Transmission of California aster yellows to potato by Cicadula divisa

Abstract does not appear. First page follows.

Introduction

Kunkel⁽¹⁾ failed to transmit New York aster yellows to potato (Solanum tuberosum) by means of the insect vector, Cicadula divisa Uhl. [C. sexnotata (Fall.)]. The following varieties of potatoes were either immune or highly resistant to the aster-yellows disease: Irish Cobbler, Green Mountain, Bliss Triumph, and Spaulding Rose.

An investigation was undertaken to determine whether potato plants could be experimentally infected with California aster yellows. A study of the symptoms and incubation period of the disease in the plant was made. Attempts were made to recover the virus from infected plants by means of previously noninfective leafhoppers. Trips were made to tie potato fields in the delta districts of the San Joaquin Valley to determine whether this virus disease occurs under natural conditions, and observations were made on the relative abundance of the leafhopper on potato plants during the season.

Methods

The varieties of potatoes used were Bliss Triumph, White Rose, and potatoes grown from seeds. The potatoes were grown in 12-inch flower pots or in large wooden pickle tubs filled with peat soil. The potato plants were enclosed in large cages and inoculated with yellows by 20 to 40 infective leafhoppers. Males were used rather than females so as to avoid egg deposition. The insects inoculated the plants during a period of 1 to 10 days and then the cages containing the males were removed from the plants. The inoculated plants were fumigated with Nico-Fume tobacco-paper insecticide after inoculation and were kept in