March, 1999
by Lee Dean
While organophosphate and carbamate insecticides are the current focus of Food Quality Protection Act regulation, herbicides will get their turn soon.
The loss of herbicide registrations under FQPA would only continue a trend already in place, said a weed scientist from the Ohio Agricultural Research and Development Center’s Wooster campus during a talk at the Ohio Fruit and Vegetable Congress in Toledo.
Another speaker presented a side of FQPA not often heard, describing how it may be helpful in registering herbicides for minor crop uses.
The way to successfully adjust to what FQPA will bring is to get off the "herbicide treadmill," according to John Cardina. The current herbicides are proving to be so efficient and economical that growers rely on them too heavily and forget other methods of weed control. Only with a more basic understanding of the bioscience of weeds can growers keep them out of fields and orchards.
A combination of circumstances paint a picture of fewer tools for growers fighting weeds. They include loss of current registrations (17 vegetable herbicides in the last 10 years), FQPA’s bias against minor crops and the lack of herbicide-tolerant plants.
"You won’t see Roundup-ready parsley for a few years," said Cardina.
Herbicide-tolerant crops have proven to be far less than a magic bullet, Cardina explained. Problems include high technology fees and loss of overseas markets, particularly in Europe where there is widespread suspicion and fear about the safety of bioengineered products.
Another major concern domestically is how the federal government plans to regulate these types of plants.
"The Environmental Protection Agency is proposing to regulate them as pesticides," said Cardina. "Who is going to buy a tomato registered as a pesticide to eat?"
With so many other doors closing, the door labeled "weed biology" is the one growers need to step through, said Cardina.
Growers should understand the concept of the weed bank, he said, which is made up of all weed seeds in the plant, on or in the soil or in associated plant litter. Weeds have an enormous capacity for seed production. On the high end, each pigweed plant is capable of producing up to 117,400 seeds.
Only one-quarter of these seeds survive in the soil, but that leaves enough potential for problems that a grower’s management efforts must address the problem, Cardina said.
The key is avoidance - protecting against seeds invading a field. Seeds can get into your fields and orchards in a variety of ways, including on machinery, crop inputs, infestation of crop seed, irrigation water, transplants and any corridor where seeds can enter. At the end of the season, collect weeds and litter, remove them from the field and burn them.
"Limiting dispersal is the most important thing in stopping an invasion of weeds," said Cardina.
A knowledge of crop condition can help in weed management. Each crop has a period of time where it must be weed free in order to be viable. Know the emergence time of both weeds and crops and plant so as to avoid competition.
Use of mulches, irrigation and cover crops are additional tools to be used. Concentrate resources on the crops at the expense of the weeds, Cardina advised.
At times, as one type of weed is successfully managed by herbicides, an opportunity exists for weeds from another family to become dominant. Cardina said growers should anticipate these species shifts by rotation, resistance management and changing tillage timing and practices.
Jerry Baron, assistant director of the IR-4 program at Rutgers University, described the provisions of FQPA that encourage registration of crop protection materials that are safer and less damaging to the environment. EPA is just beginning to review herbicides in the FQPA re-registration process, with the triazine family first in line.
IR-4 (Interregional Research Project No. 4) was established in 1963 to help the producers of minor crops obtain registrations for the conventional pesticides they need to successfully grow food and ornamental crops. A network of state and federal IR-4 cooperators develops field and laboratory data to support petitions for pesticide residue tolerances or exemptions for submission to EPA.
The good news, said Baron, is that the new law calls for fast-track registration for reduced-risk materials and offers incentives for minor use. Consideration is given if a pesticide is the only alternative, is the safest alternative or is important for integrated pest management and resistance management. EPA may waive data requirements for minor use if registrants can prove they have no adverse effect on the environment.
FQPA encourages EPA to review minor use packages at a faster rate — within 12 months of submission. The agency is not yet handling registration requests at that rate, Baron said.
"It all means that IR-4 tools are available to allow us to do our job," said Baron. "We have developed strategic plans for minor crops and minor uses. We are promoting reduced risk pest management. This helps to register softer materials and materials used in IPM."
Baron said growers can help improve the chances of registering herbicides by developing realistic use data and providing it to state organizations that ask for it, who will then pass it on to EPA.
The future of crop protection materials will include a lot of new tools, many of them reduced risk, said Baron. However, there are fewer of these tools in the area of weed control. Risk mitigation will be increasingly important. More interest will be expressed in biopesticides, with IR-4 funding $600,000 of research in that area in 1998 and 1999.
The Fruit Growers News