Blight

Here we are in the midst of summer. Perfect for picnics, all sorts of outside activities, and enjoying the freedom this season brings. We will be celebrating Independence Day and the weather forecast is great. The summer, so far, has been much better than last. Remember? Lots of rain, lower than average temperatures, and a disappointing growing season for the home gardener. Even worse, this time last year, we were plagued by late blight. While weather does play a part in the development of the disease, the pathogen, Phytophtora infestans, has to be present in order for late blight to develop.

In parts of Pennsylvania there have been confirmed cases of late blight. Late blight is a disease that can kill plants and wipe out crops in a few days if conditions favor disease growth. Those conditions described the 2009 growing season – cool to moderate temperatures with wet weather. Once you have seen late blight wipe out a garden or field, you begin to understand how important preventative measures are to protecting your home garden.

Late blight affects primarily potatoes and tomatoes, not other garden crops. Spores can blow for many miles, land on a wet tomato or potato leaf and start a new infection. So the disease can quickly spread from one garden to another. Infections can be prevented by regular spraying with fungicides containing chlorothalonil or mancozeb, but applications must begin before the disease gets started and continue through the growing season every 7 days to protect new growth. If weather is dry, you can stretch this interval; but if we have heavy rains, you may have to shorten it.

Gardeners should be spraying fungicides on their tomato and potato plants to prevent infection. Keep in mind that fungicides prevent infection they do not cure it. All plant surfaces should be covered with fungicide before conditions favor infection. Do not wait until after the rain stops to apply fungicides – they should be sprayed and dry before rain starts. Thorough coverage of all plant surfaces is needed for good control.

Remember, fungicides are to be used and handled according to labeled instructions. For more information on late blight, please contact the Penn State Master Gardener Helpline at 570-963-6842 or email: LackawannaMG@psu.edu


Steve Ward
Master Gardener Coordinator
Penn State Cooperative Extension in Lackawanna County
Penn State is committed to affirmative action, equal opportunity, and the diversity of its workforce.

Mosquitoes

The signs of the season are upon us: the smell of charcoal grills, the new or refreshed lawn furniture, tiki torches, convertibles, short shorts, and tank tops. These are in addition to the buds and blooms forming on the landscape and filling the air with colors. We all know those long, hazy days have returned. Another telltale sign, that no one wants to see, is the ubiquitous mosquito. These pests stick their pointed “noses” all over us to remind us summer is back.

Worldwide, there are 3,000 species of mosquitoes, 200 in the United State, and about 60 in Pennsylvania. Beyond their annoying bites, the mosquito is a carrier of several diseases such as West Nile virus and encephalitis. The mosquito even puts our dogs at risk by transmitting canine heartworm disease. The mosquito most often discovered in urban areas of Pennsylvania is the northern house mosquito, Culex pipiens.

Adult female mosquitoes require a blood meal in order to produce viable eggs. While feeding, the females inject saliva-containing anticoagulants that prevent the blood from clotting. Because mosquitoes take numerous blood meals, they can acquire disease organisms from an infected host and later transmit those organisms to previously uninfected hosts.

With this in mind, it is important for the homeowner to take these steps to manage the effects mosquitoes can have on the quality of life:

Encourage indoor activities: The northern house mosquito is most active at dusk to dawn. Pennsylvanians with immune system deficiencies should try to limit outside activities to daylight hours. Likewise, parents of young children and infants should keep children inside during these same hours.

Eliminate standing water: This will reduce the number of potential mosquito breeding sites.
• Remove old tires, cans, buckets, pots, and similar items that can trap rainwater.
• Position tarps and boat covers to allow rain runoff and limit ‘ponding.’
• Turn plastic wading pools and wheelbarrows upside-down when not in use.
• Keep swimming pools chlorinated.

Exclusion: All doors and windows should fit tightly and remain closed during the peak mosquito activity. Replace screening that has holes or tears.

Effective Repellents: Materials containing DEET (N,N-diethyl-meta-toluamide) are effective in repelling mosquitoes. For more information on the safe use of insect and tick repellents, or other horticultural issues, contact the Penn State Master Gardner Helpline at 570-963-6842 or email: LackawnnaMG@psu.edu


Steve Ward
Master Gardener Coordinator
Penn State Cooperative Extension in Lackawanna County
Penn State is committed to affirmative action, equal opportunity, and the diversity of its workforce