Mid-season stalk breakage in corn: Hybrid and environmental factors

Mid-season corn (Zea mays L.) stalk breakage in south central Nebraska resulted from 100 mph winds on 8 July 1993 and 80 mph winds on 1 July 1994. Corn growth stages at the time of damage ranged from V10 to V14. Observations of field studies were taken to determine: (i) the impact of stalk breakage on grain yields of different hybrids; (ii) yield compensation by remaining plants; and (iii) the influence of soil and cultural factors on susceptibility to wind damage, We recorded stalk breakage on over 100 corn hybrids in evaluation trials at one site in 1993 and at two sites in 1994 to address objective i. Twelve hybrids were chosen at each site and yield components from broken and standing plants were recorded separately to determine whether remaining standing plants compensated for broken plants (objective ii). We also evaluated stalk breakage on a N management study and a site-specific management/variable rate study to address objective iii. In 1993 stalk breakage ranged from 7 to 88%, and grain yield was reduced 1.5 bu/acre for every 1% increase in stalk breakage, Breakage in 1994 ranged from 1 to 37% at one site and from 5 to 51% at the other site. Grain yield was reduced by 1.5 and 1.8 bu/acre for every 1% increase in stalk breakage, respectively, Remaining plants did not compensate for grain loss from broken plants at any site. Percentage yield loss is directly related to percentage stalk breakage. Stalk breakage increased with increasing N rate but was reduced with sidedress relative to preplant N application and no-till relative to conventional tillage. Stalk breakage in the site-specific management study correlated (positively) with soil organic matter content. Factors that accelerated plant growth early in the growing season increased susceptibility to stalk breakage. Unfortunately, management practices that result in slow early plant growth also Limit yield potential. Planting tolerant hybrids is the best way to avoid losses. More information is needed on why individual plants break and why specific hybrids are more prone than others to mid-season stalk breakage.