The capeweed content of pastures in south-west Western Australia

1985 ◽  
Vol 25 (1) ◽  
pp. 117 ◽  
Author(s):  
GW Arnold ◽  
PG Ozanne ◽  
KA Galbraith ◽  
F Dandridge
Keyword(s):  
Western Australia ◽  
Soil Type ◽  
Dry Matter ◽  
The Other ◽  
Aerial Photographs ◽  
Dry Period ◽  
High Rainfall ◽  
South West ◽  
Agricultural Areas ◽  
Linear Regressions

The capeweed (Arctotheca calendula) content of pastures in the agricultural areas of Western Australia was estimated from coloured aerial photographs taken during flowering. Linear regressions were obtained between a visual score for capeweed content based on colour and the actual capeweed content of calibration sites. Surveys in 1972, 1973 and 1975 showed that 1973 was a year of high capeweed content in all areas compared with 1972 and 1975. The content was higher in lower-rainfall wheatbelt areas, where it averaged about 50% of pasture dry matter in 1973, than in the high-rainfall grazing areas, where the average was 37%. Fluctuations from year to year were followed on fixed sites between 1973 and 1977. The high rainfall sites varied more from year to year in capeweed content than did the low-rainfall sites. A detailed survey of one farm was made between 1972 and 1976 and this confirmed the indications from the other broadscale surveys that 1973 and 1976 were years that favoured capeweed. They were years when germination was followed by a 4-5 week dry period. Soil type and position in the landscape were also shown to influence the capeweed content of pastures.

High ear number is key to achieving high wheat yields in the high-rainfall zone of south-western Australia

2007 ◽  
Vol 58 (1) ◽  
pp. 21 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole ◽  
Senthold Asseng
Keyword(s):  
Western Australia ◽  
Spring Wheat ◽  
Harvest Index ◽  
Dry Matter ◽  
Growing Season ◽  
Growth And Yield ◽  
Yield Potential ◽  
Dry Matter Accumulation ◽  
High Rainfall ◽  
Sink Capacity

The growth and yield of spring wheat (Triticum aestivum L.) were examined to determine the actual and potential yields of wheat at a site in the high rainfall zone (HRZ) of south-western Australia. Spring wheat achieved yields of 5.5−5.9 t/ha in 2001 and 2003 when subsurface waterlogging was absent or minimal. These yields were close to the estimated potential, indicating that a high yield potential is achievable. In 2002 when subsurface waterlogging occurred early in the growing season, the yield of spring wheat was 40% lower than the estimated potential. The yield of wheat was significantly correlated with the number of ears per m2 (r2 = 0.81) and dry matter at anthesis (r2 = 0.73). To achieve 5–6 t/ha of yield of wheat in the HRZ, 450–550 ears per m2 and 10–11 t/ha dry matter at anthesis should be targetted. Attaining such a level of dry matter at anthesis did not have a negative effect on dry-matter accumulation during the post-anthesis period. The harvest index (0.36−0.38) of spring wheat was comparable with that in drier parts of south-western Australia, but relatively low given the high rainfall and the long growing season. This relatively low harvest index indicates that the selected cultivar bred for the low- and medium-rainfall zone in this study, when grown in the HRZ, may have genetic limitations in sink capacity arising from the low grain number per ear. We suggest that the yield of wheat in the HRZ may be increased further by increasing the sink capacity by increasing the number of grains per ear.

An evaluation of barley accessions for adaptation to the cereal growing regions of Western Australia, based on time to ear emergence

1994 ◽  
Vol 45 (1) ◽  
pp. 75 ◽  
Author(s):  
KJ Young ◽  
GA Elliott
Keyword(s):  
Cluster Analysis ◽  
Western Australia ◽  
The Other ◽  
Optimum Time ◽  
High Rainfall ◽  
Sowing Dates ◽  
Wide Range ◽  
Mean Time ◽  
Rainfall Region ◽  
Western Australian

Ear emergence was measured on a wide range of barley accessions for a number of sowing dates in contrasting environments of the Western Australian cereal-growing regions to determine suitable types for (i) early sowing in the low (<400 mm per annum) regions and (ii) barley production in the high rainfall (>450 mm per annum) regions. Accessions were classified into nine groups via cluster analysis using the time to ear emergence at four sites and a range of sowing dates. Australian cultivars were members of the three groups with the shortest mean time to ear emergence, and, on the basis of an optimum time to ear emergence at each site, were shown to be well adapted to a wide range of sowing times and sites. Members of only one other group showed an acceptable level of adaptation across sites and sowing dates, members of the other five groups being suited to early or very early sowings in the high rainfall region only.

