Some characteristics of "Carnamah", a very early-flowering strain of Trifolium subterraneum L., when grown as single plants

1961 ◽  
Vol 12 (1) ◽  
pp. 27 ◽  
Author(s):  
RC Rossiter ◽  
AJ Millington
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Early Flowering ◽  
Winter Period ◽  
Flower Initiation ◽  
Total Production ◽  
Initiation Rate ◽  
The Difference ◽  
Early Flower ◽  
Early Strain

A very early-flowering strain of subterranean clover was discovered in 1957 at Carnamah, W.A. From extensive studies at several field centres, it was demonstrated that the new strain – now called Carnamah – commenced flowering from 30 to 10 days before Dwalganup (the standard commercial "early" strain) when sown in the autumn-early winter period. With very early planting – late March – the difference in flowering time was even greater (about 45–50 days). The very early-flowering nature of the Carnamah strain is associated with early flower initiation. Rate of flower development (from flower initiation to flower appearance) in relation to temperature was similar for Carnamah and Dwalganup. Under spaced-plant conditions the total production of Carnamah was much less than that of Dwalganup, a finding which conforms to the results of previous single-plant studies. The new strain was not readily distinguished from Dwalganup, but several minor differences in morphology are mentioned. The chromosome number was normal for the species (2n = 16). The relevance of these data to sward conditions is discussed briefly, and it is suggested that the Carnamah strain may be more effective than Dwalganup in extending the "clover belt" inland in southern Australia.

Flower initiation in pasture legumes. I. Factors affecting flower initiation in Trifolium subterraneum L.

1955 ◽  
Vol 6 (2) ◽  
pp. 211 ◽  
Author(s):  
Y Aitken
Keyword(s):  
Low Temperature ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Cold Period ◽  
Effect Of Temperature ◽  
Flower Initiation ◽  
Temperature Level ◽  
Factors Affecting ◽  
Pasture Legumes ◽  
Precise Knowledge

The value of the annual legume Trifolium subterraneum L. (subterranean clover) in Australian agriculture warrants more precise knowledge of factors affecting flowering and prolific seeding. The effect of temperature and photoperiod on flower initiation in early and later flowering varieties has been investigated in an effort to determine the geographical limits of the use of subterranean clover in Australia. At any time of sowing, the length of the growing season of a variety depends greatly on the variety's response to the temperature level and to the photoperiod of the first few weeks after germination. In all varieties of subterranean clover so far examined flower initiation is accelerated by a period of low temperature. In the later varieties, flower initiation is prevented by an insufficient period of low temperature. The length of the necessary cold period is shortened under longer photoperiod. Early varieties are early flowering because they do not require so long a cold period or so low a temperature as late varieties.

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.

Flower initiation in Trifolium subterraneum L. II. Limitations by vernalization, low temperatures, and photoperiod, in the field at Canberra

1959 ◽  
Vol 10 (1) ◽  
pp. 17 ◽  
Author(s):  
FHW Morley ◽  
LT Evans
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Day Length ◽  
Flower Initiation ◽  
Inhibitory Effects ◽  
Low Field ◽  
The Times ◽  
Short Days

At various times throughout the winter, autumn-sown plants of five strains of subterranean clover were removed from the field to a series of day length and temperature treatments. The times to inflorescence initiation in all treatments were determined by dissection. As vernalization proceeded the requirement of all strains for long days was progressively reduced until, by midwinter, several strains had become virtually independent of day length. Similarly, with the progress of vernalization the inhibitory effects of high temperatures during short days became progressively less marked. Whereas exposure to long days at high temperatures greatly accelerated inflorescence initiation in all strains, long days at low field temperatures had little effect. Evidence is presented which suggests that the limiting effect of very low temperatures on initiation is due not only to retardation of the rate of inflorescence primordium formation (realization), but also to limitation of an inductive process other than vernalization and dark period inhibition. The flowering behaviour of the various strains is discussed in terms of their responses to the partial processes leading to inflorescence initiation, and the interrelationships of these processes are considered.

