Parasitism of Rhizoctonia lamellifera, Small

Abstract

IN the years preceding 1929, much controversy existed regarding the parasitism of the group of fungi known collectively as Rhizoctonia bataticola. The differences of opinion held by various sections of workers, and postulated principally by Small, Gadd and Briton-Jones, were largely attributable to the use of the one specific name bataticola for what now appears to be a relatively large group of sclerotium-forming fungi. Papers published by Ashby¹ in 1927 and Haigh² in 1930 showed that R. bataticola was a polymorphic fungus possessing a pycnidial stage, Macrophoma phaseoli, and was apparently distinct from two other forms which Haigh styled strain A and strain B. In 1933, I showed³ that strain A was physiologically and morphologically distinct from both strain B and M. phaseoli, and suggested that it should be designated by Small's original binomial R. lamellifera. The question of parasitism I did not touch upon.