Anti-nutrient components of guinea grass (<i>Panicum maximum</i>) under different nitrogen fertilizer application rates and cutting management

Abstract

This research was carried out in 2004 in the Department of Crop Science, University of Nigeria, Nsukka. The study investigated the anti-quality factors in Panicum maximum under different N-fertilizer application rates and cutting management. The experiment was a 4 × 4 factorial laid out in a randomized complete block design with three replications. The treatments comprised four levels of nitrogen of 0, 150, 300 and 450 kg N ha^-1 and four harvesting frequencies of 3-6-9 and 12 weekly intervals, resulting in 16 treatment combinations per block. The grass analyzed in this study had low levels of anti-nutrient constituents such as tannin, phytate, hydrogen cyanide, saponin and alkaloid. The alkaloid, hydrogen cyanide and tannin contents were depressed significantly (P < 0.05) with infrequent cutting interval. Nitrogen fertilizer application significantly (P < 0.05) increased the alkaloid, hydrogen cyanide and phytate content when compared with the control. The 9-weeks cutting interval gave significantly (P < 0.05) lowest alkaloid and phytate contents when 150 kg N ha^-1 was applied. The hydrogen cyanide and tannin contents were lower at the cutting interval of 12 weeks when 300 kg N ha^-1 was applied. Application of 300 kg N ha^-1 produced the lowest saponin content when cutting was done every 6 weeks.

Key words: Panicum maximum, cutting frequency, N-fertilizer, anti-nutrient factors, alkaloid, saponin, tannins, hydrogen cyanide and phytate.