Influence of inoculation time on severity of virus disease caused by Papaya ringspot virus

Inoculations were done in pre-kharif season (March to April) and kharif season (July to August), to study the disease severity and yield of host. The symptoms were very severe in seedlings inoculated in kharif. The foliage, stems, roots and fruits showed typical ringspot symptoms and distortion, which further increased in winters. The overall yield of the plants was only 63.9%, however, seedlings inoculated in pre-kharif season showed mild mottling and the plants were normal. Also, only slight reduction in yield of the plant was recorded. The symptoms were masked at high temperatures resulting in a mild incidence of the disease. But, at low temperatures severe expression of symptoms was noted, and also a heavy yield loss. The disease severity in the seedlings inoculated in kharif season was high due to increased population of aphids.