scholarly journals Crop density and seed production of tall fescue (Festuca arundinacea Schreber). 1. Yield and plant development

1999 ◽  
Vol 79 (4) ◽  
pp. 535-541 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch

A field study was conducted with tall fescue (Festuca arundinacea Schreber) to determine the effect of the initial population density and spatial arrangement of plants on crop development and seed yield. Individual seedling plants were transplanted at seven densities (1.6, 3.1, 6.3, 12.5, 25, 50, and 100 plants m−2) and three row spacings (20, 40, and 80 cm), and characteristics of seed production were determined for 3 yr (1991–1993). Over the 3 yr, heading commenced at dates differing by 15 d and was delayed, as density increased, by 8, 6, and 2 d, respectively, in the first, second, and third production years. The time of seed maturity differed among years (21 July to 4 August) but was generally unaffected by density or row spacing. In the first production year, seed yield increased with density up to 25 plants m−2 for each row spacing, then remained constant to at least 50 plants m−2 with both 20- or 40-cm rows; it decreased slightly at 100 plants m−2 with 20 cm rows. In the second production year, seed yield was relatively independent of plant density except that it decreased when the initial density was less than 6 plants m−2 with a row spacing of 80 cm, and tended to be greatest with the 40-cm row spacing at 6–25 plants m−2. In the third production year, seed yield was much lower than in the previous 2 yr but the pattern of response to the density and row spacing treatments was similar to that in the second production year. The seed yield of tall fescue can be optimized for at least 3 consecutive years by establishing an initial density of 20–100 plants m−2 in rows spaced 20–60 cm apart. If the maximization of first-year seed yield is a priority, then the initial establishment should be at a density of 25–50 plants m−2 in rows spaced 20–40 cm apart. Key words: Tall fescue, Festuca arundinacea Schreber, population density, plant spacing, seed production

1999 ◽  
Vol 79 (4) ◽  
pp. 543-549 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch

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 (1991–1993) 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. Key words: Tall fescue, Festuca arundinacea Schreber, population density, plant and row spacing, yield components, seed quality


1996 ◽  
Vol 76 (2) ◽  
pp. 291-298 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch

The natural growth habit of creeping red fescue (Festuca rubra L. var. rubra) involves a steady proliferation of tillers, which eventually become too dense to form seedheads. A field study was conducted to evaluate whether seed yield of fescue can be optimized for one, two or three consecutive crops by manipulating the initial population density and arrangement of plants. Individual seedling plants were transplanted at seven densities (1.6, 3.1, 6.3, 12.5, 25, 50 and 100 plants m−2) and three row spacings (20, 40 and 80 cm), and characteristics of seed production were determined for 3 yr (1991–1993). Heading commenced at dates differing by 16 d in the 3 yr and was delayed by up to 7 d as density increased. Seed maturity occurred in a 7-d period in each year (15–22 July). For a single harvest, an initial density of 12–100 plants m−2 on a row spacing of 20 cm or 12–50 plants m−2 on a row spacing of 40 cm is required to optimize yield and produce about 600 kg ha−1 of clean seed. For two consecutive harvests, an initial population density of 6–25 plants m−2 on a row spacing of 20 cm or 6–50 plants m−2 on a row spacing of 40 cm is required to optimize yield and produce a total of about 800 kg ha−1 of clean seed. For producing for either 1 or 2 yr, a density of 12–25 plants m−2 on rows no wider than 40 cm is required to optimize seed yield in each year. The probability of producing a third seed crop decreases markedly as the initial plant density increases and as the row spacing decreases. It is probably uneconomic to harvest more than two consecutive seed crops with current management practices. Key words: Red fescue; Festuca rubra var. rubra, population density, plant spacing, seed production


1996 ◽  
Vol 76 (2) ◽  
pp. 299-306 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch

