Late blight on tomatoes. Photo courtesy Purdue University
With vegetable planting season upon us, we need to take precautions to keep last year’s late blight disease from carrying over into this year’s crops.
Late blight affects members of the nightshade family, which includes tomatoes, potatoes and eggplant. A devastating, deadly fungus disease, late blight is spread through the air, on seeds or it can cling to leftover members of the nightshade family, such as tomato leaves or weeds.
Last year, the disease was reported in Marion and several other Indiana counties, along with most of the eastern United States. It had been several years since the disease was reported in Indiana, which ranks second in the nation for tomato production and processing.
When the disease strikes, there’s little the home gardener can do except pull out the plants and discard, not compost, them. Commercial growers have access to fungicides that are not available to homeowners.
As with this disease and many others, it’s important to follow good horticulture practices, such as fall cleanup, in the vegetable garden. Here are some more tips if late blight or other disease attacked your plants last year.
- Don’t use any seed potatoes or tomato, pepper or eggplant seeds harvested from last year’s crops if your plants were infected.
- Don’t buy seedlings that have leaf spots. Remove the leaves closest to the soil to prevent spores from splashing on the plant.
- Plant these vegetables in a new location in the garden to reduce the risk they will pick up the disease from the soil where they grew last year.
- Mulch around the plants to prevent water from splashing on the leaves and avoid overhead watering.
- Pull any tomato or potato volunteers.
“We normally don’t worry about volunteer tomatoes and potatoes, but (this) year, growers need to be vigilant and pull any that may come up,” said Dan Egel, a plant pathologist at Purdue University. “They could continue to spread late blight.”
Here’s a Purdue publication on Late Blight on Tomato and Potato.
