Seed-Setting in subterranean clover (Trifolium Subterraneum L.). II. Strain-environment interactions in single plants

1958 ◽  
Vol 9 (6) ◽  
pp. 745 ◽  
Author(s):  
JJ Yates
Keyword(s):  
Negative Relationship ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Atmospheric Environment ◽  
Protective Mechanism ◽  
Seed Setting ◽  
Early Maturing ◽  
The Relationship ◽  
Mature Seeds ◽  
Number Of Seeds

The relationship between seed-setting (expressed as mature seeds per inflorescence), strain, and environment was investigated in subterranean clover, with special reference to burr burial. Single plants of a range of maturity types were grown in two environments, one cool and moist, the other hot and dry but with frequent watering of the plant roots. In the mild environment, early-maturing strains buried a high proportion of burrs, and late-maturing strains relatively few. Under the more severe conditions, late-maturing types buried the majority of their burrs. Seed-setting in buried burrs was generally good, and relatively constant in all the strains and the two environments tested. The capacity to set seed above the ground varied widely amongst strains, and within each strain was greater in the mild environment. The results indicate that seed-setting is influenced strongly by the microenvironment of inflorescences and developing burrs, and that strains differ in sensitivity to such microenvironment. Burr burial is apparently a protective mechanism against unfavourable factors (probably low relative humidity and high temperature) of the atmospheric environment. Under the more severe environmental conditions, there was a positive correlation between seed-setting above the ground and percentage leaf in the plant tops. It is presumed that this was due partly to amelioration of the microenvironrnent by the foliage. The negative relationship between efficiency of seed-setting above the ground and proportion of burrs buried is discussed in terms of natural selection. The microenvironmeilt, and the differential response of strains, affected not only the number of seeds per inflorescence, but also the weight and viability of the seeds produced. The concept of a threshold embryo weight for viability is discussed.

Seed-setting in subterranean clover (Trifolium subterraneum L.) 1. The importance of the microevironment

1957 ◽  
Vol 8 (5) ◽  
pp. 433 ◽  
Author(s):  
JJ Yates
Keyword(s):  
Seed Development ◽  
Surface Soil ◽  
Subterranean Clover ◽  
Soil Surface ◽  
Trifolium Subterraneum ◽  
Protective Effects ◽  
Percentage Germination ◽  
Seed Setting ◽  
Before And After ◽  
Mature Seeds

An investigation was made of the relative efficiency of above- and belowground seeding, under unfavourable environmental conditions, in the subterranean clover variety Red Leaf, which normally sets some seed above and some below the ground. The experiment included artificial shielding of burrs in sponge rubber to simulate the protective effects of natural burial. Seed-setting, expressed in terms of mature seeds as percentage of reflexed florets, was considerably better when development occurred at or below the soil surface, or when burrs were enclosed in rubber, than when untreated burrs did not come in contact with the soil.The presence of moisture in the surface soil improved seed-setting above the ground. Breakdown of seed-forming processes occurred both before and after the stage at which seed development could be detected. Seeds formed above the surface were of light weight and gave very poor germination; seeds which had been buried or enclosed in rubber were much heavier and percentage germination was high; and those formed on the surface were intermediate.The results emphasize the importance of the microenvironment of individual inflorescences and burrs, and the value of protective or modifying influences, during the whole period of seed development in this species.

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.

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.

The effect of autotetraploidy in five varieties of subterranean clover (Trifolium subterraneum L.).

1954 ◽  
Vol 5 (3) ◽  
pp. 356 ◽  
Author(s):  
WM Hutton ◽  
JW Peak
Keyword(s):  
Moisture Content ◽  
Dry Matter ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dry Weight ◽  
The Other ◽  
Seed Setting ◽  
Plant Parts ◽  
Green Matter ◽  
Total Dry Weight

Induced autotetraploidy in the Dwalganup variety of subterranean clover (Trifolium subterraneum L.) resulted in total dry weight increases of 60 and 65.5 per cent. at flowering and maturity respectively. In the other four varieties the tetraploids had decreased yields of dry matter compared with the diploids, although the decreases for leaf weights at flowering were nonsignificant in Mount Barker and Tallarook, as was the total dry weight reduction in Tallarook at maturity. There were no significant differences between the diploids and tetraploids in percentage moisture content. When early development was stimulated by growth in a glass-house, the tetraploids of all varieties showed a significant increase in yield of green matter. The level of increased growth was maintained only in Dwalganup, and decreased in other varieties during flowering. An analysis was made of the way in which the different plant parts mere changed by tetraploidy. Where decreased growth occurred, the leaves and stems were coarser. In all varieties a reduced seed-setting followed autotetraploidy, although in Dwalganup the yield of seed per plant was not affected.

