Frosted Corn Regrowth
June 2, 1994 1(11):88-89
Joseph G. Lauer, Corn Agronomist
Frost occurred in many places in Wisconsin on May 27. Yield losses due to direct
effects of this frost alone are likely to be very small. There may be some confounding
injury effects with some herbicides. In these cases it is very difficult to predict
the outcome. We can say that growers should wait several days before doing any spraying
or even consider replanting.
When frost kills corn leaf tissue, corn producers worry about whether or not corn
plants will recover. The key to assessing corn plant viability is to observe the
growing point. The growing point is where all new tissue originates, and is below-ground
until the plant reaches the V5-V6 stage. Removal or death of above-ground leaf tissue
at early growth stages has little effect on corn yield. At least 4 days with temperatures
in the 70's should occur before assessing the effects of frost-damage on corn.
If the growing point appears healthy, with a white to yellow color several days
after a frost, plant recovery is likely.
Most of the frosted areas of corn fields should be beginning to green up by now.
Many regrowing plants may become twisted or "tied". Growers are sometimes
concerned about plants not developing normally unless "straightened out."
Carter (1990) observed the effects of several management options after a severe
frost in 1988. Corn plants frozen on May 25 and June 9 were observed to be temporarily
twisted and tied for a few days during regrowth before the entire whorl pulled loose.
Rotary hoeing or dragging to try to scrape away dead tissue had little positive
or negative effect. Only at later stages was clipping or mowing sometimes beneficial
provided that clipping height was greater than one inch above the growing point.
Plants in every frosted corn field are slightly different, so growers need to experiment
with methods appropriate to their situation in attempting to alleviate the tied