Lodging studies in Lolium perenne grown for seed: 1. Seed yield and seed yield components

1978 ◽  
Vol 90 (2) ◽  
pp. 261-267 ◽  
Author(s):  
P. D. Hebblethwaite ◽  
A. Burbidge ◽  
D. Wright
Keyword(s):  
Seed Development ◽  
Lolium Perenne ◽  
Seed Yield ◽  
Perennial Ryegrass ◽  
Yield Components ◽  
Field Experiments ◽  
Unit Area ◽  
Seed Yield Components ◽  
Seed Yields ◽  
Number Of Seeds

SummaryThe effects of lodging on the seed yield of S. 23 and S. 24 perennial ryegrass were investigated in a series of field experiments from 1973 to 1976. Natural lodging severely reduced seed yield in all years as a result of a decrease in the number of seeds per unit area. Controlled lodging at different stages of crop growth produced more variable results, indicating that lodging may affect both pollination and seed development. Disturbance of the crop during anthesis in order to aid pollination did not improve seed yields, possibly as a result of damage incurred.

Irrigation and Nitrogen Studies in s. 23 Ryegrass Grown for Seed: 1. Growth, Development, Seed Yield Components and Seed Yield

1977 ◽  
Vol 88 (3) ◽  
pp. 605-614 ◽  
Author(s):  
P. D. Hebblethwaite
Keyword(s):  
Seed Yield ◽  
Yield Components ◽  
Seed Weight ◽  
Dry Matter ◽  
Field Experiments ◽  
Unit Area ◽  
Yield Response ◽  
Seed Yield Components ◽  
Seed Yields ◽  
Number Of Seeds

SUMMARYThe effects of irrigation and nitrogen on S. 23 perennial ryegrass grown for seed were investigated in a series of field experiments from 1972 to 1974. Irrigation significantly increased seed yield by 16% in 1972 and 52% in 1974 but had no effect in the wet year of 1973. In 1972 maximum deficit reached 110 mm at the end of July and coincided with anthesis. Consequently the yield response was due to an increase in number of seeds per unit area and no other seed yield component was affected. In 1974 peak deficit also reached about 100 mm but started to build up rapidly very early in the season and had reached 80 mm by the time that the first ears emerged. Consequently the yield response was due to increases in number of fertile tillers, number of seeds per unit area and 1000-seed weight.Irrigation had no significant effect on number of florets or seeds, except in 1974 when percentage of florets which produced seed was increased by 2%.Irrigation had some effect on threshed straw yields, total dry matter, harvest index and total number of tillers but where this occurred the response was much smaller than that of seed yield which indicates that irrigation had greater effects on the reproductive development of the crop than on yield of dry matter and tillering patterns. Increasing the quantity of nitrogen from 0 to 80 kg/ha increased seed yields, all seed yield components except 1000-seed weight, threshed straw yields and total dry matter and number of tillers at most sampling dates. Increasing the quantity of nitrogen from 80 to 160 kg/ha had little further effect on the above components except in 1972 where seed yields were significantly decreased.In 1972 number of florets was increased and percentage of florets which produced seed decreased with increasing quantities of nitrogen.

Lodging studies in Lolium perenne grown for seed: 3. Chemical control of lodging

1979 ◽  
Vol 93 (3) ◽  
pp. 669-679 ◽  
Author(s):  
D. Wright ◽  
P. D. Hebblethwaith
Keyword(s):  
Lolium Perenne ◽  
Seed Yield ◽  
Perennial Ryegrass ◽  
Chemical Control ◽  
Dry Matter ◽  
Field Experiments ◽  
Unit Area ◽  
Growth Retardant ◽  
The University ◽  
Number Of Seeds

SUMMARYThree field experiments at the University of Nottingham, in 1976, 1977 and 1978, examined whether a growth retardant chemical, ancymidol, could be used to restrict stem extension, delay the onset of lodging and thereby increase the seed yield of S. 24 perennial ryegrass. Applications of ancymidol increased seed yield by up to 60% by increasing number of seeds per unit area, although this was associated with a delay in the onset of lodging in 1977 and 1978 only. Application of ancymidol increased the percentage of the total above-ground crop dry matter harvested as seed, but it was not possible to relate this to the growth of the crop between anthesis and harvest.

Is the flag leaf important in perennial ryegrass seed production?

2010 ◽  
Vol 14 ◽  
pp. 67-73
Author(s):  
J.A.K. Trethewey ◽  
M.P. Rolston
Keyword(s):  
Seed Yield ◽  
Perennial Ryegrass ◽  
Yield Components ◽  
Seed Weight ◽  
Photosynthetic Capacity ◽  
Flag Leaf ◽  
Active Radiation ◽  
Seed Yield Components ◽  
Seed Fill ◽  
Thousand Seed Weight

