Nematodes are a pest common to lawns throughout the United States. Nematodes are microscopic pests from the roundworm family. They are a major problem in areas that are warm with sandy soils. Nematodes attack both cool season and warm season grasses, and when a large colony is present the entire lawn may be destroyed.
According to the Alabama Cooperative Extension, in some nematode species the female lays single eggs, or in masses. Eggs are laid in the lawn soil or in the roots of the grass. The larvae appear just like the adults, small and eel-like when viewed under a microscope.
Nematode damage looks a lot like other grass stresses, such as drought or malnutrition. Above ground the grass will look yellow and weak and will be slow growing. The lawn may wilt as well. Below ground the grass roots will be short. In areas the roots will be irregular in shape and may branch out, states Clemson University.
Nematodes prefer soils that are coarse and sandy reports North Carolina State University. Sting nematodes prefer turf grass varieties. Ring nematodes prefer golf course greens that are sandy, with turf and high moisture. Root knot nematodes are found in lighter soils. Nematodes require high soil moisture and warm temperatures to reproduce efficiently.
Nematode damage is not diagnosed according to foliar damage due to its similarity to other ailments. A soil analysis is required to determine whether your soil is infected with nematodes. Nematode samples are taken in mid-summer when the population spikes. Samples are sent to a local university Extension service for testing to determine the extent of infestation.
A healthy turf with deep roots and a dense coverage will prevent extensive damage from nematodes. Infrequent watering that is deep prevents the soil from being too moist, while promoting root growth. Balanced soil fertility increases turf and prevents nematodes from doing too much damage. Nematicides are available to combat nematodes, in both preplanting and post-planting formulations for all stages of the turf.