bluuebunny/crossref_metadata_2025 huggingface dataset:
Tactical versus continuous stocking in perennial ryegrass-subterranean clover pastures grazed by sheep in south-western Victoria. 1. Stocking rates and herbage production
Authors: Waller R. A. , Sale P. W. G. , Saul G. R. , Kearney G. A.
Published: September 2002

A 4-year field experiment was carried out in south-western Victoria to
determine whether tactical stocking might improve perennial ryegrass
(Lolium perenne L.) persistence and prime lamb
production, compared with the more common practice of year-around continuous
stocking. Tactical stocking consisted of variable length summer, autumn and
winter rotations and continuous stocking in spring. The 2 grazing strategies
were compared on 2 contrasting pastures: an upgraded pasture, sown with newer
cultivars of perennial ryegrass and subterranean clover
(Trifolium subterraneum L.) with 26 kg
phosphorus/ha.year, and a more typical naturalised perennial ryegrass
pasture receiving 6 kg phosphorus/ha.year. Paddocks were grazed by Border
Leicester x Merino ewes, which were mated to a terminal sire to lamb in
September. The effects of the grazing systems and pasture treatments on
herbage production and stocking rate are presented in this paper. Herbage
production was similar between the treatments, but tactical stocking
significantly increased herbage mass during the growing season
(P<0.05) compared with continuous stocking. In spring
each year, the herbage mass generally exceeded 3000 kg dry matter/ha in
tactically stocked paddocks and averaged 500–900 kg dry matter/ha
higher than the mass on continuously stocked paddocks. This enabled the
year-round stocking rate to be increased by an average of 9% over the 4
years of the experiment. We considered that the stocking rates could not be
further increased, despite the higher herbage mass in spring, as stock reduced
the dry herbage to a low residual mass by the opening rains in autumn. In
contrast, stocking rates averaged 51% higher on the upgraded pasture
compared with the typical pasture over the 4 years of the experiment. This
indicates that pasture improvement and soil fertility status have a much
greater impact on productivity than changes to grazing method. However,
tactical stocking was able to increase the sustainability of prime lamb
production on upgraded pastures in a dry summer climate, by maintaining
herbage cover on the paddocks over the summer–autumn period.
Post-ratoon growth and yield of three hybrid papayas (Carica papaya L.) under mulched and bare-ground conditions
Authors: Elder R. J. , Reid D. J. , Macleod W. N. B. , Gillespie R. L.
Published: September 2002

At Yarwun (151.3°E, 23.75°S), a trial was conducted to compare 3
papaya hybrids (Hybrid 29, Hybrid 11 and Hybrid 13) under mulching with grass
hay or in bare ground. The viability of ratooning a papaya crop was also
investigated. After a 16-month cropping season plants were cut to a 750-mm
stump (ratooned) about monthly over a 3.5-month period and, following a
4.5-month regrowth period, were harvested for a period of 11 months
(post-ratoon). Hybrid 29 yielded (by weight) 54% more than Hybrid 11
and 92% more than Hybrid 13 during the 3.5-month ratooning period. At
the commencement of ratooning, Hybrid 29 plants were 41–58 cm shorter
than Hybrid 11 and 13 plants, allowing the Hybrid 29 plants to be retained for
longer before being ratooned. Hybrid 29 also returned to fruiting more quickly
with a greater proportion of plants (97%) with fruit at the first
post-ratoon harvest compared with Hybrid 11 (87%). Following regrowth
(post-ratoon) the 3 hybrids produced similar yields. All 3 hybrids were
equally susceptible to the 3 phytoplasma diseases and to nematodes. The plots
mulched with coarse grass hay yielded 70% more during the ratooning
period and 116% more post-ratoon than the plots with bare ground. This
difference was attributed in part to fewer root-knot nematodes, the roots
being more heavily infected with vesicular arbuscular mycorrhiza, the use of
the complete upper soil profile by the roots, reduced rainfall run off and
less soil loss in the mulched treatment. The highest yielding treatment,
mulched Hybrid 29, averaged the equivalent of 55 t/ha.year during
ratooning, 43 t/ha.year over the 11-month post-ratoon harvest period and
65 t/ha.year over the entire plant–ratoon cycle. These yields were
achieved in spite of drought conditions and quite severe outbreaks of the
phytoplasma diseases, dieback, yellow crinkle and mosaic, with 60% of
plant positions infected with dieback during the post-ratoon period.
Theoretical yield estimations using the data from the plant and post-ratoon
crops indicated that ratooning may give superior average monthly yields
compared with 2 successive plant crops because of the reduced time required
for the ratooned crop to return to production. The study demonstrated the
benefits of mulching, the superiority of Hybrid 29 and that ratooning may be
successfully used in papaya. In environments similar to Yarwun, Hybrid 29, or
similar hybrids, with mulching is recommended for commercial production. If
land, time or finances are limiting, consideration should be given to
ratooning the plant crop based on monthly cut outs over a 3–4-month
ratooning period with vacant plant positions replanted during ratooning.
Control of tree size and vigour in custard apple (Annona spp. hybrid) cv. African Pride in subtropical Australia
Authors: Nissen R. J. , George A. P.
Published: September 2002

