RESPONSES OF A STERILE RED FUNGUS TO SOIL TYPES, WHEAT-VARIETIES AND THE PRESENCE OF CERTAIN ISOLATES OF STREPTOMYCES

The biological activities of a sterile red fungus (SRF) capable of pla nt growth promotion and suppression of take-all disease were investiga ted in soils collected from Lancelin, Newdegate and Mt. Barker regions of Western Australia. Further, the effects of three wheat cultivars a nd the presence of two isolates of Streptomyces on the biological acti vities of the SRF were tested using the Lancelin soil. The biological activities of the SRF were greatest in the Lancelin and Newdegate (whe at field) soils and with the wheat cultivar Gutha. In in vitro studies the soil streptomycetes tested showed either a significant increase i n the exudate production by the SRF, which had antifungal and growth p romoting properties, or an inhibition of growth of the fungus. Strepto mycete A63 which stimulated the exudate production by the SRF in vitro , however, did not enhance disease protection in vivo. On the other ha nd, protection from root rot by the SRF in vivo was reduced in the pre sence of the streptomycete isolate Ax which is capable of inhibiting t he growth of the SRF in vitro.