Dynamics of flower and pod production in annual medics. (Medicago spp.). II. In swards at low and high density

1990 ◽  
Vol 41 (5) ◽  
pp. 923 ◽  
Author(s):  
PS Cocks
Keyword(s):  
Flowering Time ◽  
Seed Size ◽  
Seed Yield ◽  
Subterranean Clover ◽  
Farming Systems ◽  
High Density ◽  
Low Density ◽  
Medicago Polymorpha ◽  
Late Flowering ◽  
Annual Medics

Seven accessions of five annual medic species were grown in swards at low and high densities at Tel Hadya in north Syria. Flower shedding, seed size, and other components of seed yield were compared with data collected from spaced plants. Seed yield of the seven accessions, ranging from zero to 800 kg ha-1, was correlated with flowering time at high density but not at low density. Early flowering accessions of Medicago polymorpha and M. truncatula produced more seed at high density than at low density, but a late-flowering accession of M noeana failed to produce seed at high density. Flower shedding was greatest in dense swards and least in spaced plants. Shedding of the various accessions ranged from 70% to M. polymorpha at low density to 96% in M. rigidula and 100% in M. noeana at high density. Some accessions shed flowers uniformly from all nodes, but in other accessions late-produced flowers were more likely to be shed. The flower shedding observed here was less than found in many other legumes, but more than has been observed in subterranean clover. It seems unlikely that seed yield can be increased by selecting for increased flower retention, but it may be possible to increase seed numbers at the expense of seed size; this may be useful in pasturebased farming systems.

Distribution and variability in development of the genus Trigonella in Asia Minor and its possible use in Australian environments

1981 ◽  
Vol 32 (5) ◽  
pp. 793 ◽  
Author(s):  
GM Halloran ◽  
AL Pennell
Keyword(s):  
Flowering Time ◽  
Subterranean Clover ◽  
Asia Minor ◽  
Vernalization Response ◽  
Developmental Patterns ◽  
Late Flowering ◽  
Commercial Cultivars ◽  
Wide Variability ◽  
Upper Level ◽  
Autumn Sowing

A number of Trigonella species were examined for their possible use in Australian environments. There was a wide variability in flowering time in Trigonella. Under an outdoor autumn sowing the range in flowering time was comparable with that found within early- to late-flowering Australian commercial cultivars of subterranean clover. The upper level of vernalization response was much lower in Trigonella than in subterranean clover. Good prospects exist within Trigonella for selecting genotypes with close adaptation (in terms of appropriate developmental patterns) to a range of Australian environments, a range at least as wide as that now occupied by subterranean clover and annual medic.

Effects of phosphorus on seed yields of subterranean clover, serradella and annual medics

1985 ◽  
Vol 25 (3) ◽  
pp. 595 ◽  
Author(s):  
MDA Bolland
Keyword(s):  
Seed Yield ◽  
Subterranean Clover ◽  
Average Weight ◽  
The Third ◽  
Hard Seeds ◽  
Annual Medics ◽  
Alternating Temperature ◽  
Seed Yields ◽  
The Relationship ◽  
Number Of Seeds

In three experiments located near Esperance, Western Australia, the effect of superphosphate phosphorus on seed yields of subterranean clover, serradella and annual medics was measured on newly-cleared soils, using low seeding rates. In two experiments, the relationship between seed yield and the amount of phosphorus applied was linear for subterranean clover and serradella; seed yields increasing by 7-24 kg/ha for each kg/ha of phosphorus applied, depending on species, strain or cultivar, and location. In the third experiment, seed yields of annual medic species also increased markedly with increasing amounts of applied superphosphate phosphorus, this response also depended on species and strain or cultivar, but the responses become less marked with increasing amounts of phosphorus. For the annual medic species, the phosphorus treatments had no effect on average weight of one burr, number of seeds per burr, weight of one seed, or the rate of softening of hard seeds as measured both in a 15/60� alternating temperature oven (one cycle/day) or for samples of burrs collected periodically during summer from the field. For all legumes, the appearance of first flowers was not affected by phosphorus treatment.