The effect of management during spring on the growth of a mixed annual pasture containing capeweed (Arctotheca calendula)

1973 ◽  
Vol 13 (63) ◽  
pp. 398 ◽  
Author(s):  
JG McIvor ◽  
DF Smith
Keyword(s):  
Seed Germination ◽  
Special Reference ◽  
Spring Barley ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Seed Setting ◽  
Grass Seed ◽  
Severe Reduction ◽  
Hordeum Leporinum

A number of grazing and mowing treatments were imposed in spring on a mixed annual pasture mainly comprising capeweed (Arctotheca calendula) 36 per cent and barley grass (Hordeum leporinum) 27 per cent, with a small amount of (4 per cent) subterranean clover (Trifolium subterraneum). The effects of treatments on flowering, seed setting and subsequent autumn production were followed, with special reference to any possible reduction in capeweed content. Seed numbers of all species were reduced by grazing throughout spring (barley grass was least affected) and by late mowing (severe reduction in the grasses), but early mowing had little effect. The mowing treatments all increased the content of capeweed and subterranean clover in the pasture next autumn and reduced the amount of grass, especially barley grass. Close grazing increased barley grass content and, if it continued throughout the spring, capeweed content also increased. Seed germination following rain in January varied considerably between treatments, but was not greater than 3 per cent on any. It was highest where dry pasture residues were present, and clover and capeweed seed germinated more than grass seed. It was concluded that spring management is unlikely to offer scope for reduction in capeweed content of pastures.

The growth of barley grass (Hordeum leporinum) in annual pasture. 4. The effect of some management practices on barley grass content

1968 ◽  
Vol 8 (35) ◽  
pp. 706 ◽  
Author(s):  
DF Smith
Keyword(s):  
Management Practices ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Botanical Composition ◽  
Lolium Rigidum ◽  
Seed Setting ◽  
Grass Seed ◽  
Hordeum Leporinum ◽  
Wimmera Ryegrass

The effects of three grazing treatments and three mowing treatments on the dominance of barley grass (Hordeum leporinum) in an annual pasture were examined. Different spring grazing patterns did not markedly alter the amount of seed. Mowing favoured the legume component; topping less so than cutting lower as for hay or silage. However, none of these practices totally prevented barley grass from setting seed, and their effects were partly offset by late irrigation. Oversowing with subterranean clover (Trifolium subterraneum) did reduce barley grass seed setting but alone u-as not effective in changing botanical composition. Compared with Wimmera ryegrass (Lolium rigidum), barley grass showed greater persistence.

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.

Phosphate applied to soil increases the effectiveness of subsequent applications of phosphate for growing wheat shoots

1998 ◽  
Vol 38 (8) ◽  
pp. 865 ◽  
Author(s):  
M. D. A. Bolland ◽  
M. J. Baker
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Phosphorus Retention ◽  
Single Superphosphate ◽  
Mitscherlich Equation ◽  
Curvature Coefficient ◽  
Glasshouse Experiment ◽  
Phosphorus Application ◽  
The Relationship ◽  
Field Plots

Summary. Amounts of phosphorus ranging from 0 to 599 kg P/ha were applied as single (ordinary) superphosphate once only in 1976 to plots of a field experiment on a lateritic ironstone gravel sand. Subterranean clover (Trifolium subterraneum) and cereals (wheat, Triticum aestivum, and barley, Hordeum vulgare) were grown in rotation on the plots for 20 years after phosphorus application. In 1996, samples of the <2 mm fraction of the top 10 cm of soil were collected from the field plots to measure phosphorus retention by soil and for a glasshouse experiment. The phosphorus retention index, a measure of the capacity of the soil to sorb phosphorus, decreased from 35 to 2 mL/g as the amount of phosphorus applied 20 years previously increased from 0 to 599 kg/ha. In the glasshouse experiment, wheat was grown for 35 days in soil to which 9 amounts of freshly-applied powdered single superphosphate (0, 0.0125, 0.025, 0.05, 0.1, 0.2, 0.4, 0.8 and 1.6 g P/pot, for 1.8 kg soil/pot) were applied to the original phosphorus treatments. The value of the curvature coefficient of the Mitscherlich equation fitted to the relationship between yield of dried shoots and the amount of fresh-phosphorus applied increased with increasing amount of phosphorus applied 20 years previously. That is, the fresh-phosphorus treatments became more effective for producing dried wheat shoots as the amount of previously applied phosphorus increased.

