An analysis of the frequency and timing of false break events in the Mediterranean region of Western Australia

2001 ◽  
Vol 52 (3) ◽  
pp. 367 ◽  
Author(s):  
R. Chapman ◽  
S. Asseng
Keyword(s):  
Western Australia ◽  
Mediterranean Region ◽  
Meteorological Data ◽  
Seasonal Pattern ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Dormancy Release ◽  
The Poor ◽  
Time Periods ◽  
The Mediterranean

Historical meteorological data were used to estimate the frequency and timing of false break events at 10 locations in the annual pasture and wheat producing area in the Mediterranean climatic region of Western Australia. The seasonal pattern of false breaks identified by this analysis was compared with the dynamics of dormancy release in a field population of subterranean clover (Trifolium subterraneum L.) to determine the influence that these events may have on the legume content of annual pasture communities in this region. False break events were estimated to occur on approximately 2 of every 3 years (611–72% of years) with no significant differences across the area investigated. Changes in the risk of false break events were examined over discrete time periods. The period of greatest risk was predicted to occur during early autumn (early March to mid April). Seed softening is virtually complete in subterranean clover at this point. The seed bank strategy of this species is, therefore, not well adapted to withstand the effects of false breaks. This might largely explain the poor persistence of subterranean clover in the annual pasture communities in the Mediterranean region of Western Australia. The legume content of these pastures might be improved by selecting species with late dormancy release strategies that will give better protection from false breaks.

Effects of rainfall and temperature on the feeding value of barley straw in a semi-arid Mediterranean environment

1997 ◽  
Vol 129 (3) ◽  
pp. 353-366 ◽  
Author(s):  
A. V. GOODCHILD
Keyword(s):  
Mediterranean Region ◽  
Meteorological Data ◽  
Small Ruminants ◽  
Barley Straw ◽  
Maximum Temperature ◽  
Mean Annual Precipitation ◽  
Monthly Precipitation ◽  
Feeding Value ◽  
The Mediterranean

Annual variation in the feeding value of barley straw (Hordeum vulgare L. subsp. vulgare) is economically significant in the Mediterranean region. The relationship between the feeding value for sheep of several winter-planted barley cultivars and monthly meteorological data was analysed at Tel Hadya, northwest Syria (mean annual precipitation 330 mm) in 11 years. Indicators of feeding value included contents of neutral detergent fibre, acid detergent fibre and nitrogen (11 years), voluntary straw intake by sheep (10 years), voluntary digestible organic matter intake (9 years), in sacco dry matter loss and lignin content (8 years), in vitro digestibility (7 years) and in vitro gas production (6 years). Monthly meteorological data included total precipitation, mean minimum and mean maximum air temperatures.Conditions likely to decrease grain yield tended to increase the feeding value of straw. Low mean minimum temperature in February, low precipitation in January, February, March and April, and high mean maximum temperature in March, April and May increased one or more indicators of straw feeding value (by both bivariate and multiple regression, P<0·05). Precipitation before January affected grain and straw yield but had little effect on the feeding value of straw.Genotype × year interactions had a meteorological component; the superior feeding value of the straw of locally-adapted cultivars v. exotic cultivars was only seen in years with cool or wet springs. This has implications for the genetic selection of crops with better straw feeding value.Models based on monthly precipitation and temperature, calibrated for locations in the Mediterranean region, can predict the nutritive value of straw and aid the planning of rations for small ruminants.

