Effect of burr burial on seed production of Trifolium subterraneaum subsp. brachycalycinum and other annual legumes

1986 ◽  
Vol 26 (1) ◽  
pp. 59 ◽  
Author(s):  
MDA Bolland ◽  
WJ Collins
Keyword(s):  
Seed Production ◽  
Sandy Soil ◽  
Seed Weight ◽  
Trifolium Subterraneum ◽  
Annual Legumes ◽  
Seed Yields

On sandy soil near Esperance, W.A., prevention of burr burial compared with covering developing burrs with sand drastically reduced the seed production of three subspp. of Trifolium subterraneum (brachycalycinum, subterraneum and yanninicum) and of T. israeliticum by reducing burr production and seed weight. However, T. globosum produced similar amounts of seed from unburied and buried burrs. On sandy soil at Shenton Park, Perth, W.A., prevention of burr burial also reduced seed production of T. subterraneum subspp. brachycalycinum and subterraneum, this being due to fewer burrs, fewer seeds per burr and lighter seed. For subsp. brachycalycinum, seed yields were two to five times greater from burrs which developed within loose gravel than from those developed over sand (in which fewer burrs were able to bury) as a result of increased production of burrs, more seeds per burr and heavier seed. However, for subsp. subterraneum seed yields were similar from burrs whether developed over gravel or sand.

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.

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.

Desiccation of alfalfa for seed production with diquat and glufosinate

1996 ◽  
Vol 76 (3) ◽  
pp. 435-439 ◽  
Author(s):  
J. R. Moyer ◽  
S. N. Acharya ◽  
J. Fraser ◽  
K. W. Richards ◽  
N. Foroud
Keyword(s):  
Key Words ◽  
Seed Production ◽  
Seed Yield ◽  
Seed Weight ◽  
Viable Seed ◽  
Hard Seed ◽  
Alfalfa Seed ◽  
Percent Germination ◽  
Medicago Sativa L ◽  
Seed Yields

Recommendations for desiccation of alfalfa do not clearly define the stage at which desiccants should be applied. To obtain this information, diquat and glufosinate were applied to alfalfa (Medicago sativa L) from 1991 to 1994 at various stages of maturity to determine the effect of desiccant and stage of maturity at desiccation on seed yield 1000-seed weight and seed germinability. Alfalfa seed yields, 1000-seed weights, percent germination and percent viable seed were similar after desiccation with diquat and glufosinate. Desiccation when 60–75% of the alfalfa seed pods were brown permitted maximum seed yields. Percent germination increased slightly in seeds that were exposed to weathering under normal conditions until all pods turned brown. Both desiccants adequately desiccated alfalfa for harvesting but desiccation with glufosinate took 2 or 3 d longer than diquat. Desiccants did not reduce alfalfa growth in the spring after application. Key words: Germination, yield, hard seed, seed weight, stage

The effects of frosts on seed production in subterranean clover (Trifolium subterraneum)

1971 ◽  
Vol 11 (49) ◽  
pp. 202 ◽  
Author(s):  
WR Scott
Keyword(s):  
New Zealand ◽  
Seed Production ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
The Other ◽  
The Past ◽  
Seed Yields

Six cultivars of subterranean clover, Geraldton, Yarloop, Woogenellup, Clare, Mount Barker, and Tallarook, were grown as ungrazed swards at 1,700 feet a.s.1. in the Mackenzie Country of South Canterbury, New Zealand. In this very frosty environment seed yields tended to increase with increasing lateness of flowering although Clare and perhaps Tallarook appeared to be more frost susceptible than the other cultivars. It is suggested that the deleterious effects of frosts in reducing the seed yields of subterranean clover may have been overemphasized in the past and that the trend for seed yields to increase with increasing lateness of flowering can be partially explained by differences in runner production.

