Factors affecting the growth of Pennisetum purpureum in the wet tropics. II. Uninterrupted growth

Abstract

Six plantings of elephant grass (Pennisetum purpureum) were made at 2-monthly intervals in the wet tropics of Queensland and grown for 6 months, ratooned and grown for a further 6 months. Yields of crop fractions were taken at monthly intervals. Dry matter yield attributes were all positively and significantly correlated with each other, and negatively correlated with nitrogen and phosphorus percentages. Stem height was strongly associated with total and stem dry matter yields. Time trends in dry matter yields could be well described by logistic growth curves. It was found that dry matter yields were linearly and significantly related to crop age, degree days, radiation receipt, energy-degree days, cumulative evapotranspiration and moisture stress-free days. The crop was well adapted to the environment and could be grown and harvested year-round for agro-industrial purposes.