Natural bacteria can keep snow mold at bay

Natural bacteria can keep snow mold at bay

Winter can be a tough time for the grass on golf courses in higher latitudes, with significant damage to greens and fairways often caused by  snow, ice and wind. On top of that, there’s the problem of infestation by microorganisms such as the snow mold fungus Microdochium Nivale. Snow mold is a problem mainly in areas with cold weather but only short periods of snow cover.

Attacks require a susceptible host (grass), an active parasite (fungus) and a suitable microclimate (low temperature and high humidity). When the fungus infects grass, important functions in the plant are damaged or impeded, often leaving behind circular areas where the grass is dead or growth is stunted.

Snow mold spreads in a number of ways. Fungal spores (and mycelium) can travel on air currents, but may also stick to shoes and machinery. Snow mold may be latent in the grass, waiting for the right humidity and temperature to grow into a full-blown infestation. Meadowgrass (Poa annua) is among the most severely affected, but snow mold can affect all grasses.

Reducing pesticide use

As part of a program known as MASE, funded by Sweden’s Foundation for Strategic Environmental Research, scientists have worked to identify and refine a suitable soil bacteria that can keep snow mold in check. Testing showed that the bacterial isolate ME700 (a gram-negative bacteria) had appropriate characteristics, and that fermentation makes storage and transportation of the bacteria practical. Field trials conducted at five golf courses throughout Sweden—on courses where autumn snow mold attacks have been common—showed that ME700 can be just as effective as conventional chemical fungicides.

“ME700 has shown good results in southern Sweden and we expect similar success on golf courses in the UK,” says Leif Johansson, a researcher at MASE. Field trials of biological pesticides is carried out at the Sports Turf Research Institute in Bingley in the UK. If ME700 performs as well as is hoped in the UK, the project’s backers will look toward larger markets in northern Europe and the U.S. east coast, where local climates resemble that of southern Sweden.

The Swedish Golf Federation is following the MASE effort to find alternatives toi chemical pesticides with great interest. In its environmental guidelines, the federation recommends that its members reduce their use of fungicides. Many courses are located close to nature reserves and water supplies, and restrictions or bans on the use of chemical pesticides are considered likely in the future.

A long way to the golf course

But even if trials with ME700 are successful, it’s not certain that the bacterium can be commercialized. 
Relevant European Union legislation applies the same conditions on microorganisms and chemical pesticides alike, which means toxicity tests, environmental impact assessment, risk analysis and other studies that can run up large expenses. It takes at least five years to get the active substance approved, and a further two years for product approval. Backers have to have a strong belief in the market potential of alternative pesticides for golf courses—and they need substantial funding to make it to commercialization.

A variety of uses

Research under the MASE project indicates that naturally occurring soil bacteria can be cultured in a lab and later returned to their natural environment to supplement the existing bacterial flora. This can result in agricultural crops with greater resistance to fungal attacks and other diseases, better growth and faster maturity.

Since its inception in 2004, MASE has completed more than 200 field trials of up to ten different microorganisms. In these experiments, results were compared with standard cultivation methods, including chemical controls. Scientists have seen positive effects from the bacteria in most of the test runs to date. Attempts have been scaled up from small areas to areas covering several hundred hectares.

Article published in May 2010