New for old: the chemical challenge

Herbicide spraying, western slopes, NSW

New uses for old and current chemicals could provide a major boost for farmers.

A GRDC project coordinated by Jim Swain of Jayanare Pty Limited and consultant agronomist John Slatter has surveyed sections of the grains industry in an effort to link old and current pesticides with identified grower needs.

"We uncovered a real need to make better use of the chemicals we already have available to us," Mr Swain said.

"A shortage of desiccants is the big one followed by herbicides that will combat broad-leaf weeds in pulse crops." (Desiccants are chemicals that assist rapid and uniform crop ripening.)

A run of wet harvests has highlighted the need for desiccants across a wide range of crops. While they may not be essential, some consultants make a strong argument for them for the control of heliothis and of herbicide-resistant ryegrass as well as improving the quality of the crop.

Farmers also are looking for fungicides for the developing pulse industry. "That was certainly highlighted when Ascochyta blight hit the chickpea industry," says Mr Swain.

Registration, to close gaps

A follow-up project is attempting to get National Registration Authority (NRA) permits or label extensions for the chemicals considered to have the highest priority in closing up the gaps.

"We won't be able to get as much done as we'd like," Mr Swain says, "but we have laid the groundwork for a continuing campaign."

"The big problem is the need to conduct the residue trials needed before an MRL (Maximum Residue Level) for the product can be obtained," says Mr Swain. "Good research data is essential for any application. If it's to hand, then it takes about three months to obtain a permit and 5-8 months to have an existing label extended to cover the new uses.

"That's still better than a new registration, which can take up to 18 months."

The original manufacturer is involved in the process: "In some instances they've stopped us in our tracks by saying that, while the chemical might control the problem, past experience suggests it will also kill the crop.

"Generally the companies are very supportive, but where residue work is needed, economics and the size of the market come into consideration."

Tie-in with OA

"The grains industry is becoming focused on quality assurance programs and, to be able to sign off on a QA program, you must have a permitted national residue level. To get the necessary information about residue levels to obtain an MRL and a withholding period we need the results from at least 6-8 field trials conducted in different climatic situations over two seasons.

"That doesn't come cheaply. Particularly where we are dealing with small crops like lentils or mungbeans, the manufacturer may be unwilling to foot all of the bill."

Foreign registration can help. "If we can demonstrate a similar use pattern in this country, we can short-cut the process by simply confirming the international information. Where we have to start from scratch and the manufacturer won't fully support the project, we negotiate with all interested parties including the industry bodies to finance the necessary trial work."

Generally, Mr Swain says summer and winter cereal crops are in fair shape. The biggest challenge is to put old chemicals to work in new areas in the emerging pulse crops.

Program 3.3.2 Contact: Mr Jim Swain 02 9980 1460