`Ugly Duckling’ Corn Strain May Repel Borers

April 4, 2000

One of corn’s worst enemies – the European corn borer – may be on its way out of the corn field by a misshapen corn strain that may hold compounds that deter female corn borers from laying eggs. Corn borers cost $350 million a year in corn losses. With no preventative treatments, losses could exceed $1 billion, says USDA.

B-96 corn is "scrawny," according to the Agricultural Research Service, with weak stalks, undeveloped roots and small ears with round kernels that resemble popcorn. But B-96, a strain from Argentina, contains a chemical that other corn lines covet, and it deters female European corn borers from laying eggs, says ARS.

Scientists at the ARS facility in Ames, IA, are trying to discover new alternatives to Bt or chemical insecticides to protect corn from borers. The only practical alternative to chemical controls now is Bt corn.

By increasing a corn plant’s natural resistance to egg-laying, scientists would help preserve the effectiveness of future generations of Bt corn. The built-in resistance would discourage egg-laying, while the Bt trait would control larvae hatching from any eggs that might be laid.

Researchers have isolated and synthesized a B-96 compound and developed a laboratory bioassay to test its effectiveness. Another chemical in the same family protects yhoung corn plants from feeding borer larvae. B-96 plants continue to produce both compounds as they mature.

The scientists are studying the underlying genetic basis for the biosynthesis of these compounds, hoping to breed this trait into commercial corn – a process they say could take 10 years.