Good Fruit Grower

August 2014

Issue link:

Contents of this Issue


Page 49 of 63

50 AUGUST 2014 GOOD FRUIT GROWER 50 AUGUST 2014 GOOD FRUIT GROWER R esearch entomologist Dr. David James spent several years learning which native plants attract benefi cial insects to vineyards. Now, armed with a plant list, he's ready to encourage Washington State grape growers to bring diversity and benefi cial insects to their vineyards. His plant list is still being fi ne-tuned due to the large amount of data generated from his three-year research project. But he's anxious to get information to Washington State wine grape growers, an industry interested in reducing pesticide use, restoring and conserving benefi cial insect habitat, and bringing biodiversity back to monoculture farming. The list identifi es which plant species native to eastern Washington are best for attracting benefi cial insects, including predators and parasitoids, to wine grape vineyards. In his research, James, of Washington State University, studied the pest dynamics of eight vineyards (four conventional and four with restored habitat) in four locations and investigated perennial fl owering plants for attractiveness to benefi cial insects and their practicality as ground covers and refugia in vineyards. The four vineyards were located in Red Moun- tain, Quincy, Columbia Gorge, and Walla Walla Valley. More than 1,500 traps per season were used to evaluate insect attractiveness of some 120 plant species. "After three years, we now know that native habitat restoration will improve pest management by enhancing biological control and knowing which fl ow- ering plants are the best ones in attracting benefi cial insects," he said. The study also evaluated native plants for attractiveness to pollinators (honeybees, native bees, and butterfl ies). But he added there is much more work to do. "We need to expand our database by having more growers plant native species in larger vineyard blocks and in more locations in the state," said James. "We also need to determine if high-ranking fl owering plants are attractive when not fl owering and develop native plant ground covers that are agronomically suitable and enhance biological control. And we need to get the word out." There are two aspects of refugia, he explained. One is around the vineyards as a har- bor for benefi cials, but there's also the use of refugia as ground cover within the vine- yard. A ground cover, once established, shouldn't need in-row watering because it's a native species adapted to the desert environment. But plants must be robust, low growing, and able to stand up to abuse from tractors. Beauty with benefi ts In all four vineyard sites with restored habitat, James found signifi cantly higher num- bers of benefi cial insects than in nearby conventional vineyards and that fewer sprays were needed to manage pests. Grapes David James hopes to expand his research to more vineyards. by Melissa Hansen Blanket fl ower (Gaillardia) near an eastern Washington vineyard. Clematis fl owers are popular with butterfl ies as well as natural enemies of grape pests. Native plants attract BENEFICIAL INSECTS

Articles in this issue

Links on this page

Archives of this issue

view archives of Good Fruit Grower - August 2014