Effects of black scurf (Rhizoctonia solani) on potatoes

摘要: SUMMARY King Edward and Majestic seed tubers, selected as ‘clean’ (macroscopically symptomless), moderate severe according to the extent of black scurf, were planted in field experiments at Rothamsted between 1964 1968. Seed infection sometimes delayed plants emerging but did not affect final plant populations. Crops from severely diseased yielded, on average, 7% less than tubers (King 6–8% 0–20% less). affected tuber size distribution; compared with seed, infected King yielded slightly more chats (< 1 ½ in, 3.8 cm) 1.5 ton/acre (3.8 t/ha) large (2 ¼–3 ¼ 5.7–8.3 cm). The effects similar although differences smaller. However, total yields stocks (unselected) seldom differed significantly them. moderately had Corticium stems scurf usually Oospora pustulans seed.