The natural growth habit of creeping red fescue (Festuca rubra L. var. rubra) involves a steady proliferation of tillers which eventually become too dense to form seedheads. 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) on reproductive components and seed characteristics of red fescue were studied in a northerly environment for three production years (1991–1993) The weight proportion of cleaned to uncleaned seed decreased as density increased, from 82% at 1.6 plants m−2 to 60% at 100 plants m−2. The thousand-seed weight was 1.20–1.54 g (i.e., 830 000–650 000 seeds kg−1) and decreased as density increased. The specific seed weight was 16–25 kg hL−1; it differed among years and decreased as density increased. The germination capacity of the seed was unaffected by density but differed among years, averaging 87, 92 and 69% in the three consecutive production years. The seed yield per plant, the number of seedheads per plant, and the number of seeds per plant decreased exponentially as the density increased. The number of seeds per seedhead decreased as density increased in the first year but was less affected subsequently, except in the third year at 50 and 100 plants m−2 on 20-cm rows, when no seeds were matured. The seed yield was correlated closely with the number of seedheads per square metre, which increased with density in the first year but decreased as density increased in the two subsequent years. A relatively high density of well-spaced plants is required at establishment to optimize seedhead formation in the first crop but is detrimental to seedhead formation and seed yield subsequently. Key words: Red fescue; Festuca rubra var. rubra, population density, plant and row spacing, yield components, seed quality


2007 ◽  
Vol 87 (2) ◽  
pp. 395-403 ◽  
Author(s):  
K. F. Chang ◽  
H. U. Ahmed ◽  
S. F. Hwang ◽  
B. D. Gossen ◽  
R. J. Howard ◽  
...  

Field trials to assess the impact of chickpea type (desi vs. kabuli), row spacing and seeding rate on ascochyta blight of chickpea were conducted over 2 yr at Brooks, Alberta. A compound-leaved desi chickpea cultivar and unifoliate kabuli cultivar were sown at 20, 30 and 40 cm row spacing, and at three seeding rates (20, 40 and 60 seeds per 3 m row). Most of the variation in disease severity was associated with differences between the cultivars. Seeding rate, row spacing and their interactions had substantially smaller effects on ascochyta blight in comparison with cultivar effects. Late in the growing season, blight severity was consistently lower in the desi than the kabuli cultivar. Wide row spacing and low seeding rate reduced ascochyta blight severity and increased seed yield per plant. Wide row spacing in the first year reduced the seed yield per hectare, but row spacing did not significantly affect yield in 2005. Low in-row seeding rates increased yield only in 2004. There was a positive linear relationship between plant density and blight severity, and a negative relationship between yield per plant and both plant density and disease severity. We conclude that reduced plant population density could be one tool in a program to manage ascochyta blight of chickpea. Key words: Cicer arietinum, plant population density, ascochyta blight, yield


Author(s):  
İsmail Özaşık ◽  
Mehmet Demir Kaya ◽  
Engin Gökhan Kulan

Seed viability and vigor have been influenced by several factors including soil and climatic conditions, plant nutrition, fertilization, irrigation, plant population and post-harvest storages. The study was conducted to determine the appropriate plant density for vigorous seed production in safflower. The effects of row spacing (14 and 28 cm) and seeding rate (40, 80, 120, 160 and 200 seeds m-2) on yield, yield components and seed quality of safflower were detected in the study. The results showed that increased seeding rates resulted in enhanced seed yield and the highest seed yield was obtained from 14 cm and 200 seed m-2 with 3320 kg ha-1. The row spacing and seeding rate did not cause a significant difference in oil and protein contents. Laboratory emergence, germination after accelerated ageing (AA) and electrical conductivity tests were suitable for determining seed quality among the seed lots, while standard germination, cool and cold tests were not appropriate. The highest laboratory emergence percentage and germination after AA were determined in 80 seed m-2 but field emergence percentage in 120 seed m-2. It was concluded that the 14 cm row spacing and seeding rate of 120 seed m-2 should be advised for high yielding seed production regardless of seed vigor in safflower.


2003 ◽  
Vol 48 (1) ◽  
pp. 125-134 ◽  
Author(s):  
Savo Vuckovic ◽  
Aleksandar Simic ◽  
Branko Cupina ◽  
Ivana Stojanovic ◽  
R. Stanisavljevic

This paper surveys sowing norms (row spacing and seed rate) in both our country and the world, as well as the optimal seed rates in grass seed production. It gives a short overview of row spacings and seed rates applied in our and some other countries. Earlier, grass cultivated for the purpose of seed production was grown on small vegetation area. According to some researches, high seed yields can be achieved by cultivating grass on large vegetation area. Based on the results obtained, it can be concluded that the highest cocksfoot, timothy, meadow fescue, tall fescue seed yield was achieved with plants grown in 50 cm spaced rows employing lower seed rates (8 and 4 kg/ha of seeds). The highest Italian ryegrass and perennial ryegrass seed yield was achieved with plants grown in 20 cm spaced rows employing 20 kg/ha of seeds.


