Managing leaf mold in greenhouse tomatoes

If relative humidity is below 85%, the disease will not occur. Therefore, proper venting of greenhouses on a regular basis is important. The pathogen can survive (overwinter) as a saprophyte on crop debris or as sclerotia in the soil. Conidia (spores) of the fungus can also survive up to one year in the soil.

Leaves of infected plants will develop pale-green or yellow spots that are distinct. A dense, olive-green to brown spore mass will develop on the undersides of infected leaves.

Management of leaf mold begins with recognizing early symptoms, applying preventative fungicides, and removing all infected plant material. Protectant fungicides such as chlorothalonil used in weekly protectant spray programs will help control leaf mold. For organic growers, regular copper applications may help to suppress the disease.

Learn more at this Rutgers University Pest Advisory page.

Source and Photo Courtesy of Greenhouse Grower

Source: Greenhouse Grower