Fusarium Patch - Management

Management

There are a number of different ways to manage diseases including cultural, chemical, and biological controls. Some of these controls are more effective than others, however, the best approach to a managing any disease, including Microdochium Patch, is an integrated approach called Integrated Pest Management or IPM. IPM uses a combination of chemical, cultural and biological controls to reduce spending on pesticides and to decrease pesticide resistance. The following are some of the most important cultural controls used in managing Microdochium Patch.

Cultural Controls Raising the mowing height is an easy way to reduce stress on a turfgrass plant and make the plant less susceptible to attack by disease, but there is a fine line. Turf mowed, less than 2.5 inches and above 3 inches makes the plant is more prone to disease. Managing the moisture available to the plant is another way to help reduce the incidence of disease. The pathogen that causes Microdochium Patch requires and thrives in moist conditions, therefore making sure that you aren't overwatering the turf when conditions are right for infection is very important. Giving the plant only enough water for normal plant function is the best way to ensure disease pressure is reduced as much as possible. Also, starving the turf of moisture can be damaging as this increases susceptibility to infection. Managing the amount of nitrogen available to the plant is another key to decreasing incidence of this disease. Avoiding excess fall nitrogen application will greatly reduce disease pressure of Microdochium nivale. On top of that excess nitrogen available to plant produces rapid growth of above ground tissue. This tissue often has thin cell walls and is prone to attack by disease. Managing thatch and soil drainage are two other important ways of controlling this disease as both of these affect the amount of moisture that is available to create a favorable environment to the disease, giving the plant only enough water for normal plant function is the best way to ensure disease pressure is reduced as much as possible. Despite the fact that the above cultural controls cannot completely control Microdochium Patch, when they are all used to reduce disease pressure, they can have a noticeable impact and will help to reduce the amount of chemical control that is required.

Chemical controls Chemical controls (i.e. the use of fungicides) to specifically control turf grass diseases have been around since 1891 with the introduction of mercury chloride as a broad spectrum control. Heavy metal fungicides worked very well, but once it was determined that they were bad for the environment, their use stopped. Over the years better and better controls have been developed, all of which tend to be less toxic to animals and the environment when used properly.

There is a wide variety of chemical groups that are labeled for control of Microdochium Patch. They include, but are not limited to the methyl benzimidazole carbamates (MBCs) such as thiophanate methyl, the dicarboximides such as iprodione and vinclozolin, the DMIs such as fenarimol and propiconazole, the QoIs such as azoxystrobin, pyraclostrobin, and trifloxystrobin, the phenylpyrroles such as fludioxonil, certain aromatic hydrocarbons such as PCNB, and the cholronitriles such as chlorothalonil. There is a wide variety of chemical groups that are labeled for control of Microdochium Patch. They include, but are not limited to the methyl benzimidazole carbamates (MBCs) such as thiophanate methyl, the dicarboximides such as iprodione and vinclozolin, the DMIs such as fenarimol and propiconazole, the QoIs such as azoxystrobin, pyraclostrobin, and trifloxystrobin, the phenylpyrroles such as fludioxonil, certain aromatic hydrocarbons such as PCNB, and the cholronitriles such as chlorothalonil.

These chemical classes should be rotated so that selection pressure on the disease in limited as to avoid resistant strains of this disease. The applicator should read and follow all label rates and directions. Breaking these directions and misuse of any labeled product is breaking the law. Remember that the label is the law. The best way to control Microdochium Patch especially going into winter is to use a three way spray right before the first snow fall. A combination of a dicarboximides such as iprodione, a chloronitrile such as chlorothalonil, and a DMI such as propiconazole will give sufficient control over the span of an average winter.