ANDROPOGON GAYANUS KUNTH FORAGE PRODUCTION AND NUTRITIVE VALUES UNDER DIFFERENT CUTTING INTERVALS IN SOUTH REGION OF BENIN

Abstract

The grassland resource could be better managed if the effect of different defoliation regimes on the amount of the dry matter and nutritive value was known. Consequently, 9 accessions of Andropogon gayanus Kunth were evaluated in south region of Benin with an average 1100 mm annual rainfall during 3 years for ley pasture without any fertiliser input. Three cutting regimes (3-10-3, 5-6-5 and 6-4-6-week) were tested for dry matter production (DM), crude protein (CP) content, CP production and mineral (Ca, Mg, P, K, Na, Zn, Mn, Cu and Co) contents. Significant differences were observed between accessions (p<0.05), cutting regimes (p<0.05) and years (p<0.05) for DM and CP production. Accession and cutting regime influenced significantly CP content (p<0.05) but year had no influence. Forage harvested from 3-10-3-week regime produced significantly (p<0.05) more DM (4742 kg DMha-1) than 5-6-5-week (3635 kg DMha-1) or 6-4-6-week cutting regime (3789 kg DMha-1). But the reverse effect was observed for CP content as 3-10-3-week regime (5.68 gkg-1 DM) had significantly (p<0.05) lower CP than those of 5-6-5-week (8.55 gkg-1 DM) or 6-4-6-week cutting regimes (7.15 gkg-1 DM). Mineral concentrations varied between accessions but not by cutting regimes and years. Three accessions (n° 1, 4 and 5) consistently outproduced than others and can be harvested through 5-6-5-week cutting regime. P, Na, Zn and Cu deficiencies were the most common detected in the cropped forages