Crop density and seed production of creeping red fescue (Festuca rubra L. var. rubra). 2. Reproductive components and seed characteristics

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

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


1964 ◽  
Vol 44 (1) ◽  
pp. 96-99
Author(s):  
J. L. Dobb ◽  
C. R. Elliott

Pasture sampling cages placed on creeping red fescue (Festuca rubra L.) in early May and removed in early August of 1961 and 1962 caused 65 and 41% reductions in seed yield and 14 and 15% reductions in herbage yield, respectively. The reduction in seed yield was attributed primarily to a reduction in the number of seed-bearing culms but also to small reductions in the number of seeds per head and the 1000-seed weight. Components of herbage yield were not studied.The cages reduced light intensity. They often reduced wind velocity, lowered air temperature, and reduced the vapor-pressure deficit, although not consistently.


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


1995 ◽  
Vol 9 (2) ◽  
pp. 294-300 ◽  
Author(s):  
A. Lloyd Darwent ◽  
Leonard P. Lefkovitch

In commercial fields of creeping red fescue, spring applications of sethoxydim at 500 g/ha and fluazifop-P at 250 g/ha consistently reduced the heading, and consequently the seed production, of foxtail barley and volunteer bromegrass by ≥90% without affecting crop seed yield, 100-seed wt or germination. The effectiveness of sethoxydim at 500 g/ha and fluazifop-P at 250 g/ha to reduce heading of grass weeds was not affected by tank mixing with metsulfuron at 4.5 g/ha but was reduced when tank mixed with either dicamba plus 2,4-D at 280 plus 560 g/ha or 2,4-D alone at 560 g/ha. Metsulfuron alone, or in tank mixtures with sethoxydim (500 g/ha) or fluazifop-P (250 g/ha), effectively controlled dandelion and volunteer alsike clover (probability of ≥80% control was 0.94 or more). Dicamba plus 2,4-D provided a similar level of volunteer alsike clover control but was less effective on dandelion, while 2,4-D was ineffective on both weeds. Treatments containing dicamba plus 2,4-D reduced crop seed yield and germination, and increased seed weight.


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


1983 ◽  
Vol 100 (2) ◽  
pp. 285-292 ◽  
Author(s):  
T. O. Tayo

SUMMARYThe size of the sink on two indeterminate (cv. Hampton and cv. TGM 119) and two determinate (cv. Bossier and cv. TGM 294) cultivars of soya beans were reduced by continuously limiting the number of pods developing at each fruiting node to either one or two, starting from 2 weeks after anthesis, in three field experiments (early 1980, late 1980 and early 1981). Thiswas in order to evaluate the effects of sink size on the development of pod and seed characteristics as well as to quantify the inter-relationships between these characters under humid tropical conditions.Persistently reducing the number of pods developing at each fruiting node consistently significantly reduced the number of pods per plant, the pod and seed dry weights per plant, the total number of seeds per plant and the harvest index (seed weight as a proportion of total dry weight) in all cultivars when compared with the control. On the other hand, the treated plants of all cultivars generally had longer pods, heavier individual pods and seeds, more seeds per podand greater leaf area and leaf dry weight as well as greater specific leaf weight than the control plants. Compensation indices (percentage increases in size over control) were 25–30% for weight per pod and seed weight per pod; 11–16% for weight per seed and number of seeds per pod and 2–5% for pod length in the treated plants.Most of the characters measured (except individual weight of pods and seeds, seed weight per pod and number of seeds per pod) had significant interaction effects of sink size, cultivar and season; season had the highest correlation ratio, followed by cultivar, and sink size had the least. Also, nearly all components of seed yield were positively highly significantly correlated with one another; the number of seeds per pod and the number of pods per plant accounted for 76% of the variation in seed dry weight per plant.It would seem therefore that under the prevailing humid tropical conditions, the most important component of seed yield in soya bean is the number of seeds per pod, as affected by the sink size.


2017 ◽  
Vol 23 (1) ◽  
Author(s):  
A. B. SAGADE

The study of the effect of three well known mutagens, ethyl methane sulphonate (EMS), methyl methane sulphonate (MMS) and gamma rays (GR) on the yield contributing traits of the urdbean variety TPU-4 were carried out in the M3 generation. Effect of selected mutagenic treatments/doses of EMS (0.02, 0.03 and 0.04 M), MMS (0.0025, 0.05 and 0.01 M) and (GR) (30, 40 and 50 KR) on different yield contributing traits like plant height, plant spread, number of pods per plant, pod length, number of seeds per pod, seed yield per plant and 100 seed weight were analyzed in the M3 populations of the variety TPU-4. Seeds of M2 plants and control were harvested separately and sown to raise M3 population.. Genetic variabilty in the mutagen administered M3 progeny of the urdbean variety TPU-4 was analyzed by employing statistical methods. Data on mean values and shift in the mean of seven quantitative traits was evaluated on individual plant basis. The experimental findings revealed that concentrations / dose of the all these mutagens showed inhibitory effect on plant height, number of pods per plant, pod length and number of seeds per pod. Lower concentrations of mutagens exerted a promotory effect on plant spread, 100 seed weight and seed yield per plant while higher concentrations of these mutagens inhibited them to different extent.


