Cultivar-specific management for seed production of creeping red fescue

Abstract

A study was conducted in the Peace River region of north-western Canada with three cultivars (Boreal, Jasper, Jasper E) of creeping red fescue (Festuca rubra L. var. rubra) to identify cultivar-specific management practices for seed production. Experimental treatments included four methods of establishment [Broadcast; 30-cm rows; 15-cm rows; 15-cm rows with sulfur (56 kg ha-1 SulFer 0-0-0-95)], 10 nitrogen (N as 34-0-0) fertilizer treatments, and three methods of post-harvest management prior to winter (flail mowing and residue removal; disc mowing and residue removal; short-duration, intensive grazing with sheep) plus crop residue removal at seed harvest. Total seed yield over 2 consecutive production years was greatest with 30-cm rows although a higher first-year yield was realized with 15-cm rows. In the first production year, establishment in rows produced higher seed yield than broadcasting but, in the second, the converse was true. Within-row supplementation with sulfur decreased the total seed yield over 2 yr by 7%. In the first, second and combined production years, Boreal produced 655, 372 and 1027 kg ha-1, respectively; for the corresponding production years, Jasper produced 56, 65 and 60% of Boreal, while Jasper E produced 58, 76 and 65% of Boreal. The endophyte (Neotyphodium spp. Glenn, Bacon, Price & Hanlin and Epichloe festucae Leuchtm., Schardl, & Siegel) infection of Jasper E had no consistent beneficial or detrimental effects on seed yield. For the year subsequent to the application of the post-harvest treatments, the effects of flail and disc mowing were similar (360 versus 347 kg ha-1 seed, respectively), whereas grazing reduced seed yield to 188 kg ha-1. Splitting the application of N in fall and spring resulted in similar seed yields to fall-only N. The response to N fertilizer differed for consecutive years of production; in the first production year, seed yield increased linearly over the range 38–114 kg ha-1 N, whereas in the second production year, rates in excess of 76 kg ha-1 N markedly suppressed seed yield. A fall application of 55–80 kg ha-1 N in the establishment year, and again after the seed harvest of the first production year, was sufficient to maximize the total seed yield over 2 consecutive production years. Cultivar-specific responses in seed yield to treatment interactions were too small for agronomic exploitation. Key words: Creeping red fescue, Festuca rubra, grass seed production, cultivar-specific management, establishment method, nitrogen fertility, post-harvest management