Influence of variety and cutting height on yield and nutritive value of corn for silage

Abstract

In order to determine the yield and quality of 2 maize cultivars, evaluated at the same age and harvested at 2 different cutting heights, an experiment was conducted at the “Alfredo Volio Mata” Experiment Station of the University of Costa Rica. A native and a hybrid cultivar were used, both harvested at 107 days of age. An unrestricted random design was used, with treatments in a 2x2 factorial arrangement; the first factor, 2 cultivars and the second, 2 cutting heights (15 and 45 cm above ground level). With native corn harvested at 15 cm of height, 131.9 ton of green fodder and 15.2 ton.ha^-1 of dry biomass were obtained, while when harvested at 45 cm of height yields were 88.1 and 10.4 ton.ha^-1, respectively. With respect to hybrid corn harvested at 15 cm of height, 82.6 ton of green fodder and 11.0 ton.ha^-1 of dry biomass were obtained, while when harvested at 45 cm of height yields were 76.2 and 10.4 ton.ha^-1, respectively. Leaf: stem ratio in both green and dry biomass, regardless of cutting height, was always greater for the hybrid cultivar. No significant differences were found in dry matter concentration for the whole plant, which ranged from 11.64 to 13.68% considering both cultivars and both cutting heights. CP and NDF concentration did not differ, whether considering leaves or stems of cultivars at different cutting heights, nor when considering the whole plant. These results suggest that increasing the cutting height, from 15 to 45 cm above ground, does not significantly improve nutritional quality of maize forage for silage.