Crop density and seed production of tall fescue (Festuca arundinacea Schreber). 2. Reproductive components and seed characteristics

Abstract

Fairey, N. A. and Lefkovitch, L. P. 1999. Crop density and seed production of tall fescue (Festuca arundinacea Schreber). 2. Reproductive components and seed characteristics. Can. J. Plant Sci. 79: 543-549. The population density and spatial arrangement of plants may influence the productive life and performance characteristics of a perennial grass-seed crop. A study was conducted to determine the effects of the initial density (1.6, 3.1, 6.3, 12.5, 25, 50 and 100 plants m -2 ) and row spacing (20, 40, and 80 cm) of plants on reproductive yield components and seed characteristics of tall fescue (Festuca arundinacea Schreber), over 3 consecutive production years (1991)(1992)(1993) in the Peace region of Canada. The weight proportion of cleaned-to-uncleaned seed was 85-86% for the three lowest plant densities and then decreased, as density increased, to 82% at 12.5 plants m -2 and 66% at 100 plants m -2 . The 1000-seed weight decreased as density increased and ranged from 1.68 to 2.22 g (i.e., 595 000 to 450 000 seeds kg -1 ). The specific seed weight ranged from 18 to 31 kg hL -1 ; it differed among years, but the effect of plant density was inconsistent. The germination capacity of the seed was unaffected by plant density, but differed among years; it averaged 87%, 88% and 59% in 1991, 1992 and 1993, respectively. The seed yield/plant, the number of panicles/plant, and the number of seeds/plant decreased exponentially as plant density increased. The number of clean seeds/panicle decreased, as plant density increased, in the first year but was less affected subsequently, particularly with the 20-cm row spacing. The seed yield was correlated closely with the number of panicles m -2 (r = 0.659***). An initial density no greater than 25 plants m -2 in rows spaced 20-40 cm apart enhanced seed quality by producing a greater proportion of clean seed which had a higher 1000-seed weight. Such a plant density, however, is at the low end of the optimum range for maximizing seed yield per unit land area. , sur les composantes du rendement grainier et sur les caractères des graines de la fétuque élevée (Festuca arundinacea Schreber), dans trois années de production consécutives : 1991 à 1993, dans la région de la Rivière-de-la-Paix au Canada. La proportion en poids graines propres/graines tout-venant était de 85 à 86 % aux trois densités de peuplement inférieures, mais en fonction de l'accroissement de la densité elle descendait à 82 % à celle de 12,5 plantes m 2 et à 66 % à celle de 100 plantes au m 2 . Le poids de 1000 graines diminuait à mesure qu'augmentait la densité, présentant un écart de 1,68 à 2,22 g (c.-à-d. 595 000 à 450 000 graines kg -1 ). Le poids à l'hectolitre des graines fluctuait de 18 à 31 kg et, bien que différent d'une année à l'autre, il ne manifestait aucun effet régulier de la densité de peuplement. Le pouvoir germinatif des graines était le même quelle que soit la densité de peuplement, mais il différait selon l'année, s'établissant, dans l'ordre, à 87, 88 et 59 % en moyenne en 1991, 1992 et 1993. ...

Reproductive tillers in cut tall fescue swards: differences according to sward age and fertilizer nitrogen application, and relationships with the local dynamics of the sward

“…Except in the case of spaced rows, such as grass grown for seed production (Young et al. , 1998; Fairey and Lefkovitch, 1999), there is little information on the density, proportion and dynamics of fertile tillers (Watson and Watson, 1982; Hume and Brock, 1997). Even less is known about the fine‐scale spatial distribution of tillers (Herben et al.…”

Smooth bromegrass seed yield and yield component responses to seeding rates and row spacings in two climates

“…and perennial ryegrass (Lolium perenne L.), SYs were highest with sowing rates of 20 kg ha −1 (.4 g m −1 of row length). The effect of row spacing on tall fescue seed production has been investigated in the US and Canada (Fairey & Lefkovitch, 1999a, 1999bYoung et al, 1998aYoung et al, , 1998b. Row spacing studies also have been conducted in separate climates on red fescue (Festuca rubra L. var.…”

Seeding Rate, Row Spacing, and Nitrogen Rate Effects on Perennial Ryegrass Seed Production

“…A study evaluating SR and RSW effects on annual ryegrass indicated that SR can have significant positive effects on yield during growing seasons with unfavorable weather conditions that result in less biomass growth (Simic et al, 2009). When determining SRs that provide optimal plant density (or vegetative cover), it is important to consider loss of seedlings during establishment (Fairey and Lef kovitch, 1999b) so the effect of SR on EVC at the 20-and 30-cm RSW should be evaluated following more harsh winters. The overall greater EVC and greater response to SR at the 10-cm RSW suggests that the 10-cm RSW is optimal for promoting greater EVC in the environments tested here, which may be due to less within-row plant competition (Deleuran et al, 2009;Deleuran et al, 2010).…”