Dry weather delays sprouting of planted corn

The most recent maps on temperature and precipitation forecasts from the U.S. Climate Prediction Center show Missouri in the hottest, driest zones for May, June and July.

"It is beginning to look a lot like 1988," says Pat Guinan, with the Extension commercial agriculture program on the MU campus.

In 1988 the state suffered the driest April, May and June on record, averaging only 6.16 inches of rain during the three-month period. Hot, dry weather during the spring growing season sharply reduced crop yields.

With only a slight chance for precipitation in the six-day outlook, April could go into the record books at Columbia as the driest April on record, Guinan said. Other locations around the state may also have their driest, or second driest, April on record.

"It is not the long-range outlook that matters now," says Bill Wiebold, MU Extension agronomist. "The concern is getting the crop up and growing." Regional agronomists with University Outreach and Extension report most of the corn has been planted across southern Missouri and 70 to 80% planted in northern Missouri.

Mary Sobba, extension agronomist at Mexico, MO, said many farmers in her area have stopped planting corn because it is too dry.

In some cases corn planted three or more weeks ago has been slow to emerge. Eldon Dilworth, agronomist at Edina, in northeast Missouri, said some corn seedlings are showing. "But, I have not seen anything I can row." That is, there are not enough corn shoots emerged to define the row where seed was planted.

Dry weather is encouraging leaf-feeding insects, the agronomist reports. Outbreaks of flea beetles, which feed on emerging corn, are being seen across the state. Some 40 to 50 insects per plant were seen in some fields in east-central Missouri. The economic threshold for damage is five insects per plant said Wayne Bailey, MU Extension entomologist.

"I have seen 20 to 25 flea beetles per plant in previous years, but nothing this high," Bailey said. "Usually the corn will outgrow flea beetle damage. But, this year, the corn is not growing fast enough."

Weeds may become a problem, if it ever rains, said Bill Johnson, MU extension weed specialist. "Herbicides applied before the corn was planted have not been activated because of the dry weather.

"Generally, it takes an inch of rain to make the herbicides work, but we just haven't gotten that much precipitation in most areas," Johnson said. The drier the soil, the more rain it will take to activate the chemicals, he added.

Wiebold, the crop specialist, said light rains of a quarter-inch or less may actually do more harm than good. There will be just enough moisture to germinate the seed, but not enough to keep the roots growing. Several regional agronomists noted that farmers did more tillage than usual this spring. Farmers switched from the trend to more no-till planting this year. Early good weather allowed anxious farmers to get into the fields to work the soil.

This may be the worst year for increased tillage, Wiebold noted. Now a corn seedling must penetrate five or six inches of dry soil with its taproot in order to reach moisture.

In the telephone conference call with regional agronomists the state specialist urged going slow on recommending that farmers plow up and replant if there are poor stands. Tillage will further reduce moisture in the soil, and the seed will be planted into soil even drier than it is now.

Gary Adams, crops analyst with the MU Food and Agricultural Policy Research Institute (FAPRI), said that the dry spring in 1988 reduced corn yields by 23% below expected trend yields.

The resulting drop in production caused prices to increase to $2.54 per bushel in 1988 from $1.94 the previous year. "But we had large stocks of corn in 1988 that dampened the price increase," he added. Currently corn is selling for around $2 per bushel.

Last year, the Missouri corn crop averaged 97 bushels per acre, which was 17% below trend yield. However, the U.S. average was right on the trend yield.

"Missouri doesn't need two bad years back-to-back, Adams added.