Accumulated GDDs Oct. 1-23, 2014

Accumulated GDDs Oct. 1-23, 2014

Q: How have early October rains and cooler temperatures affected corn drydown? Is it slower than normal?

 

View season long GDDs for 20 sites at gdd-etdata

Oct. 14, 2015

Drydown slows after leaves die due to natural senescence, disease, or frost/freeze. This stops plant respiration, leaving only evaporation to remove moisture from the corn, said Tom Hoegemeyer, UNL professor of practice in agronomy and Nebraska corn breeder. In addition, saturated soils tend to increase "local" relative humidity in the field, especially with still days.  Corn can even re-absorb water from rainfall if water gets into husks, although ears on most hybrids turn down at maturity and are less apt to capture rain.

It takes an average 25 GDD to dry down corn 1 percentage point. That number can range from 15 to 35 GDD, depending on cloud cover, relative humidity, and wind. Compared to states east of us, Nebraska's lower humidity and high winds are significant advantages when it comes to drydown, Hoegemeyer said, and sunshine, even on cold days, will tend to continue drying corn.

The following data reflects accumulated GDD from Oct. 1 through Oct. 13, 2014. While GDD accumulation for the period is behind normal for most sites, a few sites in southwest and western Nebraska are ahead of normal. With the onset of warmer, drier conditions this weekend State Climatologist Al Dutcher  expects to see the difference between current and normal GDDs reduced by 5-10 units in western Nebraska and about 5 units in eastern Nebraska.

"If forecasts are correct, we should accumulate 50-60 additional units across eastern Nebraska through Monday and 60-70 units in western Nebraska," Dutcher said.

 

Growing Degree Day Summary

  Crop Ref Accumulated GDDs
  (10/1-10/13) (10/1-10/23)
    Actual 2014 Normal Actual 2014 Normal
AINSWORTH Corn 107 113 223 175
ALLIANCE Corn 106 110 217 171
ARTHUR Corn 105 115 220 179
BARTA Corn 97 113 201 177
BEATRICE Corn 112 129 226 204
BRULE Corn 119 117 248 184
BRUNSWICK Corn 89 111 185 170
CEDAR POINT Corn 109 118 231 184
CENTRAL CITY Corn 120 118 232 185
CHAMPION Corn 124 124 253 170
CLAY CENTER Corn 113 122 221 192
CONCORD Corn 88 113 187 174
COZAD Corn 124 122 241 192
CURTIS Corn 117 124 233 195
DICKENS Corn 113 120 233 189
ELGIN Corn 102 113 203 175
FIRTH Corn 117 129 243 204
GORDON Corn 90 112 198 173
GOTHENBURG Corn 116 122 229 193
GRAND ISLAND Corn 109 119 212 187
GUDMUNDSEN Corn 91 115 195 180
HALSEY Corn 104 115 214 179
HIGGINS RANCH Corn 104 111 216 172
HOLDREGE Corn 116 123 222 195
INDIAN CAVE Corn 105 129 224 205
KEARNEY Corn 110 121 214 191
LEXINGTON Corn 111 123 220 195
LINCOLN Corn 104 129 219 204
MCCOOK Corn 127 124 254 195
MEAD Corn 102 125 213 197
MERNA Corn 118 118 233 184
MERRITT Corn 105 114 223 178
MINDEN Corn 112 122 217 193
MITCHELL FARM Corn 109 114 222 179
MONROE Corn 108 119 218 186
NEBRASKA CITY Corn 102 128 215 203
NEWPORT Corn 103 111 212 172
NORTH PLATTE Corn 119 120 240 189
OAKLAND Corn 102 116 215 181
O'NEILL Corn 91 114 189 177
ORD Corn 109 117 218 182
RED CLOUD Corn 117 123 231 195
SCOTTSBLUFF Corn 118 111 237 173
SHELTON Corn 111 122 215 192
SIDNEY Corn 101 114 208 178
SMITHFIELD Corn 113 123 223 194
WEST POINT Corn 93 122 195 192
YORK Corn 113 124 225 196