What is endophytic grass?

Endophyte - What is it?
Did You Know...Endophyte is a beneficial fungus? Endophyte is a fungus that lives inside infected grass plants. Some grass varieties grown for turf seed have high levels of endophyte. Toxins produced by the fungus are harmful to insects feeding on the surface areas of the leaves. This natural insecticide is both non-appealing and sometimes fatal to the insects, thereby reducing the need for chemical insecticides. Affected insect include chinch bugs, sod webworms and billbugs, but not sub-surface insects such as Japanese beetle grubs. Endophyte enhanced varieties, as they are commonly called, also have increased growth and vigor, making the varieties better tolerable of drought stress, summer weed invasion, and other possible turf diseases. The advantages of endophyte are most obvious during the late summer and fall months. Endophyte is transmitted only by seed, and its entire life cycle takes place inside plant tissues. A plant does not become infected from its neighbours, nor can it infect other plants. Since it does not affect the appearance of the grass plant, its presence can be detected only by laboratory analysis. Although seed may decrease in endophyte over time, plants that are infected maintain their endophyte fungus.

Endophytes and Insect Tolerance
The discovery that high endophyte grasses were resistant to insect feeding was accidental. A study in New Zealand was looking at the effect of endophytes on sheep grazing. After this study it was discovered that when the tall fescue was growing in after grazing that the endophyte free tall fescue was being attacked by a grass pest called the Argentine Stem Weevil but the high endophyte plot was not attacked.
Since this chance discovery many research reports on turfgrass species containing endophytes have shown that they enhance resistance to surface feeding insects including sod webworm, bill bugs and chinch bugs. The endophyte either produces a poison or makes the plant produce a chemical which repels insects that feed on turf. Studies have shown that the amount of insect resistance is directly proportional to the percentage of endophyte living within the turfgrass plant

Endophytes and Stress Tolerance
Endophyte enhanced turfgrasses have shown increased stress tolerance. This has been expressed by reduced weed invasion, better summer survival and fall recovery after a drought. The reasons for the enhanced stress tolerance are not well understood.

How Are Endophytes Passed on From Generation to Generation?
A turfgrass plant containing endophytes will have endophytes in the leaves and sheath. When that plant goes to seed the endophytes will grow into the seed also. As long as those seeds containing the endophytes are properly stored those endophytes will remain in the seed. When that seed germinates and grows into a turfgrass plant the resulting plant will also contain the endophyte.