Effective disease management remains essential for maintaining high-quality turfgrass systems across golf courses, athletic fields, and commercial landscapes. Turfgrass diseases such as dollar spot, large patch, brown patch, Pythium blight, take-all root rot, Microdochium patch, and Bipolaris leaf spot can significantly reduce turf quality, playability, and aesthetic value while increasing maintenance costs.
Challenges in Disease Management
Environmental conditions favorable for disease development, combined with intensive turf-management practices, often create challenges for superintendents and turf managers seeking sustainable and effective control strategies. Recent advancements in fungicide chemistry and application programs have provided new opportunities to improve disease suppression while supporting integrated pest management (IPM) practices and reducing the risk of fungicide-resistance development.
To evaluate these approaches, extensive field research trials have been conducted over the last 2 years at the University of Georgia Griffin campus on several major warm- and cool-season turfgrass diseases.
Plant-Parasitic Nematodes
In addition to fungal pathogens, plant-parasitic nematodes (PPNs) represent another major constraint to turfgrass health and performance in Georgia. Because nematode injury often resembles symptoms caused by drought stress, nutrient deficiencies, soil compaction, or fungal diseases, accurate diagnosis and integrated management strategies are critical for maintaining healthy and resilient turfgrass systems.
Plant-parasitic nematodes are microscopic roundworms that commonly occur in Georgia turfgrass soils and can significantly reduce turf quality by damaging root systems. These nematodes feed using specialized mouthparts that disrupt water and nutrient uptake, weaken turf vigor, and increase susceptibility to environmental stress. Some nematode species also create wounds that facilitate secondary infections by fungi and bacteria.
Their feeding behavior varies among species, with some feeding externally on roots and others feeding within root tissues, which directly influences monitoring and management practices.
Results: Latest Research in Turfgrass Fungicides
Over the last 2 years, a series of research trials have been implemented to determine the efficacy of fungicides, rates, and timing as pre- and post-epidemic control on various turfgrass diseases (large patch, dollar spot, take-all root rot, brown patch, Pythium, Microdochium patch, Bipolaris leaf spot).
All of the fungicide trials were conducted in our turfgrass research areas at the UGA-Griffin campus. The fungicides were tested in zoysiagrass cultivar ‘El Toro’; bermudagrass cultivars ‘Princess’ and ‘TifEagle’; and bentgrass cultivars ‘A1/A4’ and ‘Penncross 2.0’.
At this stop on the Turfgrass Research Field Day tour, we will discuss and answer questions regarding the latest fungicides available to turfgrass professionals. We will also reinforce integrated management strategies.
Results obtained in these investigations provide turfgrass managers with new disease-management tools, improved disease control, and better turf quality. For a complete and up-to-date list of turfgrass fungicides, visit the GeorgiaTurf website.
This information is only a guide. Reference to products is not intended to be an endorsement. No criticism is intended of products not discussed. Individuals using such products assume responsibility for their use in accordance with the current directions of the manufacturer. Read and follow label directions for mixing and application.
Turfgrass Nematodes in Georgia: Symptoms and Favorable Conditions
Symptoms of nematode damage to turf include yellowing, wilting, poor response to fertilization, thinning turf, and weed invasion. Damaged roots are often short, dark, and poorly branched.
Nematodes favor sandy, moist soils and turf under stress, especially during warm weather. In Georgia, symptoms are commonly observed during summer when turfgrass experiences heat and drought stress.
Nematodes spread through infested soil, water, sod, and sprigs, making accurate diagnosis and preventive management important for maintaining healthy turfgrass systems.
Turfgrass Nematode Management
Healthy turf can tolerate moderate nematode populations when proper cultural practices are followed. Management strategies include deep, infrequent irrigation, avoiding excessive nitrogen fertilization, reducing turf stress, and correcting soil compaction or nutrient deficiencies. Selecting well-adapted turfgrass species also helps minimize damage.
When nematode populations are high, chemical nematicides may be needed. These products include preplant fumigants and post-planting contact nematicides, which are typically watered into established turf immediately after application.
For a complete updated list of nematicides, check the UGA turfgrass pest control recommendations publication.
Sampling for Nematodes
Accurate diagnosis of turfgrass nematodes requires proper soil sampling. A quart-sized soil sample should be collected and submitted through your local Extension office to the UGA Plant Pathology Nematode Laboratory.
Sampling is most effective when turfgrass is actively growing, because nematode populations vary throughout the year. For warm-season turfgrasses, June and July are ideal sampling periods, while late spring to early summer is best for cool-season grasses. Low nematode numbers in a sample do not always rule out nematode damage if the samples were taken during unfavorable periods.
Turfgrass Nematode Characteristics
| Common name | Scientific name | Type | Main turfgrasses affected in Georgia | Key symptoms | Conditions favoring damage | Importance in Georgia |
| Sting nematode | Belonolaimus longicaudatus | Ecto-parasitic | Bermudagrass, zoysiagrass, centipedegrass, bentgrass | Severe root pruning, wilting, chlorosis, thin turf, drought stress | Sandy soils, warm temperatures | One of the most destructive turf nematodes in the Georgia |
| Root-knot nematode | Meloidogyne spp. | Endo-parasitic | Bermudagrass, zoysiagrass, centipedegrass | Root galls, stunting, yellow patches, poor response to fertilizer/irrigation | Warm soils and stressed turf | Economically important on golf courses and sports turf |
| Lance nematode | Hoplolaimus spp. | Semi-endoparasitic | Bermudagrass, St. Augustinegrass, zoysiagrass, bentgrass | Declining roots, yellow patches, thinning turf | Compacted or stressed turf; warm humid climates | Common and difficult to manage in warm-season turf |
| Ring nematode | Criconemella/ Mesocriconema spp. | Ecto-parasitic | Centipedegrass, bermudagrass, zoysiagrass, bentgrass | General decline, poor vigor, chlorosis | Sandy soils and environmental stress | Frequently associated with declining lawns and fairways |
| Stubby-root nematode | Nanidorus spp. | Ecto-parasitic | Centipedegrass, zoysiagrass, St. Augustinegrass, bentgrass | Short, stubby roots, poor establishment, weak turf | Sandy soils;high temperatures | Important on golf greens and newly established turf |
| Spiral nematode | Helicotylenchus spp. | Ecto-parasitic | Most warm-season turfgrasses | Mild thinning and stress symptoms | Turf under drought or nutrient stress | Common but usually secondary unless turf is stressed |
| Stunt nematode | Tylenchorhynchus spp. | Ecto-parasitic | Bermudagrass and cool-season turf | Reduced growth, chlorosis, thinning | Stress conditions and poor root health | Often contributes to decline with other nematodes present |