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 Adaptation of Lentil to the Mediterranean Environment. I. Factors Affecting Yield Under Drought Conditions

1993 ◽  
Vol 29 (1) ◽  
pp. 9-19 ◽  
Author(s):  
S. N. Silim ◽  
M. C. Saxena ◽  
W. Erskine
Keyword(s):  
Drought Stress ◽  
Flowering Time ◽  
Seed Yield ◽  
Ground Cover ◽  
Farming Systems ◽  
Yield Potential ◽  
Mediterranean Environment ◽  
Early Maturity ◽  
Selection For ◽  
Seed Yields

SummaryLentil frequently suffers from drought stress towards the end of the growing season in rainfed Mediterranean farming systems. This study aimed to quantify the contribution of yield potential under irrigated conditions and of drought escape to the adaptation of lentils to drought, and to identify traits of value in selection for adaptation to a rain-fed Mediterranean environment. Twenty-five diverse lentil lines were sown under both irrigated and rainfed conditions in the 1987/88 and 1988/89 seasons in northern Syria. In 1987/88 the total seasonal rainfall was 403 mm and average rainfed biomass and seed yields were 5.0 and 1.8 t ha-l, respectively. In contrast, in 1988/89 the total season rainfall was 180 mm and average biomass and seed yields were only 0.67 and 0.12 t ha-1, respectively. Early vigour (estimated as a visual score) and percentage ground cover were strongly associated with final biomass, and were of value in predicting economic yield (seed + straw). Early maturity was correlated with seed yield. In the dry season 1988/89, 49% of the variation in seed yield among lines was accounted for by variation in flowering time. Drought escape was clearly the key response to drought. For severely drought-prone areas, selection for early flowering is therefore required. Variation in flowering time and seed yield under irrigated conditions accounted for 62% of seed yield variation under drought stress.

Flowering time of cultivars of subterranean clover in New South Wales

1987 ◽  
Vol 27 (6) ◽  
pp. 791 ◽  
Author(s):  
KA Archer ◽  
EC Wolfe ◽  
BR Cullis
Keyword(s):  
Flowering Time ◽  
Western Australia ◽  
New South ◽  
New South Wales ◽  
Subterranean Clover ◽  
Sowing Date ◽  
Late Flowering ◽  
Acceptable Accuracy ◽  
South Wales ◽  
The Relationship

The period from sowing to flowering was determined for 8 subterranean clover cultivars sown in late March, late April and late May at 9 environmentally distinct locations in New South Wales. The length of the period to flowering depended on cultivar (ranging from a mean of 1 12 days for Northam to 151 days for Larisa) and site (from a mean of 1 18 days at Grafton to 145 days at Canberra). There was a greater range in the period from sowing to flowering between cultivars at earlier flowering sites compared with late flowering sites. The period from sowing to flowering decreased with later sowings so that clovers sown late (May) flowered on average less than 14 days after those sown early (March). A relationship was developed between temperature and latitude and the period to flowering for each sowing date and cultivar. This relationship accounted for 95% of the variation in flowering time observed in this study and was used to predict with acceptable accuracy the flowering time of subterranean clover cultivars in a study undertaken in Western Australia in 1972 and 1973. We believe the relationship could be useful in predicting flowering time in subterranean clovers.

A physiological analysis of the effect of sowing density on the growth rate of subterranean clover

1982 ◽  
Vol 33 (2) ◽  
pp. 213 ◽  
Author(s):  
J-L Prioul ◽  
JH Silsbury
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Growth Curves ◽  
Subterranean Clover ◽  
Crop Growth ◽  
High Density ◽  
Planting Density ◽  
Low Density ◽  
Response Curves ◽  
Crop Growth Rate

The initial planting density of subterranean clover swards is known to affect the subsequent crop growth rate in such a way that a low density crop reaches the same final yield as does one sown at high density. To explain this phenomenon, daily carbon influxes and effluxes were measured during the growth of 'low' and 'high' density swards in a constant environment. The growth characteristics of individual plants in the sward and the photosynthetic responses of individual leaves to light were measured during ontogeny. Good agreement was found between the growth curves reconstructed from daily carbon increment and growth curves previously derived from dry matter sampling. The crop growth rate of a low density sward was found to be higher than that of a high density sward, and this is shown to be due to a lower respiratory loss. The high respiration rate of a high density crop can be attributed to plant mortality when dry matter density is higher than 400 g m-2. The photosynthetic light response curves of individual leaves at the top of the canopy were not found to be affected by the initial planting density, which suggests that subterranean clover plants are extremely well adapted to growth under sward conditions.

