How Do Nematodes Affect Turf?
As plant-parasitic nematodes feed they damage the root system and reduce the ability of the grass to obtain water and nutrients from the soil. Roots may be abnormally short and appear darkened or rotten when damaged by plant-parasitic nematodes (Figure 6). Often the roots will appear “cropped off” an inch or so below the soil surface in a cup-cutter sample (Figure 7). Root galls or knots associated with certain nematode damage to other crops may not be evident on grass. Figure 6. Healthy grass roots (left) and dark, rotting grass roots damaged by nematodes (right). Figure 7. Healthy bermudagrass roots (right) and roots that have been cropped off at about 1/2 inches deep by nematodes (left). When nematode population densities get high enough, or when environmental stresses such as high temperatures or prolonged low light occur, aboveground symptoms may become evident. Symptoms include yellowing, wilting, browning, or thinning out. Often, as the grass thins out weeds, particularly spurge
