Studies on the nutrition of pasture plants in the South-west of Western Australia. III. The effect of sulphur on the growth of subterranean clover (Trifolium subterraneum L.)

1952 ◽  
Vol 3 (1) ◽  
pp. 7 ◽  
Author(s):  
RC Rossiter

Sulphur applied as calcium sulphate or sodium sulphate significantly increased the growth of subterranean clover on a number of sandy soils in pot culture and also on a gravelly sand under field conditions at Kojonup. In the field trial a significant response was also obtained in the volunteer annual, capeweed.Total sulphur in the tops of both clover and capeweed was markedly increased by sulphur application; the lowest values were observed in one of the pot-culture trials, where deficiency symptoms were most prominent. Some reasons are suggested for the earlier appearance of deficiency symptoms in the field trial, where the deficiency was less severe than in the pot-culture experiments.


1956 ◽  
Vol 7 (2) ◽  
pp. 98 ◽  
Author(s):  
JN Black

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.



1992 ◽  
Vol 43 (7) ◽  
pp. 1597 ◽  
Author(s):  
JM Wroth ◽  
RAC Jones

In 1989 and 1990, infection with subterranean clover mottle sobemovirus (SCMV) was widespread in subterranean clover ( Trifolium subterraneum L.) pastures in the south-west of Western Australia. The virus was detected in 61% of the pastures sampled and incidences of infection ranged from 1 to 50%. The virus was more common in old pastures than in pastures resown with newer cultivars during the preceeding 5 year period. When 12 isolates of SCMV were inoculated to subterranean clover plants grown in the glasshouse, symptoms varied from mild to severe. SCMV isolates P23 and F4 decreased the herbage dry weight of cw. Daliak and Woogenellup grown in plots as spaced plants by 81-88% while the Type isolate caused losses of 92%. By contrast, losses were 37-49% with cv. Karridale, a cultivar in which systemic infection was either delayed or prevented during winter. Infection decreased seed yield by c. 90% in cvv. Karridale and Woogenellup with all three isolates; seed weight was decreased 21-55%. A small proportion of cv. Woogenellup transplants outgrew the infection in new shoots during late spring to produce abundant healthy foliage. SCMV seed transmission rates in seed collected from infected transplants of cv. Woogenellup were 0.06, 0.07 and 0.43% for the Type, P23 and F4 isolates respectively. It was concluded that SCMV was present in most pastures, but at low incidences, and that it persists in them from year to year. Extended growing seasons and hard grazing are likely to increase its incidence.



1994 ◽  
Vol 45 (1) ◽  
pp. 119 ◽  
Author(s):  
MJ Unkovich ◽  
JS Pate ◽  
P Sanford ◽  
EL Armstrong

Precision of estimation of the proportion of legume N derived from N2 fixation (%Ndfa) was assessed in relation to subterranean clover (Trifolium subterraneum L.) pastures and crops of pea (Pisum sativum L.) and lupin (Lupinus angustifolius L.) under south-west Australian conditions. By using a standardized 10-point sampling procedure of paired sampling of legume and reference plant and reference plant 15N natural abundance (S15N) values in the range from +2.9 to +4. 0%o, %Ndfa of sample crops of lupin and field pea and a clover pasture were assessed with respective precisions of 93� O.6%, 76� 2.4% and 91�1.3% (� s.e., n = 10). Effects on S15N due to isotope discrimination during fixation and subsequent distribution of N by the three study legumes were studied using sand-cultured, fully symbiotic plant material. The resulting S15N data (B values) showed consistently more negative values for shoots than roots (all species), no significant effects of cultivar on B values (all species), a marked effect of rhizobial strain on B value (subclover) and a tendency for B values to fall with plant age (pea and lupin). The likely magnitude of errors in %Ndfa estimates due to incorrect choice of B value was indicated. By using data for reference plant S15N values from field surveys and previously assessed error factors in mass spectrometric measurement of S15N, precision of estimation of %Ndfa by using bulked material from the 10-point field sampling procedure was predicted for situations ranging from where a legume was obtaining only minimal amounts (10%) through to the bulk (90%) of its N by atmospheric fixation.



1955 ◽  
Vol 8 (3) ◽  
pp. 330 ◽  
Author(s):  
JN Black

An experiment is described in which the growth of subterranean clover (Trifolium subterraneum L.) in the early vegetative stage was measured over 52 consecutive weekly periods. To eliminate possible trends of growth rates with age, plants of comparable morphological stage were used for each period. The variety Bacchus Marsh was grown in pot culture in the open at the Waite Agricultural Research Institute, Adelaide, South Australia.