Effects of seed size and maturity on the growth and yield of faba bean (Vicia faba L.)

1998 ◽  
Vol 49 (1) ◽  
pp. 79 ◽  
Author(s):  
S. Agung ◽  
G. K. McDonald
Keyword(s):  
Flowering Time ◽  
Seed Size ◽  
Faba Bean ◽  
Dry Matter ◽  
South Australia ◽  
Growth And Yield ◽  
Dry Matter Production ◽  
Annual Rainfall ◽  
Late Flowering ◽  
Matter Production

The importance of seed size and flowering time to yield in faba bean has not been well defined for many of the faba bean growing areas of southern Australia. The objective of this work was to examine the relative importance of these traits to yield of dryland faba bean at 2 sites in South Australia. Grain yield, seed growth rate, the partitioning of dry matter to the seed, and water use efficiency for dry matter production and yield of faba bean cultivars differing in seed size and maturity were measured. Early-, intermediate-, and late-flowering accessions in each of 3 seed size classes, large (>1200 mg/seed), medium (800-1200 mg), and small (<800 mg), were grown at the Waite Institute (623 mm average annual rainfall) and Charlick Experiment Station (509 mm). A small-seeded and intermediate flowering cultivar, Fiord, which is well adapted in South Australia was also included. Dry matter production and grain yields at the Waite Institute were higher than at Charlick and the difference tended to be greater in the large-seeded accessions. Average yields at the 2 sites were about 400 g/m 2 and were not consistently related to seed size, although the highest yielding accession at both sites was large-seeded. Among the small- and medium-sized seed accessions, the early-flowering accession yielded more than late-flowering accessions, but among the large-seeded accessions there was no relationship between flowering time and yield. Although there were significant differences between accessions and sites in individual yield components, yield was not significantly correlated with any particular component. There was strong compensation between seed number and seed size and high yields were obtained from a range of seed sizes. In contrast there was a positive relationship between dry matter production and yield. Partitioning of dry matter during pod filling and harvest index differed little between genotypes. Yield was therefore related to biomass accumulation, and whether this was partitioned between a small number of large seeds or a large number of small seeds was not an important factor.

Further studies on losses in productivity caused by infection of annual pasture legumes with three viruses

1992 ◽  
Vol 43 (5) ◽  
pp. 1229 ◽  
Author(s):  
RAC Jones
Keyword(s):  
Mosaic Virus ◽  
Seed Size ◽  
Seed Yield ◽  
Alfalfa Mosaic Virus ◽  
Subterranean Clover ◽  
Yellow Mosaic Virus ◽  
Root Production ◽  
Pasture Legumes ◽  
Burr Medic ◽  
Severe Isolate

Trials were done in 1988-90 to examine the effects of infection with three non persistently aphid-transmitted viruses on the productivity of manually inoculated spaced plants of annual pasture legumes growing in plots. Alfalfa mosaic virus (AMV) decreased herbage and root production (dry weights) of three subterranean clover (Trifolium subterraneum L.) cultivars by 20-49%. Cucumber mosaic virus (CMV) decreased herbage and root production of a murex medic (Medicago murex Wild.) cultivar by 78-90% and of two burr medic (M. polymorpha L.) cultivars by 56-82%. A mild isolate of bean yellow mosaic virus (BYMV) decreased herbage and root production of a subterranean clover cultivar by 31-40%, but with a severe isolate the corresponding losses were 60-63010 in the same cultivar and 79-80% in another. The severe BYMV isolate caused losses in herbage and root production of 38-61% in two burr medic cultivars. Seed yield losses recorded due to infection of subterranean clover were 71% with AMV and 58-76% with BYMV (severe isolate); both viruses decreased seed size as well as seed yield. CMV decreased seed yield by 94% in a burr medic cultivar; it also decreased seed size.

