CROP GROWTH, DISEASE AND YIELD COMPONENTS OF RUSTED PHASEOLUS BEANS IN ETHIOPIA

Crop growth and disease epidemics in sprayed and non-sprayed bean plot s, artificially infected with rust (Uromyces appendiculatus) 3 weeks a fter emergence, were assessed weekly in two cultivars, at two location s for two seasons. Disease intensity was regulated by the application of a fungicide at 5 spray frequencies. Fungicide application influence d leaf area index (LAI) and reduced rust intensity. The fungicide had no significant effect on other diseases and dead leaf area. Fungicide application increased seed yield (SY) by increased numbers of pods per plant (PP). Rust severity was strongly correlated with pustule densit y but the overall relationships among rust assessment parameters depen ded on cultivar and location. Seed yield and pods per plant were highl y correlated with LAI. The relationships between LAI and seeds per pod or seed weight depended on cultivar and location. Overall rust assess ment parameters (rust severity and pustule density) showed close, nega tive relationships with seed yield, seed weight and pods per plant but not with seeds per pod. The relationships obtained in the partially r esistant line 6-R-395 were less definite than those in the susceptible line Mexican 142. The yield parameters seed yield and pods per plant showed strong positive relationships.