Water use of wheat, barley, canola, and lucerne in the high rainfall zone of south-western Australia

2005 ◽  
Vol 56 (7) ◽  
pp. 743 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Western Australia ◽  
Dry Matter ◽  
Grain Filling ◽  
Rooting Depth ◽  
Dry Matter Accumulation ◽  
High Rainfall ◽  
Annual Crops ◽  
Significant Difference

Water use of wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), canola (Brassica napus L.), and lucerne (Medicago sativa L.) was measured on a duplex soil in the high rainfall zone (HRZ) of south-western Australia from 2001 to 2003. Rainfall exceeded evapotranspiration in all years, resulting in transient perched watertables, subsurface waterlogging in 2002 and 2003, and loss of water by deep drainage and lateral flow in all years. There was no significant difference in water use among wheat, barley, and canola. Lucerne used water at a similar rate to annual crops during the winter and spring, but continued to extract 80−100 mm more water than the annual crops over the summer and autumn fallow period. This resulted in about 50 mm less drainage past the root-zone than for annual crops in the second and third years after the establishment of the lucerne. Crop water use was fully met by rainfall from sowing to anthesis and a significant amount of water (120−220 mm) was used during the post-anthesis period, resulting in a ratio of pre- to post-anthesis water use (ETa : ETpa) of 1 : 1 to 2 : 1. These ratios were lower than the indicative value of 2 : 1 for limited water supply for grain filling. High water use during the post-anthesis period was attributed to high available soil water at anthesis, a large rooting depth (≥1.4 m), a high proportion (15%) of roots in the clay subsoil, and regular rainfall during grain filling. The pattern of seasonal water use by crops suggested that high dry matter at anthesis did not prematurely exhaust soil water for grain filling and that it is unlikely to affect dry matter accumulation during grain filling and final grain yield under these conditions.

Yield of wheat and canola in the high rainfall zone of south-western Australia in years with and without a transient perched water table

2004 ◽  
Vol 55 (4) ◽  
pp. 461 ◽  
Author(s):  
Heping Zhang ◽  
Neil C. Turner ◽  
Michael L. Poole
Keyword(s):  
Western Australia ◽  
Crop Production ◽  
Dry Matter ◽  
Unit Area ◽  
Wheat Yield ◽  
Soil Surface ◽  
Wheat Roots ◽  
Area Index ◽  
High Rainfall ◽  
Perched Water Table

The yields of wheat and canola in 2 successive years with and without the development of a perched watertable were compared in the high rainfall zone of south-western Australia. In 2001, no perched watertable was observed and wheat and canola yields were close to their estimated potentials. In 2002, a perched watertable developed at less than 30 cm below the soil surface for more than 8 days and at less than 50 cm below the soil surface for at least 30 days at the tillering stage of wheat and at the rosette stage of canola. The air-filled porosity of the soil fell below the critical value of 10% at 10 and 30 cm depth for about 40 days. This reduced the maximum leaf area index of canola by 46% and of wheat by 30%, and reduced the shoot dry matter of wheat at flowering by 27% and by 40% at podding in canola compared with those in 2001. The growth of the wheat roots was constrained at depths from 50-90 cm from the soil surface in 2002 compared with 2001. However, the roots of canola and wheat were able to grow to at least 1.4 m in both 2001 and 2002. In both years, a much higher proportion (>10%) of roots was present in the clay subsoil compared with previous reports in south-western Australia and enabled the crops to utilise a greater amount of water from the clay subsoil. The wheat yield in 2002 was 37% lower than in 2001 and well below the potential, largely as a result of a reduced tiller number per plant and ears per unit area. Despite the greater reduction in dry matter in canola than in wheat in 2002, the seed yield of canola was 17% higher in 2002 than in 2001. Canola, an indeterminate crop, was able to respond to the late rain that occurred in 2002 compared with 2001 and produced a significantly higher seed number per unit area. In 2002, grain size in wheat was 25% larger than in 2001, but this increase was insufficient to compensate for the yield loss resulting from the fewer ears per unit area. It is concluded that early transient perched watertable induced subsurface waterlogging, and that the subsurface waterlogging can be a major constraint to crop growth in the high rainfall region of southwestern Australia, and that reducing waterlogging could be a key to achieving higher crop production.