Copper nutrition of subterranean clover (Trifolium subterraneum L. cv. Seaton Park). II. Effects of copper supply on distribution of copper and the diagnosis of copper deficiency by plant analysis

1981 ◽  
Vol 32 (2) ◽  
pp. 267 ◽  
Author(s):  
DJ Reuter ◽  
AD Robson ◽  
JF Loneragan ◽  
DJ Tranthim-Fryer
Keyword(s):  
Copper Concentration ◽  
Copper Deficiency ◽  
Critical Concentration ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Maximum Growth ◽  
Young Leaf ◽  
Early Flowering ◽  
Plant Age ◽  
Vegetative Development

The effect of copper supply upon the distribution of copper within Seaton Park subterranean clover was examined from early vegetative growth to plant maturity in one glasshouse experiment, and in a second experiment was assessed at early flowering. The copper content of old leaf blades of copper-adequate plants decreased progressively with senescence of the blades. Copper deficiency delayed senescence and export of copper from the older blades so that both the relative and net changes were substantially smaller than for blades of copper-adequate plants. However, copper concentrations in senesced old leaf blades still reflected copper supply. At full senescence these blades contained appreciable quantities and concentrations of copper which contrasted with the low levels found in senesced leaves of wheat and peanuts in previous studies. Copper concentration in whole plant tops was not satisfactory for diagnosing copper deficiency, since the critical concentration decreased with plant age and during late vegetative development 'Piper-Steenbjerg' curvature developed in the relationship between copper concentration and yield. It is possible that the curvature resulted partly from unusually high concentrations of copper in the old petioles of severely deficient plants. Analysis of copper in young leaf blades provided a sensitive means of diagnosing copper deficiency in subterranean clover. The estimated critical concentration for these blades (3 �g/g for maximum growth) did not change with plant age, at least until early flowering. In early growth, the copper concentration of young leaf blades may be used to forecast impending copper deficiency.

Vernalization as a factor influencing the rate of development in subterranean clover (Trifolium subterraneum L.)

1975 ◽  
Vol 26 (6) ◽  
pp. 959 ◽  
Author(s):  
WJ Collins ◽  
DF Smith
Keyword(s):  
Environmental Conditions ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Flower Initiation ◽  
Rate Of Development ◽  
Practical Consequence ◽  
Normal Field ◽  
Delayed Flowering

An investigation of the influence of vernalization on the rate of development in three cultivars of subterranean clover was conducted under controlled environmental conditions. Effects were evaluated in terms of the time from imbibition to flower initiation or flowering, i.e. including the time during which vernalization was imposed. In these terms, vernalization actually delayed flowering in the Yarloop and Mt. Barker cultivars, hastening it only in Tallarook. Some practical considerations are discussed. The effects of periods of higher temperatures after vernalization on the rate of development were also studied. No evidence was found for the occurrence of devernalization. If devernalization docs occur in subterranean clover, it is unlikely to be of practical consequence in normal field situations.

Factors affecting the productivity of irrigated annual pastures. 2. Defoliation by dairy cows

1986 ◽  
Vol 26 (3) ◽  
pp. 305 ◽  
Author(s):  
CR Stockdale
Keyword(s):  
Grazing Intensity ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Total Production ◽  
Pasture Production ◽  
Factors Affecting ◽  
Grazing Intensities ◽  
Seed Reserves ◽  
Clover Seed

