Certain techniques can be used to determine which pathogen is causing<unk>  One standard technique for distinguishing strains is microscopy. Under a microscope, M. pinodes can be diagnosed by the presence of pseudothecia. P pinodella can be diagnosed by the size of conidia produced. P. pinodella produces conidia that are smaller than the conidia of M. pinodes or A. pisi. A. pisi can be diagnosed by the color of the conidia. In comparison to the light colored, buff spore masses of M. pinodes and P. pinodella produced on oatmeal agar, A. pisi spores masses are carrot red. Other techniques for diagnosis involve serological assays, isoenzyme analysis, restriction fragment length polymorphisms (RFLPs), random amplified polymorphic DNA (RAPD) assays, and by using monoclonal antibodies.
Ascochyta diseases of pea
Polymeal
Black rot 
Scabies
Scrubs 
Black spot leaf disease
Tomato fever
Black foot disease of grapevine