Damage Functions for Sting Nematode (Belonolaimus longicaudatus) on Bermudagrass Turf

Abstract

Sting nematode (Belonolaimus longicaudatus) is one of the most aggressive and damaging parasites of bermudagrass, a widely used turfgrass in the southeastern United States. A damage threshold model for sting nematode on bermudagrass was developed with data collected during a 2‐yr field trial at multiple locations in South Carolina. Soil cores and visual turf quality ratings were collected on multiple sampling dates from plots at each location. Bermudagrass root weight and sting nematode density were determined for each core. A total of 678 soil cores were collected and used for root weight, turf quality, and nematode density regressions. Models discussed in this paper include linear and nonlinear regressions, a segmented regression model, and the first Seinhorst model for sting nematodes on bermudagrass. Results suggest reduced turfgrass quality is detectable before reductions in root weights are observed. Our findings support the use of low action–level thresholds for sting nematodes on bermudagrass, such as those applied in South Carolina (17 nematodes 100 cm–3 soil).