In addition, fruit from grafted plant have increased shelf life compared with fruit from own-rooted plants, he says.
Squash-like qualities in melons
Dyer says he didn’t have the same outcome, citing his own work. He says the fruit from the grafted plants typically had undesirable squash-like characteristics that were presumably imparted by the rootstock.
“You could have stuff that was almost perfect, but even the best of the stuff will have an off taste to it,” he says. “At first you won’t notice it, but as you eat on it, you’ll start to taste it.
“The melon will be hard and have a rind on it like a squash. And more times than not, instead of a red color, you’ll end up with an orangey red color.”
Research shows benefits
Based on his research, Hassell says he believes that growers can get by with fewer grafted plants per acre because they yield more fruit. In fact, he has found each grafted plant produces an average of one more marketable melon than non-grafted plants.
But the benefits don’t come without a cost. Because grafting is a time-consuming, intricate operation, grafted plants cost more than three times as much as own-rooted plants, Hassell and Baquerizo say.
“You need skilled people,” Baquerizo says. “Not everybody can graft. It’s almost like an art.”
Hassell agrees: “It’s not something somebody who has a small operation can do because you have to have healing chambers to put the plants into after they’re grafted for over a week. They have to be close to 100 percent humidity. Then you bring them out of it gradually. It’s quite a process.”
Dyer agrees and says the cost was one reason he decided to drop his work on perfecting grafted plants.
“All of [the grafting] is done by hand, so it’s very labor intense and a very costly process to do,” he says.
Because of the delicate squash stems, Syngenta uses a silicone-like clip—rather than the plant tape used on trees and vines—to hold the graft union together as it heals.
The grafted plants also are slightly taller than own-rooted plants because the graft union needs to be kept away from the soil, Baquerizo says. Otherwise, adventitious roots from the scion could move into the soil, becoming infected with soil-borne diseases and negating the benefits of grafting.
A marriage of seed and transplants