Seed softening patterns from single seed crops of subterranean clover (Trifolium subterraneum L.) in a cool temperate environment

1995 ◽  
Vol 35 (8) ◽  
pp. 1117 ◽  
Author(s):  
PM Evans ◽  
EJ Hall
Keyword(s):  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
First Year ◽  
Original Seed ◽  
Cool Temperate ◽  
Set Up ◽  
Negative Exponential ◽  
Seed Crops ◽  
The Relationship

An experiment was set up in northern Tasmania with 7 cultivars of subterranean clover widely ranging in maturity and levels of hardseededness. They were planted as pure swards and in a mixture with perennial ryegrass. After seed set in the first year, all seedling regenerations were counted and then killed, and seed populations were measured each summer for 6 years. No significant differences in seed losses existed between the pure swards and the mixtures or between cultivars. Negative exponential functions of the relationship between seed banks and time fitted the data well with r2 ranging from 0.87 (Nungarin) to 0.998 (Trikkala). By mid-summer of the sixth year the percentages of the original seed left in the ground were: Enfield 12%, Woogenellup 19%, Trikkala 20%, Nungarin 21%, Larisa 24%, and Karridale and Mt Barker 31%. Seeds at higher latitudes were lost at about half the rates experienced at lower latitudes with drier, hotter summers. The higher percentages of seed remaining in plots with later maturing cultivars suggest that environmental conditions favoured the production of hard seeds while the reverse was the case with very early, hardseeded cultivars like Nungarin.

scholarly journals The influence of patterns of flowering of some subterranean clover (Trifolium subterruneum L.) accessions and cultivars on total seed set and autumn germination in a cool temperate environment with sporadic summer rain

1994 ◽  
pp. 127-131
Author(s):  
M.L. Smetham ◽  
D.W. Jack ◽  
Sandy E.H. Hammond
Keyword(s):  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Late Flowering ◽  
Cool Temperate ◽  
Stony Soil ◽  
Temperate Environment ◽  
Total Seed ◽  
Seed Yields ◽  
Summer Rain

Fifteen accessions and 3 cultivars of subterranean exnected for this site. It is concluded that lateclover (Trifolium subterranean L.) were sown in autumn in shallow stony soil south of Christchurch, New Zealand. The following growing season was atypical, with drought occurring briefly but one month earlier than usual, the rest of the season being wetter than usual. Contrary to previous results highest seed yields were given by mid- to lateseason flowering lines. Early flowering lines were severely disadvantaged by the early drought, resulting in seed yields of only 20-25 kg/ha. High seed yields were linked with the ability of lines to recommence flowering after drought and continue this for a prolonged period. Two late flowering accessions, 014454B and 014205B, yielded more than 200 kg/ha seed, outyielding the late flowering cv. Tallarook in spite of this cultivar having the same ability as the other two to reflower. Six highseed yielding lines gave naturally regenerated seedling numbers near to or exceeding 1000/m2. Apparent hardseededness at the time of autumn germination averaged 49% which was lower than expected for this site. It is concluded that late fldwering lines of subterranean clover should always be included in mixtures of this species for pasture to ensure adequate regeneration in wetter than normal seasons. Keywords: accessions, cultivars, flowering, hardseededness, regeneration, seed production, Trifolium subterraneum

Time distribution of seedlings emergence from single seed crops of several annual pasture legumes

1972 ◽  
Vol 12 (59) ◽  
pp. 628 ◽  
Author(s):  
GB Taylor
Keyword(s):  
Seed Set ◽  
Seedling Emergence ◽  
Subterranean Clover ◽  
Hard Seed ◽  
Barrel Medic ◽  
The Third ◽  
Single Seed ◽  
Pasture Legumes ◽  
Original Seed ◽  
Seed Crops

Seedling emergence from single seed crops of Dwalganup and Geraldton subterranean clover, Yamina cupped clover, Troodos and Kondinin rose clover, and Cyprus barrel medic, was studied in a low rainfall wheatbelt environment in Western Australia. The proportion of the original seed set recovered as seedlings was highest from the subterranean clovers in the first year but about the same for all genotypes in the second year. Few subterranean clover seeds were recovered in the third regeneration year either as seedlings or residual hard seeds, whereas significant proportions of the original seed of the other genotypes were obtained. More than 10 per cent of the original seed of Cyprus barrel medic and Yamina cupped clover remained ungerminated at the end of the third season. Between about 35 and 75 per cent of the original seed set was not accounted for in the genotypes studied. The proportions of the total seedling numbers that emerged following summer and early autumn rains were generally highest from the subterranean clovers and least from the cupped clover and medic. It is suggested that these different patterns of emergence within years were the result of differences in embyro dormancy rather than different patterns of hard seed breakdown.

