Variable paths to seed production within the Kangaroo Valley cultivar of Lolium perenne

1991 ◽  
Vol 42 (1) ◽  
pp. 151 ◽  
Author(s):  
SG Shah ◽  
CJ Pearson ◽  
AC Kirby

Components of seed yield were measured in an erect, early-flowering biotype and a prostrate, late-flowering biotype of Lolium perenne cv. Kangaroo Valley at temperatures from 15/10 to 24/19�C (12/12 h day/night). We aimed to determine if each biotype had distinctive components of seed yield, and if these varied according to temperature. The two biotypes had distinctive paths to seed yield. Seed yield per plant in an erect biotype depended more on seed weight per spike and less on spike number than in a prostrate biotype. The distinctive paths to seed yield, and relative stability in paths across temperatures, indicated that it was possible to select genotypes from within the Kangaroo Valley cultivar which had particular correlations among components of yield. Floral development was accelerated, but seed yield per plant and most of its components were reduced, at high temperature; only the mean daily rate of dry weight accumulation by individual seeds was the same at all temperatures. At any temperature, seed weight per spike declined almost linearly with lateness of spike emergence within a plant: spikes which emerged within 21 days of the earliest spike contributed 80% of the seed yield per plant. We conclude that biotypes can be selected within the Kangaroo Valley cultivar to have distinctive components of seed yield and, based on the two biotypes we studied, commercial seed production should be based at a location having relatively low temperatures.

2005 ◽  
Vol 53 (3) ◽  
pp. 353-356
Author(s):  
◽  

Studies were made on the fodder and seed production of ryegrass (Lolium perenne L.) using twelve treatment combinations with four levels of nitrogen (30, 60, 90 and 120 kg/ha/cut) and three levels of phosphorus (0, 50 and 100 kg P2O5/ha), laid out in a randomized block design with four replications. The mean of two years indicated that nitrogen at 120 kg/ha/cut increased the green fodder (834 q/ha) and dry matter yield (129 q/ha) significantly over the lower doses. After leaving the same crop for seed production during mid-March, nitrogen at the rate of 60 kg/ha gave the highest seed yield (7.61 q/ha). Beyond this dose the seed yield decreased drastically due to lodging. Phosphorus at the rate of 50 kg P2O5/ha gave 5% higher dry matter (99.6 q/ha) and 7.4% higher seed yield (7.26 q/ha) over the control.


Weed Science ◽  
1990 ◽  
Vol 38 (2) ◽  
pp. 113-118 ◽  
Author(s):  
S. Kent Harrison

Multiple regression and response surface plots were used to analyze the effects of common lambsquarters population density and interference duration on weed growth and soybean seed yield. Under favorable growing conditions in 1986, weed biomass production at all population densities and interference durations was four to five times that produced in 1987, under less favorable conditions. However, there was no significant treatment by year interaction for soybean seed yield reduction by common lambsquarters, and production of each kg/ha weed biomass resulted in an average soybean yield reduction of 0.26 kg/ha. Utilizing 5% yield loss as an arbitrary threshold level, the regression equation predicted a common lambsquarters density threshold of 2 plants/m of row for 5 weeks of interference after crop emergence and 1 plant/m of row for 7 weeks. Seed production by individual common lambsquarters plants was highly correlated (r=0.92) with weed dry weight, and seed production ranged from 30 000 to 176 000 seeds/plant.


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.


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 (3) ◽  
pp. 435-439 ◽  
Author(s):  
J. R. Moyer ◽  
S. N. Acharya ◽  
J. Fraser ◽  
K. W. Richards ◽  
N. Foroud

Recommendations for desiccation of alfalfa do not clearly define the stage at which desiccants should be applied. To obtain this information, diquat and glufosinate were applied to alfalfa (Medicago sativa L) from 1991 to 1994 at various stages of maturity to determine the effect of desiccant and stage of maturity at desiccation on seed yield 1000-seed weight and seed germinability. Alfalfa seed yields, 1000-seed weights, percent germination and percent viable seed were similar after desiccation with diquat and glufosinate. Desiccation when 60–75% of the alfalfa seed pods were brown permitted maximum seed yields. Percent germination increased slightly in seeds that were exposed to weathering under normal conditions until all pods turned brown. Both desiccants adequately desiccated alfalfa for harvesting but desiccation with glufosinate took 2 or 3 d longer than diquat. Desiccants did not reduce alfalfa growth in the spring after application. Key words: Germination, yield, hard seed, seed weight, stage