In cereals, the importance of the flag leaf for contributing carbohydrate during seed fill is well documented. However, in ryegrass this relationship is not so clear. This paper reports on an investigation of the effect on seed yield components of reduced photosynthetic capacity to the flag leaf, stem and head of perennial ryegrass (Lolium perenne). The hypothesis was that reduced photosynthetic capacity of the flag leaf does not affect seed yield components in perennial ryegrass. Following flowering, photosynthetic capacity was reduced by defoliation or shading the flag leaf, stem, or head of individual tillers. Seed yield components were measured at harvest. Reduced photosynthetically active radiation (PAR) to the flag leaf and stem did not affect thousand seed weight or seed yield when compared with control plants whereas reducing PAR to the head had a significant effect. The seed head itself may be more important than the flag leaf during seed fill, but when the seed head is shaded substantial re-mobilisation of stored carbohydrates can occur. Keywords: flag leaf, green leaf area, Lolium perenne, photosynthetically active radiation, seed fill, seed yield, thousand seed weight, water-soluble carbohydrates

scholarly journals Heritabilities and phenotypic correlations for seed yield and seed yield components of beans

1969 ◽  
Vol 72 (2) ◽  
pp. 301-308
Author(s):  
Manuel Mateo Solano ◽  
James S. Beaver ◽  
Freddy Saladín García
Keyword(s):  
Seed Yield ◽  
Yield Components ◽  
Narrow Sense ◽  
Phenotypic Correlations ◽  
Seed Yield Components ◽  
F2 Generation ◽  
Seed Yields ◽  
Advanced Generation ◽  
Weight Number ◽  
100 Seed Weight

Indeterminate bean (Phaseolus vulgaris L.) lines derived from crosses between small-seeded indeterminate and large-seeded determinate genotypes were used to estimate the heritabilities and phenotypic correlations for seed yield and seed yield components. The F2  generation of six bean populations was planted at the Fortuna Substation, Juana Díaz, Puerto Rico, in October 1984. Seed yield per plant, 100 seed weight, number of pods per plant, and number of seed per pod were measured for 50 plants selected at random from each population. A total of 50 F3 plant rows of each population were planted in February 1985 at the Fortuna Substation, and in March 1985 on a small farm in the Constanza valley of the Dominican Republic. Narrow sense heritabilities were estimated by using parent-offspring regressions of the F2 and F3 generation, and phenotypic correlations were estimated by using means of the F3 lines. Mean seed yields per plant of the indeterminate F3 lines were significantly less than the indeterminate parents, whereas the 100-seed weights of the indeterminate F3 were significantly less than the determinate parents. Narrow sense heritabilities for seed yield and seed yield components were intemediate to low. These results indicate that selection for greater seed yield would be more effective by evaluating advanced lines in replicated trials. Spearman rank correlations between locations for seed yield and seed yield components varied among populations. Multilocation testing of advanced generation lines may be the most effective way to identify bean genotypes that perform well in contrasting environments.

scholarly journals Do Weeds From Seeds or Regrowth in Coexistence Periods Alter Biochemical and Yield Characteristics of Soybeans?

2019 ◽  
Vol 11 (10) ◽  
pp. 264
Author(s):  
Ana Paula Rockenbach ◽  
Mauro Antônio Rizzardi ◽  
Adriana Favaretto ◽  
Theodoro Schneider ◽  
Andréa Michel Sobottka
Keyword(s):  
Secondary Metabolism ◽  
Seed Yield ◽  
Yield Components ◽  
Field Experiments ◽  
Rio Grande ◽  
Total Phenols ◽  
Rio Grande Do Sul ◽  
Soybean Yield ◽  
Volunteer Corn ◽  
Seed Yields

The objective of this study was to evaluate changes in soybean secondary metabolism and soybean yield components when subjected to coexistence periods with volunteer corn and established horseweed (Conyza spp.) regrowth. Two field experiments were conducted in the agricultural years 2015/2016 and 2016/2017 at Passo Fundo University, Passo Fundo, Rio Grande do Sul, Brazil. Experiment I was conducted in the agricultural year 2015/2016 in order to establish periods of coexistence between soybean and corn. The treatments consisted of two soybean densities in the main plots (175,000 and 350,000 plants ha-1) and different periods of coexistence between soybean and corn in the subplots. Experiment II was conducted in the agricultural year of 2016/2017 in order to investigate the interference of regrowth horseweed during coexistence periods with soybean. The total phenols, flavonoids, saponins, soybean yield components and seed yields were evaluated. Volunteer corn that initiates growth after the V4 soybean stage and horseweed regrowth during cultivation do not adversely affect secondary metabolism, seed yield or soybean yield components.

scholarly journals Genetic variability of seed yield and seed yield components of autochthonous Lolium perenne L. populations

Genetika ◽  
2013 ◽  
Vol 45 (2) ◽  
pp. 553-563
Author(s):  
Zeljko Lakic ◽  
Dejan Sokolovic ◽  
Snezana Babic ◽  
Svetko Vojin ◽  
Jela Ikanovic ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Seed Yield ◽  
Perennial Ryegrass ◽  
Yield Components ◽  
Seed Weight ◽  
Average Length ◽  
Spike Length ◽  
Phenotypic Variance ◽  
Seed Yield Components ◽  
Significant Difference