Varietal reaction and genetic resistance of subterranean clover (Trifolium subterraneum L.) to subterranean clover stunt virus infection

1960 ◽  
Vol 11 (5) ◽  
pp. 723 ◽  
Author(s):  
NW Grylls ◽  
JW Peak
Keyword(s):  
New Zealand ◽  
Virus Infection ◽  
Iberian Peninsula ◽  
Genetic Resistance ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Third Generation ◽  
Subterranean Clover Stunt Virus ◽  
Mediterranean Regions ◽  
The Mediterranean

Resistance to subterranean clover stunt virus was explored in 390 strains and named varieties of subterranean clover from the Mediterranean regions, England, France, the Iberian peninsula, New Zealand, and Australia. High levels of genetic resistance were shown in the Australian varieties Tallarook, Hill's Small, and Bass B. Resistance of a selected group of F2's was found to be midway between that of the parents. In selected groups of F4 generation hybrids, and in selected second and third generation backcrosses, resistance equal to that of Tallarook was shown. The apparent recovery of some plants during tests in the glass-house was shown to be a form of temporary tolerance to the virus.

Comparing different sources of sulfur for high-rainfall pastures insouth-western Australia

2003 ◽  
Vol 43 (10) ◽  
pp. 1221 ◽  
Author(s):  
M. D. A. Bolland ◽  
J. S. Yeates ◽  
M. F. Clarke
Keyword(s):  
Western Australia ◽  
Field Experiments ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Residual Value ◽  
Single Superphosphate ◽  
Pasture Production ◽  
Leaching Losses ◽  
S Deficiency ◽  
Different Sources

The dry herbage yield increase (response) of subterranean clover (Trifolium subterraneum L.)-based pasture (>85% clover) to applications of different sources of sulfur (S) was compared in 7 field experiments on very sandy soils in the > 650 mm annual average rainfall areas of south-western Australia where S deficiency of clover is common when pastures grow rapidly during spring (August–November). The sources compared were single superphosphate, finely grained and coarsely grained gypsum from deposits in south-western Australia, and elemental S. All sources were broadcast (topdressed) once only onto each plot, 3 weeks after pasture emerged at the start of the first growing season. In each subsequent year, fresh fertiliser-S as single superphosphate was applied 3 weeks after pasture emerged to nil-S plots previously not treated with S since the start of the experiment. This was to determine the residual value of sources applied at the start of the experiment in each subsequent year relative to superphosphate freshly-applied in each subsequent year. In addition, superphosphate was also applied 6, 12 and 16 weeks after emergence of pasture in each year, using nil-S plots not previously treated with S since the start of the experiment. Pasture responses to applied S are usually larger after mid-August, so applying S later may match plant demand increasing the effectiveness of S for pasture production and may also reduce leaching losses of the applied S.At the same site, yield increases to applied S varied greatly, from 0 to 300%, at different harvests in the same or different years. These variations in yield responses to applied S are attributed to the net effect of mineralisation of different amounts of S from soil organic matter, dissolution of S from fertilisers, and different amounts of leaching losses of S from soil by rainfall. Within each year at each site, yield increases were mostly larger in spring (September–November) than in autumn (June–August). In the year of application, single superphosphate was equally or more effective than the other sources. In years when large responses to S occurred, applying single superphosphate later in the year was more effective than applying single superphosphate 3 weeks after pasture emerged (standard practice), so within each year the most recently applied single superphosphate treatment was the most effective S source. All sources generally had negligible residual value, so S needed to be applied each year to ensure S deficiency did not reduce pasture production.

Occurrence of Phytophthora clandestina in Trifolium subterraneum paddocks in Australia

2001 ◽  
Vol 41 (2) ◽  
pp. 187 ◽  
Author(s):  
R. Aldaoud ◽  
W. Guppy ◽  
L. Callinan ◽  
S. F. Flett ◽  
K. A. Wratten ◽  
...  
Keyword(s):  
Western Australia ◽  
Root Rot ◽  
New South ◽  
New South Wales ◽  
South Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Soil Samples ◽  
South Wales ◽  
Differential Cultivars