Five methods of controlling tree size, viz. growth retardant (foliar-sprayed and trunk-injected paclobutrazol), root-restriction bags, cherimoya rootstock and sugar apple (Annona squamosa) interstock, were evaluated for their effects on growth, yield and fruit quality of custard apple (Annona spp. hybrid cv. African Pride) in subtropical Australia. Compared with trees on their own roots, sugar apple interstock was highly effective in dwarfing 'African Pride' trees, reducing tree canopy volume by 72-90%. Root-restriction bags (woven fibreglass) proved to be only partially effective in controlling tree size due to growth of major roots through the seams. Compared with trees on their own roots, cherimoya rootstock alone, and sugar apple interstock increased fruit weight per unit canopy volume by a maximum of 3- and 5-fold, respectively. Sugar apple interstock reduced the severity of fruit disorders 'woodiness' and 'brown pulp' by about 75 and 50%, respectively.
Impact of early and late dry-season fires on plant mortality and seed banks within riparian and subriparian infestations of rubber vine (Cryptostegia grandiflora)
Authors: Bebawi F. F. , Campbell S. D.
Published: September 2002

This study compared the efficacy of first and second fires applied during the
early (August–September) and late dry season (October–November) on
mortality of riparian (climbing) and subriparian (freestanding) infestations
of rubber vine (Cryptostegia grandiflora R. Br.). The
impact of fire treatments on germinable seed banks of monocotyledonous and
dicotyledonous species was also determined. Individually, fire season, habitat
type and number of fires significantly affected mortality of rubber vine
plants. Late-season fires promoted higher mortality of rubber vine
(96%) than early season fires (77%), with rubber vine in
subriparian habitats more susceptible (90% mortality) than that growing
in riparian areas (68% mortality). On average, fire mortality increased
from 32% after the first fire up to 86% following 2 fires.
Sensitivity of juvenile, mature, and old rubber vine plants to fire was in the
order of mature>juvenile>old. Early fires significantly reduced seed
banks of monocotyledonous plants, particularly in riparian habitats. Late
fires significantly reduced seed banks of both dicotyledonous and
monocotyledonous plants. No rubber vine seeds were detected in the germinable
seed bank of either burnt or unburnt plots.
Co-learning in the development of lotus pasture technology in Australia
Authors: Roberts K. C. , Coutts J. , Bilston L. , Ayres J. F.
Published: September 2002

A 5-year project was undertaken in New South Wales, Australia, to develop and implement lotus pasture technology (Greater lotus, Lotus uliginosus; birdsfoot trefoil, Lotus corniculatus). The project was modelled on a core experiment/co-learning paradigm. A core experiment investigated issues of species adaptation and grazing management, and a co-learning phase aimed at promoting simultaneous improvement and adoption of lotus technology. Most participants felt that involvement with co-learning gave them increased technical knowledge of lotus. Increased knowledge facilitated changes that included farming practice changes (such as establishing lotus pastures or modifications to grazing management), or changing the approach to learning and problem solving towards a co-learning mode.
The strengths of the co-learning model were that it was flexible, farmers and industry sponsors worked together, and it increased the effectiveness of the project. The weaknesses were that those groups with informal structures found it difficult to function as a team, and the time limits imposed by the project limited the learning experience.
Frequency of feeding lupin and canola meal supplements to young sheep influences wool growth and mitotic rate but not staple strength
Authors: Masters D. G. , Mata G. , Liu S. M. , Schlink A. C.
Published: September 2002

