A Disease of some Legumes in Papua New Guinea Caused by Sclerotium sp.

Abstract

A leaf and stem disease of peanut (groundnut, Arachis hypogaea), is reported from New Britain. It is caused by a clamped fungus, with no perfect state known as yet, which is designated Sclerotium sp. at present. Large sclerotia, distinct from those of the common sclerotial species, up to 6 mm long, very irregular in shape and pale tan to orangy tan in colour, but never dark brown, were found on the surface of the soil and on moribund parts of Xanthosoma sp. in the field, and formed on the soil surface after inoculation and sparsely on nutrient agar. Peanut, cowpea and Poona pea (Vigna unguiculata ), snake or yard long bean (V. unguiculata ssp. sesquipedalis), snap or dwarf bean (Phaseolus vulgaris) and Crotalaria anagyroides were susceptible when inoculated with four different isolates from the sclerotia and the peanut, while Xanthosoma sp. was immune.