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Turf Talk
Turning the Worm
Challenges of managing nematodes in turfgrass and the search for solutions by AARON TUCKER, Virginia Tech Turfgrass Science
Investigating the interaction between PGRs and nematodes A study was conducted to investigate whether plant-parasitic nematodes interact with PGR applications. Results suggest that nematode populations do not consistently influence the effects of PGRs. In only one instance did we observe visible damage following Anuew ® PGR applications in areas with high lance nematode pressure. While this indicates potential for interaction, the findings do not suggest a widespread or predictable pattern.
It’ s not just drought, disease or heavy foot traffic that pose a threat to the greens on your course. Microscopic organisms beneath the surface can quietly undermine turf health— often before symptoms appear above the ground.
Nematodes are plant-parasitic roundworms that attack turfgrass roots, reducing vigor, weakening stands and making it harder to maintain high-quality playing conditions. Managing these organisms has become increasingly challenging due to a limited range of effective chemical options and evolving resistance in nematode populations.
Environmental Protection Agency( EPA) restrictions on organophosphate nematicides, such as fenamiphos, along with inconsistent performance of newer products, have narrowed the toolbox for turf managers.
Since the EPA’ s restriction of fenamiphos, fluopyram has become the most commonly used chemical for nematode management. While fluopyram is effective against many species, it fails to control the lance nematode— a species known to damage several turfgrass varieties. Research shows that fluopyram has little to no effect on lance nematode populations, and overuse may encourage resistance in root-knot and sting nematodes. These limitations have increased interest in understanding and managing lance nematodes, particularly in Virginia.
Turfgrass is a vital part of the golf industry and a significant economic driver in Virginia. The standards for quality playing surfaces require intensive management, including frequent mowing, precise fertilization and proactive pest and disease control. Nematode pressure complicates that equation.
My work at Virginia Tech has focused on several aspects of lance nematode management, including: 1. Investigating interactions between plant growth regulator( PGR) use and lance nematode presence.
2. Developing a molecular approach for identifying and quantifying lance nematodes.
3. Exploring the relationship between lance nematode populations and root biomass under varying nitrogen inputs. qPCR for nematode identification and quantification Quantitative polymerase chain reaction( qPCR) is a well-established method for organism detection but has been underutilized in turfgrass nematology. We adapted a qPCR approach for identifying and quantifying lance nematodes in golf course putting greens. The results demonstrate that qPCR can be a viable tool for nematode diagnostics, offering accuracy and consistency— though further refinement is needed for broader implementation.
Relationship between nematode populations and root biomass To better understand how lance nematode populations affect turfgrass health, we studied creeping bentgrass( CBG) root biomass in relation to nematode counts. Findings revealed a significant negative linear relationship between lance nematode populations and root biomass, meaning higher nematode levels were associated with reduced root development. Interestingly, while nitrogen inputs increased lance nematode counts, they did not significantly impact root biomass. These results suggest that nitrogen may promote nematode proliferation without necessarily improving turf’ s ability to withstand feeding pressure.
Nematodes remain a difficult and often underdiagnosed challenge for turfgrass managers. This work represents a starting point in developing practical, researchbacked strategies for managing lance nematodes and maintaining high-quality turf in golf course settings.
AARON TUCKER
12 V IRGINIA G OLFER | J U LY / A UGUST 2025 vsga. org