Effect of gypsum on establishment, persistence and productivity of lucerne and annual pasture legumes on two grey Vertosols in southern New South Wales

2010 ◽  
Vol 61 (6) ◽  
pp. 435 ◽  
Author(s):  
B. S. Dear ◽  
M. B. Peoples ◽  
R. C. Hayes ◽  
A. D. Swan ◽  
K. Y. Chan ◽  
...  
Keyword(s):  
New South ◽  
New South Wales ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Legume Seed ◽  
Pasture Production ◽  
Annual Legumes ◽  
South Wales ◽  
Seed Yields ◽  
Pasture Yield

Changes in pasture yield and botanical composition due to gypsum application were examined on Vertosols at two locations of differing soil sodicity, Grogan and Morangarell, in southern New South Wales. Two pasture treatments were examined. One was an annual pasture comprised of 3 annual legumes (2 subterranean clover Trifolium subterraneum L. cultivars, Clare and Riverina, and balansa clover T. michelianum Savi cv. Paradana), while the second treatment consisted of lucerne (Medicago sativa L.) cv. Aquarius sown in a mixture with the same annual legumes. Gypsum had no effect on the establishment or persistence of lucerne at either site. Gypsum increased the number of subterranean clover seedlings present in autumn in annual swards at the more sodic Grogan site in each of the 4 years, but provided no difference when the clover was in a mixture with lucerne. Annual legume seed yields in annual-only swards increased with gypsum by up to 58% at Grogan and 38% at Morangarell. Seed yields of both cultivars of subterranean clover declined as a proportion of the total annual legume seed bank when lucerne was included in the mixture, in contrast to balansa clover (at Grogan) and the naturalised annual legumes, burr medic (M. polymorpha L.) and woolly clover (T. tomentosum L.), which all increased in relative seed yield in the presence of lucerne. Total pasture production at the Grogan site increased with gypsum by up to 15% per annum in annual swards and 36% in lucerne swards depending on the season. Yield responses to gypsum by the lucerne component were observed in 10 of the 13 seasonal yield measurements taken at Grogan. However, total pasture yield and seasonal yields were unaffected by both gypsum and pasture type at the less sodic Morangarell site. It was concluded that sowing a diverse mixture of annual legumes or polycultures was conducive to maintaining productive pastures on these spatially variable soils. Lucerne dried the soil profile (0.15–1.15 m) more than annual pastures at both sites. The combination of gypsum and lucerne enhanced water extraction at depth (0.6–1.15 m) at the Grogan site increasing the size of the dry soil buffer whereas gypsum increased soil water at depth (>0.6 m) under annual swards.

Assessment of annual legumes for pastures in the low rainfall wheatbelt of central western New South Wales

1976 ◽  
Vol 16 (82) ◽  
pp. 739 ◽  
Author(s):  
BJ Scott ◽  
H Brownlee
Keyword(s):  
Dry Matter ◽  
New South ◽  
New South Wales ◽  
Trifolium Subterraneum ◽  
Dry Matter Production ◽  
Annual Legumes ◽  
South Wales ◽  
Matter Production ◽  
Plant Densities ◽  
Seed Yields

Dry matter production and seed yields of a range of annual legumes grown in ungrazed swards were measured between 1966 and 1971 on seven sites in the low rainfall wheatbelt of central western New South Wales. Jemalong and Hannaford barrel medics (Medicago truncatula) were the highest yielding medic cultivars tested. Jemalong medic was slightly superior to Hannaford in dry matter production but seed yields were equal. The short season subterranean clovers (Trifolium subterraneum), Dwalganup and Geraldton, yielded much less dry matter and seed than the medics in most experiments. Although the mid-season subterranean clovers, Woogenellup and Clare, persisted for the duration of our experiments, their production was not as consistent as that of the medics, and plant densities decreased. The rose clovers (T. hirtum), Sirint and Kondinin, the cupped clovers (T. cherleri), Beenong and Yamina, and Snail (M. scutellata) and Paragosa (M. rugosa) medics did not produce satisfactory swards.

The effect of withholding water during flowering on seed production in Trifolium subterraneum L

1977 ◽  
Vol 28 (2) ◽  
pp. 301 ◽  
Author(s):  
P Andrews ◽  
WJ Collins ◽  
WR Stern
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Seed Weight ◽  
Marked Reduction ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Strain Response ◽  
Long Duration ◽  
Prolonged Stress ◽  
Practical Implications

An experiment was conducted in a glasshouse to study the effects of withholding water during flowering on seed production in subterranean clover. Two strains, Northam A (long duration of flowering) and Geraldton (shorter duration) were grown as swards in boxes, defoliated weekly until flowering, and subjected to the following watering regimes: T1, a control; T2, water withheld over the whole of the flowering period; T3 and T4, water withheld for short periods only, during flowering. Regular determinations were made of soil water, leaf water potential and inflorescence number. Seed yield and some of its components were measured in all treatments. The prolonged stress (T2) reduced seed yield by about 80% in both strains. Rates of inflorescence production, duration of flowering and individual seed weight were also reduced. The shorter stress treatments (T3, T4) had no effect on seed yield in the longer-flowering cultivar Northam A, but in cv. Geraldton, T4 caused a marked reduction in seed yield. The practical implications of this differential strain response are discussed.