Copper nutrition of subterranean clover (Trifolium subterraneum L. cv. Seaton Park). III. Effects of phosphorus supply on the relationship between copper concentrations in plant parts and yield

1981 ◽  
Vol 32 (2) ◽  
pp. 283 ◽  
Author(s):  
DJ Reuter ◽  
AD Robson ◽  
JF Loneragan ◽  
DJ Tranthim-Fryer
Keyword(s):  
Copper Deficiency ◽  
Phosphorus Deficiency ◽  
Potassium Phosphate ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Young Leaf ◽  
Plant Parts ◽  
High Concentrations ◽  
Four Levels ◽  
The Relationship

The effects of phosphorus supply on the relationship of copper supply with copper concentrations in various plant parts and yield of Seaton Park subterranean clover were examined. Plants were grown in a glasshouse for 40 and 74 days in pots with four levels of potassium phosphate (0, 13, 39, 65 mg phosphorus/pot) and six levels of copper sulfate (0, 50, 100, 200, 400, 800 pg copper/pot) added, in factorial combination, to a sand deficient in both phosphorus and copper. By increasing the phosphorus levels copper deficiency was induced partly by promoting growth and diluting copper concentrations in plants; and also by depressing copper absorption. Increasing phosphorus changed the distribution of copper in plant tops and the shape of curves relating copper concentration in whole plant tops to yield. At 39 mg phosphorus/pot, the relationship at Day 74 had a marked 'Piper-Steenbjerg' curvature, largely as a result of unusually high copper concentrations in the stems plus petioles of severely copper-deficient plants. At 65 mg phosphorus/pot, the relationship had no 'Piper-Steenbjerg' curvature for whole tops and only a relatively small curvature for stems plus petioles. The data suggests that 'Piper-Steenbjerg' curves in subterranean clover result primarily from high concentrations of copper in the stems plus petioles of severely deficient plants. At both harvests, young leaf blades had critical copper concentrations of around 3 �g copper/g at both 39 and 65 mg phosphorus/pot. However, copper-deficient plants with severe phosphorus deficiency did not respond to copper, and generally had copper concentrations below this critical level in all plant parts. The results confirm the value of copper analysis of young leaf blades for diagnosing copper deficiency in subterranean clover with moderately deficient to luxury supplies of phosphorus.

The nutritive value of subterranean clover (Trifolium subterraneum L.), rose clover (Trifolium hirtum All.) and soft brome grass (Bromus mollis L.)

1986 ◽  
Vol 26 (6) ◽  
pp. 665 ◽  
Author(s):  
PER Ridley ◽  
HL Davies ◽  
IN Southey
Keyword(s):  
Organic Matter ◽  
Nitrogen Balance ◽  
Nutritive Value ◽  
Negative Relationship ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Late Spring ◽  
Superior Performance ◽  
Digestible Energy ◽  
Brome Grass

Medium Peppin Merino wethers were fed, ad libitum, subterranean clover (cv. Woogenellup), rose clover (cv. Kondinin) and soft brome grass cut in September (spring), November (late spring) and January-February (summer). The nitrogen contents of the subterranean clover ranged from 1.89 to 3.13%, of the rose clover from 1.62 to 2.84% and of the soft brome from 0.42 to 2.86%. Mean daily organic matter intakes (kg) in spring, late spring and summer were respectively: for subterranean clover 0.78, 1.09 and 0.42; for rose clover 0.60, 0.87 and 0.62; for soft brome grass 0.87, 0.81 and 0.20. Organic matter digestibilities in spring, late spring and summer were, respectively: for subterranean clover 0.82 ,0.69 and 0.61; for rose lover 0.80, 0.62 and 0.54; for soft brome 0.83, 0.72 and 0.58. There were highly significant differences ( P < 0.001) in nitrogen balance between seasons. The estimated digestible energy intakes (MJ/day) in spring, late spring and summer were, respectively: for subterranean clover 12.7, 14.5 and 4.9; for rose clover, 9.2, 9.9 and 6.9; for soft brome, 13.6, 10.1 and 2.1. Within seasons there were significant (P < 0.05) differences in nitrogen balance between species. There were significant differences between species in mean retention time in the alimentary tract in late spring (P<0.001) and summer (P<0.001) but not in spring. There was a highly significant negative relationship between acid-detergent fibre content and both organic matter and fibre digestibilities. The superior digestible energy intakes of the 2 clovers explain at least some of the superior performance of sheep grazing clover compared with those grazing grass pastures.

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