Hurricane Beryl didn’t cause much physical damage in Maine, but the storm could bring disease to potatoes, tomatoes and cucumbers here as it passes over.
Beryl, downgraded to a post-tropical cyclone after a destructive landing in Texas on July 8, later passed over areas of Ontario with confirmed cases of late blight. The storm’s path could carry crop-destroying late blight to Maine, and the weather conditions it brings with it are favorable to other diseases, too.
Late blight, a fungal disease that causes lesions and rot, has been a risk for Maine potatoes in past years and can easily spread from one field to another. Potatoes are Maine’s most valuabl e crop and brought in $291.5 million last year, according to the United States Department of Agriculture.
The major contributor to the 19th century Irish Potato Famine, certain strains of late blight also affect tomatoes. Stems, leaves and fruits of plants wither and often die. In recent years, there were no large outbreaks here.
Cases were found in two Ontario counties this month. The strain of the disease found in both areas is especially aggressive on potatoes and tomatoes.
The blight produces a lot of spores that can travel long distances through the air on wind currents and storm fronts, according to the University of Michigan Extension.
There’s no certainty blight will be carried here, the Maine Organic Farmers and Gardeners Association’s crop specialist Caleb Goossen said in a July 10 pest report. But the humid and wet conditions are favorable for the disease and other plant issues. Hot weather is typically unfavorable for them, but the dampness could mitigate that.
Jim Dill, who works with potato growers to manage pests and disease through the University of Maine’s Cooperative Extension, said the disease traveling is a possibility.
Representatives of the Maine Potato Board did not return a request for information Thursday.
The storm remnants also pass over parts of Massachusetts where cases of downy mildew have been confirmed. That water mold infects the leaves of cucurbit plants like cucumbers, squash, melons and pumpkins, reducing their ability to photosynthesize and sometimes killing them. Downy mildew causes spotty yellow-brown lesions on plant leaves.
It has only been found on cucumbers in Maine so far, according to Goossen, meaning it may be a strain that doesn’t reach those other species.
Humid conditions can help other diseases like early blight, which is more common in Maine, spread too. Early blight looks similar to late blight, but the brown or black spots it creates are bordered by the veins in the plant leaves.
Warm temperatures have helped plants grow quickly this month, leading to more overlapping vegetation that can reduce airflow.
Goossen recommends home growers consider pruning or thinning crops. If using fungicides on leaves as a preventative measure, the period right after rainfall is a critical time.
Commercial and home growers should use fungicides preventatively or at the first sight of blight, rather than trying to control it once it spreads.
If you find blight on your plants in a home garden, throw them away in a sealed bag. Don’t put them in your compost pile or leave them in the field.
