There is little doubt that golf courses spend more money each year trying to control dollar spot than they do on any other single disease. It is a problem that never seems to end despite the fact that a number of fungicides have been introduced to supposedly end the problem. One of the first of these fungicides was Benlate, marketed originally under the trade name of Tersan 1991 back in the early 70s. At first, turf managers were reporting tremendous success with this chemical in their battles with dollar spot. After a few years, it just quit working regardless of how often or in what concentration it was used. The dollar spot organism had built up a resistance to Tersan 1991. In the 30+ years since the advent of Tersan 1991 there have been other chemicals introduced that showed great promise in the battle against dollar spot. Many of these new chemicals also became ineffective after they were continually used.
The problem is that the dollar spot organism has a remarkable ability to mutate after it is exposed to a particular chemical a number of times. Whenever a fungicide is applied, it does not kill one hundred percent of the target species every time it is applied. It may kill ninety-five percent of the target species, but a few of them are only marginally affected. These few organisms that survive start to build up immunity to the chemical in question. This process is somewhat similar to vaccinating a person against a certain disease by giving him a small dose of the disease. This causes his body to become resistant to that particular disease.
Each time a fungicide is applied, a few more pathogens survive and go on to build up strains that are more and more resistant to the chemical being used. Finally, a strain is developed that is almost totally immune. The superintendent usually responds by increasing the frequency of applications and upping the rate of chemical used. That just develops an even more resistant pathogen. When all else fails, it is usually time to switch to a newer form of chemistry and the process begins all over again.
Nature Safe is quite effective in reducing the incidence of dollar spot and many other diseases (see Dollar Spot Research on Page 4). This effectiveness is not based on killing the pathogen, but on building the population of beneficial microorganisms that compete with it. Most pathogens are very good survivors and are very poor competitors. Pathogens are at an extreme disadvantage when forced to compete with overwhelming populations of beneficial organisms. The pathogens subjected to severe competition react by going into a dormant state. They are not much of a problem to the turf in this dormant state.
This suppression of the pathogens does not mean that no fungicides will be required. It does mean that fewer applications of fungicide will be needed to maintain healthy turf. By making fewer applications of a particular fungicide, we lessen the chance that resistant strains will get a chance to build up and cause future problems.
The best thing about using the competitive exclusion approach to reducing the incidence of disease is that pathogens cannot build up a resistance or immunity to competition. There are so many different types of beneficial organisms that are produced through a regular use of Nature Safe, that the pathogens cannot withstand all of them. They are literally being attacked from all sides. Most fungicides have only one mode of action. When such a fungicide is used regularly, the pathogens can find a way to overcome the particular mode of action of that chemical.
Nature Safe is not the only product that will increase the populations of beneficial soil microbes. It is the only organic fertilizer that contains the highest amount of available amino acids that increase soil microbe activity – between 20% and 300% more than our competition.
The tremendous increase in beneficial soil microbes will reduce the need to apply a fungicide as frequently. This will reduce the annual cost of turf maintenance and it will make it less likely that resistant strains of the pathogen will be produced. The end result is that Nature Safe not only provides the highest level of nutrition to the plant, but it also helps to reduce the cost of turf maintenance by making necessary chemicals much more effective.