Biomass yield, chemical composition and in vitro digestibility of maize leaves defoliated at different times

Abstract

This experiment was conducted to determine the effect of defoliation time on the productivity of maize, forage and in vitro digestibility of maize leaves (ML). The response of grain yield, plant height, days to 50% silking, ear height and leaf yield as well as the chemical composition of ML variety "Obasuper" to defoliation time were evaluated in a randomized complete block design with four defoliation treatments 3, 6, 9 weeks after planting (WAP) and undefoliated treatment replicated four times. Results showed that defoliating maize at 9 WAP and beyond did not have any significant (P>0.05) effect on the grain and leaf yield as well as other yield components of maize. Grain and leaf yield at 9 WAP averaged 2778.35 and 975.74 DM kg/ha respectively. The DM, crude protein (CP) and fibre fractions contents of ML varied significantly (P<0.05) among the defoliation treatments with maize defoliated at 9 WAP having a CP content of 12.6%. Ether extract and ash contents were not affected (P>0.05) by defoliation time. The in vitro digestibility of ML decreased significantly (P<0.05) with increase in the time of defoliation ranging from 59.2 and 66.4%. IT was concluded that maize variety "Obasuper" can produce forage of high quality and quantity when defoliated 9 weeks after planting wihout any anyadverse effect on the grain yield of maize.