Be Prepared for Late Blight

Be Prepared for Late Blight
	Source: Yard -N-Garden: The Newsletter for Gardeners In the North Country**
Last year tomato and potato crops were devastated by Late Blight. The good news is that the disease CANNOT live in the soil. The bad news is that it can over winter on infected potatoes that were left in the ground or saved for seed. Just because you did not grow potatoes doesn't mean you are safe. This disease is air borne. One infected plant can infect within several miles. While some late blight strains are more active on potatoes than tomatoes, and vice versa, growers of both crops should be planning to take preventive action.
Home gardeners need to be watchful and share information if late blight shows up. Once the disease is detected it is often difficult, if not impossible, to control. It can develop very rapidly, especially in wet weather.
Three things you can do: (1) plant disease resistant varieties, (2) test your soil; and (3) rotate your crops. The following tomato varieties are resistant or tolerant to late blight: Plum Regal, Legend, and Mountain Magic. Finding seed may be difficult but you may find transplants of these varieties in local nurseries. While soil cannot be tested for diseases, a soil test can tell you what nutrients are lacking. Plants are more susceptible to infection or insect attack when they are stressed. While late blight doesn't live in the soil, early blight and a number of other diseases and insects do. Rotating your crops is a simple way to outsmart pests.
Tomato growers should thoroughly inspect their plants and isolate anything suspicious. Infected tomato transplants may have darkened areas on the leaves or stems. Bagging suspicious plants overnight may result in sporulation. Any fine, white sporulation on the edge of the dark areas should make you suspect late blight. Take suspicious material to your local Cornell Cooperative Extension office for positive ID. Get the word out in the spring to neighboring home gardeners.
**Yard - N - Garden is a monthly newsletter published by the Agriculture Program of Cornell Cooperative Extension of Oswego County to subscribe contact Karen Meyers at (315) 963-7286