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Regional Archives — The Altamont Enterprise, September 7, 2006

Wet growing season leads to disease

By Melissa Hale-Spencer

Rains swamped gardens this summer and gardeners swamped the cooperative extension with questions about their ailing plants.

The extension has averaged about 100 queries a week, said Susan Pezzolla, the community educator at Cornell Cooperative Extension on Martin Road in Voorheesville.

"Wet weather in the spring and a rainy summer laid the groundwork for more disease," said Pezzolla this week. "Environmentally, a lot in the garden is driven by weather."

Too much water is a problem, she said, particularly in heavy clay-like soils that don’t drain well.

"Roots can’t breathe and rot off," said Pezzolla.

Also, humidity with moisture creates fungus, she said. "Spores multiply more readily when conditions are right."

In backyard gardens, too, there are often problems with over planting, said Pezzolla. "We all come back with too many seedlings. Plants end up too tightly packed," she said.

Recent concerns about tomato plants, which looked healthy earlier in the summer, led Pezzolla to caution against assuming it’s tomato blight. "People use ‘blight’ loosely for anything going on in the garden," she said. "Early blight, we see quite a bit of. Late blight, we hardly see any."

She urges gardeners with concerns to bring samples to the extension offices at 24 Martin Road. There’s a drop box where people can leave soil samples, and pieces of ailing plants. It’s important to leave contact information with the sample, said Pezzolla.

"You can’t really tell for sure what’s going on until you look under a microscope," said Pezzolla. "We see a lot of septoria leaf spot and bacterial canker in August and September. We also see blossom end rot and cat facing."

The latter, she explained is scarring on the bottom of the tomato that resembles the face of a cat.

"Both of these have to do with the culture of the tomatoes," said Pezzolla of the blossom end rot and cat facing. She explained, "That means how they were grown as opposed to disease."

John Mishanec, based in Albany, issues regular reports on area vegetable growers and the problems they are facing.

Pezzolla cited his Aug. 30 report on tomatoes, which begins, "You learn something new every year. This summer with all the early season rain, it was surprising we did not find bacterial canker in June or July.

"We started seeing a lot of bacterial canker the first week of August. The thing that was different about it was there were very few ‘birds eye’ spots on the fruit. The way I used to tell the difference between septoria and bacterial canker was because you always saw the ‘birds eye’ spots on the fruit with the bacterial canker.

"They both produce the same leaf-spot symptoms. Septoria does not make the spots on the fruit."

Mishanec learned this year, however, that bacterial canker does not always have spots. When the fruit is small, it is susceptible to spots, less so once it gets bigger. In May and June, when it was rainy, tomato plants had plenty of water and were not stressed so no leaf symptoms of bacterial canker were visible.

"In August, the fruit had grown but the root systems were small and the plants became stressed," Mishanec concludes. "This is when the bacteria, which was present all along, started to show in the plants. The edges of the leaves became black and, if you cut the stem, you could see the discoloration in the vesicular tissue."

So lots of tomato plants are now showing bacterial canker, says Mishanec. Some of the fruit has spots, but most of it is clean while the plants are dying back. He recommends applying copper plus Manzate to the plants; the Manzate makes the copper more available, he says.

His Aug. 30 dispatch goes on to comment on problems with sweet corn, pumpkins, and cucumbers — and how to solve them.

Pezzolla stresses that, while many of the problems faced by commercial growers are also found in home gardens, it is important to have problems addressed individually.

Gardeners can come to the cooperative extension with samples to be examined on weekdays between 8:30 a.m. and 4 p.m.; no appointment is needed.

Master gardeners, trained volunteers, offer advice on a hotline at 765-3500 week days from 9 a.m. to 1 p.m. or gardeners can e-mail albanymastergardeners@cornelledu for advice.

Pezzolla herself began as a master gardener 30 years ago and "got totally hooked," she said.

"We’re here to help you," she said. "With diseases, it’s often very hard to correct a problem. You need to learn from it and be watchful in the future and ward off something before it becomes a disaster."

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