Fungicide Sprays for Tomatoes

tomato fungicide spray

Fungicide sprays for tomatoes use chemical compounds or biological organisms to kill or inhibit fungi or fungal spores. The active ingredient in most spray fungicides for tomatoes is either copper or sulfur.

Using organic fungicides on tomato crops can lower impact to the environment, increase vitamin and mineral content in soil, and provide a long-term cost-savings.

The National Organic Standards Board of the Organic Materials Review Institute only allows the use of copper and sulfur based products in organic crop production for controlling disease. However, sulfur can easily burn off as the air temperature rises, making it of limited use to organic gardening and making copper based products the ideal method of preventing tomato blight.

  • Serenade Disease Control Spray is a non-toxic spray which guards plants from the most common fungal and bacterial garden diseases. The product is a biofungicide and is made from beneficial bacteria and fungi. The biofungicide triggers flowers, vegetables, and lawns natural response to fight diseases thereby eliminating the need to use chemicals which can irritate the skin and lungs. Two main responses inhibit the growth of bacteria: pathogens are prevented from attaching to the leaves of the plant and thereby are unable to infect the plant; and if the pathogens are able to attach to the leaves, the product outcompetes them for space on the leaves. In addition, the product destroys the pathogens ability to reproduce. In addition, the product is non-toxic to the environment. Fruits and vegetables can be harvested and consumed the same day as they are treated.

  • Bonide Copper Spray or Dust prevents powdery rust, black spot, and late blight. This fungicide is made by combining copper fertilizer with a naturally-occurring fatty acid. Copper is one of the oldest fungicides and bactericides used to control plant diseases. The copper and fatty acid acid mix and produce a copper salt (known as true soap).

  • Concern Copper Soap Fungicide (discontinued) prevents rusts, black spot, Powdery Blue Fungus, Downy Mildew, and late blight on flowers, fruits, and vegetables. The product works by combing a soluble copper fertilizer with a fatty acid to produce true soap.

Comments from Other Gardeners
  • Nick says:

    I have always used Bonide fungicide. It is organic, copper based and will treat fungus on a variety of vegetables, shrubs and my prized tomato crop. At the first sing of a problem I spray carefully getting all surfaces of the plant.Then I repeat once a week making sure to get all new growth and buds.

  • Sam says:

    Make sure when you spray that you use a mask and eye protection. I also always wear long sleeves when spraying anything on my plants and I only use organic controls. Be sure to spray underneath the leaves and always read the label carefully before using any product.

  • LilyRose says:

    I spray fungicide on the soil and on my emerging seedlings to prevent damping off and other problems. I have even sprayed the seeds.

  • Theresa says:

    LilyRose – great idea. What kind of fungicide do you use on the seeds and do you have better luck when you spray the seeds? I’d be curious to see if it affects sprout ratios or growth rates.

  • Wolf says:

    When is the best time of the day to spray fungicide on fruit trees and tomatoes? Day or evening?

  • pm says:

    I was wondering about the same question that Wolf asked— what time of day is best for spraying tomatoes and zucchini. I have never tried the fungicides before and do not want to overdue or make a stupid mistake.

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