Response of defoliated swards of subterranean clover and yellow serradella to superphosphate applications

1991 ◽  
Vol 31 (6) ◽  
pp. 777
Author(s):  
MDA Bolland
Keyword(s):  
Field Experiment ◽  
Sandy Soil ◽  
Dry Matter ◽  
Maximum Yield ◽  
Subterranean Clover ◽  
Soil Surface ◽  
Trifolium Subterraneum ◽  
Herbage Yield ◽  
Ornithopus Compressus ◽  
The Relationship

The effect of superphosphate applications (0, 25, 50, 75, 100 and 125 kg P/ha to the soil surface) on the dry matter (DM) herbage production of dense swards of subterranean clover (Trifolium subterraneum cv. Junee) and yellow serradella (Ornithopus compressus cv. Tauro) was measured in a field experiment on deep, sandy soil in south-western Australia. The swards were defoliated with a reel mower at weekly intervals from 88 to 158 days after sowing, to a height of 2 cm for the first 9 cuts, 4 cm for the tenth cut and 5 cm for the eleventh cut. Yellow serradella was more productive than subterranean clover. Consequently, for the relationship between yield and the level of phosphorus (P) applied, yellow serradella supported larger maximum yields and required less P than subterranean clover, to produce the same DM herbage yield. Maximum yields of yellow serradella were 12-40% larger. To produce 70% of the maximum yield for yellow serradella at each harvest, yellow serradella required about 50% less P than subterranean clover. However, when yields were expressed as a percentage of the maximum yield measured for each species at each harvest, the relationship between yield and the level of P applied was similar for both species, and they had similar P requirements.

The short-term effects of rock phosphate and super-phosphate on a subterranean clover pasture.

1955 ◽  
Vol 6 (4) ◽  
pp. 553 ◽  
Author(s):  
RC Rossiter ◽  
PG Ozanne
Keyword(s):  
Rock Phosphate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Phosphorus Recovery ◽  
Available Phosphorus ◽  
First Year ◽  
Short Term ◽  
Pasture Production ◽  
Total Plant ◽  
Second Year

A 2-year field experiment is described, in which an annual-type pasture was grown on a soil of lateritic origin with various initial rates of rock phosphate and superphosphate. The soil was acutely deficient in plant-available phosphorus at the outset. Application of superphosphate led to the expected increases in total pasture production, but rock phosphate also gave substantial yield increases, even during the first season. Differential species effects were noted; subterranean clover (Trifolium subterraneum L.) and cape-weed (Cryptostemma calendula Druce) responded about equally to superphosphate, but the clover responded to rock phosphate to a greater extent than did cape-weed. Both relative efficiency for total plant growth and percentage utilization of applied phosphorus were much higher with the soluble phosphatic fertilizer than with rock phosphate, especially in the first year. However, phosphorus recovery from rock phosphate was as high in the second year as in the first, whereas there was a marked decrease in the second year from superphosphate.

Increased seed production of subterranean clover pastures in response to fertilizers supplying calcium

1974 ◽  
Vol 14 (71) ◽  
pp. 749 ◽  
Author(s):  
PG Ozanne ◽  
KMW Howes
Keyword(s):  
Seed Production ◽  
Calcium Concentration ◽  
Field Experiments ◽  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Unit Weight ◽  
Gypsum Plaster ◽  
Total Seed ◽  
Seed Yields

The effects of four common fertilizers containing calcium on seed production in subterranean clover (Trifolium subterraneum) were measured at six locations over five years in a total of fifteen field experiments. Calcium as a sulphate, carbonate or phosphate salt was applied to subterranean clover pastures either at the start of the growing season (autumn) or at flowering (spring). Gypsum, plaster of Paris, or lime gave large increases in seed yield per unit area and also per unit weight of tops. Spring applications of superphosphate increased seed yields in only two out of four experiments. Gypsum applied in spring at 200-500 kg ha-1 was as effective as 2,000 kg ha-1 of lime applied in autumn. Applications of lime in spring were much less effective. Increased seed yields were due to increases in burr yield, seed number per burr, and mean weight per seed. They were usually accompanied by increases in calcium concentration in the seed. Responses in seed production to calcium applications were obtained in all three sub-species of Trifolium subterraneum. In two experiments, newly sown on a soil type on which subterranean clover regeneration and persistence is commonly very poor, applied calcium doubled or quadrupled seed set. In 13 experiments using soils on which subterranean clover had persisted as the major component of the pasture for several years, calcium in the year of application increased the total seed bank by 6 to 31 per cent, and the current seed set by a greater amount.

