Mulch your garden with approximately one inch of a high quality mulch, but DO NOT overmulch as this can lead to wet soils that can contribute to increased humidity. Increase spacing between plants to increase airflow and decrease humidity and foliage drying time. Use early blight-resistant vegetable varieties whenever possible. Rotate vegetables to different parts of your garden each year to avoid areas where infested debris (and thus spores of Alternaria solani) may be present. Destroy infested plants by burning or burying them. How do I avoid problems with early blight in the future? Early blight is best controlled using preventative measures. If you decide to use fungicides for disease control, be sure to read and follow all label instructions of the fungicide that you select to ensure that you use the product in the safest and most effective manner possible. Fungicides labeled for use on vegetables and containing copper or chlorothalonil may also provide control of early blight if they are carefully applied very early in the course of the disease (before symptoms develop is best) and on a regular basis throughout the rest of the growing season. Thinning of whole plants or removal of selected branches from individual plants may slow the disease by increasing airflow and thus reducing humidity and the length of time that leaves remain wet. How do I save a plant with early blight? Once symptoms of early blight appear, control is difficult. Denser foliage leads to high humidity and longer periods of leaf wetness that favor the disease. Early blight symptoms typically begin as plant canopies start to close.

Where does early blight come from? Early blight is caused by the fungus Alternaria solani, which survives in plant debris or on infected plants. Early blight can lead to total defoliation of lower leaves and even the death of an infected plant. Eventually multiple spots on a single leaf will merge, leading to extensive destruction of leaf tissue. As these spots enlarge, concentric rings appear giving the areas a target-like appearance. What does early blight look like? Symptoms of early blight first appear at the base of affected plants, where roughly circular brown spots appear on leaves and stems. The second common tomato blight, Septoria leaf spot, is detailed in University of Wisconsin Garden Facts XHT1073. Early blight can also be a serious disease on other popular vegetables including eggplants, peppers, and potatoes. What is early blight? Early blight is one of two common fungal diseases that can devastate tomatoes in both commercial settings and home gardens. Note spots with concentric rings (arrow) and yellow haloes.īrian Hudelson, UW-Madison Plant Pathology

Spray again after a few weeks to protect new growth.Early blight of tomato. Start from June, especially if the weather’s wet.

Spray potato crops with a protective fungicide before signs of blight appear.

When they're ready for harvest, make sure you dig up every last potato so blight has nowhere to hide during the winter.

Crop rotation helps prevent a build up of disease spores in the ground, and avoids infected plants growing from potato tubers that were missed during last year’s harvest.

In dry weather, water plants in the morning so that any moisture on the leaves can evaporate during the day.

Better airflow helps the foliage to dry quickly after rain, slowing the spread of blight between plants.

Always choose an open planting site with good airflow and leave sufficient space between plants.

Early crops, harvested before the worst of the blight season, have less chance of being exposed.

Plant healthy, disease-free seed potatoes from a reputable supplier.

There’s little you can do to save an infected crop, so stopping blight is all about taking precautions to reduce the chances of the disease attacking your crop: Careful harvesting and crop rotation reduces your chances of getting potato blight.

Early blight potato diseases