Varietal Response of Napier Grass (Pennisetum purpureum Schumach.) to Spacing and Nitrogen Levels under Dryland Conditions of Southern India

Feeding livestock with high-quality fodder containing minimal anti-nutritional factors such as oxalates, phytates, and tannins is essential for sustaining animal health, feed efficiency, and productivity. Soluble oxalates in particular reduce feed intake, cause oral damage, and hinder forage digestibility by limiting rumen microbial activity. Since fodder quality is strongly influenced by plant variety, spacing, nitrogen fertilization, and seasonal variation, this study was undertaken to compare two Napier grass varieties - Pusa Giant and IGFR-10 under three spacing levels and three nitrogen doses in order to identify the most suitable combination for dryland smallholder farmers of southern India. Results indicated that Pusa Giant consistently outperformed IGFR-10 in terms of growth, yield, and reduced anti-nutritional factors. A spacing of 60 × 60 cm recorded significantly higher performance compared with closer or wider spacings, while nitrogen application at 200 kg ha-1 gave the highest yields, followed by 175 and 150 kg ha-1. The interaction effect revealed that the combination of Pusa Giant with 60 × 60 cm spacing and 200 kg N ha-1 produced the maximum green fodder yield (233.93 t ha-1) with comparatively lower levels of anti-nutritional compounds. The study concludes that Pusa Giant Napier grass grown at an optimum spacing of 60 × 60 cm with 200 kg ha-1 nitrogen is the most productive and nutritionally suitable practice for smallholder farmers in dryland regions. Its adoption ensures enhanced year-round fodder availability, improved digestibility, better livestock health and productivity, and higher economic returns, thereby offering a practical and sustainable strategy for fodder production in southern India.