The aim of this study was to examine genetic variability, heritability and correlation of seed yield components and seed yield of progenies of autochthonous populations and cultivars of perennial ryegrass, and that on the basis of these results distinguish genotypes that would be later used in the creation of new local cultivars of perennial ryegrass. Research was carried out on experimental fields and laboratories of the Agricultural Institute of Republic of Srpska in Banja Luka in 2007. and 2008., on 6 natural populations of perennial ryegrass collected in Bosnia and Herzegovina and two cultivars, Maja and Calibra as standard. Following parameters were analyzed: number of generative tillers per plant, time of flowering, spike length, number of spikelets per spike, seed yield per spike and plant and 1000 seed weight. Analysis of the results of the number of generative tillers per plant indicates a statistically significant difference in the studied populations and cultivars of perennial ryegrass. The highest average number of tillers per plant was found in the cultivar Maja (193.8), and the least number was detected in population Dragocaj (78.9), so statistical differences were highly significant. The longest period to beginning of flowering was determined in cultivar Calibra (56.5 days) and the shortest in population Laminci (43 days). The average length of spike of perennial ryegrass in the studied population was 22.78 cm and was significantly lower than cultivar Maja. Statistically significant differences between populations and variety Maja in the number of spikelets per spike were detected. The average seed yield per spike of studied populations was in level with cultivar Maja and 37.5% higher compared with variety Calibra. In the studied populations of perennial ryegrass seed yield ranged from 5.21 g (Dragocaj population) to 15.40 g (Kupres population). Weight of 1000 seeds was highest in the variety Calibra (2.60 g) and lowest in population Maglajani (1.94 g). Proportion of genetic to phenotypic variance for time of flowering, the number of generative tillers, seed yield per spike and plant and 1000 seed weight indicate that the variability of these traits in this collection of genotypes, largely derived from plant genotype. In this investigation, the presence of a highly significant positive genetic correlation was found between time of flowering and spike length (0.98), time of flowering and 1000 seed weight (0.97), number of generative tillers and seed yield per plant (0.91) and spike length and 1000 seed weight (0.98).

Spring Nitrogen Rate and Timing Influence on Seed Yield Components of Perennial Ryegrass

1996 ◽  
Vol 88 (6) ◽  
pp. 947-951 ◽  
Author(s):  
William C. Young ◽  
Harold W. Youngberg ◽  
David O. Chilcote
Keyword(s):  
Seed Yield ◽  
Perennial Ryegrass ◽  
Yield Components ◽  
Nitrogen Rate ◽  
Seed Yield Components

Relationships among rate and duration of flowering and seed yield components in subterranean clover (Trifolium subterraneum)

1974 ◽  
Vol 25 (3) ◽  
pp. 435 ◽  
Author(s):  
CM Francis ◽  
JS Gladstones
Keyword(s):  
Seed Size ◽  
Seed Yield ◽  
Unit Area ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Main Determinant ◽  
Flowering Duration ◽  
Seed Yield Components ◽  
Flowering Rate ◽  
Number Of Seeds

Time of flowering, duration of flowering, rate of inflorescence production per unit area, viability of seeds harvested 20 and 30 days after anthesis, and seed yield and its components were measured on 24 subterranean clover strains grown as irrigated swards. Seed yield was unrelated to time or duration of flowering, but positively correlated with rate of inflorescence production, total inflorescence, burr and seed numbers, number of seeds per burr, and seed size. Rate of inflorescence production was the main determinant of total inflorescence numbers per unit area and an important determinant of total burr and seed numbers per unit area. It was negatively related to flowering duration, and weakly so to seed size. Seed size was unrelated to strain maturity. Seeds of small-seeded and fast-flowering strains on average attained viability faster than those of large-seeded and slow-flowering strains. Number of seeds per burr increased slightly with lateness of flowering, but was unrelated to seed size or flowering rate. It is concluded that rapid flowering and high seed number per burr should be useful primary selection criteria in selecting subterranean clovers for seed yield and general adaptation in southern Australia.

scholarly journals Heterosis in soybeans for seed yield components and associated traits

2002 ◽  
Vol 45 (4) ◽  
pp. 401-412 ◽  
Author(s):  
Fábio Pandini ◽  
Natal Antonio Vello ◽  
Ângela Celis de Almeida Lopes
Keyword(s):  
Seed Yield ◽  
Yield Components ◽  
Seed Weight ◽  
Aerial Part ◽  
Agronomic Traits ◽  
Indirect Selection ◽  
Seed Yield Components ◽  
Per Se ◽  
Selection For ◽  
Number Of Seeds

The objective of this research was to quantify heterosis of agronomic traits and evaluate direct and indirect correlations among seed yield and other traits. A diallel involving six parents was grown in two localities. Seed yield (PG), one-hundred seed weight (PCS), number of pods per plant (NV), weight of aerial part of the plant (PPA), harvest index (IC) and number of seeds per pod (NGV) were evaluated. Positive values of heterosis were detected for all traits. Estimates of heterosis components were significative for most traits, showing effects of aditivity and dominance. The specific heterosis was more important than the variety heterosis, mainly in the locality Anhembi. MTBR-95-123800 presented the best potential per se and as parent in crosses, but it was excelled by some of the hybrids in the two localities. Number of pods per plant demonstrated to be suitable for indirect selection for PG.

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