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.

The interrelation of age, permeability and viability of subterranean clover seeds

1969 ◽  
Vol 9 (40) ◽  
pp. 513
Author(s):  
JA Carpenter
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
The Other ◽  
Small Samples ◽  
Long Term Storage ◽  
Common Effect ◽  
Seed Content ◽  
The Common ◽  
Term Storage

The proportions of impermeable seeds, and the viability of permeable and impermeable seeds were measured in samples of Trifolium subterraneum seed that had been stored in a laboratory for up to 34 years. Viability of permeable seed decreased from 99 per cent after storage for 1 year to 8 per cent after 30 years. On the other hand, all impermeable seeds were viable for 1 to 5 years, and 83 per cent were viable after 30 years. The impermeable seed content of the older seed lots was generally higher than that of the younger ones. This difference was related to the high retention of impermeability of the seeds during storage, and to changes in the severity of threshing methods. The impermeable seed content was also correlated positively but poorly with the viability of both permeable and impermeable seeds, independent of the age of the seed. These associations are probably due to the common effect of the environment on all these variables during seed ripening. A small varietal component in each variable was detected. The implications of these data for the long-term storage of small samples of seed are discussed.

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.

An analysis of seed yield in some strains of subterranean clover (Trifolium subterraneum L.) when grown in binary mixtures

1981 ◽  
Vol 32 (3) ◽  
pp. 445 ◽  
Author(s):  
RC Rossiter ◽  
MJ Palmer
Keyword(s):  
Competitive Advantage ◽  
Seed Yield ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
The Other ◽  
Pair Member ◽  
Replacement Series ◽  
Beginning Of Flowering ◽  
Seed Yields

Two experiments using various strains of subterranean clover are described. The first experiment was conducted in the field with mixtures of Dwalganup/Northam A, DwalganupI/Daliak and Yarloop/Seaton Park, and the second in an open-sided glasshouse with Yarloop/Seaton Park. In the field experiment, the plots were grazed continuously from late July until early November when the swards were completely dry; in the glasshouse experiment, the swards were defoliated weekly until shortly after the beginning of flowering. Mixtures were arranged according to the de Wit replacement series. Seed yields for the Dwa1ganup/Northam A mixture showed the classical (de Wit) competition for the same resources, with Northam A the better competitor. On the other hand, for the Dwalganup/Daliak and Yarloop/Seaton Park mixtures there was no clear evidence of a competitive advantage of one strain over the other pair member, at least under our defoliated conditions. Whether or not this absence of 'competition' (as usually understood) is common in clover-strain mixtures is as yet unknown. We emphasize, however, that long-term success of clover strains in mixtures is not invariably associated with competitive advantage.

scholarly journals A Conservative Approach to a Peripheral Ameloblastoma

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Rocco Borrello ◽  
Elia Bettio ◽  
Christian Bacci ◽  
Marialuisa Valente ◽  
Stefano Sivolella ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Soft Tissues ◽  
Complete Removal ◽  
The Other ◽  
Conservative Approach ◽  
Choice Of Treatment ◽  
Long Term Follow Up ◽  
One Year

Peripheral Ameloblastoma (PA) is the rarest variant of ameloblastoma. It differs from the other subtypes of ameloblastoma in its localization: it arises in the soft tissues of the oral cavity coating the tooth bearing bones. Generally, it manifests nonaggressive behavior and it can be treated with complete removal by local conservative excision. In this study we report a case of PA of the maxilla in a 78-year-old female patient and we describe the four different histopathological patterns revealed by histological examination. After local excision and diagnosis, we planned a long term follow-up: in one year no recurrence had been reported. The choice of treatment is illustrated in Discussion.

Long-term persistence of subterranean clover Trifolium subterraneum L.) cultivars at three sites in south-western Victoria

1997 ◽  
Vol 37 (5) ◽  
pp. 531
Author(s):  
S. G. Clark ◽  
J. Li ◽  
A. M. Johnson ◽  
G. N. Ward ◽  
J. F. Chin
Keyword(s):  
Perennial Grass ◽  
Subterranean Clover ◽  
Late Summer ◽  
Trifolium Subterraneum ◽  
Contamination Level ◽  
Black And White ◽  
Small Plot ◽  
Black Seeds ◽  
Western Victoria ◽  
Annual Weeds