The influence of grazing intensity on the productivity of an irrigated annual pasture was studied for 3 years in northern Victoria. Lax-, medium- and hard-grazing intensities were described by post-grazing pasture heights of 7.2, 5.2 and 3.0 cm, respectively. Also, one instance of variable grazing frequency occurred, in winter of year 1. Hard-grazed plots produced 1 3 and 17% less herbage in years 1 and 2, respectively, than did lax- and medium-grazed plots, which produced similar amounts of herbage. When the interval between grazings was extended, the variation in productivity was reversed; lax grazing resulted in 9% less total production than heavier grazing. In years 1 and 2, there was little effect of grazing treatment on botanical composition until spring, at which time there was a marked reduction in the amount of subterranean clover (Trifolium subterraneum) in the hard-grazed plots, with a concomitant increase in grass content. There were no significant effects of grazing intensity on the amounts of weeds in either year. However, in year 3, weeds were important contributors to pasture production early in the season. This, together with reduced clover seed reserves and increased incidence of disease in subterranean clover with hard grazing, suggests that the long-term regenerating ability of an annual pasture may be impaired if severely grazed at regular intervals.

Flower initiation in Trifolium subterraneum L. 1. Analysis of the partial processes involved

1959 ◽  
Vol 10 (1) ◽  
pp. 1 ◽  
Author(s):  
LT Evans
Keyword(s):  
High Temperatures ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
The Other ◽  
Controlled Environment ◽  
Flower Initiation ◽  
Inhibitory Process ◽  
Inhibitory Effects ◽  
Other Hand ◽  
Short Days

The influence of various temperature and photoperiod regimes on flower initiation and flowering in eight strains of T. subterraneum has been examined, using the controlled environment facilities of the Earhart Laboratory. Flower initiation in subterranean clover appears to be under the control of three interacting partial processes, two of which are synergistic and promotive while the third is inhibitory. The promotive processes are possibly both light-independent, one being favoured by high temperatures and the other (the vernalization process) by low temperatures. The inhibitory process, on the other hand, is restricted to the diurnal dark period and is favoured by high temperatures. The interaction between the vernalization and dark inhibitory processes is such that in the absence of dark inhibition no vernalization is required by any strain, while on. the other hand sufficient vernalization can apparently overcome all dark inhibitory effects. Treatment with gibberellic acid eliminates the need for vernalization by plants of at least one early-flowering strain when. grown in short days at high temperatures. The strains of subterranean clover differ markedly in their responses to the three partial processes. In their response to the dark inhibitory process two strains are more affected by night temperature than by night length, while in two other strains the opposite is the case, which suggests that the dark inhibitory process could be resolved into more than one component.

The productivity of irrigated legumes in northern Victoria. 3. Frequency and intensity of defoliation of subterranean clover

2005 ◽  
Vol 45 (12) ◽  
pp. 1587 ◽  
Author(s):  
C. R. Stockdale
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Ground Level ◽  
Total Production ◽  
Ground Seed ◽  
Above Ground Level ◽  
Flower Production ◽  
Matter Production ◽  
Below Ground ◽  
Seed Yields

An experiment was undertaken to consider the effects of a range of defoliation treatments on aspects of the productivity of a subterranean clover (Trifolium subterraneum L.) sward (predominantly cv. Trikkala), with particular emphasis on flowering and seed production. There were 2 heights of defoliation, 2.8 and 7.0 cm (rising plate meter) above ground level, and at each height of defoliation, there were 4 intervals of harvest, 4, 6, 9 and 12 weeks. Treatments were arranged randomly within blocks, and there were 4 replicates. Harvests were conducted between autumn (6 April) and spring (13 November). The total production of herbage varied from 5.7 to 8.7 t DM/ha of harvested material, with variations in response due to both height and frequency of defoliation. Harvested yield increased from 6.2 to 7.4 t DM/ha (P<0.05) as interval between harvests was extended, and plots harvested to 2.8 cm above ground level yielded more (7.7 t DM/ha; P<0.05) harvested herbage than those harvested to 7.0 cm (6.0 t DM/ha). While there were differences in production due to defoliation management, nutritive characteristics (DM digestibility, crude protein, neutral detergent fibre) of harvested herbage were similar in all treatments throughout the year. Production of above and below ground seed increased (P<0.05) as interval between harvest increased, and was greater (P<0.05) at the higher defoliation height. Defoliating at 4- and 6-week intervals interrupted the reproductive development of Trikkala; late September–early October harvests substantially reduced both subsequent petiole extension and flower production. This resulted in Trikkala seeds of lower weight in the above ground seed pool (P<0.05). This may have impacted on regenerating ability in the next autumn because Trikkala seeds that were less than about 4 mg in weight were less likely to germinate than heavier seed. In conclusion, the highest dry matter production occurred with intensive, infrequent defoliation whereas highest seed yields were produced with lax, infrequent defoliation.

