Early growth of Makarikari and Rhodes grasses in different nitrogen and water regimes

Abstract

(a) Rhodes grass cv. Pioneer and (b) Makarikari grass cv. Pollock or Bambatsi were grown with 0 or 450 kg N/ha applied as urea before planting, under 3 irrigation regimes. After 24 wk the plants were harvested and DM production (DMP) determined. Total DMP was greater in (a) than (b) for all treatments; N increased DMP of (a) more than (b) in all water regimes, while increased water stress decreased DMP of all grasses. There was no difference in leaf DMP between grasses in any water regime at low N; with high N levels DMP of (a) was >(b). Stem DMP of (a) was >(b) in all water and N regimes and was the main componant contributing to the total DMP differences. Crown DMP was greater in (b) than (a). Root DMP of (a) was >(b). There was no difference in tiller number with low N; with high N (b) was >(a) in all water regimes. Water use of (a) was >(b) in all treatments and was increased by N in (a) but not in (b).