Seed-borne fungi of cowpea: transmission and effect of Macrophomina phaseolina

Abstract

Seed health testing by the blotter method was done to establish seed-borne fungi of cowpea seed samples collected rom castern Uganda. Twenty different fungal species were encountered on the seed samples of which Fusariur emitectum, Phoma sp., Alternaria tenius, Aspergillus sp., Rhizopus sp. and Chaetomium sp. were most common was encountered more frequently in the first season than the second one, although its range of infection was low, 0.3-4.3%. Germination tests were done on 13 samples selected on the basis of their M.phaseolina infection levels and grouped as low (1.0-1.5%), moderate (1.8-2.5%) and high (2.8-4.3%) infection categories. There was no significant difference (P ≤ 0.05) in germination percentage between chlorine treated and non-treated seed samples except in the high M.phaseolina infection category. In transmission studies, the fungus caused seed, stem and root rots. Affected seedlings wilted and later died and the transmission rate of the fungus was 1:1.