2016 ◽  
Vol 1 (01) ◽  
pp. 30-34
Author(s):  
R. K. Gupta ◽  
V. K. Dwivedi

The data were recorded on five random selected plants for 12 quantitative characters and statistical analyzed. The analysis of variance for all the twelve characters is showed the mean square due to genotypes was highly significant. The mean values of various characters like days to 50 per cent flowering were recorded maximum for genotype IC560719 and Pusa Karishma (84.00 days)with mean 69.08 days The maximum days to 75% maturity were observed in IC-560700 genotype (142.00 days) with a mean of 135.07 days. The plant height highest recorded in the genotype IC-560696 (217.60 cm) with mean of 188.14 cm. The maximum number of primary branches per plant (16.47) was recorded in the genotype NPJ-113 with mean of 10.13. The genotype NPJ-113 produced maximum number of secondary branches per plant (35.47) with mean of 19.78. The maximum length of siliqua was recorded for Kranti (7.03) with mean of 5.24cm. The maximum number of seeds per siliqua was recorded in Kranti genotype (19.13) with mean value 14.91. The maximum 1000-seed weight recorded 5.57g for Pusa Jai Kisan with mean wt. 3.96 g. Pusa Mustard-21 produced highest biological yield (191.13g) with mean 79.00g. The genotype Pusa Jagannath had maximum harvest index (30.98%) with mean value 23.87%. The oil content in mustard maximum in 42.00 % were recorded in Pusa Agrani with mean oil content was 39.16 percent. The genotype Pusa Mustard-21 showed highest seed yield per plant (47.00g) with a mean seed yield of 18.58. The higher heritability estimates in broad sense for biological yield per plant (99.6%), number of primary branches per plant (91.4%), number of secondary branches per plant (98.4) plant height (99.2%), 1000-seed weight (99.4%) and days to 50 per cent flowering (98.5). Expected genetic advance at 5% selection intensity was recorded higher for biological yield per plant (71.60) and number secondary branches per plant (10.87).


2004 ◽  
Vol 44 (1) ◽  
pp. 57 ◽  
Author(s):  
L. J. Latham ◽  
R. A. C. Jones ◽  
B. A. Coutts

Field experiments provided quantitative information on the yield losses caused by virus infection within 4 different combinations of non-persistently aphid-transmitted virus and cool-season crop legume: Alfalfa mosaic virus (AMV) in chickpea, faba bean and lentil, and Cucumber mosaic virus (CMV) in lentil. Virus infection foci were introduced into plots and naturally occurring aphids spread infection from these to the other plants. Plants were tagged individually when typical virus symptoms first appeared during the growing period. Paired plant comparisons between symptomatic and asymptomatic plants were made to measure different yield loss parameters. Late infection with AMV in faba bean cv. Fiord diminished shoot dry weight by 41% and seed yield by 45%, but plants infected earlier recovered sufficiently from their initial shock reaction not to produce significant yield losses. In plants of lentil cv. Matilda first showing symptoms at different times, infection with AMV decreased shoot dry weight by 74–76%, seed yield by 81–87% and individual seed weight by 10–21%, while CMV diminished shoot dry weight by 72–81%, seed yield by 80–90% and individual seed yield by 17–25%. Early infection with AMV killed plants of chickpea cv. Tyson while later infection decreased shoot dry weight by 50%, seed yield by 98% and individual seed weight by 90%. The first tentative evidence for seed transmission of AMV in faba bean is reported with a transmission rate of 0.04%.


2001 ◽  
Vol 52 (6) ◽  
pp. 645 ◽  
Author(s):  
P. Si ◽  
N. Thurling

0t, n.s.). These relationships suggested that it might be possible to develop early flowering cultivars with increased seed yield by selecting for higher RGR before anthesis. RGR of BC 2 F 3:4 lines in the field during winter was correlated with RGR at low temperatures (13/4°C) in a controlled environment, suggesting that genotypes producing more dry weight at anthesis grew more at the low temperatures normally experienced in the field. This was supported by a significant (P < 0.05 0.05) negative correlation (r = –0.69**) between growth in the field and potassium leakage from leaf tissue at 4


1972 ◽  
Vol 78 (2) ◽  
pp. 179-182 ◽  
Author(s):  
S. Abu-Shakra ◽  
A. Bassiri

SUMMARYSoya beans grown on land planted the previous year with inoculated soya beans produced more nodules, lodging, seed yield, 1000 seed weight, and protein content and less seed oil concentration as compared to those grown on land that was planted with non-inoculated soya beans. Nitrogen fertilization (120kg N/ha) reduced the total number of nodules per plant. Increasing inoculation rates of the seed increased the dry weight of nodules per plant. Location, nitrogen fertilization, and inoculation increased or decreased the levels of certain amino acids but had no significant effect on the sulphur amino acids, cystine and methionine.


2021 ◽  
Author(s):  
Manish Sharma ◽  
Y.G.SHADAKSHARI

Abstract The present research aimed to study gene effects for seed yield and its component traits in sunflower hybrids having diverse cytosterile sources from Helianthus annuus and H. argophyllus. Five lines and ten testers were crossed in a line x tester mating design to develop 50 F1 hybrids for genetic analysis. The analysis of variance revealed significant differences among the traits studied. Seasonal variation was found significant for all the traits except stem diameter, volume weight and seed filling percentage. The mean squares of lines and testers from crosses both determine the GCA were also significant for most of the traits which revealed the prevalence of additive variances and additive gene action. The mean squares of lines x tester interactions were also significant for all the traits considered. The significance of lines x tester interactions indicated that SCA is also important in the expression of traits and demonstrated the value of non-additive variances and dominant genes controlling the various traits. Among the diverse cytosterile lines, ARG-6-3-1-4 was identified as the best general combiner for stem diameter, volume weight, seed yield, hull content, oil content and oil yield. While, the line ARG-2-1-2 was best general combiner for days to 50 per cent flowering, head diameter, 100 seed weight and seed filling percentage. The tester M17-R was observed to be best general combiner for earliness and volume weight, while RHA 93 was the best general combiner for plant height, seed yield and oil content. The best cross combinations; MUT-2-8-3-2 x GKVK 3 was found to be good specific combiner for stem diameter, 100 seed weight, seed yield, seed filling percentage, oil content and oil yield, while ARG-6-3-1-4 x GKVK 3 was good specific combiner for days to 50% flowering, plant height and 100 seed weight.


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