Gardeners Beware - Late Blight is Early!

For many of you seasoned gardeners, late blight is something you have likely heard about and probably dealt with at some point. The devastating fungal disease known as late blight primarily affects tomatoes and potatoes and usually becomes a problem in our region around late August. However, due to the rainy, overcast weather we have experienced so far this summer, the disease seems to have appeared early. According to the UNH Cooperative Extension, cases have already been confirmed in New Hampshire, Maine, New York, and Pennsylvania.

UNH Cooperative Extension plant health specialist Cheryl Smith says that symptoms to look for include the following:

“Large, irregularly shaped, water-soaked, olive-green-to-brown spots on the leaves. Under wet or very humid conditions, a slight fuzzy, white fungal growth may be visible on the underside of the leaf. Leaf lesions begin as tiny, irregularly-shaped dark green or brown spots. Brown to blackish irregular lesions also develop on upper stems. Firm, brown spots develop on tomato fruit, and infected fruit often looks bumpy.” (Weekly Market Bulletin - July 1, 2009)

It is particularly important to keep an eye out for this fungal infection due to its ability to produce high amounts of spores that can travel long distances. This means that if the disease grows untreated, it can easily become a source for spreading the disease to neighboring crops and beyond. Anyone with tomato or potato plants, even home gardeners with a relatively few number of plants, should check daily for signs of the fungus, as it is known to grow rapidly and cause extensive damage in a short time. According to Smith, if your plants do not show signs of the disease, it is not necessary to take action.

For assistance with this and other gardening questions, please feel free to contact us at West Lebanon Feed & Supply. You can also find plenty of resources at the UNH Cooperative Extension website: http://extension.unh.edu/.

References
State of N.H. Department of Agriculture. Weekly Market Bulletin. July 1, 2009 Edition. (UNH Cooperative Extension Cited.) Vol. 88, No. 18.