damage can be severe in some lawns in southeastern and southcentral North
Carolina where soils are very sandy. Turf affected by nematodes usually
appears weak and thin. It may have symptoms of nutrient deficiencies or
wilts rapidly during dry weather. Similar symptoms may be caused by other
problems such as poor fertility, lack of moisture and some diseases. Root
stunting, excessive branching and even death of roots may occur with some
nematodes. These symptoms are not usually adequate to identify nematodes
as the major problem, therefore, soil samples must be assayed for nematodes.
Also, a soil fertility test is recommended to eliminate nutritional problems
as a major factor.
are small eel-like worms that are too small to be seen without a microscope.
Nematodes that attack plants have small needle-like stylets which are
used to puncture plant cells to obtain nutrients. Different nematode species
that attack turfgrasses cause root stunting, death of roots, knots on
roots and some cause no apparent harm even at high numbers. Nematodes
usually do not kill the host plants, but they do increase damage from
other stresses, such as drought. Ground pearls (soil insects) cause serious
damage in sandy soils on centipedegrass that can resemble nematode injury.
If this insect is present, some of the suggestions for reducing nematode
damage may be useful.
that are found most frequently in soil from turfgrasses are ring, stunt,
spiral, lance, stubby-root and sting. Only the sting and the stubby-root
nematodes have been shown to cause severe damage on turfgrasses in research
projects at North Carolina State University. The sting nematode is known
to be the most damaging nematode and frequently occurs in the sandy soils
of eastern and southcentral North Carolina. It is difficult to grow good
quality turfgrasses where this nematode is present.
are not currently labelled for the control of nematodes on turfgrasses
in home lawns. Good turf management practices must be used in place of
nematicides in home lawns to grow healthy turfgrasses that can tolerate
some nematode damage. Some organic soil amendments, such as shrimp and
crab shells, may encourage fungi that kill nematodes. Incorporation of
organic matter in the soil before planting will help the soil increase
antagonistic microorganisms and help grow healthier turfgrasses. High
rates of organic matter should be used carefully on centipedegrass because
too much nitrogen may be released and cause excessive growth that would
result in decreased drought and cold tolerance.
practices can be used to help minimize the damage from nematodes. The
use of good fertilization programs to insure proper levels of nutrients,
irrigation to supply adequate soil moisture, and recommended cutting heights
will help turfgrasses tolerate certain levels of damaging nematodes. In
some cases an alternative turfgrass may be considered. For example, centipedegrass
is more susceptible to the sting nematode than bermudagrass or bahiagrass
. Therefore, bermudagrass would be the best choice for use in residential
lawns where high quality turf is desired if irrigation is available. Zoysiagrass
has been observed to be very sensitive to damage from sting nematodes
and would not be a good replacement for centipedegrass in sting nematode
infested soil. Bahiagrass may be the best choice for lower quality lawns
and in large commercial lawns in eastern North Carolina. Very little damage
from nematodes has been observed on this course textured grass.
management practices must be incorporated into lawn management systems
where nematode damage occurs. This approach will offer new challenges
to turf managers and homeowners since chemicals are no longer available
to control nematodes in residential lawns.
Disease Information Notes Home Page
Carolina Insect Notes
Carolina Agricultural Chemicals Manual
assistance with a specific problem, contact your local North Carolina Cooperative Extension
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