Oct 21, 2019

Combating new grape pests and raspberry mulch trials discussed at 2019 GLEXPO

Two researchers in the northern U.S. are researching new pests local growers are seeing in grapes. At the Grape Session during the 2019 Great Lakes Fruit, Vegetable and Farm Market EXPO, Heather Leach and Christelle Guedot will introduce some research into these pests, which are currently localized but could spread and damage grapes in other regions. Grape growers need to be aware of what neighboring states are experiencing in case those pests migrate.

Additionally, a Washington state-based researcher, Lisa Wasko DeVetter, will present trial results for biodegradable and non-biodegradable plastic mulches in use with raspberry plants grown from cuttings, blueberry pollination and machine-harvesting berries during a berries session.

Leach is investigating the spotted lanternfly in Pennsylvania. As an Extension agent, Leach is working with grape growers to discover the impact spotted lanternfly is having on grape harvests and figure out what insecticides are most effective and on what schedule.

Spotted lanternfly, when left alone to flourish – or even when treated too late – can decimate grape yields. The infestation can not only destroy the current year’s crop, but it can also damage the vine to an extent that the vine dies over the winter. “We are running experiments right now about what the spotted lanternfly feeding does to the physiology of the grapevine so we can establish thresholds. Now, we say that if you have 10 per vine to start spraying, but we are hoping to give better options,” Leach said.

With current infestations in Pennsylvania, many grape growers have seen pesticide costs triple but still struggle with controlling the spotted lanternfly. “Juice growers can’t afford to do the extra sprays for spotted lanternfly,” Leach noted.

The primary goal of discussing this pest in Michigan is to increase growers’ awareness of it. Besides sharing her research, Leach is also excited about this year’s EXPO for other reasons. “This is my seventh EXPO. It’s my favorite conference of the year. It’s a great way to connect with the growers and understand what is important to them. I’d like to get a sense of their concerns about spotted lanternfly,” Leach said.

Christelle Guedot researches social wasps in vineyards and in grapes at harvest and the impact they have on grape growing. Her research involves attracting and trapping social wasps to determine when each species was active throughout the season. Repellents are also part of the research, but not every species has a determined repellent yet.

“We are doing a push-pull strategy in September, and I hope to give attendees details about pulling (wasps) out of grapes,” Guedot said. Future research in the study includes determining if wasps are causing primary or secondary damage to grapes.

This will be Guedot’s first EXPO. “I am super excited to meet people, connect with research and Extension agents and growers, and to see if there is anything we can do to help them. I am Extension, so I am driven by helping growers, learning about problems they face and finding out about differences between their experiences in Michigan versus Wisconsin.” Guedot will also speak at several other sessions.

DeVetter, of Washington State University Extension, will discuss research on trials using several different plastic mulches with tissue culture transplants. The mulches include biodegradable and non-biodegradable plastics. “I’ll also present on some alternative raspberry training systems we’re investigating, as well as blueberry pollination and machine-harvesting for fresh market,” DeVetter said.

DeVetter’s hope is that her current research will help berry growers make production both more sustainable and more profitable. Any growers with an interest in alternatives to plastic mulch, blueberry pollination and alternative harvesting and training systems should plan to attend DeVetter’s session.

With the variety of educational opportunities coming to the 2019 Great Lakes EXPO, growers won’t want to miss out. To learn more about this year’s EXPO and to register to attend, visit glexpo.com.