Tuesday, April 5, 2011
In the last few years the word endophyte has appeared in reference to grass seed. What does the term endophyte mean? Endophytes are fungi that live inside infected grass plants in a symbiotic (mutually beneficial) relationship that improves disease and insect tolerances of the grasses. Some grass varieties grown for turf seed have high levels of endophytes. Endophyte enhanced varieties, like Jonathan Green’s Black Beauty Ultra Grass Seed Mixture, have increased vigor and growth. This results in a better lawn than grass plants that do not contain any endophytes.
The key word is “beneficial”. We usually think of a ‘fungus’ as something that is bad, that we do not want to be associated with. However, endophytes are all natural and desirable in turf grasses and will not have any negative effect on the grass growth. While living off its grass plant host, endophytes produce defensive chemicals or alkaloids that are non-appealing and sometimes fatal to certain insects. One effect of these toxic alkaloids is that the plants taste bad. This natural-biological insecticide causes insects to spend more time moving and less time feeding on your grass leaves. These insects in the lawn are vulnerable to predators and pathogens. Newly hatched larvae and nymphs also are more prone to starve in Jonathan Green endophyte-enhanced lawns. Additionally, endophyte infected plants produce lower amounts of aromatic compounds that are known to attract insect pests. In other words, in addition to tasting bad to the bugs, endophytes may actually “hide” their host from certain insect enemies.
There are many benefits to endophytes. Endophytes are effective against many above ground insects. A lawn with Jonathan Green Black Beauty mixture with endophytes performs better during periods of heat and drought since a healthier growing plant has a better survival rate when these problems appear. This theory also helps ward off some degree of disease damage since a healthy growing plant can withstand some disease pressure better. A more vigorous growing lawn can ward off some of summers weed invasion too!
Endophytes in lawns increase the range of environmental adaptation; since they perform better in poor quality soil, endophytes increase seed survival, germination and establishment. In the long run, there is one great benefit to endophytes; their effect does not diminish over time. This will help to reduce the amount of maintenance, including fertilizers and pesticides required to keep a healthy growing lawn. For those who do not want to use any pesticides on their lawn, this is the next best ticket to a healthy lawn.
The insect pests that endophytes help to repel are, annual bluegrass weevils, armyworms, bluegrass billbugs, chinch bugs, cutworms, green aphids and sod webworms. A healthy growing Jonathan Green lawn is the best defense since turf grass can tolerate a certain amount of insects, which are present in the lawn naturally. Wow! If we can get these guys to leave the grass alone our lawns would look so much better!
Endophtyes can be introduced by the turf grass breeder through a selection of certain turf species including, perennial ryegrass, tall fescue and fine fescues (chewings, creeping & hard). Kentucky bluegrass and bent grasses have not been able to ‘hold’ onto endophytes in a stable stage so these grasses currently do not contain endophytes. Seed can only transmit endophytes and its entire life cycle takes place inside plant tissues. A plant does not become infected from its neighbors, nor can it infect other grass plants, endophytes can only be detected by a laboratory analysis. The level of endophyte may decrease over time on seed based on how it is stored, cool and dry storage is best for grass seed if you are not going to use it all at one time. The appearance of the plant does not change if it contains endophtyes except that your lawn may look better than your neighbor’s, perhaps you will have the best lawn in town.
Beware: endophytes are not desirable in pasture and/or livestock grazing areas. Research had shown that when animals feed on endophytic grasses that the alkaloids can interfere with developing offspring. Be sure to seed pasture areas that will be grazed with endophyte-free varieties of forage-type tall fescues, and perennial ryegrass; use tetraploid perennial ryegrasses.
The world would be a better place if we all introduced more endophytes into our lawns. Good seeding.Back