Protection from Corn Rootworm Produced by Dow/Pioneer Hi-Bred Collaboration

A collaboration between Dow AgroSciences LLC (Indianapolis) and Pioneer Hi-Bred International Inc. (Des Moines, IA) has produced corn hybrids with built-in protection against the corn rootworm, a major and particularly difficult pest. The companies announced that in field tests, corn plants that carried the trait for a form of Bacillus thuringiensis (Bt) toxin showed protection against corn rootworm exceeding what chemical insecticides currently provide. No other approach to this pest, which costs U.S. farmers $1 billion annually, has shown this level of resistance. The companies estimate that U.S. farmers could have seed products with the new trait by 2002 if regulatory reviews go as planned.

Corn rootworms feed on the plant's root system, reducing its yield and ability to withstand wind and a farmer's ability to harvest the fallen crop. To minimize the losses, U.S. farmers treated 14.4 million acres with soil insecticides at a cost of $195 million in 1998, according to a 1998 survey of corn growers by Doane Marketing Research Inc.

Pioneer and Mycogen Corp., a company acquired by Dow in 1998, entered into a collaboration in December 1995 to develop high-value insect resistance traits from the bacillus family. By screening libraries containing hundreds of different Bt's, company researchers were able to find one that was effective against the corn rootworm when expressed at high levels. In field tests comparing the Bt-hybrid to untreated plants and plants treated with insecticide, the hybrid scored 9 in a 9-point scale, while the insecticide-treated plants scored only 5-6. Untreated plants, exposed to rootworm, scored 1 (see figure).

"This is great news for farmers and the environment," said Roger Kemble, Pioneer research director. "Field tests have confirmed we can protect corn from this very challenging pest in a way that is more effective, efficient, and provides a non-chemical alternative."

"We have been excited about the potential of these experimental products for some time," said Ron Meeusen, vice president for R&D Plant Genetics and Biotechnology at Dow AgroSciences. "The results of this summer's field tests confirmed we have reached a major milestone in our research collaboration."

Dow AgroSciences LLC, a wholly owned subsidiary of the Dow Chemical Co., provides pest management and biotechnology products that improve the quality and quantity of the earth's food supply and contribute to the safety, health and quality of life of the world's growing population.

Pioneer Hi-Bred International, Inc. supplies agricultural genetics and develops and integrates agricultural technology. The company develops, produces, and markets a full line of seeds, forage/grain additives and services to grain and livestock producers, grain processors and other customers worldwide.

For more information: Ted McKinney, Dow AgroSciences, Dow AgroSciences, 9330 Zionsville Rd., Indianapolis, IN 46268-1054. Tel: 317-337-4792. Email: Tamckinney@dowagro.com. Doyle Karr, Pioneer Hi-Bred International, 800 Capital Sq., 400 Locust St., Des Moines, IA 50306. Tel: 515-270-3428. Email: karrda@phibred.com.