Abstract
Using etiolated potato sproutings, the pathogenicity of potato scab-causing Streptomyces spp. was simply assessed. The cut sproutings (6-8cm long) were wrapped individually with a piece of tissue paper containing a concentrated spore suspension of the isolates with different pathogenicity. After keeping for 7 days at 25°C and high humidity under dark conditions, the sproutings were examined for necrotic and raised lesion formations. The pathogenicity of the isolates examined by this simple method was completely coincided with that assessed by the conventional soil inoculation method.
