of Rhode Island GreenShare Factsheets
infected with nonpathogenic fungal endophytes may meet demands
for reduced pesticide use and for lower inputs for maintenance
and production of sod. Discovery of the symbiotic relationship
between these fungi and turfgrasses occurred when cattle grazing
grass developed symptoms such as delirium and "livestock staggers." At
the same time, infection with endophytic fungi, which occurs naturally
on over 15 million acres of grassland throughout the U.S.,
results in turfgrasses with higher overall vigor and insect resistance
compared with non-endophytic varieties. As such, endophyte-enhanced
turfgrasses may be used for a low-input, biological control option
for sustainable turf care programs.
term "endophytic" refers to a situation where one organism lives
inside another. In this case, a fungus and grass form a relationship
that is mutually beneficial and enhances the reproductive success
of each. The fungal endophytes Acremonium coenophialum and
A. lolii manifest no visible signs on their fescue and perennial
ryegrass hosts. These endophytes are transferred from plant to plant
via seed. The mycelium of the fungus then grows into the sheath,
stem, and leaf tissues of the developing grass seedling and maturing
plant. Finally, the fungal endophyte enters the flowering stem and
seed. The endophyte is passed to the next generation of turfgrass
plants through the seed.
grasses tend to be comparatively vigorous, especially under conditions
of minimal fertilization and irrigation. Infected plants produce
greater numbers of tillers and roots, making them more drought-tolerant,
more competitive with weed species, able to recover more rapidly
from injury and generally more persistent in the field. The higher
performance is particularly notable under stressful conditions such
as high temperature, as well as nutrient and water deficiency. The
result is a grass that is highly suitable for medium to low input
grasses have shown high resistance to foliar-feeding insects such
as billbugs, chinch
bugs, sod webworms, fall army-worms
and argentine stem weevils. Biologically active alkaloids are found
only in infected grasses. The insecticidal effects produced by these
compounds deter insect infestations, resulting in a population decline.
Alkaloid levels in the roots are low, however, and endophytes are
thus not effective against root feeders such as white grubs.
number of endophyte-infected, improved cultivars of tall fescue,
perennial ryegrass and fine fescues is increasing. A combination
of these endophyte-infected varieties is often marketed as a low-maintenance
mixture. Despite attempts to incorporate endophytic fungi into Kentucky
bluegrass and bentgrasses, these high quality grasses are still
endophyte-free. In order to maintain the viability of the endophyte,
seeds must be stored at cool temperatures (approx. 40 degrees F)
and under dry conditions. Even under excellent storage conditions,
the percentage of viable endophytes in a seed lot will decline over
time. In contrast, however, endophytes last indefinitely in plants;
the endophytic content of a lawn typically increases over time as
endophytic tillers outcompete non-endophytic ones.
of endophytic grasses provides a self-sustaining biological control
option for turf. Outbreaks of insect and other pests may be prevented
as a result of the insecticidal effects resulting from the interaction
as well as from the vigorous nature of turf growth. The enhanced
tolerance to stresses, as compared with non-endophytic varieties,
makes endophyte-infected grasses particularly suitable for low-budget,
low-input, low-maintenance situations. Endophytic grasses may form
an integral part of an IPM strategy for turf in that they can withstand
a range of mowing, fertilization, and irrigation practices. They
are also compatible with the use of most insecticides and herbicides,
and are only temporarily affected by fungicides. Endophytic grass
seed is available at better garden centers and seed stores. It is
only slightly more expensive than other seed and well worth the
investment. Use only fresh seed to maximize endophyte content.
from the University of Massachusetts Extension, 1999
are poisonous! Read and follow all safety precautions on labels.
Handle carefully and store in original containers out of reach
of children, pets or livestock. Dispose of empty containers
immediately, in a safe manner and place. Pesticides should never
be stored with foods or in areas where people eat.
When trade names are used for identification, no product endorsement
is implied, nor is discrimination intended against similar materials.
Be sure that the pesticide you intend to use is registered for
the state of use.
The user of this information assumes all risk for personal injury
or property damage.
information, call the URI CE Gardening and Food Safety Hotline
at 1-800-448-1011 or (401)874-2929 from outside Rhode Island;
Monday-Thursday between 9 am and 2 pm.
of Rhode Island Cooperative Extension provides equal program