1Botany Department, University of Gorakhpur, Gorakhpur-273001.
*Part of the Ph.D. thesis of senior author, approved by the University of Gorakhpur, Gorakhpur, (1981).
Relationship of the potato purple top roll pathogen with its vector Orosius albicinctus Distt. was investigated using white clover as source and test plants. The minimum acquisition access period was 6 hr but the maximum transmission was achieved after acquisition access of 7 days. Nymphs and female adults were more efficient transmitters than males. The incubation of the pathogen was 6–14 days in the vector. The minimum and optimum inoculation feeding periods were 1 and 9 days and 4 to 5 inoculative individuals were required per plant to accomplish maximum transmission.
