One slow day last summer a young woman walked into the greenhouse where I work and unwrapped a small bundle of roses. The canes looked healthy: green with wide-spaced thorns, smooth leaves and a well-formed pink flower. But the side shoots were red, swollen, covered with thorns and had a pitifully misshapen flower. Insects? A virus? Herbicide damage?
A little research yielded the diagnosis: rose rosette disease.
“No cure,” the literature read. “Dig up, roots and all, burn or wrap and put in the trash, but do not compost.”
The young woman burst into tears. The bush had been planted in remembrance of her husband, an early casualty of the Iraq war.
The rose bush, and by extension its owner, was a victim of horticultural meddling. A plant introduced as the next problem-solver over time causes new problems. A new solution leads to worse consequences, for which there may or may not be new solutions.
In this case, the problem started when the multiflora rose — dense, thorny and vigorous — came from Japan in 1886 as a hardy rootstock for cultivated roses. In the 20th Century, government agencies planted it to control soil erosion and as cover and food for wildlife. The commercial nursery trade marketed it as a “living fence”; farmers planted young whips by the thousands.
All too soon, agricultural lands, pastures and natural landscape communities were overrun. By 1987 the multiflora rose was listed in Illinois, among other states, as an exotic weed whose sale or planting is prohibited.
So how to control this invasive plant? The usual options are digging, repeated mowing, burning or using herbicides — labor-intensive, possibly dangerous, potentially toxic.
Another option was rose rosette disease, which is transmitted by a microscopic eriophyid mite and is fatal to multifloras. It was touted as a “safe” method of control that would save labor.
Rosarians urged caution. But landscape managers promoted the use of rose rosette disease. And it backfired.
Not only are multifloras still a nuisance; worse, the disease has spread to nurseries and decimated ornamental rose gardens.
Human-introduced invasive plants and the resultant need for control have long caused problems worldwide: Rhododendrons clot hillsides in Wales, and Canadian goldenrod runs rampant through China.
But today, thanks to biotechnology, potentially more complicated problems may have been introduced via such familiar genetically engineered plants as herbicide-resistant corn, soybeans, cotton and alfalfa; “Bt” (toxic to certain insects) corn and cotton; and “gene-stacked” crops that resist both herbicides and insects.
These new kinds of alien invasives cover an estimated 282 million acres worldwide. No one can predict with certainty the possible consequences of their continued use. Anyone with the slightest knowledge of ecology has to wonder what will happen to surrounding biocommunities.
Nature likes to mix things up. While controlled situations are possible in the lab or test greenhouse, impermeable boundaries don’t exist outdoors. Recent evidence shows that genetically engineered pollen mixes with related wild plants, and that herbicide-resistant properties have spread to noxious weeds.
Last year it was discovered that Bt crop pollen harms non-target insect species — the food of fish and amphibians — disrupting aquatic ecosystems.
A truly complicated web of consequences is unfolding.
Smart, hardworking people of goodwill are developing healthier, systems-based methods. Biologists study whole ecosystems. Organic farmers build soil health through natural means. Gardeners and farmers have moved from “nuke every insect” to integrated pest management. Some governments recognize the utility of “unproductive” lands such as wetlands. Even some economists are including the value of non-human biocommunities when measuring economic health and wealth.
Given this, the practices of using diseases as biocontrol agents without knowing how they will spread, or bioengineering crops for a single profit-driven purpose seem simple-minded in the extreme.
When considering such steps, the doctors’ adage, “First, do no harm,” should be paramount. Such an ethos, applied with the force of law, might push those in the business of applied agricultural and horticultural biotechnology toward more sophisticated thinking, broader goals and safer practices.
Humans have been managing landscapes for at least 10,000 years. We should have learned something by now.
As it turned out, last summer was notable for the spread of rose rosette disease among ornamental roses in the Chicago area. In September I discovered the outrageous growth on a climbing rose that had long produced deep red, heavenly scented blooms.
I had planted it when my oldest child first learned as a toddler to recognize a rose and wanted one for our yard. I nearly burst into tears.
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A.A. Fisher teaches at Triton College and works at the Good Earth Greenhouse.
afisher@triton.edu
