Biological control of Rhizoctonia solani on potatoes by antagonists. 1. Preliminary experiments with Verticillium biguttatum, a sclerotium-inhabiting fungus

Research paper by H. Velvis, G. Jager

Indexed on: 01 May '83Published on: 01 May '83Published in: European Journal of Plant Pathology


A common mycoparasite,Verticillium biguttatum, was found to kill sclerotia ofRhizoctonia solani placed on an inert material (perlite) as well as in soil at 15°C and 20°C, but not at 10°C. Compared with the effectivity ofV. biguttatum, that ofGliocladium roseum, Gliocladium nigrovirens, Hormiactis fimicola andTrichoderma hamatum on sclerotia was only low. In laboratory experiments, treatment of sclerotia-bearing seed potatoes withV. biguttatum reduced disease symptoms in the first stage of growth of the potato plant.V. biguttatum was found to occur on the subterranean part of the potato plant. On untreated plants the surface of the sprouts was colonised byV. biguttatum originating from the soil, presumably partly in response to the presence ofR. solani mycelium. In a preliminary field experiment,Verticillium treatment did not reduce symptoms on the stem. However, there was a marked reduction in sclerotium formation on the newly formed potato tubers. This offers perspectives for a commercial use ofV. biguttatum in the control ofR. solani.