Back
April 29, 2014

When Would Corn Planting in the U.S. be Considered Late?

On Thursday of this week the calendar turns to May and when planting progresses slowly such as this year, the question is often asked - when does it becomes late for corn planting and when would farmers start to think about switching some of their corn acreage to soybeans.

To answer the first part of that question, I do not consider it late for planting corn in the central Corn Belt unless the corn is planted after about May 15th. Generally, corn yields in the central Corn Belt start declining if the crop is planted after mid-May and the declines accelerate the later the corn is planted, but I am not as concerned about late planting as I was years ago.

The concern for late planted corn has always been that the crop could encounter hotter and dryer conditions during pollination and early grain filling, but the improved corn genetics allows the corn plant to much better tolerate the potential hotter and dryer conditions that may prevail later in the summer. We only need to look at what happened last year in the U.S. when we had record slow planting, but the nationwide corn yield ended up at 158.8 bu/ac, which is just slightly below trend line. Of course, it is better to plant earlier rather than later, but the dire consequences for late planted corn do not seem to be as dire as they were in the past.

The recent corn crops in Argentina have also exhibited the same tendency. This will make the third year in a row that the later plated corn in Argentina has done better than much of the earlier planted corn.

The second half of the question is when farmers will think about switching some of their intended corn acres to soybeans. In the central Corn Belt farmers will not make that decision until probably early June and even then it will be influenced by the weather forecast, corn prices, insurance prices and coverage, etc.

That question may be much more relevant in the northwestern Corn Belt states of North Dakota, South Dakota and northern Minnesota. Farmers in North Dakota have already indicated in the March Planting Intension Report that they intended to reduce their corn acreage by one million acres. Spring is arriving very late in North Dakota (it's still snowing in some areas) and the forecast for May continues to call for below normal temperatures in the state. In the latest weekly report, state officials in North Dakota indicated that the average start date for field work is expected to be May 1st. With that late of a start, it is possible that the farmers in the state may actually plant less corn than what they had originally indicated.