Ohio produces 4-5,000 acres of pumpkin (Cucurbita pepo) annually, making it a valuable fall crop for many growers to sell at their farm market. Soil borne diseases like Plectosporium blight (Plectosphaerella cucumerina) are known to infect foliage, vines and fruit, thereby lessening marketable yield. The objective of this study was to determine if the use and incorporation of a mustard cover crop prior to planting a pumpkin cash crop could act as a biofumigant, reducing the inoculum and symptoms of Plectosporium blight in pumpkin. A five treatment replicated trial consisting of two mustard cover crop hybrids known to have biofumigant properties were sown in April 2019. Two types of fungicide controls and an untreated check were also part of the trial. The cover crops were incorporated into the soil and the pumpkin cash crop was transplanted in the field two weeks after. No significant difference in disease severity between the treatments was observed on the petioles or fruit, though mean fruit weight was significantly higher in the fungicide control treatment. Despite having a successful spring seeding and incorporation of the mustard cover crop, the weather in late July through September was hot and dry, conditions that did not allow this fungal disease to fully develop on the treatments, limiting conclusions about the efficacy of using cover crops to reduce Plectosporium blight based on this trial.