES

Three sources of flat apple disease induced symptoms of cherry rasp leaf when inoculated into sweet cherries (Prunusavium L.). Similarly, three sources of cherry rasp leaf virus induced symptoms in apple (Maiussyivestris Mill.) identical to those associated with flat apple disease. The herbaceous host range for the virus isolated from flat apple disease is identical to the herbaceous host range of the virus isolated from cherry rasp leaf. In agar-gel diffusion tests, both the virus isolated from flat apple disease and the virus isolated from cherry rasp leaf reacted in a homologous manner to rasp leaf anti-serum without any evidence of spurs. The serological test was done by Dr. Richard Stace-Smith (Agriculture Canada, Vancouver, B.C., Canada) with his rasp leaf anti-serum. It is concluded that cherry rasp leaf is the causal agent of flat apple disease in apple.