Flower initiation in relation to maturity in crop plants. III. The flowering response of early and late cereal varieties to Australian environments

1966 ◽  
Vol 17 (1) ◽  
pp. 1 ◽  
Author(s):  
Y Aitken
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Leaf Number ◽  
Flower Initiation ◽  
Tropical Environments ◽  
Before And After ◽  
Delayed Initiation ◽  
Tropical Australia ◽  
The Difference ◽  
Early Flower

The difference between early- and late-flowering characters in wheat, rye, barley, and oats has been studied by growing some Australian and overseas varieties in several field environments with mean temperatures ranging from 10 to 22°C, and mean photoperiod of 10½ to nearly 16 hr, together with vernalization and prolonged photoperiod. Similar genotypes were found in each of the four cereals. Early varieties all flowered at a low leaf number, which showed that the genotypes for early flower initiation in these varieties are almost or entirely insensitive to temperature and photoperiod. In consequence, varieties with such genotypes can be expected to flower early, even in tropical Australia. In contrast, the genotypes for lateness caused initiation at a higher leaf number, and more sensitivity to temperature and photoperiod, both before and after flower initiation. Contrary to the common assumption that very late varieties need a period of cold followed by long photoperiod for flower initiation, they were found to initiate both in summer (i.e, high temperature) and in winter (low photoperiod) at Melbourne. High temperatures (above 15°C), however, delayed initiation, which resulted in flowering at a higher leaf number than when the same varieties were grown at low temperatures. In addition, the young reproductive shoot died after initiation in a combination of high temperature and a 14–12 hr photoperiod, as happens when such varieties are springsown in temperate latitudes. Such a response also prevents flowering in tropical environments, where high temperatures are combined with a moderate photoperiod all the year round.

Pre-maturation cold acquisition in Trifolium subterraneum

1974 ◽  
Vol 25 (6) ◽  
pp. 875 ◽  
Author(s):  
WJ Collins ◽  
DF Smith
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Seed Maturation ◽  
Flower Initiation ◽  
Appearance Time ◽  
Rate Of Development ◽  
Wide Range ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Different Levels

The influence of different levels of temperature during seed maturation on the subsequent rate of development in plants grown from that seed was studied in a range of subterranean clover cultivars. In one study the cultivars Carnamah, Yarloop, Woogenellup and Mt. Barker were grown at 7, 11, 14 and 17°C, and the seed produced grown on at 17°. Observations were made on the rate of leaf appearance, time of flower initiation, and time and node of first flowering. The rate of development was closely related to the temperature under which the seed was produced—the lower the temperature the faster was the rate of development. This effect was greatest with the later-flowering cultivars. In a second experiment, seed of a number of cultivars harvested commercially from a wide range of sites in southern Australia was grown on at 17°C and the rate of development observed. Time of flowering varied markedly between samples of only three cultivars. Accordingly seed of these samples were grown on for a further generation in a controlled environment. Within two of the cultivars, Mt. Barker and Bacchus Marsh, the differences in flowering observed in the previous generation persisted, which suggests that such differences were not based on environmental factors. In the cultivar Woogenellup the differences in flowering disappeared, which suggests that the original differences arose through different environmental conditions occurring during seed maturation. Cold acquisition in the maturing embryo does not seem to be a matter of practical consequence at present in subterranean clover, but may become so with changes in the location of seed production.

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