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If your lawn or landscape area has encountered a fungal disease, it can be an embarrassing discovery. Often fungi growth on a lawn reflects poorly on the maintainer of the landscape but even if you take good consistent care of your lawn, fungi might appear beyond your control. This is when a fungicide may be necessary to implement on your lawn to kill off the fungus and to make sure it doesn’t spread further. A fantastic product which can effectively control disease and fungus is chlorothalonil. 

On this page we will give you some background of this fungicide active ingredient and explain how it works so well to eliminate fungus and disease. Here you can also shop the fungicide products we have in stock which contain this active ingredient. 

What is Chlorothalonil?

Chlorothalonil is a broad spectrum fungicide used to control fungi which grow on trees, vegetables, turf, small fruits, ornamentals, and other crops.  It also controls mold, mildew, algae, bacteria, and fruit rots in cranberry bogs. In addition, chlorothalonil has uses as a pesticide pest control  agent, wood protectant and acaricide

First registered to the EPA in 1966, chlorothalonil is used prominently for agricultural use and is regarded as the third most used fungicide in the US, behind only sulfur and copper. The active ingredient comes in a variety of different formulations such as a dust, dry or water-soluble grains, a wettable powder, a liquid spray, a fog, and a dip. It may be applied by hand, by ground sprayer, or by aircraft.

How does Chlorothalonil Work?

The mode of action of chlorothalonil is by reacting with fungi enzyme systems in a way that ultimately leads to cell death. The active ingredient reduces fungal intracellular glutathione molecules to alternate forms which cannot participate in essential enzymatic reactions, ultimately leading to cell death, similar to the mode of action of trichloromethyl sulfenyl.

Chlorothalonil is not a systemic fungicide. As a result, products containing chlorothalonil must be reapplied regularly during the growing season. 

View our selection of chlorothalonil formulated products below. For more information about chlorothalonil or other active ingredients in our pesticides, please call us with your questions at 800-479-6583 or email us at askapro@solutionsstores.com.


How is Chlorothalonil Used?

In the US, the chlorothalonil is mainly used to control fungal growth on peanuts, potatoes, and tomatoes. It is also used on golf courses and lawns, and other agricultural crops.  Chlorothalonil has the ability to deliver broad spectrum control of vegetable, flower, fruit and ornamental diseases including but not limited to anthracnose, leaf blights, downy mildew, powdery mildew, leaf curl, scab, black spot fusarium leaf spot and many other diseases.


Is Chlorothalonil Safe To Use?

According to the EPA, Chlorothalonil has been labeled a Category II toxin which means that it is "moderately toxic". Chlorothalonil is non-toxic to birds but highly toxic to fish.


When handling or applying any of the chemicals we have in stock, we highly recommended for safety purposes to wear personal protective equipment required to lessen the risks of chlorothalonil being inhaled, ingested or coming in contact with the skin. The minimum PPE suggested when working with chlorothalonil based products includes chemical resistant gloves, eye protection, and long sleeved clothing. Please make sure to follow the label instructions for the proper directions in applying the product and knowing what safety measures to apply.


To learn more about different fungus and disease and to see our other fungicide products, visit our disease and fungus control page.

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