S. TUDSRI, S.T. JORGENSEN, P. RIDDACH and A. POOKPAKDI

Department of Agronomy, Faculty of Agriculture, Kasetsart University, Bangkok, Thailand

Abstract

A field study was conducted under rainfed conditions to determine the effect of different cutting heights (0, 10, 20 and 30 cm) and dry season closing dates (November and January) on dry matter production and fodder quality of 5 different cultivars of napier grass (Pennisetum purpureum). The experiment was carried out at Suwanvajokkasikit Research Station, Pakchong, Nakornratchasima, Thailand between 1994–1996.
Dry matter yield of the 5 napier grass cultivars increased with higher stubble remaining, differences reaching significance in the second year. Delaying the closing date produced a negative effect on regrowth for the following season, especially when a low cutting height had been imposed. Nitrogen, phosphorus and potassium levels in leaf and stem were not affected by cutting height. NDF% was lower in herbage from 0 cm cutting height compared with 30 cm cutting. Cutting heights of 20 cm and 30 cm can be recommended through the growing season.