What is in this article?:
• The big downside of grafting is cost.
• The big upside of grafted transplants is that a plant can be built that has a disease resistance package tailor made for a specific field and a specific combination of disease problems.
GRAFTED TOMATOES, left, are virtually unscathed by bacterial wilt and un-grafted plants of the same variety show damage from the disease.
Grafting plants can solve bacterial wilt problems in a field of tomatoes and can significantly reduce damage from rootknot nematodes, but that doesn’t mean that profit will follow, says Virginia Tech Horticulturist Josh Freeman.
“I’m not an evangelist for grafting, but I can make a field of tomatoes whole by switching from non-grafted transplants to grafted plants.
“We’ve seen tomato fields with 95 percent or higher loss from bacterial wilt and by using grafted plants, we can cut the loss to less than five percent. But, that doesn’t mean the field will be profitable” the Virginia Tech specialist says.
Freeman, who works extensively with growers on Virginia’s Eastern Shore, says he got interested in grafting because of a worsening problem with bacterial wilt.
Fumigants are widely used, but new regulations have reduced fumigant use rates and growers and not getting the same results they used to with high rates of methyl bromide.
Using soil fumigants has become a costly proposition and many small growers simply cannot afford them anymore. “We seem to be in the waning era of using these soil applied pesticides for many growers,” he says.
“With fumigants, we are buying time on a tomato crop. By the time the grower gets three-fourths or so through the growing season, roots have made it out of the fumigated area and the crop is exposed to diseases that can take out virtually all the production.”
Virginia growers, Freeman says, have no good varietal options that have resistance to bacterial wilt.
With resistant cultivars, growers get softer, small fruit and other negative qualities that can make their crop unmarketable. So, in cases like that grafting is an obvious answer.
The big downside of grafting is cost.
For a small vegetable grower the cost of grafted transplants may be 45 cents or so per plant if they graft themselves versus 10-12 cents for seeded transplants.
However, in a bigger commercial operation, the cost of commercially produced grafted transplants may be 75 cents or more versus 8-10 cents for seeded transplants.