Evaluation of <i>Asystasia gangetica</i> as a potential forage in terms of growth, yield and nutrient concentration at different harvest ages

Abstract

The objective of this experiment was to analyze growth dynamics, yield and nutrient concentration of Asystasia gangetica (L.) T. Anderson at different harvest ages. A pot experiment was conducted at Green House Laboratory of Agrostology, Faculty of Animal Science, Bogor Agricultural University, Indonesia, during the growing season of 2018. Seedlings were transplanted into 115 polybags arranged in a completely randomized design with 23 replications. Plant height, number of leaves, number of branches, dry matter (DM) yields and nutrient concentrations at 30, 40, 50, 70 and 90 days after transplanting (DAT) were determined. Whereas plant height, number of leaves, number of branches and DM yields increased with age, nutrient concentrations followed different patterns. Crude protein % in leaf peaked at 24.2% at 40 DAT then decreased progressively to 8.4% at 90 DAT, while corresponding figures for stem were 10.6 and 2.8%, respectively. Crude fiber concentrations in leaf increased from 10.6% at 30 days to 17.3% at 90 days; corresponding figures for stem were 23.2 and 39.2%. From this pot study, cutting between 40 and 50 days after planting seemed to represent a suitable compromise between DM yield and protein percentage. Studies are needed to determine the repeatability of these results under field conditions and the regrowth potential of plants following harvesting.