ISSUE 1 May 10, 2007
DELAYED CORN PLANTING - 2007
The rains of last week effectively stopped all planting in North Dakota and in the wetter regions of the state, planting will likely be delayed a week or more. Furthermore, fields or areas of fields that had been planted that have had standing water for more than three of four days will almost certainly need to be replanted. The question on many growers’ minds is, how late can I plant corn and at what point do I need to switch to an earlier maturing hybrid or consider growing a different crop?
For ND, the optimum period for planting corn is early May. In most years there is little or no yield reduction if planting is delayed to May 20th, particularly in the southern half of the state, so stay with your full season hybrid until the last week of May. For plantings during the last week in May or first week in June, consider growing hybrids that are 5 days earlier in relative maturity. After the first week in June you should consider growing another crop. When considering late plantings of corn, review your crop insurance contract, as planting date can affect your coverage. Late planted corn has the ability to "catch-up" to a limited extent by hastening its development. Nevertheless, a challenge with late planted corn in ND is dealing with the extra grain moisture at harvest. Most years limited field drying occurs after November 1st, so excessive moisture after that date must be removed with artificial drying. With all of the extra acres of corn in ND this year, drying facilities will likely be inadequate, so be conservative with the relative maturity of the hybrids that you plant late, particularly if you do not have your own drier.
At what point does it make sense to switch from corn to soybeans as the optimum planting date for soybeans is later in May than corn? If you have applied all or most of the nitrogen fertilizer that was required for your corn crop, given the high price of fertilizer this year, switching to soybeans may not be a viable option. Furthermore, high nitrate levels can accentuate the iron chlorosis problem in soybeans.
Although planting date influences yield, do not rush out and plant when the field is too wet. Poor and uneven stands that are associated with "mudding it in" will negatively impact yields more than planting the crop a few days later.
Extension Agronomist for Cereal Crops