1951 ◽  
Vol 2 (1) ◽  
pp. 1 ◽  
Author(s):  
RC Rossiter

The results of pot-culture experiments and field trials designed to examine the effects of copper, zinc, and potassium on the growth of Dwalganup subterranean clover on a number of Western Australian soils are presented and discussed. Highly significant yield increases from application of one or more nutrients were observed on all soils examined. The effects of applied copper were greater in the second year than in the seeding year under deficiency conditions in the field. Significant interaction effects were observed only with copper and potassium. Maximum yields in two of the field trials were low even with application of all three nutrients. Reasons for this are suggested. Data on leaf area changes indicated that, in contrast to the increasing severity of potassium deficiency with age of the plant, both copper and zinc deficiency tended to diminish after the commencement of the flowering stage. The importance of such time trends in the interpretation of interaction effects is emphasized. The economic significance of the potassium problem is stressed and a number of aspects requiring investigation are outlined.



1990 ◽  
Vol 41 (3) ◽  
pp. 499 ◽  
Author(s):  
BJ Scott ◽  
AD Robson

The objectives of this study were to examine Mg distribution in subterranean clover (Trifolium subterraneum L.), to identify an appropriate tissue for diagnosis of deficiency and to establish minimum tissue concentrations associated with maximum plant growth. Plants were grown in solution culture with both discontinued (40 8M and 160 8M reduced to nil) and constant supply (0, 5, 10, 20, 40, 80, 160 8M Mg). Magnesium was depleted from old leaves when Mg supply to the roots was interrupted. However, deficiency symptoms occurred first on the young tissue under these conditions. Under constant but inadequate supply, initial deficiency symptoms occurred in old tissue. Symptoms in leaves were associated with Mg concentrations in the leaf of < 1046 8g g-1 with constant root supply and 586 8g g-1 when supply was interrupted. At luxury constant supply, concentrations of Mg tended to be higher in the older leaves than in the young leaves; the reverse occurred with inadequate supply. Tissue choice for diagnosis was not critical, but the minimum Mg concentration in tissue commensurate with maximum shoot growth varied from 740 8g g-1 for the unifoliate leaf to 1310 8g g-1 in the youngest open leaf (YOL), when plants were grown under constant Mg supply. Current supply of Mg to roots was reflected more rapidly in the concentrations in young leaf than in old leaf tissue.



2010 ◽  
Vol 61 (9) ◽  
pp. 708 ◽  
Author(s):  
Tiernan A. O'Rourke ◽  
Megan H. Ryan ◽  
Hua Li ◽  
Xuanli Ma ◽  
Krishnapillai Sivasithamparam ◽  
...  

Subterranean clover (Trifolium subterraneum) is grown extensively as a pasture legume in agronomic regions with Mediterranean-type climates in parts of Africa, Asia, Australia, Europe, North America and South America. Root diseases of subterranean clover, especially those caused by oomycete pathogens including Aphanomyces, Phytophthora and Pythium, greatly reduce productivity by significantly decreasing germination, seedling establishment, plant survival and seed set. For this reason, experiments were conducted to determine the species of Aphanomyces causing root disease on subterranean clover in the high-rainfall areas of south-west Western Australia. The effects of flooding, temperature and inoculum concentration on the development of root disease on subterranean clover caused by this Aphanomyces sp. were also investigated as was its host range. Morphological and molecular characteristics were used to identify the pathogen as a new species Aphanomyces trifolii sp. nov. (O’Rourke et al.), which forms a distinct clade with its nearest relative being A. cladogamus. A. trifolii caused significant lateral root pruning as well as hypocotyl collapse and tap root disease of subterranean clover. The level of disease was greater in treatments where soil was flooded for 24 h rather than for 6 h or in unflooded treatments. The pathogen caused more disease at 18/13oC than at lower (10/5oC) or higher (25/20oC) temperatures. The pathogen caused more disease at 1% inoculum than at 0.5 or 0.2% (% inoculum : dry weight of soil). In greenhouse trials, A. trifolii also caused root disease on annual medic (M. polymorpha and M. truncatula), dwarf beans (Phaseolus vulgaris) and tomatoes (Solanum lycopersicum). However, the pathogen did not cause disease on peas (Pisum sativum), chickpea (Cicer arietinum), wheat (Triticum aestivum), annual ryegrass (Lolium rigidium) or capsicum (Capsicum annuum). A. trifolii is a serious pathogen in the high-rainfall areas of south-west Western Australia and is likely a significant cause of root disease and subsequent decline in subterranean clover pastures across southern Australia.