Author(s):  
B.R. Guy

A series of seed production trials was established at Kimihia Research Centre, Lincoln, Canterbury to investigate row spacing sowing date and sowing rate requirements for Endura, the hexaploid cultivar of caucasian clover. In 1991 a trial with 30 cm or 45 cm row spacings with a sowing rate of 8 kg/ha coated inoculated seed was used. Although there were no significant differences in the first year (101 kg/ha cf. 111 kg/ha), the 45 cm row spacing yielded significantly higher than the 30 cm row spacing, in the second year (709 kg/ha cf. 371 kg/ha). Wider rows produced more flowers per unit area - 448 m-2 for 45 cm compared with 288 for 30 cm. In 1992 a sowing rate trial was established using 2 kg or 6 kg/ha of coated and inoculated seed in 45 cm row spacings. The lower sowing rate treatment of 2 kg/ha produced a significantly higher seed yield, of 208 kg/ha. The effect of sowing date (December, January, February) on seed yields was investigated. All sowing date treatments were sown at 6 kg/ha in 45 cm rows. The highest seed yield of 126 kg/ha was from January sowing. Weed seed content in the field-dressed samples harvested was associated with sowing date and decreased with each progressive sowing. The results indicate a strong negative correlation between plant density and seed yield. With early sowing, weed control is vitally important for successful seed production. Keywords: row spacing, seed yield, sowing date, sowing rate, Trifolium ambiguum


2002 ◽  
Vol 82 (4) ◽  
pp. 687-692 ◽  
Author(s):  
B. D. Gossen ◽  
J. J. Soroka ◽  
H. G. Najda

Little information is available on the management of turfgrass species for seed production in the Canadian prairies. The objective of these studies was to assess the impact of residue management and row spacing on seed yield under irrigation. A factorial experiment was seeded at Saskatoon, SK, in 1993 to assess the impact of burning or scalping (very close mowing with residue removal) vs. mowing, and 20- vs. 40-cm row spacing on seed yield of Kentucky bluegrass (KBG) (Poa pratensis), creeping red fescue (CRF) (Festuca rubra subsp. rubra) and creeping bentgrass (CBG) (Agrostis palustris). Also, a residue management trial on KBG was seeded at Brooks, AB, in 1993. At Saskatoon, yield was higher at 20-cm spacing across all three species in 1994, but spacing had no impact on winter survival, stand density, tiller growth or yield in subsequent years. Burning and scalping consistently resulted in earlier spring green-up, a higher proportion of fertile tillers, and higher seed yield than mowing. Even with residue management, yield declined after one harvest in CBG and CRF, and after two harvests in KBG. At Brooks, residue management had a similar impact on yield of KBG. A second trial at Brooks examined the impact of row spacing (20, 40, 60 cm) and seeding rate (0.5 to 6 kg seed ha-1) on KBG. Seed yield was highest at 40-cm spacings in 1994, at 60 cm in 1995, and at 40 to 60 cm in 1996. Seeding rate did not have a consistent effect on yield. We conclude that a combination of residue management and 20- to 40-cm spacings provide the highest, most consistent seed yields for these turfgrass species in this region. Key words: Burning, clipping, turfgrass, seed production, row spacing, Poa, Festuca, Agrostis


1988 ◽  
Vol 28 (3) ◽  
pp. 367 ◽  
Author(s):  
DF Beech ◽  
GJ Leach

Six accessions of chickpea (Cicer arietinum L.), representing both desi and kabuli types, were grown at a range of row spacings (180-710 mm) in 3 experiments on a vertisol at Dalby, south-eastern Queensland to assess their adaptation and yield potential. Row spacing and sowing density (28-1 12 seeds m-2) were confounded in 2 experiments where intra-row density was constant, but were varied independently in the third. Differences in yield between accessions were either small or not significant in 1979, with above-average water availability (mean seed yield: 253 g m-2), and in 1980, when water was severely limited (mean seed yield: 79 and 120 g m-2 in the 2 experiments). However, the proportion of seed that was machine-harvestable was highest in the commercial cv. Tyson (71%), and also at the closest row spacing (83%). Seed nitrogen concentration was about 0.5% higher in cv. Tyson than in other accessions. It declined with an increase in row spacing and was associated with a higher proportion of small seeds. We conclude that there will be scope for alternatives to cv. Tyson as new market opportunities develop. Furthermore, the flexibility in its growth pattern makes chickpea well suited to the variable moisture regime of the wheatlands of subtropical eastern Australia.


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