In 1995–96, a survey of soil samples from subterranean clover (Trifolium subterraneum L.) paddocks was conducted across Victoria, South Australia, New South Wales and Western Australia, to determine the distribution and the prevalence of races of Phytophthora clandestina (as determined by the development of root rot on differential cultivars), and the association of its occurrence with paddock variables. In all states, there was a weak but significant association between P. clandestina detected in soil samples and subsequent root rot susceptibility of differential cultivars grown in these soil samples. Phytophthora clandestina was found in 38% of the sampled sites, with a significantly lower prevalence in South Australia (27%). There were significant positive associations between P. clandestina detection and increased soil salinity (Western Australia), early growth stages of subterranean clover (Victoria), mature subterranean clover (South Australia), recently sown subterranean clover (South Australia), paddocks with higher subterranean clover content (Victoria), where herbicides were not applied (South Australia), irrigation (New South Wales and Victoria), cattle grazing (South Australia and Victoria), early sampling dates (Victoria and New South Wales), sampling shortly after the autumn break or first irrigation (Victoria), shorter soil storage time (Victoria) and farmer’s perception of root rot being present (Victoria and New South Wales). Only 29% of P. clandestina isolates could be classified under the 5 known races. Some of the unknown races were virulent on cv. Seaton Park LF (most resistant) and others were avirulent on cv. Woogenellup (most susceptible). Race 1 was significantly less prevalent in South Australia than Victoria and race 0 was significantly less prevalent in New South Wales than in South Australia and Western Australia. This study revealed extremely wide variation in the virulence of P. clandestina. The potential importance of the results on programs to breed for resistance to root rot are discussed. in South Australia.

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.

A comparison of the effects of feed supplements cobalt and selenium, and perennial and annual pastures on the production of medium Peppin Merino weaner sheep in south-western Australia

1989 ◽  
Vol 29 (3) ◽  
pp. 361
Author(s):  
HL Davies ◽  
PP Mann ◽  
B Goddard
Keyword(s):  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Grass Species ◽  
Feed Supplement ◽  
Protein Meal ◽  
Wool Production ◽  
Phalaris Aquatica ◽  
High Protein Meal ◽  
Cereal Group

Two experiments on weaner production are reported. In experiment 1, the liveweight and wool production were measured in medium Peppin Merino sheep that grazed at 10.5 weanerstha 8 plots of a mixed Phalaris aquatica-subterranean clover pasture or 8 plots of annual pasture (Trifolium subterraneum cv. Woogenellup and volunteer annual grass species). This was repeated over 2 years using autumn-born sheep; 4 groups on each pasture type were offered no supplement, 2 groups a cereal supplement (340 goats), and 2 groups of supplement isoenergetic with the cereal group but having a high protein meal replace some of the cereal (250 g oats and 60 g protein). The feed supplement was offered over the summer (January-April). The sheep on 2 of the unsupplemented plots and 1 of the 2 plots receiving either a cereal or cereal + protein supplement were offered access to a composite mineral block formulated to meet the mineral requirements of sheep with the exception of cobalt and selenium. There were 16 sheep on each plot within each group of 16 weaners, 4 were given an intraruminal cobalt 'bullet', 4 were given 5 mg of selenium orally, 4 given cobalt plus selenium and 4 were untreated controls. Experiment 2 was in year 3 with spring-born weaners on the same plots. The mineral block treatment was discarded on the plots receiving supplement and the effect of supplementary feeding at the beginning of March was compared with feeding in early January; barley was also compared with oats and protein. The stocking rate was raised to 13.5 sheep/ha. There were no statistically significant differences in sheep liveweight due to pasture type in either of the years of experiment 1 or experiment 2. Supplementation with cereals or protein-fortified cereals resulted in a significantly ( P < 0.05) increased liveweight at the end of March (5.6 kg in year 1,2.4 kg in year 2 of experiment 1, and 2.5 kg in experiment 2), and wool production (0.49 kg clean wool in year 1 and 0.3 1 kg in year 2 in experiment 1, and 0.49 in experiment 2). There was a significant liveweight response on the perennial plots to selenium + cobalt in year 1 of experiment 1. All cobalt-treated sheep were heavier ( P < 0.001) in year 2. Neither selenium nor cobalt significantly affected liveweight in experiment 2. The proportion of Phalaris aquatica on the perennial pasture diminished from 18% to less than 9% by the end of year 2 in experiment 1. These results suggest that, if perennial pastures cannot be maintained, then their establishment in the south-west of Western Australia would not result in greater animal production than on annual pasture. Decisions on using supplements would be dependent upon feed and wool prices.

