Arkansas: Coping with late-planted corn and grain sorghum this year

May 1, 2008 - Getting corn and grain sorghum planted this year has been a frustrating challenge for many producers to say the least. Flooding rains and continuing wet weather has delayed corn planting in parts of Northeast and areas of Central Arkansas now for going on six weeks.

According to the April 28 Arkansas Agricultural Statistics Service Report, only 66% of the corn has been planted. This compares to 98% in 2007 and 94% for the 5-year average. Grain sorghum planting is also considerably behind normal plantings with only 13% of the crop planted compared to 75% in 2007 and 59% for the 5-year average.

Many producers already have their corn and grain sorghum forward contracted so the question for many is not how late I can plant corn or sorghum, but what kind of yields can I expect when planting later than normal.

We learned a lot last year on corn planting dates after the Easter freeze. Many acres of corn were replanted after the freeze in Mid-Late April and there were concerns that yields would be hurt from a perceived late planting. As it turns out, corn planted during that time frame ended up being some of the best corn that producers ever had.

Two charts in this week's Arkansas Corn And Grain Sorghum News show average corn yields and planting dates in the University of Arkansas Corn Hybrid Testing trials from 2000-2007 at Marianna in East-Central Arkansas and 2001-2007 at Keiser in Northeast Arkansas.

At Marianna over the 8 year period, average corn yields increased from 175 bu/acre to over 240 bu/acre with planting date having no apparent impact on yields when planted in April. Keep in mind that the number of Bt hybrids over these years was increasing as well.

At Keiser yields increased from an average of 175 bu/acre to near 220 bu/acre. At Keiser, similar to Marianna, average yields increased over the 7 year period with planting date appearing to have little impact on yield. The latest planting date at Keiser was May 8th, which had as high of average yield as any previous year.

Data from the University of Arkansas Corn hybrid testing trials over the last 7 and 8 years demonstrates that corn can be planted in late April in East-Central Arkansas and Early May in Northeast Arkansas without losing yield potential.

What about Planting Corn in May???

Planting corn in Mid-Late May has been successful for several producers in recent years. One particular field that I kept tabs on in Northeast Arkansas was planted in Mid-May. With good agronomic practices, timely irrigation, and a foliar fungicide, a field wide yield of near 200 bu/acre was realized.

In plots that I have had at Marianna the last three years yields on Late May planted corn averaged 166, 153, and 211 bu/acre. The first two years, a tall hybrid was planted and in-season lodging reduced overall yield potential. However in 2007 with different hybrids, and no lodging, excellent yields were realized even with late May planting.

In all instances mentioned for May plantings, Bt hybrids were planted.

Tips for May planted corn

Plant Bt hybrids where applicable. Adhere to the 50% refuge requirement. Corn Borer impacts will be greater in May planted corn compared to earlier planted corn.
Plant full season hybrids. Full season hybrids tend to have greater heat tolerance compared to shorter season hybrids.
Budget for a foliar fungicide. Disease pressure will be greater for late planted corn.
Irrigate properly. Corn will be growing in a warmer/drier climate, making proper irrigation critical.
Select hybrids with strong stalks and short stature plant height. Late planted corn will likely grow taller than early planted corn and having strong stalks will be important.
Be timely with fertilizer and herbicide applications. The plant will be growing quicker with late planting, so the application window will be smaller for inputs.

Grain Sorghum

Soil temperatures, until recently have been too cool for good grain sorghum emergence and early season growth. Grain sorghum would rather be planted in warmer conditions, just like cotton.

According to the calendar and past years we are behind on grain sorghum planting, but in reality, we are just now getting into more ideal soil temperatures for grain sorghum planting.