We conducted a study to determine the relationship between turfgrass management intensity and natural occurrence of entomopathogenic nematodes (EPNs) on golf courses in Ohio. 159 soil samples were collected from putting greens, fairways and rough areas – three distinct surfaces that are managed differently. EPNs were recovered from soil samples using the insect baiting technique. Soil samples were also analyzed for texture, organic matter, pH, phosphorus, calcium, magnesium and potassium. Principal components and correlation estimates were used to determine possible predictors of nematode occurrence in turfgrass. We found that surface type and soil texture were important factors in predicting nematode occurrence. Putting greens differed significantly from fairways and rough areas in the number of EPN-positive sites. EPNs were recovered from 42.9% of the fairways and 57.1% of the rough areas, but not from putting greens. Putting greens also differed significantly from fairways and rough areas in organic matter, pH, calcium and phosphorus. The fairways and rough areas did not however differ in EPN-positive sites and soil parameters. Presence of EPNs significantly correlated with sand, silt, phosphorus, organic matter and magnesium, but not with clay, pH, calcium or potassium. The nematode species were identified as Heterorhabditis bacteriophora, Steinernema carpocapsae, and S. glaseri. These results suggests that EPNs are more likely to occur in less intensively managed sites that receive fewer inputs, and have relatively high sand, low pH, and moderate phosphorus and magnesium contentThe Ohio State University/OARD