Summary. The seed banks of 6 subterranean clover (Trifolium subterraneum L.) cultivars were sampled at 3 abandoned cultivar evaluation experiments in south-western Victoria (Hamilton, Macarthur and Timboon). Two were var. yanninicum (Trikkala and Larisa) and 4 were var. subterraneum (Denmark, Goulburn, Karridale and Leura). Seed was sampled in late summer–early autumn 1993, between 6 and 10 years after the sites were established and between 3 and 7 years after the sites were abandoned. The collected seed was separated into black and white seed, and a sample of the black seed was grown in a glasshouse and identified as either belonging to the sown cultivar or belonging to another cultivar/genotype. All white seed was assumed to belong to the sown cultivar. The aim was to determine if these widely used cultivars were persisting under farm management conditions and competition from perennial grass, other subterranean clover and annual weeds. With some variation between sites all cultivars were found to be persisting satisfactorily. Over the 3 sites, white-seeded cultivars averaged 460 kg/ha and 6640 seeds/m2; black-seeded cultivars averaged 260 kg/ha and 5590 seeds/m2. Contamination with other subterranean clover cultivars/ecotypes was generally low, except at Macarthur where the white-seeded cultivars were heavily contaminated (Trikkala 39% pure; Larisa 57% pure) with black seeds highlighting the poor adaptation of var. yanninicum to light soil types. Of the black seeds, over the 3 sites, average contamination level was 13% and ranged from 41% (Goulburn at Macarthur) to 1% (Leura at Timboon). The study indicates that in south-western Victoria, all the recently released cultivars are likely to persist and be productive, and that the small-plot evaluation techniques used to identify potential new cultivars are likely to be adequate if replicated in space and if the clovers are sown in mixed swards with perennial grass.

Effect of perennial pasture species on surface soil moisture and early growth and survival of subterranean clover (Trifolium subterraneum L.) seedlings

1997 ◽  
Vol 48 (5) ◽  
pp. 683 ◽  
Author(s):  
B. S. Dear ◽  
P. S. Cocks
Keyword(s):  
Mineral Soil ◽  
Subterranean Clover ◽  
Late Summer ◽  
Soil Surface ◽  
Trifolium Subterraneum ◽  
Annual Grass ◽  
Growth And Survival ◽  
Eastern Australia ◽  
Standing Dead ◽  
Clover Seed

Subterranean clover seedling numbers and growth in swards containing 1 of 5 perennial pasture species [phalaris (Phalaris aquatica) cv. Sirolan, cocksfoot (Dactylis glomerata) cv. Currie, lucerne (Medicago sativa) cv. Aquarius, wallaby grass (Danthonia richardsonii) cv. Taranna, and lovegrass (Eragrostis curvula) cv. Consol] were compared with those in typical annual pastures and pure clover swards in the wheatbelt of eastern Australia. Presence of a perennial species or the volunteer annual grass (Eragrostis cilianensis) increased the rate of drying of the soil surface (0–5 cm) after late February and May rain, compared with subterranean clover swards. Perennials differed in the rate they dried the soil surface, with the more summer-active lucerne and consul lovegrass drying the profile more rapidly than phalaris. The amount of water in the surface 5 cm, 6 days after the rainfall event on 27–28 February, was strongly negatively correlated (r = –0·75, P < 0·01) with the amount of green perennial biomass, but not related to standing dead material or surface residues. Where perennials were present, a smaller proportion (2–4%) of the clover seed pool produced seedlings in response to late summer rain, compared with pure clover swards (18%). A higher proportion of the seed pool produced seedlings (19–36%) following rain in late autumn but there was no difference between species. The more summer-active perennials (cocksfoot, danthonia, and lucerne) markedly depressed the survival of emerged clover seedlings following both germinations. Of the seedlings that emerged in early March, the proportion remaining by 29 March was 57% in phalaris, 21% in lucerne, 13% in danthonia, and 1% in cocksfoot, compared with a 78% increase in seedlings in pure subterranean clover swards. By 15 May, all perennials had <2 clover seedlings/m2 surviving, compared with 37 in the annual pasture and 964 plants/m2 in pure subterranean clover. Following the May germination, the highest proportion of emerged seedlings surviving until 29 May was in the phalaris swards (40%) and least in the cocksfoot and danthonia swards (2–4%). Presence of a perennial or annual grass decreased (P < 0·05) relative water content of clover seedlings on 15 March from 74% in pure clover swards, to 48% in annual pasture, 34% in phalaris, and 29% in lucerne swards. Clover seedlings growing in pure subterranean swards on 15 March (17 days after germinating rain) were 4 times larger than those in lucerne and twice as large as those in either phalaris or annual pasture. Seed size did not differ between treatments, but available mineral soil nitrogen was significantly higher (P < 0·001) in pure subterranean clover swards (32 mg N/g) compared with perennials (3–13 mg N/g). Strategies such as heavy grazing in late summer to reduce green biomass of the perennials or sowing the perennials at lower densities may reduce the adverse effects that perennials have on subterranean clover seedlings in these drier environments.

Phosphorus, sulphur, and molybdenum deficiencies in soils from eastern Australia in relation to nutrient supply and some characteristics of soil and climate.

