scholarly journals Studies of Dormancy in the Seeds of Subterranean Clover (Trifolium Subterraneum L.) II. The Interaction of Time, Temperature, and Carbon Dioxide During Passage Out of Dormancy

1961 ◽  
Vol 14 (2) ◽  
pp. 173 ◽  
Author(s):  
LAT Ballard
Keyword(s):  
Carbon Dioxide ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dormancy Breaking ◽  
Temperature Dependent

The dormancy-breaking action of C02 on imbibed seeds of subterranean clover ('1'rijolium 8ubterraneum L.) is temperature dependent, the efficiency falling off sharrlly above 25�C and approaching zero at 30�C. Within the effective temp. erature range the action is rapid, exposure of seeds to CO2 for 6 hr having signifiC!,fit effect.

scholarly journals The Effect Of Carbon Dioxide Treatment Of Seeds On Flowering In Subterranean Clover

1962 ◽  
Vol 15 (2) ◽  
pp. 406
Author(s):  
AE Grant Lipp ◽  
LAT Ballard
Keyword(s):  
Carbon Dioxide ◽  
Subterranean Clover ◽  
Dormancy Breaking ◽  
Seed Testing ◽  
Low Concentrations

Dormancy breaking in the germination of .small-seeded legumes by low concentrations of CO2 has been reported by Ballard (1958) and Grant Lipp and Ballard (1959). They suggested the usefulness of this treatment in seed testing, and for securing uniform material for experimental purposes. Any possible effect which this treatment may have on flowering would be unimportant in the former application; but in some instances would be of relevance for the latter (cf. Morley and Evans 1959).

Germination and dormancy breaking by ethephon in mature and immature seeds of Medicago truncatula (medic) and Trifolium subterraneum (clover)

1978 ◽  
Vol 29 (1) ◽  
pp. 43 ◽  
Author(s):  
D Globerson
Keyword(s):  
Carbon Dioxide ◽  
Seed Germination ◽  
Medicago Truncatula ◽  
Germination Rate ◽  
Trifolium Subterraneum ◽  
Dormancy Breaking ◽  
Controlled Conditions ◽  
Immature Seeds ◽  
Mature Seeds

The effects of ethephon (2-chloroethylphosphoric acid) and temperature on seed germination were studied in two cultivars of Medicago truncatula (medic) and one cultivar of Trifolium subterraneum (clover) grown under different controlled conditions. Ethephon promoted germination of immature and fresh mature seeds and increased the germination rate of old mature seeds. Ethephon thiourea and carbon dioxide had different effects on the germination of seeds of the medic cultivars. At 30°C, untreated seeds germinated poorly while the presence of 10 ppm ethephon increased germination significantly.

scholarly journals Studies of Dormancy in the Seeds of Subterranean Clover (Trifolium Subterraneum L.)

1969 ◽  
Vol 22 (2) ◽  
pp. 279 ◽  
Author(s):  
LAT Ballard ◽  
AE Grant Lipp
Keyword(s):  
Carbon Dioxide ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Second Phase ◽  
Low Oxygen ◽  
Anaerobic Conditions ◽  
Breaking Dormancy ◽  
Low Concentrations ◽  
Stimulation Of ◽  
Oxygen Concentrations

When imbibed dormant subterranean clover seeds were exposed to low concentrations of oxygen for up to 6 days, and then transferred to either air or 100% oxygen atmospheres, germination was markedly increased above that of seeds held only in air. Stimulation of germination was similar whether the atmosphere of the second phase was air or 100% oxygen; it was maximal when that of the first phase contained no oxygen, and became insignificant above concentrations in the region of 5% oxygen. The additional germination was roughly proportional to the duration of exposure to low oxygen concentrations, and the effects of two separated exposures to low oxygen were additive. These effects could be produced only in those dormant samples whose seeds or embryos could also be made germinable by exposure to 2�5% carbon dioxide. At higher temperatures, anaerobic conditions were less effective in breaking dormancy, paralleling the reduced efficacy of carbon dioxide at these temperatures.

