Plants of the White Rose and Netted Gem potato varieties naturally or artificially inoculated with the witches'-broom of potato virus expressed symptoms only after the progeny of inoculated plants was grown, but symptoms occurred on the foliage of the X virus-immune potato seedling 41956 within eight weeks after grafting. Tomato and tree tomato served as indicator plants on which two apparent strains of the virus could be distinguished. The first strain caused the symptoms on tomato usually associated with the disease on this suscept, but the second strain caused a disease similar to tomato big bud. Attempts to transmit the virus by means of dodder and insects were unsuccessful. An abrupt cessation of cambial activity and consequent underdevelopment of secondary conductive tissue precede the appearance of disease symptoms on potato.
Assessment of foliar application of nano and micro sodium silicate on leaf photosynthetic characters of potato seedling at stolen-initiation stage
