THE INFLUENCE OF MIXTURES OF STYLOSANTHES SPP ACCESSIONS ON THE OCCURRENCE OF ANTHRACNOSE CAUSED BY COLLETOTRICHUM-GLOEOSPORIOIDES

The effectiveness of using accession mixtures of Stylosanthes spp. to manage anthracnose (Colletotrichum gloeosporioides) in pastures in nor thern Australia was examined during three consecutive years. Two mixtu res containing six accessions were compared with the components grown as pure stands. No significant differences in anthracnose incidence (p roportion of infected plants/plot) were indicated between the two mixt ures and the mean incidence of their respective components grown in pu re swards. Areas under the disease progress curves for the accessions were not significantly different between pure and mixed stands of the cultivars other than Seca and Verano. Resistant cultivar Seca develope d more disease in a mixture than in a pure stand, and moderately resis tant Verano had less disease in a mixture than in a pure stand. In the short term, no apparent anthracnose control advantage is achieved in highly susceptible accessions of Stylosanthes spp. when they are inclu ded in mixtures with less susceptible accessions. Long term studies in volving grazing animals are necessary to adequately evaluate control o f this disease: through the use of mixtures.