Cool summer effects on Corn

 

042913_2028_HaveILostAn2There has been some talk this past week about early frosts and the cool summer.  I have put together the 5 year historic data for a cross section of the area for rainfall and temperature as well as the information for 2004 and 2009, two cool years.

The year has been cool.  We are at least 150 CHUs below the 5 year average for heat in all three areas.  Rainfall has in general been average.  The benefit to the rainfall we have had is the corn plant is healthy and taking full advantage of all the heat it is getting.  As some corn was planted late, there is a need for more heat to bring it to maturity.  Under normal conditions corn requires about two months to reach black layer from silk emergence and pollination.  With an El Nino developing, this tends to result in below normal summer temperatures in the Great Lakes basin with warmer temperature in the fall and winter.

In general, the cool weather and good moisture has been good for the corn crop conditions. Where moisture is not limited the crop has been able to grow well. Where moisture has been limited, the cooler temperatures have reduced potential stress and allowed much of the corn crop to pass through pollination with limited stress. The current crop has good leaf area and colour.  There is very little firing or stress.  Remember that 2004 and 2009 also were cool summers and while not bumper crops had average yields above the long term trend line.

I have attached a link to a corn growth stage calculator which will give you a maturity date estimate based on variety, location and planting date.
http://www.weathercentral.ca/corn1.cfm

Precipitation and Heat Comparison by Year

       
Location: West Kent/East Essex  
       
Date: May 1 to August 11    
       

Year

Precipitation (mm)

Growing Degree Days (GDD)

Corn Heat Units (CHU)

2014

314

1470

2319

2013

472

1551

2444

2012

292

1732

2598

2011

470

1660

2510

2010

397

1695

2597

5 Year Av

389

1622

2494

2009

285

1459

2326

2004

431

1456

2315

       
Location: Lambton South East    
       
Date: May 1 to August 11    
       

Year

Precipitation (mm)

Growing Degree Days (GDD)

Corn Heat Units (CHU)

2014

216

1206

1915

2013

395

1276

2027

2012

253

1399

2127

2011

558

1351

2105

2010

260

1429

2220

5 Year Av

336

1332

2079

2009

298

1150

1840

2004

 402

1227

1956

       
Location: Huron West    
       
Date: May 1 to August 11    
       

Year

Precipitation (mm)

Growing Degree Days (GDD)

Corn Heat Units (CHU)

2014

294

1141

1851

2013

225

1152

1859

2012

140

1353

2113

2011

283

1266

2010

2010

348

1306

2114

5 Year Av

258

1244

1989

2009

225

1032

1685

2004

317

903

1475