1955 ◽  
Vol 6 (5) ◽  
pp. 673 ◽  
Author(s):  
KD McLachlan
Keyword(s):  
Phosphorus Deficiency ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Parent Material ◽  
The Other ◽  
Podzolic Soils ◽  
Sulphur Deficiency ◽  
Eastern Australia ◽  
Yield Responses ◽  
Western Victoria

Subterranean clover (Trifolium subterraneum L.) was grown on 32 virgin soils in pot cultures, and the yield responses to phosphorus, sulphur, and molybdenum were determined for each soil. The soils were collected from a wide area in eastern Australia, extending from south-western Victoria to southern Queensland. Sulphur deficiency occurred almost as frequently as phosphorus deficiency. In fact, 75 per cent. of the soils were deficient in both phosphorus and sulphur. Thirty-one per cent. were deficient in all three elements. The effect of the interaction between the elements on the occurrence and intensity of the deficiencies is shown. Molybdenum responses were obtained only after the other deficiencies had been corrected. A deficiency in one of the elements is no indication of deficiency or sufficiency of either of the other two. There was no correlation between the occurrence or intensity of the deficiencies and the geological origin of the soil parent material, the climate of the regions from which the soils were collected, or such soil characters as colour, organic matter, and texture. Responses to phosphorus were less on the black earths than on the red or yellow podzolic soils; those on the red earths were intermediate. The intensity of sulphur deficiency increased, and the intensity of molybdenum deficiency decreased, with increasing soil pH.

The growth of barley grass (Hordeum leporinum) in annual pasture. 3. Some factors affecting balance with subterranean clover (Trifolium subterraneum)

1968 ◽  
Vol 8 (35) ◽  
pp. 702 ◽  
Author(s):  
DF Smith
Keyword(s):  
Soil Nitrogen ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Moisture Stress ◽  
Nitrogen Addition ◽  
The Other ◽  
Early Start ◽  
Factors Affecting ◽  
Two Factors ◽  
Hordeum Leporinum

Mixed swards of barley grass (Hordeum leporinum) and subterranean clover (Trifolium subterraneum) of two densities were grown at two levels of nitrogen. Growth was started at two different times mid- April and mid-May-and at each time half the plots were subjected to moisture stress. The swards were harvested after nine weeks of growth. The survival of clover plants was reduced by an early start, moisture stress and nitrogen addition : much more so than barley grass. The root : shoot ratios of both species were calculated ; both showed some sensitivity to the time of break and moisture stress, and the grass was also affected by the other two factors. Total sward production and the ratios of clover to grass varied widely Grass daminance was favoured by moisture stress or a late break, and both of these factors tended to override the effect of higher soil nitrogen in determining clover-grass balance. Total sward production more dependent on density than any other factor, especially with the later start. Higher nitrogen was effective in boosting production only if the break was early and there was no moisture stress.

Seed production and persistence of Carnamah and other early strains of Trifolium subterraneum in the wheatbelt of Western Australia

1967 ◽  
Vol 7 (24) ◽  
pp. 25 ◽  
Author(s):  
GB Taylor ◽  
RC Rossiter
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Early Flowering ◽  
The Other ◽  
Factors Affecting ◽  
Seed Yields

Seed production and persistence of the Carnamah, Northam A, Dwalganup, and Geraldton strains of subterranean clover (Trifolium subterraneum L.) were examined in undefoliated swards in the wheatbelt of Western Australia. The early flowering characteristic of Carnamah was not always associated with higher seed yields. Only when there was a well-defined, early finish to the growing season, or when flowering was very much earlier in Carnamah (viz., following an early 'break' to the season), did this strain clearly outyield both Northam A and Geraldton. The seed yield of Dwalganup was generally inferior to that of the other strains. Factors affecting regeneration are discussed. Under low rainfall conditions, poorer germination-regulation of Carnamah, compared with Geraldton and Northam A, would be expected to result in poorer persistence unless offset by higher seed yields in the Carnamah strain.

scholarly journals Common Chord Progressions and Feelings of Remembering

2020 ◽  
Vol 3 ◽  
pp. 205920432091684
Author(s):  
Ivan Jimenez ◽  
Tuire Kuusi ◽  
Christopher Doll
Keyword(s):  
Popular Music ◽  
North American ◽  
Musical Training ◽  
The Other ◽  
Long Term Memory ◽  
Term Memory ◽  
One Year

Although Western tonal syntax can generate a very large number of chord successions of various lengths and degrees of complexity, some types of music, from Renaissance dances to recent pop, tend to rely more heavily on the repetition of relatively simple, short harmonic patterns. Doll recently identified short chord progressions commonly found in North American and British popular music and proposed that these chord progressions can be stored in long-term memory in the form of harmonic schemata that allow listeners to hear them as stereotypical chord progressions. However, considering the challenges that many listeners face when trying to consciously grasp harmony, it seems likely that the feelings of remembering chord progressions varies from listener to listener. To investigate these potential differences, we asked 231 listeners with various levels of musical training to rate their confidence on whether or not they had previously heard six diatonic four-chord progressions. To control for the effect of extra-harmonic features, we instantiated the chord progressions in a way that resembled the piano of a famous song and controlled for participants’ familiarity with that song and whether they had played its chords. We found that ratings correlated with typicality for the two groups of participants who had played an instrument for at least one year and to a lesser extent for the other participants. Additionally, all our players thought of specific songs more often and mentioned songs that better matched the stimuli in harmonic terms. What we did not find, however, was any effect associated to how long participants had played an instrument or the type of the instrument they had played. Our research supports the notion that both musical training and extra-harmonic features affect listeners’ feelings of remembering chord progressions.

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