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East-Central and Southeast Iowa Crop Information

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May 30, 2013

 

FLOODS OF 2013

 

Although most growers in the area have finished with corn planting, some now may be faced with decisions on re-planting due to the extensive rains and flooding. One question is how long can corn and soybeans be submerged and survive? By the time fields are dry enough to get into, it will be obvious whether or not the crop survived. As long as air temperatures are in the 70s or cooler, emerged corn and soybeans can survive being submerged up to 4 days, and sometimes longer. With air temperatures in the 80s, one day is about it. For more information on corn getting flooded see http://www.agronext.iastate.edu/corn/production/management/early/survival.html.

 

You can use the following table to help to make decisions on re-planting corn:

 

 

Planting Date

Population
(Plants/Acre)

April 20-May 5

May 5-May 15

May 15-May 25

May 25-June 5

June 5-June 15

Percent Maximum Yield

45,000

97

93

85

68

52

40,000

99

95

86

69

53

35,000

100

96

87

70

54

30,000

99

95

86

69

53

25,000

95

91

83

67

51

20,000

89

85

77

63

48

15,000

81

78

71

57

44

10,000

71

68

62

50

38

 

Numerous gaps of up to 4-6 feet can reduce yields by an additional 5-6%. This table comes from Roger Elmore’s article at http://www.agronext.iastate.edu/corn/production/management/planting/replanting.html.

 

 

When to Switch to a Shorter Season Hybrid?

 

Work done by several seed companies and universities, including Iowa State University, has shown that full season adapted hybrids will out yield shorter season hybrids even when planting is delayed. Roger Elmore had studies in 2010-2011 that showed that full season hybrids yielded more than shorter season hybrids even when planted in late June at Crawfordsville http://www.ag.iastate.edu/farms/11reports/Southeast/RegionalCornReplantSE.pdf. Does this mean we should stick to full season hybrids even with a late June planting? That would have been the right decision at Crawfordsville in those 2 years, but may not be the right decision this year, depending on what the rest of the season brings and on when the first freeze hits. Planting corn in late June is risky to begin with and sticking to full season hybrids increases the risk that it won’t make it to maturity if we do have an early frost. The research does show that we don’t want to switch to shorter season hybrids too soon and don’t want to get carried away and switch to very short season hybrids, but as planting and re-planting gets delayed further into June, I would back off to something shorter than full season corn to reduce the risk of having very wet, poor quality corn in the fall.

 

Switch from Corn to Beans?

 

One potential problem with switching from corn to soybeans is that the labels of most corn herbicides will not allow soybeans to be planted in the field until the following year. This includes any herbicide containing atrazine, regardless of the rate. Although sometimes you can get lucky and have soybeans survive when planted into fields that have received low rates of corn herbicides, this would be off label and be risking loosing another crop with no chance to re-plant it. If corn herbicides have been applied and planting is delayed or re-planting is needed, its best to stick with corn. The following table showing re-plant intervals for various corn herbicides comes from Mike Owen’s article in the ICM News at http://www.extension.iastate.edu/CropNews/2008/0531MikeOwen2.htm.

 

Rotational interval to plant soybeans for some herbicides used in corn

 

 

 

 

PREVENTED PLANTING

 

Crop Insurance and Prevented Planting

Article by Kristen Schulte, Farm & Ag Business Management Specialist, kschulte@iastate.edu

 

Heavy rainfall, floods and cool temperatures across the Midwest have slowed planting this spring. The final planting date for corn in Iowa is May 31. The final planting date for soybeans in Iowa is June 15. Final planting dates and other crop insurance information can be found at www.rma.usda.gov/aboutrma/fields/mn_rso/.

 

Prevented planting is a failure to plant an insured crop with the proper equipment by the final planting date designated in the insurance policy’s actuarial documents or during the late planting period, if applicable, due to an insured cause of loss that is general to the surrounding area and that prevents other producers from planting acreage with similar characteristics.  More information can be found on the Prevented Planting fact sheet at www.rma.usda.gov/fields/mn_rso/2013/2013preventedplanting.pdf.

 

Here are some basic guidelines if you are unable to plant because of an insurable cause of loss by the final planting date. You may;

 

The most important thing you can do if you are unable to plant the crop by the final planting date is contact your crop insurance agent to review your policy and options before you make a decision. You are required to provide notice that you were prevented from planting an insured crop within 72 hours after the final planting date.

 

For more information, see the ICM News article by Steve Johnson and William Edwards at http://www.extension.iastate.edu/CropNews/2013/0528sdjohnson.htm.

 

FOR YOUR CALENDAR

 

June 6, 2013

9:00 a.m to 3:30 p.m.

Cover Crops Field Day – Coe College - Cedar Rapids

 

Free program, lunch and transportation to field demonstrations are on your own.  Topics include designing cover crop mixes, cover crop management systems, soil function demonstrations, and field demonstrations.  Learn how diverse cover crop mixes can boost your soil health from Ohio Farmer Dave Brandt and NRCS Agronomist Ray Archuleta.  For more information, contact Rick Bednarek, 515-284-4135.

 

June 26, 2013, 1:00 p.m.

ISU NE Research & Demonstration Farm Spring Field Day – Nashua

 

As details become available, they will be posted at http://www.extension.iastate.edu/Pages/eccrops/meetnerf.html.

 

June 27, 2013

SE Iowa Research Farm – Crawfordsville

 Spring Field Day

1:00 p.m.-3:00 p.m.

 

Topics include:

 

Special Session for CCAs – 9:00 a.m. -noon

 

Certified Crop Advisors can receive 5 hours of credit, including 3 hours of soil and water management, by attending a Special Session for CCAs from 9:00 a.m. to noon followed by the spring field day tour.

 

Topics in the morning include:

 

Pre-Registration is required for the CCA session ($50 fee, including lunch). To pre-register by June 25, please send me an e-mail note (fawcett@iastate.edu) or call the Johnson County extension office (319-337-2145). The $50 fee can be paid at the door (cash or check).

 

Other details will be posted at http://www.extension.iastate.edu/Pages/eccrops/meetserc.html.

 

 

If you have any questions, please feel free to contact the Iowa State University Extension Office.

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Last Update: May 30, 2013
Contact: Jim Fawcett fawcett@iastate.edu


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