The weekend's cold weather could delay corn planting

For much of northeast Iowa, Saturday night is forecast for low air temperatures in the upper 20s.   ISU Extension agronomist Brian Lang in Decorah says cool soil temperatures this weekend raise concerns with two aspects of corn germination and emergence.

Lang says the initial 24 to 36 hours after corn is planted are the most crucial hours.  He says corn might be affected by soil temperatures dropping into the low 40's and may experience "imbibitional chilling," which occurs when the corn seeds absorb cold water.  That might disrupt normal germination.  Factors of how cold for how long relative to hybrid tolerance all play a role, says Lang.

Corn planted several days prior to exposure to soil temperatures in the 40's also might experience "cork-screwing" of the seedlings as they attempt to emerge. Says Lang, "Again, how cold for how long relative to hybrid tolerance all play a role."  He urges farmers who do plant to be sure to scout corn upon initial emergence.

Germinating soybeans are not threatened by imbibitional chilling.

Lang says an excellent article about this issue can be found at: https://www.agry.purdue.edu/ext/corn/news/articles.14/EarlyCold.html