Application of non-selective herbicides during flowering of pasture legumes can reduce seed yield and alter seed characteristics

1998 ◽  
Vol 38 (6) ◽  
pp. 583 ◽  
Author(s):  
A. Wallace ◽  
R. A. Lancaster ◽  
N. L. Hill
Keyword(s):  
Seed Yield ◽  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Farming Systems ◽  
Early Summer ◽  
Hard Seed ◽  
Time Of Application ◽  
Pasture Legumes ◽  
Clover Seed

Summary. Spraytopping, the application of a low rate of non-selective herbicide (usually glyphosate or paraquat) to annual grass seed heads in the spring or early summer for seed set control is widely practised throughout Australia. While grasses are the targets of the spray treatment, annual pasture legumes may also be damaged by spraytopping, particularly if the legumes are flowering at the time of application. The effect of applying glyphosate (90, 112 or 162 g a.i./ha), paraquat (100 g a.i./ha) and glyphosate plus MCPA (90 + 150 g a.i./ha) to subterranean clover (Trifolium subterraneum L. cv. Dalkeith) and annual medic (Medicago polymorpha L. cvv. Serena, Santiago and Circle Valley) pastures at various times during flowering was investigated during the spring of 1993 and 1994. Experiments were located at Tincurrin and Tenindewa, Western Australia. Subterranean clover seed yield was most affected by applications of glyphosate (90 and 162 g a.i./ha) and glyphosate plus MCPA (90 + 150 g a.i./ha) during early–mid flowering. Seed yield was reduced by as much as 88% following application of glyphosate plus MCPA when 20% of the subterranean clover plants were flowering. Treatment with paraquat (100 g a.i./ha) during mid–late flowering reduced seed yield of subterranean clover by 25–50% in experiment 1 only. Medic seed yield was reduced up to 90% depending on cultivar when glyphosate (112 g a.i./ha) was applied during early–mid flowering. In addition to seed yield, the level of hard seed was assessed. Treatment of subterranean clover during early–mid flowering with glyphosate (90 and 162 g a.i./ha) significantly reduced the quantity of hard seed produced. Thirty–forty percent of subterranean clover seed was germinable soon after seed set, compared with 7–17% germinable for the seed from untreated plants. Treatment with glyphosate (112 g a.i./ha) reduced the proportion of hard seed in the medics when applied during mid flowering. Treatment with paraquat had little effect on the proportion of hard seed formed. This work demonstrates that using a spraytopping technique for control of seed set in annual grasses may dramatically reduce seed yield in pasture legumes. Spraytopping can further reduce the ability of legumes to persist in cropping rotations by reducing the amount of hard seed formed. Implications for practical farming systems are outlined.

scholarly journals Diversity within subterranean clover and biserrula for persistence traits with potential use in New Zealand hill country

2016 ◽  
Vol 16 ◽  
pp. 299-307
Author(s):  
K. Ghamkhar ◽  
T. Faithful ◽  
P.G.H. Nichols ◽  
M.H. Ryan
Keyword(s):  
New Zealand ◽  
Microsatellite Markers ◽  
Flowering Time ◽  
Core Collection ◽  
Growth Habit ◽  
Subterranean Clover ◽  
Late Flowering ◽  
Hill Country ◽  
Forage Species ◽  
Potential Use

As part of an investigation into the potential of alternative forage species and/or germplasm in New Zealand's hill country and the traits required for their success, two F2 populations, their original parents, and 34 cultivars of subterranean clover (Trifolium subterranean) were evaluated for hardseededness in Australia. The 34 cultivars were also screened for burr burial strength and flowering time. Microsatellite markers were also used to investigate their association with these traits. The polygenic nature of hardseededness was confirmed and markers associated with this trait were detected and traits for New Zealand's hill country were identified. Additionally, a core collection of 30 (two cultivars and 28 wild) biserrula (Biserrula pelecinus) accessions was screened for flowering time, growth habit and leaflet size. Also, a subset of five accessions of biserrula exhibited traits that are desirable for hill country, namely, mid-late flowering and adaptation to lowmedium rainfall. Keywords: biserrula, flowering time, hardseededness, hill country, subterranean clover

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