Challenges With Managing Disease Complexes During Application of Different Measures Against Foliar Diseases of Field Pea

Studies were undertaken across five field locations in Western Australia to determine the relative changes disease severity and subsequent pea yield from up four foliar pathogens associated with a complex (viz. genera Didymella, Phoma, Peronospora, Septoria) different varieties sown at three times densities. Delaying sowing of significantly (P < 0.05) reduced Ascochyta blight (all locations) Septoria (one location), increased downy mildew (four locations), but had no effect on seed yield. In relation 80 days after sowing, all early time more severe than mid late sowing. Increasing actual plant density 20 25 plants m ?2 58 78 it irrespective date variety. Compared Dundale, Wirrega, Pennant, variety Alma showed less blight, mildew, location each). Grain was highest for locations. Varieties Alma, Wirrega outyielded Pennant The percentage isolations individual first varied greatly, genus Didymella ranging 93% Phoma 6 23% This fluctuating nature pathogen types proportions within complex, along variation occurrence Peronospora Septoria, highlights challenges understand manage complexities co-occurring pea. While search effective host resistance continues, there is need opportunities further exploring exploiting cultural management approaches focusing crop sequence diversification, intercropping, manipulating stand density, application improved sanitation residue/inoculum practices. We discuss constraints toward overcoming managing complexes