Effects of SOURCE, a Novel Foliar-Applied Chemistry, on Plant Parasitic Nematode Populations and Soybean Production in the Delmarva Region

Plant parasitics pose a unique challenge to soybean producers despite crop rotation, variety resistance, and use of chemicals. Soybean nematodes cause an average 10-15% loss in yield with reductions being much higher in fields with high nematode population. Soils with low organic matter as is found in much of the Mid-Atlantic region can create challenges to managing nematode populations, even with crop rotation. With hybrid selection, this may eventually give way to heavy selection pressure that can create nematodes that can evolve resistance to cultivars over time. Chemical use of nematicides such as seed treatments can be costly and can negatively impact people and the microbiome. This project focused on the impact of using SOURCE, a novel NSS (novel synthetic strigolactone) on nematode populations, soybean plant health, and yield in the Mid-Atlantic for the 2023 season. Trials were conducted in two locations in the Delmarva area identified as having high nematode populations. Replicated treatments with and without NSS were mapped and sampled for nematodes. Soil samples were collected in treatment strips throughout the season to measure nematode populations and species variation. Additionally, yield data was collected in test strips to determine the effect of NSS on yield. Results showed no significant differences of nematode populations between treated and untreated, however the large plot trial did have an increase of 4.7 bu/A in the treated area versus the untreated. Future large and small plots trials should be considered with the addition of tissue samples taken in season.