Seed and herbage production of Westerwolds ryegrass as influenced by applied nitrogen

Abstract

Seed production, plant characteristics and herbage regrowth of three cultivars of Westerwolds ryegrass (Lolium multiflorum Lam.) were determined during 3 production years. Ryegrass was fertilized with nitrogen at 60, 90 and 120 kg ha-1 applied either all at the two- to three-leaf stage or split (3:2) between the two- to three-leaf stage and stem elongation. Seed yield of three cultivars ranged from 742 to 1440 kg ha-1. Nitrogen fertilizer at 90 kg ha-1 resulted in near maximum seed yields. Single and split applications of nitrogen resulted in similar seed yields. Density of fertile tillers ranged from 541 to 911 m-2 among the cultivars and responded linearly to applied N. A positive relationship was detected between the density of fertile tillers and seed yield. Herbage in aftermath averaged 2280 kg ha-1 dry matter, 125 g kg-1 crude protein, 597 g kg-1 neutral detergent fibre and 344 g kg-1 acid detergent fibre. Key words: Lolium multiflorum, Westerwolds ryegrass, nitrogen fertilizer, seed, tiller, spikelet, herbage, herbage composition