The watermelon crop has declined dramatically in Washington because of disease, but Washington State University researchers are developing a solution that involves grafting watermelon plants onto squash and other vine plant rootstocks. “We’ve lost about a third of our state’s watermelon production over the last 10 years because of Verticillium wilt,” said Carol Miles, a professor of vegetable horticulture at the WSU Northwestern Washington Research and Extension Center in Mount Vernon. “Growers have switched to other crops that are less susceptible.” The fungus also affects tomatoes, potatoes, eggplant and many other crops and plants. “Grafting is very old technology, going back over 1,500 years in China,” said Miles. “Farmers in Japan have been grafting watermelon since the 1920s. In the Mediterranean region, farmers have been grafting watermelon, tomato and eggplant for almost 20 years. We just need to find out what works best for our region, and we’ll solve the Verticillium wilt problem.”
This article appears in the May 2015 issue of Acres U.S.A.