2011 ◽  
Vol 1 (6) ◽  
pp. 260-267
Author(s):  
Reza Talebi ◽  
Ezzat Karami

The morpho â€physiological traits associated with seed yield in chickpea (Cicerarietinum L.) were evaluated on thirty five chickpea genotypes under twodifferent water regimes. In optimum condition, the highest correlation wasbelonged to number of seeds/plant and number of pods/plant (0.944**) andin water deficit condition, the strongest correlation of seed yield was observedwith number of seeds/plant (0.875**), number of pods/plant(0.789**) and 100  â€seed weight (0.438**). Physiological traits (RWC, Chlorophylland Carotenoid) indicated low and positive correlation with yield, buthigh positive correlation with other seeds yields related traits in optimumcondition while, under water deficit condition, chlorophyll content and RWChad low and non â€significant negative correlation with seeds yield. Carotenoid,number of seeds/plant and 100 â€seed weight showed more direct positiveeffect on yield in optimum environment and in stress condition, numberof seeds/ plant and 100 â€seed weight showed highest direct effect on seedyield. Results of factor analysis showed that four factors explained 88.54%and 34.5% of the total variance caused in the characters in optimum andwater deficit environment, respectively. In general, the results suggestedthat a chickpea cultivar, for increased yield under non â€stress conditions,should have maximum number of seeds and pods per plant and under stressconditions should have maximum number of seeds and pods per plant andalso keep the high level of RWC and chlorophyll content in their leaves. Thus,identifying these traits as selection criteria in chickpea breeding programmay be useful for breeders to introduce suitable drought resistant chickpeacultivars for arid regions.


2000 ◽  
Vol 80 (4) ◽  
pp. 809-811 ◽  
Author(s):  
N. A. Fairey ◽  
L. P. Lefkovitch

Six trials were conducted on commercial seed fields of creeping red fescue (Festuca rubra L. var. rubra) in the Peace region to evaluate the sensitivity of seed production to the method and time of application of N fertiliser. In each trial, 68 kg ha−1 N was applied using three methods (surface-broadcast, granular, ammonium nitrate 34-0-0; foliar/soil spray of 28-0-0 solution N; soil-injected 28-0-0 solution N) at each of three times (fall, early spring, late spring). No statistically significant (P = 0.05) interaction, or main effect, of method and time of N were revealed for seed yield, fertile tiller density or for several seed quality characteristics. Seed yield varied greatly among trials (142 to 1240 kg ha−1) and averaged 566 kg ha−1. The results indicate that there is considerable flexibility in the method and time of application of N fertiliser for seed production of creeping red fescue in the Peace region, provided it is applied before the commencement of vigorous plant growth in the spring. Key words: Creeping red fescue, Festuca rubra L., nitrogen fertility, grass seed production, grass seed quality


Genetika ◽  
2015 ◽  
Vol 47 (2) ◽  
pp. 383-393 ◽  
Author(s):  
Khosro Mohammadi ◽  
Reza Talebi

To determine the association between genetic parameters and morphological traits in chickpea (Cicer arietinum L.) genotypes, a field experiment was conducted with 49 different landrace, breeding lines and cultivated chickpea genotypes using a 7?7 lattice square design with 2 replications in the 2012-2013 growing season. Genetic parameters including genetic, environmental and phenotypic variances; coefficients of variation; heritability; correlation coefficients; factor analysis and path coefficients were estimated, and cluster analysis was performed. High heritability values observed in measured traits indicating that these traits are controlled mainly by additive genes and that selection of such traits may be effective for improving seed yield. Number of seeds per plant, 100-seed weight and plant biomass had a positive direct effect on seed yield. These traits also had positive and highly significant phenotypic correlations with seed yield. Using principal component (PC) analysis, the first three PCs with eigenvalues more than 1 contributed 70.94% of the variability among accessions. The germplasm were grouped into 3 clusters. Each cluster had some specific characteristics of its own and the cluster I was clearly separated from cluster II and III. Overall the results, it can be concluded that seed yield in chickpea can be improved by selecting an ideotype having greater number of seeds per plant, 100-seed weight and plant biomass.


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