Presentation Abstract: Two new plant pathogens or pathogen groups have become an issue for growers of vegetables crops in Ontario. Field, greenhouse and laboratory trials were conducted at the Muck Crops Research Station (MCRS), University of Guelph and University of Guelph Simcoe Research Station. The projects involved evaluation of the effect of fungicides or biological control products to control Stemphylium leaf blight of onion and asparagus and Fusarium root rot of carrots and Fusarium wilt spinach. The project also evaluated various disease forecasting models to determine the best time to initiate spray programs to stop the spread of stemphylium leaf blight of onion and asparagus.