Reliability of canola production in different rainfall zones of Western Australia

2007 ◽  
Vol 58 (4) ◽  
pp. 326 ◽  
Author(s):  
Imma Farré ◽  
Michael Robertson ◽  
Senthold Asseng
Keyword(s):  
Soil Water ◽  
Western Australia ◽  
Soil Type ◽  
Oil Content ◽  
Sowing Date ◽  
Soil Types ◽  
Minor Effect ◽  
High Rainfall ◽  
History Of

The area of canola in the wheat-based farming systems of the wheatbelt of Western Australia (WA) expanded rapidly during the 1990s and has subsequently decreased. Due to the short history of canola production in WA, there is little information on yield and oil content expectations in relation to rainfall, location, and soil type. In this paper we: (1) present the recent history of canola production in the context of the long-term climate record; (2) assess the effect of location, rainfall, soil type, and soil water at sowing on yield and oil content; and (3) determine cut-off sowing dates for profitable canola production. Simulations were run using the APSIM-Canola model with long-term climate records for 3 selected locations from the low-, medium-, and high-rainfall zones and different soil types. Analysis of recent trends in canola area showed that poor seasons and price volatility in the last few years have contributed to farmers’ perception of risk and hence the decline in area sown. Long-term simulations showed the importance of location, sowing date, soil type, and stored soil water at sowing on grain yield. Yield was negatively related to sowing date. Light-textured soils had lower yields and larger yield penalties with delayed sowing than heavy-textured soils. Soil water at sowing gave a yield advantage in most years in all locations studied, but especially in low- and medium-rainfall locations. Variation in oil content was most strongly affected by sowing date and location, while soil type and soil water at sowing had a minor effect. Long-term simulation analysis can be used as a tool to establish the latest possible sowing date to achieve profitable canola for different locations and soil types, given different canola prices and growing costs. Given the vulnerability of profitability to seasonal conditions, in the low- and medium-rainfall zone, the decision to grow canola should be tactical depending on stored soil water, sowing opportunities, seasonal climate outlook, prices, and costs. In contrast, in the high-rainfall zone, canola production is relatively low risk, and could become a reliable component of rotations.

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.

Persistence of several annual legumes in mixtures under continuous grazing in the south west of Western Australia

1974 ◽  
Vol 14 (70) ◽  
pp. 632 ◽  
Author(s):  
GB Taylor ◽  
RC Rossiter
Keyword(s):  
Medicago Truncatula ◽  
Western Australia ◽  
Subterranean Clover ◽  
The Other ◽  
Annual Rainfall ◽  
Annual Legumes ◽  
South West ◽  
Continuous Grazing ◽  
Average Annual Rainfall ◽  
Average Rainfall

Two experiments are described: one in the wheatbelt in areas receiving 320 and 400 mm average annual rainfall, and the other in a medium rainfall area with an average rainfall of 640 mm. In the first experiment various combinations of barrel medic (Medicago truncatula) and cupped (Trifolium cherleri) and rose clovers (T. hirtum) with subterranean clover (T. subeterraneum) were grown at four sites. Each site was continuously grazed by sheep for periods ranging from three to five years. At all sites subterranean clover became dominant within a few years of establishment. The second experiment involved rose and subterranean clovers in ungrazed pure swards and mixed swards which were either grazed or ungrazed. Grazing was continued for three years. Grazing had a profound effect on the composition of the mixture: whereas subterranean clover dominated the grazed sward, in the absence of grazing rose clover over-topped the subterranean clover and dominated the mixture. The success of subterranean clover in grazed mixtures is attributed largely to relative inaccessibility to the grazing animal, particularly of seedlings but also of seeds.

