Research combats melon disease

By Tom Lollis

Anthony KeinathMelon producers have a fighting chance against one of their worst diseases, gummy stem blight, because of research at Clemson’s Coastal Research and Education Center.

Anthony Keinath, vegetable pathologist, has been tracking the fungus Didymella bryoniae, especially as it affects watermelons, a 7,000-acre crop in South Carolina worth about $7 million. After the use of a family of fungicides called strobilurins became widespread, Keinath found resistance to the treatment in 32 South Carolina samples of the pathogen from 2001-2005. 

“Two of the 32 were from transplants, so some of the resistant isolates may have come into the state that way,” Keinath said. “The disease is being managed well with a new fungicide called Pristine, a mix of one part strobilurin and two parts of another active ingredient.”

He recommends that growers rotate the eradicant Pristine with a protectant fungicide, use healthy transplants and rotate fields out of cucurbits for two growing seasons. He also advises growers not to reuse plastic mulch from a melon crop for another cucurbit crop other than summer squash, which is not susceptible to gummy stem blight. The best procedure is to pull plastic up and disk crop debris into the soil.

For information: Anthony Keinath, 843-402-5390,