Preventing tomato late blight this year.

To help prevent late blight this growing season, Beth Gugino, assistant professor of plant pathology at Penn State University, recommends making sure that all late blight-infected tomato and/or potato plant tissue from this past season is dead and home gardeners refrain from composting diseased plant material.

“Late blight cannot withstand the freezing winter temperatures of the Northeast, but may be able to live in the center of a warm compost pile,” said Gugino. “As long as the plant tissue is alive, the pathogen can survive.”
Late blight is a fungus (Phytophthora infestans) that primarily affects tomatoes, potatoes and certain solanaceous weeds such as bittersweet nightshade.
 
There is no need to remove dead tomato plant tissue from last season or to treat the soil since freezing temperatures killed both the plant tissue and the fungus late blight. 
 
The pathogen can’t survive in or on tomato seeds, or on tomato cages and stakes between the seasons.
 
Currently there are no tomato varieties resistant to late blight. Breeding work is under way and some resistant varieties are in the final stages of development and are expected to be available as soon as this year.

For more: Beth Gugino, Penn State University, Department of Plant Pathology, (814) 865-7328; bkgugino@psu.edu; http://live.psu.edu/story/42417.