2012 ◽  
Vol 63 (9) ◽  
pp. 840 ◽  
Author(s):  
C. K. Revell ◽  
M. A. Ewing ◽  
B. J. Nutt

The south-west of Western Australia has experienced a declining trend in annual rainfall and gradual warming over the last 30 years. The distribution of rainfall has also changed, with lower autumn rainfall, patchy breaks to the season, and shorter springs. This has important implications for the productivity of legume pastures in the region, which is dominated by annual species, particularly subterranean clover (Trifolium subterraneum L.), annual medics (Medicago spp.), serradella (Ornithopus spp.), and biserrula (Biserrula pelecinus L.). For annual pasture legumes, appropriate patterns of seed softening and germination behaviour, efficiency of phosphorus and potassium uptake, responses to elevated levels of atmospheric CO2, and drought resistance of seedlings and mature plants will assume increasing importance. While these traits can be targeted in pasture breeding programs, it will also be important to exploit farming system opportunities to optimise the annual legume component of the feed base. These opportunities may take the form of incorporating strategic shrub reserves and grazing crops to allow for pasture deferment in autumn–winter. Perennial forages may become more important in this context, as discussed in terms of the development of the perennial legume tedera (Bituminaria bituminosa var. albomarginata C.H. Stirton).



1996 ◽  
Vol 127 (2) ◽  
pp. 169-174 ◽  
Author(s):  
M. H. Awan ◽  
D. J. Barker ◽  
P. D. Kemp ◽  
M. A. Choudhary

SUMMARYSoil surface moisture is a dominant factor influencing the establishment of surface sown seed, but its measurement is difficult. A cobalt chloride (CoCl2) saturated paper strip (20×5 mm) technique was developed as a cheap but sensitive indicator of soil surface moisture. The influence of soil surface moisture on the seedling survival of three oversown legume species, subterranean clover (Trifolium subterraneum L. cv. Karridale), strawberry clover (T.fragiferum L. cv. Grasslands Onward) and Caucasian clover (T. ambiguum Bieb. cv. Monaro) was investigated in a glasshouse and a field experiment at Palmerston North, New Zealand, between 1 October and 30 November 1993. Intact sods were sprayed with glyphosate, placed in plastic trays (420×300×50 mm) and transferred to the glasshouse or field. Three soil surface moisture treatments were imposed in the glasshouse. In the field trial, the plastic trays were buried flush with the soil surface in contact with the subsoil and exposed to natural wind and rainfall. Bare seed was oversown in a 20 × 20 mm grid and then pushed into the soil with a roller studded with metal rods to simulate treading by sheep. The low soil surface moisture treatment and the field trial had the lowest seedling survival. The main cause for this was low surface moisture caused by wind, which hindered radicle entry into the soil. Subterranean clover was less susceptible to low surface moisture and had better net seedling survival in all the treatments than the other two legume species.



1995 ◽  
Vol 46 (4) ◽  
pp. 763 ◽  
Author(s):  
SJ McKirdy ◽  
RAC Jones

When leaf samples were collected from 94 Trifolium subterraneum (subterranean clover) pastures from six districts in spring 1993 in the south-west of Western Australia and tested by enzyme-linked immunosorbent assay, no alfalfa mosaic virus (AMV) or subterranean clover red leaf virus (SCRLV) was detected. In contrast, when 21 irrigated T. repens (white clover) pastures from one district (Bunbury) were sampled and tested in January (summer) 1994, AMV was detected in 16, with eight having infection levels >86%, while SCRLV was found in seven at infection levels of <12%. When a further five T. repens pastures were tested for AMV in October (spring) 1994, the virus was found in all with incidences up to 100%. None of the T. repens pastures with high levels of AMV infection had been resown with T. repens within the last 20 years, whereas those resown within the last five years had little or no infection. AMV was detected in 9/91 annual medic (Medicago spp.) pastures from seven wheatbelt districts sampled in spring 1991 or 1993; a single pasture of M. polymorpha (burr medic) cv. Serena was 21% infected, but the other eight infected ones had <3%. AMV seed transmission was detected in 1/19 commercial seed stocks of M. polymorpha harvested in 1991-93. AMV infection was followed over a 12-year period in M. murex (murex medic) cv. Zodiac seed stocks. It persisted readily through successive seed harvests during this period. It is concluded that infection with AMV and SCRLV is currently not a threat to T. subterraneum pastures in the south-west of Western Australia and that AMV seems not to be one in wheatbelt annual medic pastures provided these are sown with healthy medic seed. In contrast, AMV poses a potential threat to the productivity of irrigated T. repens pastures. SCRLV is also sometimes present in T. repens pastures, but was not found at serious levels.



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