The germinability of soft seed of a number of strains of subterranean clover

1970 ◽  
Vol 10 (44) ◽  
pp. 293 ◽  
Author(s):  
GB Taylor
Keyword(s):  
Carbon Dioxide ◽  
High Temperatures ◽  
Seed Treatment ◽  
Laboratory Tests ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dormant Seed ◽  
Seed Treatments ◽  
Embryo Dormancy

The effect of several seed treatments on germination of 13 strains of subterranean clover (Trifolium subterraneum) seed was examined at two constant temperatures in the laboratory. Tests were conducted on soft seed obtained after scarification of seed sampled on three occasions during the summer and autumn. Germinability varied between strains, but always increased with time after harvest ripeness. Leaching with water promoted some germination in even the most dormant seed. Treatment with carbon dioxide was effective in promoting germination at 20�C, but was less effective than leaching at 30�C. The results suggest that protection against germination by embryo dormancy is likely to be confined to conditions of comparatively high temperatures (>20�C) when associated with summer rains having little or no leaching effect.

scholarly journals Studies of Dormancy in the Seeds of Subterranean Clover (Trifolium Subterraneum l.) I. Breaking of Dormancy by Carbon Dioxide and by Activated Carbon

1958 ◽  
Vol 11 (3) ◽  
pp. 246 ◽  
Author(s):  
LAT Ballard
Keyword(s):  
Carbon Dioxide ◽  
Activated Carbon ◽  
Activated Carbons ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Low Concentration ◽  
New Methods

Two new methods for breaking the dormancy of subterranean clover (Trifolium subterraneum L.) seeds are described, viz. treatment of imbibed seeds with a low concentration of carbon dioxide, and with activated carbons.

Competition among seedlings of perennial grasses, subterranean clover, white clover, and annual ryegrass in replacement series mixtures

2000 ◽  
Vol 51 (3) ◽  
pp. 377 ◽  
Author(s):  
G. M. Lodge
Keyword(s):  
White Clover ◽  
Plant Competition ◽  
Perennial Grass ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Perennial Grasses ◽  
Maximum Likelihood Estimates ◽  
Annual Ryegrass ◽  
Replacement Series ◽  
Successful Establishment

Seedlings of 3 perennial grasses, Danthonia linkii Kunthcv. Bunderra, D. richardsonii Cashmore cv. Taranna(wallaby grasses), and Phalaris aquatica L. cv. Sirosa,were each grown in replacement series mixtures with seedlings ofTrifolium repens L. (white clover),Trifolium subterraneum L. var. brachycalycinum (Katzn.et Morley) Zorahy & Heller cv. Clare (subterraneanclover), and Lolium rigidum L. (annual ryegrass). Plantswere sown 5 cm apart in boxes (45 by 29 by 20 cm) at a density of 307plants/m2. Maximum likelihood estimates were usedto derive parameters of a non-linear competition model using the dry matterweights of perennial grasses and competitors at 3 harvests, approximately 168,216, and 271 days after sowing. Intra-plant competition was examined inmonocultures of each species, grown at plant spacings of 2, 5, and 8 cm apartwith plants harvested at the above times.Competition occurred in all perennial grass–competitor mixtures, exceptin those of each perennial grass with white clover and thephalaris–subterranean clover mixture (Harvest 1) and those withD. richardsonii and phalaris grown with white clover(Harvest 2). For D. richardsonii (Harvests 1 and 2) andD. linkii (Harvest 1 only) grown with white clover andthe phalaris–subterranean clover (Harvest 1), the two species in themixture were not competing. In the phalaris–white clover mixture, eachspecies was equally competitive (Harvests 1 and 2). These differences incompetition and aggressiveness reflected differences in individual plantweights in monocultures where there was an effect (P < 0.05) of species ondry matter weight per box, but no significant effect of plant spacing.These data indicated that for successful establishment,D. richardsonii and D. linkiishould not be sown in swards with either subterranean clover or white clover,or where populations of annual ryegrass seedlings are likely to be high.Phalaris was more compatible with both white clover and subterranean clover,but aggressively competed with by annual ryegrass.

scholarly journals Host plant recognition by the root feeding clover weevil, Sitona lepidus (Coleoptera: Curculionidae)

2004 ◽  
Vol 94 (5) ◽  
pp. 433-439 ◽  
Author(s):  
S.N. Johnson ◽  
P.J. Gregory ◽  
P.J. Murray ◽  
X Zhang ◽  
I.M. Young
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Plant Roots ◽  
Grass Species ◽  
Movement Rates ◽  
Sitona Lepidus ◽  
Macro Scale ◽  
Significant Difference ◽  
Invasive Techniques ◽  
Root Feeding

