Frosty temperatures may force crop replanting in Iowa

Temperatures dipped below freezing in some areas of northern Iowa over Mother's Day weekend, causing concern that some farmers may need to replant corn and soy in one of the earliest planting seasons in many years.

The weekly Iowa Crops and Weather Report, released May 10 by the Iowa office of USDA's National Ag Statistics Service, cites temperatures in the 28-30 degree range overnight on May 8-9 in areas of northern Iowa.

A few farmers have reported leaves of young corn plants getting nipped by frost over the weekend. But the plants are young and the growing point is still under ground, so those plants are expected to recover and re-grow new leaves.

However, corn and soy can run into problems when cold, wet weather prohibits the seedlings from growing. Sitting in cool, wet soils makes them more susceptible to seed rots, seedling diseases and stand loss.

Most of the corn that was frosted was less than 3-leaf growth stage corn, noted analysts. The growing point is still below ground so the corn should recover - although there is a chance that seedling rot could infect the seedling. Cool, wet conditions create more risk of seedling rot and slow the recovery.

The weekly statewide survey results released on Monday (May 10) show that 93% of Iowa's 2010 corn crop was planted as of May 9. Also as of Monday, 44% of Iowa's soybean acres are now planted, well ahead of average. Nationwide, 81% of the corn and 30% of the soybeans are planted as of May 9, said the USDA report.