GOSHEN, Ind. — I learned a couple of new words this week. Imbibe means to take up water. “Imbibitional chilling” refers to cold injury that a seed may get when it takes in water in cold soils.
Our soils have certainly stayed cool this spring, along with temperatures above the ground. Last week, we finally had some soils dry out enough for planting to begin in earnest. However, soil temperatures and air temperatures remained cool. Friday night and Saturday morning, temperatures dipped well below 25 degrees F around Elkhart County.
Seeds that were planted within 24 to 48 hours prior to the hard freeze Friday night are at risk of imbibitional chilling. Purdue University corn agronomist Bob Nielsen wrote a recent article describing this physiological phenomenon regarding corn seed. Purdue soybean agronomist Shaun Casteel has commented that soybean seed runs the same risk. The “first drink” of water that the seed uptakes should be above 50 °F. Cold water taken up during this critical window can cause cell membrane damage and impact seedling growth and even survival.
Both Nielsen and Casteel suggest that growers keep a close eye on fields that were planted late last week to see if there were germination issues caused by chilling.
There is some debate about what specific temperature and timing causes imbibitional chilling. However, corn seeds that imbibe cold water (in the low 40s) in the first 48 hours after planting undoubtedly are affected.
By the way, this phenomenon is not limited to corn and soybeans. Garden seed planted late last week could also be affected. I saw quite a few people planting gardens during the warm weather that led up to the freeze. Consider checking on those seeds if you have not already.
— Jeff Burbrink, Extension Educator, Purdue Extension Elkhart County
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