The effects of moisture supply and defoliation during flowering on seed production and hardseededness of Trifolium subterraneum L

1990 ◽  
Vol 30 (4) ◽  
pp. 515 ◽  
Author(s):  
KA Archer
Keyword(s):  
Seed Production ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Flowering Period ◽  
Viable Seed ◽  
Hard Seeds ◽  
Moisture Supply ◽  
Early Maturing ◽  
Seed Yields ◽  
Production Characteristics

The effect of length of the flowering period on seed production characteristics of 3 cultivars of subterranean clover (Trifolium subterraneum L.) was determined by varying the period of watering postflowering. The subterranean clover cvv. Nungarin, Seaton Park and Woogenellup were grown in polystyrene boxes and given 1 of 4 watering treatments: continuous (WC); until approximately 34 days after flowering commenced (WE); until Nungarin finished flowering (WN); as for WE but with watering recommenced after plants became wilted (WEL). Plants were either undefoliated or were repeatedly defoliated during flowering. Flowering in all 3 cultivars was terminated early and seed yields were reduced by WE (e.g. WC v. WE for Seaton Park, 1620 � 61 v. 320 � 61 kg/ha), but each of the cultivars was able to produce appreciable numbers of viable seed on the WE treatment, ranging from 406 � 95 seeds/dm2 for Woogenellup to 791 � 95 seeds/dm2 for Seaton Park. WEL increased seed size in all cultivars by approximately 50%, and increased seed numbers in Seaton Park to 1083 � 106 seeds/dm2. Nungarin produced most seeds on the WN treatment (1232 � 104 seeds/dm2), but approximately half of these were lost if the soil was kept moist during seed maturation. In comparison, little loss of seed was detected from Seaton Park and Woogenellup under continuous watering, possibly due to differences between cultivars ii seed dormancy and periods of exposure of maturing seeds to moisture. The development of initial hard seeds in Nungarin and undefoliated Seaton Park was adversely affected by continuous moisture. Repeated defoliation during flowering reduced seed yields in all cultivars (e.g. UD v. D for Seaton Park, 1130 � 44 v. 310 � 46 kg/ha), due to decreases in both seed numbers and size. The results indicate that choice of maturity of subterranean clover cultivars for areas with unreliable spring rainfall is not necessarily restricted to those early maturing cultivars which will always finish flowering prior to moisture restrictions.

Response of burr burial in subterranean clover (Trifolium subterraneum) to defoliation

1975 ◽  
Vol 15 (72) ◽  
pp. 69 ◽  
Author(s):  
GH Walton
Keyword(s):  
Sandy Soil ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Absolute Yield ◽  
Natural Rainfall ◽  
Buried Seed ◽  
Selection For ◽  
The Absolute ◽  
Seed Yields

Four defoliation treatments before flowering were imposed on twelve genotypes from three subspecies of Trifolium subterraneum. The experiment was conducted on a sandy soil with irrigation supplementing the natural rainfall. The severest defoliation doubled the percentage and tripled the absolute yield of buried seed. Highly significant differences were found between the genotypes within subspecies, indicating that selection for subterranean clover pastures with a range of ability to bury burrs is possible. No differences in genotype or subspecies response to defoliation nor differences of absolute seed yields were obtained. It is suggested that sward density is very important when experiments evaluating subterranean clover genotypes include defoliation treatments of the swards.

Increase Longleaf Pine Seed Yields by Inhibiting Conelet Abortion

1987 ◽  
Vol 11 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Robert C. Hare
Keyword(s):  
Boric Acid ◽  
Seed Production ◽  
Seed Yield ◽  
Longleaf Pine ◽  
Foliar Spray ◽  
Seed Yields

Abstract A single foliar spray with either antiethylene compounds or cytokinins shortly after anthesis reduced conelet abortion by half and doubled seed production. Spraying with boric acid plus Cytex® , a relatively economical form of cytokinin derived from seaweed, was equally effective,and addition of certain antiethylene compounds further improved seed yield. South. J. Appl. For. 11(1):6-9.

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