Responses of intensively grazed dairy pastures to applications of fertiliser nitrogen in south-western Australia

2007 ◽  
Vol 47 (8) ◽  
pp. 927 ◽  
Author(s):  
M. D. A. Bolland ◽  
I. F. Guthridge
Keyword(s):  
Western Australia ◽  
Dry Matter ◽  
Maximum Yield ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Mineral Elements ◽  
Italian Ryegrass ◽  
Total N ◽  
Dry Matter Digestibility

For the first time, we quantified pasture dry matter (DM) responses to applied fertiliser nitrogen (N) for intensively grazed, rain-fed, dairy pastures on sandy soils common in the Mediterranean-type climate of south-western Australia. The pastures are composed of subterranean clover (Trifolium subterraneum L.) and annual and Italian ryegrass (Lolium rigidum Gaud. and L. multiflorum Lam.). Six rates of N, as urea (46% N), were applied to 15 m by 15 m plots four times during 2002 and after each of the first 5–7 grazings in 2003 and 2004, throughout the typical April–October growing season. Total rates of N applied in the first year of the experiments were 0, 60, 120, 160, 200 and 320 kg N/ha, which were adjusted in subsequent years as detailed in the ‘Materials and methods’ section of this paper. The pastures in the experiments were rotationally grazed, by starting grazing when ryegrass plants had 2–3 leaves per tiller. The amount of pasture DM on each plot was measured before and after each grazing and was then used to estimate the amount of pasture DM consumed by the cows at each grazing for different times during the growing season. Linear increases (responses) of pasture DM to applied N occurred throughout the whole growing season when a total of up to 320 kg N/ha was applied in each year. No maximum yield plateaus were defined. Across all three experiments and years, on average in each year, a total of ~5 t/ha consumed DM was produced when no N was applied and ~7.5 t/ha was produced when a total of 200 kg N/ha was applied, giving ~2.5 t/ha increase in DM consumed and an N response efficiency of ~12.5 kg DM N/kg applied. As more fertiliser N was applied, the proportion of ryegrass in the pasture consistently increased, whereas clover content decreased. Concentrations of nitrate-N in the DM consistently increased as more N was applied, whereas concentrations of total N, and, therefore, concentration of crude protein in the DM, either increased or were unaffected by applied N. Application of N had no effect on concentrations of other mineral elements in DM and on dry matter digestibility and metabolisable energy of the DM. The results were generally consistent with findings of previous pasture N studies for perennial and annual temperate and subtropical pastures. We have shown that when pasture use for milk production has been maximised in the region, it is profitable to apply fertiliser N to grow extra DM consumed by dairy cows; conversely, it is a waste of money to apply N to undergrazed pastures to produce more unused DM.

Taxonomic and pathogenic characteristics of a new species Aphanomyces trifolii causing root rot of subterranean clover (Trifolium subterraneum) in Western Australia

2010 ◽  
Vol 61 (9) ◽  
pp. 708 ◽  
Author(s):  
Tiernan A. O'Rourke ◽  
Megan H. Ryan ◽  
Hua Li ◽  
Xuanli Ma ◽  
Krishnapillai Sivasithamparam ◽  
...  
Keyword(s):  
New Species ◽  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Root Disease ◽  
Molecular Characteristics ◽  
Root Pruning ◽  
High Rainfall ◽  
South West ◽  
A New Species

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.

