Clipping Corn following Early-Season Frost
1990
Carter, P. R.
Regrowing corn (Zea mays L.) plants often develop tied, twisted, or bowed whorls due to growth obstruction by dead leaf tissue, following early season frost damage that kills aboveground foliage but not the growing point. Field studies were conducted in Wisconsin in 1988 after a natural frost to evaluate the effect of postfrost clipping, within 4 d to remove dead tissue, or after 8 to 12 d to unravel tied whorls, on subsequent growth and grain yield. Clipping studies were conducted in Columbia County following a 25 May frost when corn was at the V3 stage, and at two sites in Trempealeau County following a 9 June frost when corn was at V6 (Site 1) and VS (Site 2) stages. At the Columbia County site, clipping at 4 in. or manually unraveling tied whorls 8 d postfrost did not alter plant survival or grain yield compared to untreated plants. Plant survival and grain yield were also unaffected at Trempealeau County Site 1 by clipping 4 d postfrost at either 4 or 5 in., or 12 d postfrost at 10 in., compared to not clipping. At Trempealeau County Site 2, clipping 4 d postfrost at 4 in. increased grain yield 409/0 compared to not clipping (99 vs. 69 bu/acre), while clipping 4 d postfrost at 2 in., increased plant mortality and decreased yield 30% (48 vs. 69 bu/acre). At this site, clipping at 8 in., 12 d postfrost resulted in levels of plant survival and grain yield similar to those where plants were not clipped. These results indicate that the risk of further damage due to clipping following early season frost is minimal, provided that clipping height is > 1 in. above the growing point. Clipping may increase grain yield in some cases. More studies of corn response to postfrost clipping under diverse conditions are needed.
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