Produce pests

As summer farming gets well under way, there are some pests causing a stink, and others a scourge, in Washington County crops.

From pythium root rot, a fungus, to stink bugs and even the spotted wing drosophilia, a vinegar fly, pests are abounding this growing season.

Levi Morrow, agriculture and natural resources program director for the Washington County Ohio State University Extension office, said these pests have infiltrated area farms and home gardens, but there hasn’t been an enormous problem yet.

“We haven’t had anything that has been overly devastating this year,” he said. “There’s nothing out there that’s going to devastate (crops). We’ve been pretty lucky.”

Pythium root rot has been seen in Reno, said Morrow.

Sally Miller, professor of plant pathology at The Ohio State University’s Ohio Agricultural Research and Development Center (OARDC) in Wooster, said the pythium root rot is more common than a lot of people think.

“Pythium root rot is caused by a fungus-like microorganism,” said Miller. “It’s a water mold; that’s a nickname for it.”

She said the fungus thrives in wet conditions and is harmful to many plants.

“It lives in the soil,” Miller said. “When you have very wet conditions, it starts to grow. It germinates…(and can) survive in the soil for many years…Gardeners probably have it a lot. The roots (of the plant) are attacked; the pythium chews off the roots (in what we call) rat tail symptom.”

While the fungus doesn’t always kill the plant, Miller said it’s common.

“Root rotting may not be that bad,” she said. “The plant can put on more roots (but) sometimes it does kill some plants.”

Miller said there are a few things farmers and gardners can do to help erradicate the problem.

“The main thing is to keep the plants out of water,” she said. “Put the plants on raised beds is one thing that helps. Adding good, quality compost to increase organic matter (as well). Pythium is opportunistic; once the plant is weakened (with water), it’s their opportunity to kind of strike. We want to approach how we can make the soil healthy (again through) drainage and organic matter.”

In addition to fungus, there are several pests of the insect variety that are fast becoming a nuisance in the county: the brown marmorated stink bug and the spotted wing drosophilia.

Celeste Welty, extension entomologist and associate professor of entomology at The Ohio State University, said one common problem with stink bugs is that not many people know what young ones look like.

“The ones seen in homes over the winter are strictly adults,” she said. “We’re seeing the mostly immature form now. The really small ones are about one-sixteenth of an inch. The medium ones really resemble ticks, but have a much softer body than ticks; they have the same general appearance.”

Typically the bugs are a neutral color, a light gray or darker, but can have reddish bodies. They also have black and white striped antennae and legs.

Welty said the brown marmorated stink bug likes to snack on peaches, raspberries, apples, sweet corn and soybeans.

“They love fruit crops,” she said. “They love things soft and sweet.”

She said controlling these bugs isn’t as easy as many would like.

“(Treatments are) still very experimental,” she said. “We’re still working on stuff.”

However, one thing Welty said seems to help is trap cropping, such as putting plants like sunflowers around the border of the cash crop to help draw the stink bugs away. She also said there is talk of getting a natural predator of the bug introduced, but the government has not yet allowed it.

“It’s a tiny wasp that comes from China (like the stink bug),” she said. “The wasp does a very good job of keeping it under control.”

Morrow said the stink bugs are being closely monitored, but not because they’re causing too much of a problem.

“We are monitoring the stink bugs right now, just to get the levels of the population,” he said. “Typically they’re not devastating to any of our field crops.”

The spotted wing drosophilia (SWD) is similar to something many have seen, said Welty.

“In the kitchen, if you have old banana peels and see fruit flies, that’s exactly what these are like,” she said. “It is the exact thing, different species. The ones in the kitchen go for overripe fruit; this one goes for fruit just before it’s harvested, a week before it’s ripe. That’s the reason it’s so devastating.”

Welty said a lot of people notice the fruit or berry “melting away,” which is one of the biggest signs of the SWD’s presence.

“You just have to diagnose the problem and get into a control program,” she said.

One of the positives is it can be controlled.

“The bad news is it’s wide spread and devastating,” said Welty. “One raspberry can have up to 10 larvae…The good news is once people get diagnosed, it takes 10 days to get it really under control. Unfortunately, the main method recommended right now is chemicals…which targets mainly commercial growers.”

She said one good way to test for the larvae is to grab a few cups of berries and put them in a Ziploc bag with a mixture of water and salt. The larvae should come out of the fruit and float to the surface.

Despite all the negatives these pests can bring, Morrow said it’s been a good year for the county’s crops and should continue to be.

“It’s really been a pretty good growing season so far,” he said. “I think we’ll be looking at great crops across the board and some happy farmers. We love years like this where we have a favorable growing season; I think we’re going to be in pretty good shape.”