EFFECTS OF AN ISOLATE OF RHIZOCTONIA-SOLANI KUHN AG8 FROM DISEASED BARLEY ON THE GROWTH AND INFECTION OF POTATOES (SOLANUM-TUBEROSUM L)

An isolate of Rhizoctonia solani AG8 from a barley plant affected with barley stunt was incorporated into soil and caused severe stunting of cv. Desiree potatoes grown in pots. Fresh weight of foliage, stem bases, roots and tubers were greatly decreased. Most main roots were pruned off and a large number of lateral roots developed, resulting in an unusually fibrous root system; many of these lateral roots were also pruned off. Infected plants did not have stem canker or stolon infection nor was black scurf found on progeny tubers.