This summer's late blight disease affected nearly everyone's tomato crop.

The following information from Penn State University plant pathologist Beth K. Gugino might be helpful when planning and preparing for next year.

Here are the five most asked questions and related answers:

QUESTION: Do I need to treat the soil this fall to prevent late blight from developing next year?ANSWER: No. The late blight pathogen is an obligate pathogen and thus requires living plant tissue to survive over winter.Once the tomato plant tissue is dead, the pathogen cannot survive on the drop debris like many other vegetable pathogens.The specialized overwintering survival structure (oospore) of the late blight pathogen requires two mating types (equivalent to male and female) to go through sexual reproduction and form.To our knowledge, there is only one mating type in Pennsylvania and the Northeast. Without the compatible mating type, no oospores form, and therefore, there is no risk of this season's late blight surviving in the soil and being a source of the disease next season.This means there is no need to treat the soil this fall or next spring to prevent late blight next year. The late blight pathogen can, however, survive in potato tubers, so it will be important to destroy any volunteer potato plants next year.

QUESTION: Can the late blight pathogen survive in or on tomato seed?ANSWER: No. Fortunately this pathogen is not able to get inside seed and it does not produce a type of spore that is able to survive on the outside of the seed. Thus, there is no concern late blight will develop as a result of growing plants next year from seeds that were in tomatoes infected with late blight.There are other pathogens, especially bacterial pathogens, that can survive in and/or on the seed. Thus, there are other reasons to only use seed from healthy plants.

QUESTION: Could the late blight pathogen survive on tomato cages and stakes between seasons?ANSWER: No. Therefore, it is not necessary to discard or even disinfect the cages or stakes to manage this disease. It is a good idea, however, to disinfect stakes and cages to help control bacterial diseases (bacterial spot, bacterial speck, bacterial canker).These bacterial pathogens can survive over winter in the cracks and crevices and be a source of the disease next season.Disinfectants include: quaternary ammonium chloride salts (Green-Shield), sodium hypochlorite (Clorox or other household chlorine bleach), and hydrogen dioxide (Osicate).Clean off solid and organic matter first because this inactivates disinfectants and can protect pathogens that are inside. This is especially important when using bleach. Soak at least 10 minutes. Disinfectant solution can be reused until it becomes dirty or ineffective (replace Green-shield after 24 hours; half-life for bleach is only two hours).

QUESTION: Are there late blight-resistant tomato varieties I should consider planting in the future?ANSWER: Currently, there are some potato varieties described as having some resistance.These include: Elba, Kennebec, Allegany, Sebago, Rosa, Defender, Jacqueline Lee and Ozette. Elba is considered the most resistant. There are some tomato varieties in the final stages of development that are expected to be available as soon as the 2010 planting season.

QUESTION: What can growers do to prevent another late blight epidemic next year?ANSWER: Make sure all late blight-infected tomato plant and fruit tissue from this season is dead or destroyed. Once dead, the pathogen can no longer survive since it is an obligate pathogen and cannot survive outside a living host.Destroy potato tubers that appear to be infected by late blight and volunteer potatoes that grow next year. The late blight pathogen cannot survive in infested dead plant debris, but it can survive in tubers.Next year, make sure to plant healthy disease-free transplants. Examine your plants regularly for symptoms of late blight, especially if cool, wet conditions prevail like this past year.In general, good disease management focuses on creating a less favorable environment for the pathogen. The pathogen survives and spreads more effectively when leaf surfaces are wet. Avoid wet leaves by watering at the base of the plant or by using overhead irrigation during mid-morning so the leaves dry quickly. Improve air circulation by spacing plants farther apart and eliminating weeds. These practices also will help with the management of other common diseases.Luke Fritz is executive director of the Butler County Farm Service Agency.