Monday, November 24, 2014

Control the itch to ‘mud in’ corn crop to meet a planting date

Posted on April 24, 2013 at 1:00 a.m. | Updated on April 24, 2013 at 1:27 p.m.

Jeff Burbrink

Around Area Farms

Anyone who has been growing corn the past 40 years can testify they have heard over and over how important it is to plant corn in a timely fashion. When cold, wet weather like we’ve experienced the past two weeks strikes in April, it can set a farmer on edge, pacing back and forth, worrying and waiting for conditions to change.

Maybe we take things like that too literally at times. Bob Nielsen, Purdue Extension’s corn specialist, pointed out recently that many, many things affect the final yield of a corn crop, not just the planting date.

It is true that corn grain yield potential declines with delayed planting after about May 1. Estimated yield loss per day with delayed planting varies from about 0.3 percent per day early in May to about 1 percent per day by the end of May. But Nielsen points out that yield potential goes down because of a number of factors, including a shorter growing season, greater insect and disease pressure, and higher risk of hot, dry conditions during pollination.

It is possible for early-planted corn in one year to yield more than, less than or equal to later-planted corn in another year depending on how things go that year. For example, the crop years 2012 and 2009 represent early and late planting date years in Indiana. About 94 percent of the state’s crop was planted by May 15 in 2012, but only 20 percent of the crop was planted by May 15 of 2009. Yet the earlier-planted 2012 crop yielded 38.7 percent below trend yield for that year and the later-planted 2009 crop yielded 9.3 percent above trend yield. Why? Factors other than planting dates do make a difference in the final yield.

In fact, Nielsen said that planting date accounts for only about 23 percent of the variability in corn yields from year to year. Insects, disease, drought, excessive moisture or heat, early or late frosts and other factors all contribute to the amount of grain put in the bin.

The bottom line is, “mudding in” a crop of corn just to meet a theoretical date on the calendar has potential to be more damaging to corn yields than waiting until planting conditions are right.

Jeff Burbrink is an Extension educator in agriculture and natural resources. Write to him at 17746 E. C.R. 34, Goshen, IN 46528; call 533-0554; or fax 533-0254.