The cage method of sampling to assess herbage mass and herbage consumed on annual rangeland vegetation

1988 ◽  
Vol 10 (1) ◽  
pp. 6
Author(s):  
BB Zahran ◽  
AM Holm ◽  
WR Stern ◽  
WA Loneragan
Keyword(s):  
Western Australia ◽  
Soil Type ◽  
The Other ◽  
Soil Types ◽  
Stocking Rate ◽  
Sheep Grazing ◽  
Annual Species ◽  
Short Supply ◽  
Seasonal Trends ◽  
Stocking Rates

The cage method of sampling vegetation was used to estimate herbage mass and herbage consumed by sheep, grazing a pasture dominated by annual species, near Camawon, Western Australia. Using paired quadrats (2m x lm), one caged and the other open, herbage mass and herbage consumed were measured at five stocking rates on two soil types, on eight occasions between December 1983 and January 1985. The data were highly variable; nevertheless, some effects of season, soil type and stocking rate could be observed. The results showed clear seasonal trends. Some soil type x stocking rate interactions were detected during the dry periods of the year when herbage mass was low. Generally, the cage method tended to over-estimate herbage consuped. Sheep consumed approximately 119 to 116 of the available herbage at low and high stocking rates respectively when feed was plentiful; when feed was in short supply the corresponding figures were approximately 113 and 1/2. The limitations of the method are discussed and some suggestions made concerning its applicability in rangeland studies.

Requirement of field pea for inoculation with Rhizobium and lime pelleting in soils of Western Australia

1993 ◽  
Vol 33 (6) ◽  
pp. 767 ◽  
Author(s):  
J Evans ◽  
C Wallace ◽  
N Dobrowolski ◽  
I Pritchard ◽  
B Sullivan
Keyword(s):  
Pisum Sativum ◽  
Western Australia ◽  
Dry Matter ◽  
Field Experiments ◽  
Field Pea ◽  
Acidic Ph ◽  
Rhizobium Strain ◽  
South West ◽  
Seed Inoculation ◽  
Soil Responses

The requirement of field pea (Pisum sativum) for seed inoculation with Rhizobium and for lime pelleting of inoculated seed was investigated in field experiments in the south-west of Western Australia, especially at locations where inoculated field pea had been grown 2 years previously. At most sites with previous pea cropping, the nodulation, total dry matter and nitrogen, and grain yield of pea were not improved by seed inoculation or lime pelleting. At these sites soil populations of R. leguminosarum by. viciae at sowing were >103/g soil. Responses to inoculation were measured at sites where the soil was very acidic [pH(CaCl2) <4.5], or mildly acidic (to pH 4.9) and of light texture (>90% sand + gravel), or where pea had not grown previously. There were fewer rhizobia at sowing at these locations. Lime pelleting was not generally required to maximise field pea growth or yield, but yield was affected by the inoculant Rhizobium strain.

A case of homing after translocation of chuditch, Dasyurus geoffroii (Marsupialia : Dasyuridae)

2017 ◽  
Vol 39 (1) ◽  
pp. 118 ◽  
Author(s):  
Edward G. Cannella ◽  
Jan Henry
Keyword(s):  
Body Weight ◽  
Western Australia ◽  
Threatened Species ◽  
Good Condition ◽  
The Other ◽  
Home Ranges ◽  
The South ◽  
South West ◽  
As Stress ◽  
Original Point

Fauna translocations are often used for conservation purposes. This has been especially prevalent in the translocation of threatened species in south-west Western Australia. Translocations can fail for several reasons such as stress, disease and predation and, less frequently, homing behaviours of translocated individuals. We report on one of eight chuditch, Dasyurus geoffroii, that was recaptured near the original point of capture 12 days after release at the designated translocation site in George State Forest Block, 14 km to the south. During that period she had lost 12.5% of her body weight, but was otherwise in good condition. It is possible that this event was unique to this individual and the other seven chuditch remained within the translocation site of George Block. However, this species is known to travel long distances and have large home ranges. It is important to determine the propensity of this species to attempt homing after translocation in an effort to determine whether a minimum release distance is necessary.

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