Izmir subterranean clover (Trifolium subterraneum L. var. subterraneum)

2007 ◽  
Vol 47 (2) ◽  
pp. 226 ◽  
Author(s):  
P. G. H. Nichols ◽  
G. A. Sandral ◽  
B. S. Dear ◽  
C. T. de Koning ◽  
D. L. Lloyd ◽  
...  
Keyword(s):  
Seed Production ◽  
Seed Set ◽  
New South ◽  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Good Seed ◽  
Improvement Program ◽  
South Wales ◽  
Pasture Legume

Izmir is a hardseeded, early flowering, subterranean clover of var. subterraneum (Katz. et Morley) Zohary and Heller collected from Turkey and developed by the collaborating organisations of the National Annual Pasture Legume Improvement Program. It is a more hardseeded replacement for Nungarin and best suited to well-drained, moderately acidic soils in areas with a growing season of less than 4.5 months. Izmir seed production and regeneration densities in 3-year pasture phases were similar to Nungarin in 21 trials across southern Australia, but markedly greater in years following a crop or no seed set. Over all measurements, Izmir produced 10% more winter herbage and 7% more spring herbage than Nungarin. Its greater hardseededness and good seed production, makes it better suited to cropping rotations than Nungarin. Softening of Izmir hard seeds occurs later in the summer–autumn period than Nungarin, giving it slightly greater protection from seed losses following false breaks to the season. Izmir is recommended for sowing in Western Australia, New South Wales, Victoria, South Australia and Queensland. Izmir has been granted Plant Breeders Rights in Australia.

Effect of timing of forage conservation on forage yield and quality, seed yield and seedling regeneration of four subterranean clover (Trifolium subterraneum) cultivars

2008 ◽  
Vol 48 (8) ◽  
pp. 1133 ◽  
Author(s):  
B. S. Dear ◽  
B. F. Hackney ◽  
G. M. Dyce ◽  
C. A. Rodham
Keyword(s):  
Seed Yield ◽  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Forage Yield ◽  
Seedling Regeneration ◽  
Yield And Quality ◽  
Cutting Height ◽  
Seed Yields ◽  
Forage Yields

Swards of four cultivars of subterranean clover (Trifolium subterraneum L.) were cut at three different times to determine the effect on forage yield and quality, seed set and seedling regeneration in two successive seasons in southern New South Wales. The four cultivars of subterranean clover (Seaton Park LF, Junee, Goulburn and Clare) were cut on 23–25 September (early cut), 8–10 October (mid cut) or 22–23 October (late cut), to simulate an early silage, late silage or hay cut. Additional treatments imposed included either grazing or leaving the regrowth after cutting and raising the cutting height from 3 to 6 cm. Forage yields ranged from 3.5 to 9.3 t dry matter (DM)/ha in the first year and from 2.0 to 5.9 t DM/ha in the second year. Herbage yield was influenced by both cultivar and harvest time with the highest yields achieved with the mid cut. Lower forage yields at the later cut were attributed to losses due to respiration and decay under dense leaf canopies. Changes in forage quality were consistent across both years, with in vivo DM digestibility declining from 76–79% to 69–70% as cutting time was delayed. Crude protein fell from 22–24% to 14–17% over the same period, depending on cultivar. Seed yields in both years were influenced by both cutting time and cultivar with a positive relationship (R2 = 0.45–0.61) between herbage present in late spring after a period of regrowth and subsequent seed yield. The early flowering cultivar Seaton Park LF had the highest seed yield in both years and the more erect cultivar Clare had the lowest. Seed yields declined with later cutting time but increased by an average of 39% when the cutting height was raised from 3 to 6 cm. Seedling regeneration reflected seed yield responses with the largest seedling regeneration occurring in treatments cut early. The study found that forage conservation in early October is likely to yield more and be of higher quality than swards cut later in the season. Seed set is greatly reduced by all cutting strategies to levels unprofitable for seed harvesting but may be adequate for pasture regeneration.

Time application of superphosphate and the yield of pasture on an acid soil.

