EFFECT OF PASTURE SAMPLING CAGES ON SEED AND HERBAGE YIELDS OF CREEPING RED FESCUE

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.

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


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.


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.


1959 ◽  
Vol 39 (3) ◽  
pp. 355-363 ◽  
Author(s):  
R. S. Fulkerson

The effects of six seeding rates and five row spacings on seed yield, seed quality and the yield components—number of fertile culms per square foot, number of seeds per culm and seed weight were studied in orchard grass.Row width had a marked effect on seed yield each year. Rate of seeding affected seed yield to a lesser extent and a row width × seeding rate interaction did occur. Seeding rates and row width caused small relatively unimportant differences in seedling establishment and early seedling vigour only in the third harvest year. Considering seed yield, seed quality and the ease of weed control, the best treatment combination appeared to be a seeding rate in the area of [Formula: see text] in 14-in. rows for stands to produce for 2 or 3 years.Seed yield was positively and closely correlated with the number of fertile culms in the first 2 crop years but a negative relationship was found in the third crop year. Seed weight was negatively correlated with seed yield. The number of seeds per panicle was closely associated with yield in the third crop year and negatively correlated with seed weight and culm numbers.


1973 ◽  
Vol 13 (65) ◽  
pp. 676 ◽  
Author(s):  
JG McIvor ◽  
DF Smith

Two experiments were done in pots to assess the effect of defoliation at different times on the seed yield of capeweed (Arctotheca calendula). Yield components measured were: number of seedheads per plant, number of seeds per seedhead, number of seeds per plant, and weight of individual seeds. Of the components of yield, number of florets per seedhead and individual seed weight were maintained under all treatments; number of seedheads and number of seeds per seedhead were more affected by defoliation. Whether grown as spaced plants or in swards, leaf removal did not significantly reduce the number of seeds produced unless combined with bud and flower removal at late flowering only. The results are discussed in relation to the growth and persistence of capeweed in pastures.


Euphytica ◽  
2019 ◽  
Vol 215 (10) ◽  
Author(s):  
Joanna Wolko ◽  
Agnieszka Dobrzycka ◽  
Jan Bocianowski ◽  
Iwona Bartkowiak-Broda

Abstract Rapeseed breeding programs are focused mainly on improving plant potential and seed yield. One of the ways to improve seed yield in oilseed rape is heterosis, which is hybrid vigor that results in a greater biomass, increased seed yield, and faster development. The purpose of this study was to estimate yield-related trait heterosis for single cross and three-way cross hybrids of winter oilseed rape (Brassica napus L.). A population of 60 doubled-haploid (DH) lines and two generations of hybrids were evaluated in field trials to assess six yield-related traits: plant height, number of branches per plant, number of siliques per plant, silique length, number of seeds per silique, and thousand seed weight. Heterosis effects for each trait were estimated by a comparison of the particular hybrid with: (1) the trait mean over both parents—mid-parent heterosis and (2) to the value of better parent—best-parent heterosis. Traits with clear positive heterosis and traits with varied heterosis were observed in this study. For the first group, we include plant height, silique length, and the number of seeds per silique—a large number of hybrids expressed significant positive heterosis for these traits, independent from the year of observations and the type of hybrid. For the second group, with varied heterosis, we can include the number of branches and siliques per plant and thousand seed weight. For these traits, hybrids exhibited both positive and negative significant heterosis, without a clear pattern for the years and types of hybrids.


1992 ◽  
Vol 70 (1) ◽  
pp. 200-204 ◽  
Author(s):  
Andrea L. Corbett ◽  
Pam G. Krannitz ◽  
Lonnie W. Aarssen

The flowers of the arctic poppy (Papaver radicatum L.) track the sun, and the petals of the flowers reflect light towards the ovary. This study investigated the importance of petals to reproductive success in this species. We measured light intensity, ovary temperature, seed weight, and number of seeds produced by flowers that had their petals removed versus flowers with their petals intact. Flowers without petals do not track the sun. Irradiance was greater when the photocell was held coincident with the angle of sun-tracking flowers than when facing upward. Flowers with petals had significantly higher overy temperatures both at the ovary surface and in the ovary interior than did flowers lacking petals. In pairs of flowers on the same individual plant, those with their petals removed had significantly fewer and smaller seeds than control flowers with petals intact. There were site differences in the significance of the treatment effect, but not in the magnitude of the differences between flowers with and without petals. Therefore, the presence of petals resulted in increased irradiance and temperature at and in the ovary, which affected reproductive success. Key words: heliotropism, Papaver radicatum, petals, reproductive success, temperature.


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