Tomato Blight

Controlling blight on tomatoes and potatoes.
Blight is basically a fungal infection. Theories abound on what actually causes the plant disease. Some say that soil which is nutrient-deficient creates a breeding ground for blight. Others say that a lack of lime is the problem. Finally, many successful gardeners insist that the fungus is bred by heavy rain fall, mixed with humidity and certain soil conditions. Regardless of the exact cause, blight can be detrimental to your crop.

The early stage of blight is when small black or brown circles begin to form on the lower leaves of the plant. The spot usually consists of a dark outer ring with a lighter center. As blight spreads, the number of spots multiply and the leaves begin to turn yellow. The fungus moves up the plant, damaging the leaves in its path.

Blight, if left untreated, can completely devastate your crop. If you do not attempt to treat it, your plants may not form fruit or even flower effectively. If you discover blight, you must attempt to treat it. You must remove all of the damaged leaves to help stop the spread.

A great treatment for Late Blight is EXEL, a broad-spectrum bio-rational systemic fungicide for the use on turf, fruit trees, ornamentals, flowers and vegetables. Produced by Organic Laboratories EXEL is an all natural product.

Preventative and curative: EXEL cures and prevents a wide variety of difficult to control diseases. Including Pythium and Phytophthora (responsible for root rot), leaf and stem blights, leaf spots, rusts, powdery mildew, downy mildew, sudden oak death and many others.
Systemic: a foliar or root application will work through the entire plant to prevent disease and attack any existing disease above and below ground.
Biostimulant: once inside the plant, EXEL increases plant metabolism resulting in increased plant vigor, faster growth, more bloom, and increased yield.
Nutritional: EXEL also give a nutritional boost of potassium and phosphorous - essential nutrients for quality plant growth.
Safe: EXEL is an EPA registered fungicide with minimal impact on the environment, re-entry time is as soon as sprays have dried upon the leaves.
Serenade is a OMRI listed product that also controls late blight as well as bacterial spots, powdery mildew, rust, gray mold, scab, and more. This fungicide attacks harmful garden diseases on roses, vegetables, fruits, flowering plants, trees, and shrubs. Unlike sulfur-based disease control products, Serenade is non-irritating to skin and lungs. And, unlike neem oil-based products that can injure plant foliage, there is no weather or timing restrictions limiting its application. If is completely non-toxic to bees and beneficial insects.

Late blight won’t overwinter in Northeast!
Late blight (Phytophthora infestans) has caused big headaches for vegetable gardeners. But, some good news is: Late blight won’t overwinter in the area, except in infected potato tubers according to UConn Home and Garden Education Center.

Experts say late blight won’t overwinter in the area, except in infected potato tubers. The pathogen, Phytophthora infestans, survives in living tissue and will be killed by freezing temperatures.  Late blight will not survive the winter on any part of the tomato plant, in the soil, or on alternate weed hosts, such as nightshade. Therefore, you do not need to be concerned about your soil harboring this pathogen and creating a source of infection for next year. Tomato fields can be harrowed or plowed down as usual at the end of the season before planting a cover crop. For extra protection, tomato stakes can be stored under a tarp in the sun for a week or two to help deactivate spores or dipped in a (10%) chlorine bath in the spring. Late blight will only survive the winter in infected tubers. Potato growers must take great care next year to manage volunteer plants that emerge from this year’s fields or this whole late blight cycle can start all over again. Tubers can be left on the surface and will be killed by freezing temperatures this winter. However, buried tubers can produce infected plants next year that must be destroyed early before the spores start to spread.  Kill volunteer plants with post-emergence herbicides or cultivation equipment.