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

Mid-season corn (Zea mays L.) stalk breakage in south central Nebraska resu lted from 100 mph winds on 8 July 1993 and 80 mph winds on 1 July 1994. Cor n 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 susceptibil ity 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 o bjective i. Twelve hybrids were chosen at each site and yield components fr om 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 brea kage ranged from 7 to 88%, and grain yield was reduced 1.5 bu/acre for ever y 1% increase in stalk breakage, Breakage in 1994 ranged from 1 to 37% at o ne 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, Rem aining plants did not compensate for grain loss from broken plants at any s ite. Percentage yield loss is directly related to percentage stalk breakage . Stalk breakage increased with increasing N rate but was reduced with side dress relative to preplant N application and no-till relative to convention al tillage. Stalk breakage in the site-specific management study correlated (positively) with soil organic matter content. Factors that accelerated pl ant growth early in the growing season increased susceptibility to stalk br eakage. Unfortunately, management practices that result in slow early plant growth also Limit yield potential. Planting tolerant hybrids is the best w ay to avoid losses. More information is needed on why individual plants bre ak and why specific hybrids are more prone than others to mid-season stalk breakage.