1961 ◽  
Vol 1 (2) ◽  
pp. 81
Author(s):  
KD McLachlan
Keyword(s):  
Acid Soil ◽  
Total Yield ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
First Year ◽  
Botanical Composition ◽  
Time Of Application ◽  
Relative Ability ◽  
Main Effect ◽  
Earlier Application

Superphosphate was applied in summer (December) or in autumn (March) to an existing mixed pasture of subterranean clover (Trifolium subterraneum L.) and phalaris (Phalaris tuberosa L.), growing on apodsolic soil of p H 5.8. Time of application effects were recorded at the lowest level of applied phosphate. The main effect was on the botanical composition of the pasture. The summer application favoured clover, the autumn one grass. This effect is explained as a change in the relative ability of the species to compete for superphosphate. These results suggest how time and rate of application of superphosphate may be used to manage pasture composition. In the first year, when clover growth was encouraged, the earlier application also increased the total yield of pasture. In the second and third years, changes in the yield of grass were offset by changes ill the yield of clover and the effect of time of application on total pasture yield was not significant.

Long term patterns of seed softening and seedling establishment from single seed crops of subterranean clover

1984 ◽  
Vol 24 (125) ◽  
pp. 200 ◽  
Author(s):  
GB Taylor ◽  
RC Rossiter ◽  
MJ Palmer
Keyword(s):  
Seedling Establishment ◽  
Subterranean Clover ◽  
Late Summer ◽  
Trifolium Subterraneum ◽  
The Other ◽  
Hard Seed ◽  
Single Seed ◽  
One Year ◽  
Seed Crops

Single seed crops of eight varieties of subterranean clover (Trifolium subterraneum) were grown in swards in four successive years in a medium rainfall environment at Bakers Hill, Western Australia. Measurements were made of seed production, the progress of seed softening within the first two summers, and residual hard seed and seedling numbers after the break of season for up to six successive regeneration years. Patterns of seed softening were also measured in a laboratory oven with a diurnal temperature fluctuation of 60/15�C. Approximately half the seeds of all varieties softened over the first summer and generally well over half the residual seeds softened during the second summer. Up to 18% of seeds of the hardest seeded variety, Northam, and 11% of Geraldton seeds persisted to the end of the third summer as hard seeds. Seed softening patterns showed a significant variety x regeneration year interaction due mainly to a slower rate of softening of Northam seeds relative to the other varieties after the first summer. In six of the varieties, seeds generally softened more slowly in the laboratory than in the field but in the case of the other two varieties this trend was reversed. Nevertheless, ranking of varieties for rate of seed softening was similar in field and laboratory. Seedling establishment ranged from 28 to 100% of soft seeds, depending on the incidence of late summer and autumn rains. It appeared that all varieties in the study would regenerate satisfactorily at densities of more than 15 plants/dm2 after at least one year in which little or no seed is set. Slower rates of softening would probably be desirable in drier regions or in rotation systems involving cropping.

Influence of cultivar and season on the response of Trifolium subterraneum to simazine

1992 ◽  
Vol 32 (8) ◽  
pp. 1095 ◽  
Author(s):  
BS Dear ◽  
DJ Conlan ◽  
MF Richards ◽  
NE Coombes
Keyword(s):  
Seed Set ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Yield Response ◽  
Yield Losses ◽  
Lolium Rigidum ◽  
Herbage Yield ◽  
Annual Grasses ◽  
Clover Seed ◽  
Seed Yields

The tolerance of 6 cultivars of Trifolium subterraneum (subterranean clover) to simazine applied at 0.63 and 1.25 kg a.i./ha was determined under weedfree conditions in the field by measuring herbage and seed yields. Large herbage yield losses occurred as a result of the simazine in spring in the 2 years of the experiments. In 1989, spring herbage yield losses of the cultivars at the 0.63 and 1.25 kg/ha simazine rates averaged 56 and 82%, respectively. In 1990 the spring herbage yield losses were 27 and 51%. Significant variation in tolerance was observed between cultivars in both years, with Trikkala being the most tolerant and Karridale the most susceptible cultivar. Rate of herbicide had the greatest effect on herbage yield, with cultivar having a smaller effect. In 1989, with relatively favourable spring conditions, clover seed yields were depressed by simazine, but in 1990 when drier conditions prevailed during flowering and seed set, seed yields were unaffected or slightly increased by simazine in all cultivars except the early-flowering cultivar Dalkeith. Seed yields of simazine-treated swards were 196-1480 kg/ha in 1989 and 359-686 kg/ha in 1990. The seed yield response in 1990 suggests that herbicides which retard growth in winter help to conserve soil water and, therefore, may benefit seed filling later in the season. The presence of Lolium rigidum at spraying did not reduce the effect of the herbicide on clover herbage yield and had no effect on seed set. Although simazine may reduce herbage yields and, in some cases, seed yields, its use may be justified for the control of annual grasses when other factors such as disease control, pasture quality, and level of weed competition are considered.

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