Growing a Healthy Crop for Christmas
Concerned about leukemia in their community, these North Carolina Christmas-tree growers voluntarily reduced pesticide use
Six years ago, Christmas-tree farmers in and around the peaceful Appalachian Mountain community of Boone, North Carolina, faced up to a horrible possibility: That their heavy use of chemicals to control insect pests and weeds in their fields of Fraser firs might be contributing to the community's high incidence of childhood leukemia—a rate 9.2 times higher than the number expected for a population of 36,000, according to federal cancer statistics. Local doctors were also concerned that the chemicals might be seeping into water supplies throughout Watauga County. They turned to the North Carolina Central Cancer Registry for help.
The farmers later made an impression on the registry's field staff. "Their feeling was, 'We drink the water too. If you're concerned, we're concerned,— says Tim Aldrich, director of the registry. Aldrich and other North Carolina authorities were indeed concerned. Though no evidence existed that conclusively linked local chemical-pesticide use to the cancer rate, the possibility of such a link was enough to spark a revolution in Watauga County's Christmas-tree industry.
Today, after coordinated educational efforts between state agricultural officials and tree growers, hundreds of Watauga County farmers have cut back drastically on the number and amount of toxic chemicals they use. Their new farming practices are also producing more habitat for wildlife. "We've simply substituted knowledge for chemical application," says Gene Brewer, county agricultural director for the North Carolina Cooperative Extension Service.
At tree farms throughout the area, growers have completely eliminated some chemicals from their standard rotation. They are applying other pesticides as sparsely as one-tenth the amount recommended by manufacturers, turning instead to natural biological-control methods to rid their fields of insect pests. The results of this revolution are heartening.
The plump, glossy Fraser firs are selling as well as ever — Watauga County alone produced 542,000 trees worth $12.2 million last year — and markets for the trees continue to expand throughout the country. "They go in every direction: north, south, east and west," says longtime Boone tree farmer Kenneth Dotson. "We're planting more and more every year."
Whether or not the chemicals used on the Christmas-tree farms contributed to the area's excessive leukemia rate, growers say they are pleased to be taking steps to improve groundwater supplies for communities downstream. And they're happy to see wildlife flourishing in their fields and in nearby streams and woodlands. "We've seen more wildlife in the last five years than we saw 30 years ago," says Dotson, whose land now provides habitat for a range of songbirds, waterfowl, wild turkeys, foxes and deer.
Dotson's two sons, Jerry and Tom, who now run the family's farm operation, were just schoolboys when their parents began planting Christmas trees in 1962 to halt severe erosion caused by hillside vegetable farming. Growing corn, beans and potatoes on steep slopes near Boone, says Kenneth Dotson, "was washing our land away."
Like other area farmers, the Dotsons began planting fast-growing white pines. But the family soon switched to more profitable Fraser firs. The firs sell for higher prices than pines because of their attractive, long-lasting needles. However, the firs also require more care to grow, including frequent shaping and fertilizing. A Fraser fir takes as long as nine years to reach a marketable 6-foot height.
From the beginning, the tree farmers applied chemicals liberally. "We thought that if a little was good, a lot would be better," recalls Kenneth Dotson's wife, Pauline. The farmers also preferred to keep their fields neat by mowing closely between the rows of Christmas trees.
Farmers used blanket sprayings of toxic diazinon or Chlordane to kill the grubs that feed on the firs' roots, and they sprayed heavily with herbicides to eliminate weeds. The woolly aphid, which attacks the bark and kills trees, was doused with another potent chemical.
Such tactics continued throughout the county until 1989, when residents received bad news: three reported cases of childhood leukemia within 1 square mile, and three more scattered nearby — an unusually high number. Local doctors who diagnosed the cases noticed that the sick children all lived in an area where Christmas trees and tobacco were grown. The doctors called the North Carolina Cancer Registry, which could not find a conclusive link between local chemical use and the leukemia.
"The link of pesticides with cancer risk is generally accepted," says Registry Director Aldrich. However, he adds, the sourceof the health problems may be found beyond local groundwater contamination. At the National Cancer Institute in Maryland, Director of Occupational Studies Aaron Blair agrees that a link between pesticide use and elevated cancer rates seems strong. But he cautions that farmers are exposed to many suspected carcinogens, including diesel exhaust, fuel oil and airborne microtoxics that could come from sources outside the immediate area.
Rather than wait for researchers to better pinpoint the source of the leukemia, Watauga County tree farmers decided to take matters into their own hands. They turned to county Agricultural Extension Director Brewer, who developed a series of workshops to teach new techniques for dealing with tree-farm pests.
Previously, the Watauga tree growers had started their planting cycle in late winter with what one farmer called "killing the earth"—a field treatment of "pre-emergence" herbicide to controlweeds before they even sprouted. Growers mowed grass regularly, even though grubs prefer short grass for laying eggs. To compensate, the growers had to use more chemicals to kill the grubs. Today, many farmers are skipping the pre-emergence herbicide treatment and letting the grass grow taller. As a result, grubs no longer pose a serious problem at most farms.
After the trees are shaped in summer and harvested in fall, growers are allowing a cover crop of rye to mature and die back naturally. The cover crop provides nutrients for the soil and food for wildlife. "The appearance of the farm is not as good. It's not picture perfect," says local grower Carroll E. Garland. "But we do not have soil washing away, and we do not have the effects of chemicals." The first time Garland planted a field without chemicals, he noticed ducks returning to a nearby pond. That field recently produced his biggest harvest of trees.
Farmers like Garland and the Dotsons now rely on North Carolina agriculture officials to help them determine fertilizer application doses for each of their fields. Throughout the county, use of chemicals has declined from an average of 192 ounces per acre per year to 45 ounces.
Pediatrician Bill Horn, one of the Boone doctors who first noticed the cancer cluster in Watauga County six years ago, now voices cautious optimism that the unusual rate of leukemia has dropped since the Christmas tree growers adopted new horticultural practices. Horn notes that there has not been a new case of childhood leukemia in the original cluster area in four years.
Meanwhile, growers themselves are seeing other benefits from the changes. "It used to be in the nursery business that your neighbor was your competitor," says Jerry Dotson. "Now they're our allies. Our only competitor in Christmas trees today is the artificial tree."
Writer Nan Chase lives in Boone, North Carolina.