Comparison of the phosphate requirements of burr medic and yellow serradella with subterranean clover in the low rainfall wheatbelt of Western Australia

1992 ◽  
Vol 32 (8) ◽  
pp. 1077 ◽  
Author(s):  
BH Paynter
Keyword(s):  
Seed Production ◽  
Western Australia ◽  
Maximum Yield ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Yield Response ◽  
Absolute Maximum ◽  
Absolute Yield ◽  
Burr Medic ◽  
Internal Efficiency

Burr medic (Medicago polymorpha) and yellow serradella (Ornithopus compressus) were compared with subterranean clover (Trifolium subterraneum) in their response to freshly topdressed phosphate in the low rainfall wheatbelt of Western Australia. Species were compared on the amount of applied phosphorus (P) required for 90% maximum yield and the ratio of their curvature coefficients from the Mitscherlich relationship between P applied and absolute yield. On marginally acidic, medium-textured soils, burr medic had a higher external shoot requirement for applied P than subterranean clover. Relative differences between the species were affected by season, initial concentration of bicarbonate-extractable P in the soil (0-10 cm), and timing of plant harvest during the growing season. Burr medic generally achieved a higher absolute maximum yield at each harvest, a larger absolute yield response, and a larger percentage response to applied P than subterranean clover. There was no difference between burr medic and subterranean clover with respect to the internal efficiency of P use for shoot production. For seed production, the external requirements of burr medic and subterranean clover for applied P were similar according to the criterion of P required at 90% maximum yield, but burr medic had a higher requirement if curvature coefficient was the criterion for comparison. Burr medic also had a higher internal efficiency of P use for seed production than subterranean clover. On an acidic, light-textured soil, yellow serradella had a lower requirement for applied P than subterranean clover, according to both criteria for all harvests in 2 separate years.

Distribution and abundance of annual legume seeds in the wheatbelt of Western Australia

1995 ◽  
Vol 35 (2) ◽  
pp. 189 ◽  
Author(s):  
JA Fortune ◽  
PS Cocks ◽  
CK Macfarlane ◽  
FP Smith
Keyword(s):  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Farming Systems ◽  
Annual Rainfall ◽  
Soil Parameters ◽  
Widespread Species ◽  
Legume Seeds ◽  
Clover Seed

The size and composition of pasture legume seedbanks were estimated from 2 surveys on a 460-km west-east transect of the wheatbelt of Western Australia. Survey 1 (in spring) sampled naturalised legumes, and survey 2 (in summer) measured the amount and botanical composition of legume seed from selected sites. Seedbanks were examined in greater detail on 2 farms in the higher rainfall part of the wheatbelt. Survey 2 revealed that mean seedbank size of the poorest 40% of sites (those with 5200 kg seed/ha) was 61 kg/ha, and that 72% of seeds were naturalised clovers. In contrast, the best 60% of sites (those with >200 kg seed/ha) averaged 533 kg seed/ha, of which only 35% was naturalised clover seed, the remainder in both surveys being mainly subterranean clover (Trifolium subterraneum). Mean seed bank size (kg/ha) varied from 359 (survey 2) to 587 (survey 1) and, in both surveys, was poorly correlated with long-term mean annual rainfall and a number of soil parameters. On the 2 farms, seedbank size ranged from 300 to 345 kg/ha (in spring) and from 650 to 740 kg/ha (in summer). Trifolium glomeratum (cluster clover) and subterranean clover were the most widespread species in both surveys. They were present at 35 and 30 of the 57 survey sites, respectively, and at both farms. Most of the subterranean clover collected was cv. Geraldton (22 of 30 sites), the next most frequent cultivar was Dwalganup (6 sites). The currently recommended cultivar, Dalkeith, was found at only 5 sites. Several other legumes including T. tomentosum (16 sites), T. suffocatum (8 sites), Medicago truncatula (7 sites), T. hirtum (4 sites), and M. minima (4 sites) were common, while M. littoralis, M. polymorpha, T. dubium, T. cernuum, T. cherleri, and T. carnpestre were found at single sites. With few exceptions, these are naturalised species and were characterised by flowering times about 20 days later than sown legume cultivars, and seed sizes < 1 mg. The value of these widespread annual legumes to agricultural productivity and sustainability needs to be quantified and their adaptation to wheatbelt farming systems assessed.

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