Assessment of Napier grass accessions in lowland and highland tropical environments of East Africa: water stress indices, water use and water use efficiency.

Background: Low rainfall is a major limitation to expanding the dairy industry in semi-arid environments in East Africa. In such dry areas, plants need to keep their tissues hydrated and stomata open for carbon exchange and to grow. On this basis, we assessed the productivity of 10 lines of Napier grass (Pennisetum purpureum Schum.