fungicides

Asked August 21, 2020, 4:09 PM EDT

The fungicides that sell for $30.00 - do they really work. Have tomato blight really bad and have done everything that suppose to do, but still have it - does these fungicides really work - namely (Organic Complete Disease Control) sold by Jung. Also have a clematis that the leaves turn brown black.

Stearns County Minnesota

1 Response

It’s difficult to prevent tomato leaf disease (blight) entirely, especially late in the season, even when control measures are taken.

According to most authorities, using fungicides can be beneficial but their use is generally recommended only as a last resort.

Fungicides do not eliminate disease that is already present but may extend the life of healthy stems and leaves. Fungicides are most effective when they are applied as soon as or even before any evidence of disease is visible.

Experts at Iowa State University say this about fungicides: “While cultural practices may help control tomato blights, fungicides are often needed. Apply fungicides (chlorothalonil, maneb, or copper-based fungicides) at 7 to 14 day intervals beginning 2 to 4 weeks after transplanting. Thorough coverage is essential. Be sure to spray both the upper and lower leaf surfaces as well as the centers of the plants. Spray to the point of runoff.”
https://hortnews.extension.iastate.edu/1996/4-26-1996/tomato.html

Although other fungicides are available, including the one you mentioned, we can’t vouch for their effectiveness.

The clematis may be affected by a disease called clematis wilt. Go here to learn about this disease and what to do about it: