Assessment of Selected Pea Genotypes Reaction to Ascochyta Blightunder Field Conditions and the Impact of Disease Severity on YieldComponents

The response of pea (Pisum sativum) genotypes to ascochyta blight disease and the effect of disease severity onyield components were evaluated in a 4-year trial under field conditions. Peas were inoculated with Ascochytapinodes, the anamorph of Mycosphaerella pinodes, or with Phoma pinodella separately and with a mixture ofboth species. Mean infection ratings of all inoculation treatments were significantly higher compared to controls, with the highest infection for inoculation with A. pinodes. Pea genotypes significantly differed for ascochytablight severity. The differences in extent of infection of the least and the most infected genotypes were quiteconsistent throughout the study. Frequencies of A. pinodes and P. pinodella isolated from diseased leaffragments of ten pea genotypes depended on growing season. Deleterious effects of the inoculation withAscochyta, Phoma and Ascochyta+Phoma treatments on all evaluated agronomic parameters were observed. Greater lodging of plants in all fungi-inoculated treatments was noticed. Inoculated plants revealed decreasedseed yield components as follows: number of pods and seed per plant was reduced by 12% - 19% and 18,5 - 22%,respectively. Seed weight per plant decreased by 18% - 27,7% in comparison with controls. There were alsoquite large differences between pea genotypes in reduction of all yield components