AbstractThis study investigated the ability of neonatal larvae of the root-feeding weevil, Sitona lepidus Gyllenhal, to locate white clover Trifolium repens L. (Fabaceae) roots growing in soil and to distinguish them from the roots of other species of clover and a co-occurring grass species. Choice experiments used a combination of invasive techniques and the novel technique of high resolution X-ray microtomography to non-invasively track larval movement in the soil towards plant roots. Burrowing distances towards roots of different plant species were also examined. Newly hatched S. lepidus recognized T. repens roots and moved preferentially towards them when given a choice of roots of subterranean clover, Trifolium subterraneum L. (Fabaceae), strawberry clover Trifolium fragiferum L. (Fabaceae), or perennial ryegrass Lolium perenneL. (Poaceae). Larvae recognized T. repens roots, whether released in groups of five or singly, when released 25 mm (meso-scale recognition) or 60 mm (macro-scale recognition) away from plant roots. There was no statistically significant difference in movement rates of larvae.

The influence of seed size and depth of sowing on pre-emergence and early vegetative growth of subterranean clover (Trifolium subterraneum L.)

1956 ◽  
Vol 7 (2) ◽  
pp. 98 ◽  
Author(s):  
JN Black
Keyword(s):  
Leaf Area ◽  
Seed Size ◽  
Vegetative Growth ◽  
Dry Matter ◽  
Relative Rate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
Total Leaf Area ◽  
Pot Culture

Changes in the pre-emergence distribution of dry matter in subterranean clover (Trifolium subterraneum L.) variety Bacchus Marsh were followed at 21°C, using three sizes of seed and three depths of sowing, ½, 1¼, and 2 in. Decreasing seed size and increasing depth of sowing both reduce the weight of the cotyledons a t emergence. Seed of the three sizes were sown a t three depths in pot culture a t staggered intervals so that emergence was simultaneous. Dry weight in the early vegetative stage was proportional to seed size, and total leaf area and leaf numbers showed similar trends. Plants of each seed size grew at the same relative rate. No effect of depth of sowing could be detected, and this was shown to be due to the cotyledon area a t emergence being constant for any given seed size, regardless of varying depth of sowing and hence of cotyledon weight. It was concluded that seed size in a plant having epigeal germination and without endosperm is of importance: firstly, in limiting the maximum hypocotyl elongation and hence depth of sowing, and secondly, in determining cotyledon area. Cotyledon area in turn influences seedling growth, which is not affected by cotyledon weight. Once emergence has taken place, cotyledonary reserves are of no further significance in the growth of the plants.

CANTERBURY EXPERIENCE WITH SUBTERRANEAN CLOVER (Trifolium subterraneum)

1935 ◽  
pp. 64-68
Author(s):  
H. Neave ◽  
C.H. Hewlett
Keyword(s):  
Personal Experience ◽  
Subterranean Clover ◽  
Trifolium Subterraneum

The information contained in this paper is principally first-hand knowledge extending over a period of six years gained from personal experience from our own "Oakleigh" farm.

Varietal reactions of Trifolium subterraneum L. to Phaseolus virus 2 Pierce.

1954 ◽  
Vol 5 (4) ◽  
pp. 598 ◽  
Author(s):  
EM Hutton ◽  
JW Peak
Keyword(s):  
Trypan Blue ◽  
Continuous Distribution ◽  
Systemic Infection ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Epidermal Cells ◽  
Severe Strain ◽  
Resistant Varieties ◽  
Lethal Reaction ◽  
The Mean

A number of varieties of subterranean clover (Trifolium subterraneum L.) were tested with a severe strain of Phaseolus virus 2 Pierce. Northam First Early, Dwalganup, and Pink Flowered gave lethal necrotic reactions while the rest developed mottles and chlorosis of different degrees of intensity. Reductions in the mean fresh weights of plants of five subterranean clover varieties ranged from 26.1 to 76.7 per cent. Epidermal cells of mottled leaves contained irregular aggregates of viroplasts stained by treatment with phloxine-trypan blue. Viroplasts in young tip leaves did not stain if the plants were held at temperatures below 44.6°F while those in mature basal leaves were not so affected. The lethal-reactors Northam First Early, Dwalganup, and Pink Flowered were resistant in the field to Phaseolus virus 2. With hand inoculation in the glass-house an average of 10 per cent. of plants of these varieties remained free from systemic infection, whereas all the plants of mottle-reacting varieties became systemically infected. The virus had a discontinous distribution in plants of lethal-reactors, compared with a continuous distribution in those of mottle-reactors such as Mount Barker. The lethal reaction is heritable in a dominant fashion in most crosses, so that the development of desirable new virus- resistant varieties is possible.

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