As of 8 June, USDA predicted that 98 percent of the corn was planted while 7% was in need of replanting. That means that 1.2 million acres of ground intended for corn in 2008 either remains unplanted or needs replanted. These numbers will likely increase in the next report because of recent flooding.
Yield potential for corn planted now has dropped significantly in Iowa since we are more than 6 to 7 weeks after the optimum planting date. However, we still have a chance to get a crop but the yield may not be what we have experienced over the last few years. If we could plant today, 13 June, we might achieve 70% yield potential. In most of Iowa, it is much too wet to plant. If corn is planted in the last week of June, yield potential might be as little as 50%.
Consider planting shorter-season hybrids when planting in June to insure they mature prior to the first fall killing frost. Remember we had a killing frost on September 15 throughout a large part of north central Iowa last year. Planting earlier-season hybrids was recommended beginning in late May.
Many have asked if there seed is available for replanting. Palle Pedersen, Extension Soybean Agronomist, and I sent an email earlier this week to several major seed companies in Iowa. We asked about their inventory for replanting. Responses from the different companies varied but over all we are in a good situation. The reason is that planting progress in more northern states has been easier than in Iowa this year and left over seed is being moved south into Iowa.
All companies have corn seed available. Here is a summary of the responses we got back for corn (See Palle’s recent CropWatch Blog for soybean seed supply information):
• Corn seed is available for planting/replanting. Many companies are positioning themselves by moving 90 and 100 day corn into Iowa.
• The open window for planting corn, however, is closing fast.
• Farmers will likely continue to plant corn trhough June because of high prices, if nitrogen and/or herbicide have been applied, or for numerous other reasons.
The best advice is to be calm, manage the planted fields and hope that we get some dry weather in the near future. The Iowa corn crops needs a period of above normal heat unit accumulation from now until tasseling and a cooler than normal period after tasseling.
More information on corn management decisions is: http://www.agronext.iastate.edu/corn/