Late Spring Frost and Postfrost Clipping Effect on Corn Growth and Yield

Abstract

Lack of knowledge regarding early-season frost-damage effects on corn (Zea mays L.) restricts the ability of producers to make decisions regarding replanting and yield expectations. Our first objective was to monitor corn growth and yield within fields with a range of late-spring frost injury. The second objective was to evaluate post-frost clipping effects on plant growth and yield. Several days after a severe 21 June 1992 frost, plots were established at several Wisconsin sites in which within-field frost-damage to corn with 9 to 12 emerged leaves ranged from major (65 to 100 % of leaves damaged) to minor (less than 5 % of leaves damaged). Damage within fields varied primarily due to slight topography differences, with greatest damage in low-lying areas. Although nearly all plants recovered from the injury, plants with greatest damge were delayed in silking (7 to 10 d later), had reduced final plant (16 to 25 in. shorter) and ear (12 to 20 in. shorter) height and lower grain yield (42 to 59 % lower) compared with plants with least damage. Postfrost clipping reduced grain yield by 15 to 34 % at three sites, resulted in no differences at two sites, and increased yield about 10 % at one site. Based on these results and previous studies, there is little consistent benefit to clipping frost-damaged corn