CHARLESTON — Plant scientists at the Clemson University Coastal Research and Education Center in Charleston have developed a technique for producing more fruits and vegetables.

Richard L. Hassell leads a research team that focuses on grafting disease-resistant roots to fruit- and vegetable-producing tops. The scientists recently patented a process to eliminate rootstock regrowth, reducing labor costs and increasing harvests.

Watermelons and their kin – melons, squashes and cucumbers – are very susceptible to soil diseases that destroy their vines. Commercial growers around the world plant vast numbers of grafted vegetable plants.

For grafting to succeed, the plants must be genetically related. However, the rootstock has a powerful drive to grow its own shoots and leaves. If regrowth occurs, the rootstock will nourish its offshoot, leaving the fruit-producing top to wither.

vegetable grafting technique

Richard Hassell demonstrates patented grafting technique developed at Clemson Coastal Research and Education Center.
Image Credit: Clemson University: Peter Kent

To prevent rootstock regrowth, farm workers must scout young grafted plants in greenhouses and fields and pinch off the rootstock’s new growth. Hassell’s method chemically destroys the rootstock offshoot at the growth point. The chemical scarring has been 100 percent effective on watermelon research, a major advance that reduces graft failure and labor costs and increases crop yields.

Grafting has a following among organic growers. The disease-tolerant rootstock replaces the use of chemicals. What’s more, research suggests that grafted plants respond better to environmental stresses and produce longer during the growing season than non-grafted plants.

Clemson plant disease expert Tony Keinath specializes in soil-borne diseases.

“There’s no cure for them,” he said, adding that growers have been able to control disease with chemicals, but some products they have relied on have been taken off the market. This makes Hassell’s work a major advance that reduces graft failure and labor costs and increases harvests.

The grafting research is funded by the USDA National Institute of Food and Agriculture as part of a federal initiative to improve production of specialty crops.