In Australia, young sheep often require supplements for part of the year to
survive. This study investigated the influence of supplementary-feeding
interval, supplement type and pattern of weight loss on wool growth, fibre
diameter and staple strength. Weaners (64, 6–7-month old) were fed a
basal diet of oaten hay, oaten straw and minerals every day and, in addition,
were fed 1 of 2 supplement types. The design was factorial (2 by 3) and the
factors were: frequency of supplementation (daily or weekly), type of
supplement (lupin seed or canola meal) and pattern of weight loss (88
g/day loss for 1 month followed by 16 g/day for the second month or a
gradual loss of 36 g/day for the full 2 months). Feeding supplements daily
did not have any significant effect on fibre diameter (16.2
v. 16.2 m) or coefficient of variation of fibre diameter
(18.7 v. 19.2%) during the experiment, or on
staple strength (27.0 v. 28.4 N/ktex) compared with
the weekly feeding. Similarly, staple strength was not affected by the type of
supplement (26.3 N/ktex for lupin-fed sheep v. 29.0
N/ktex for canola meal-fed sheep). There was a significant interaction
between feeding interval and supplement type on the rate of wool growth.
Weekly feeding of canola meal increased wool growth relative to daily feeding
(0.067 v. 0.062 g/100 cm2
.day) whereas, weekly feeding of lupins decreased wool growth relative to
daily feeding (0.055 v. 0.059 g/100
cm2.day). Weekly feeding of lupins also increased levels
of urea in plasma relative to all other groups for 2 days after feeding and
reduced mitotic rate in the skin (relative to the canola meal-fed group) 3
days after the supplementation. While there were also some differences between
treatments in plasma glucose, creatine kinase and amino aspartate
transaminase, all groups remained within the normal range. These results
indicate that the interval between supplementary feeding is unlikely to
contribute to low staple strength in grazing weaners but will influence the
efficiency of use of nutrients for wool growth.
Residual value of molybdenum trioxide for clover production on an acidic sandy podzol
Authors: Brennan R. F.
Published: September 2002

The residual value (RV) of molybdenum (Mo) for clover (Trifolium subterraneum L.) production was measured for an acidic sand when the fertiliser was spread over the soil surface (topdressed). The RV of Mo, as molybdenum trioxide, the most widely used Mo fertiliser in Western Australia, was measured using yield of dry herbage (DM), Mo concentration of DM, and Mo content of DM (yield of DM multiplied by the Mo concentration of DM). The RV of Mo fertiliser was measured in 1993 for fertiliser Mo applied once only to plots not treated with Mo before, either in 1993 (current Mo) or 1-10 years previously (previous Mo). Relative to the nil-Mo treatment, additions of Mo fertiliser increased DM yield by about 1.20 t/ha (20% DM increase) in October. When 80 or 320 g Mo/ha was applied, all yields were on the maximum yield plateau except for Mo applied 10 years previously. The yield for the 80 g Mo/ha treatment applied 10 years earlier decreased by about 15% relative to the other current and previous Mo treatments. However, as measured using Mo concentration and Mo content in DM, there was a continuous decline in the effectiveness of previous Mo relative to current Mo the longer the previous Mo was in contact with the soil. The decrease in RV was about the same as measured using Mo concentration or content in tissue. Molybdenum applied 5 years previously was about one-third as effective as current Mo for Mo content or Mo concentration of DM.
Factors affecting Merino wool contamination in crossbreeding
Authors: Fulwood W. K. , Fleet M. R. , Fotheringham A. S. , Bennie M. J.
Published: September 2002

Fleeces of Merino ewes were tested to identify whether contaminant sheep fibres increased from Damara-ram mating alone, whether extent of colouration of the crossbred lamb coat, day of birth and number of lambs being reared affect transfer to the maternal fleece, and whether increased fleece bulk or shearing the ewes 3.5�months post-weaning reduced the concentration of contaminant fibres. Measurement of fleeces from 26 ewes mated to a Merino ram and 26 ewes mated to a Damara ram did not show a significant increase in the presence of pigmented or heavily medullated white fibres. In contrast, wool samples from 54 Merino ewes taken the day after weaning of their Damara crossbred lambs showed pronounced contamination by pigmented fibre as well as relatively high levels of heavily medullated white fibres. The concentrations of pigmented fibres were highest in the fleeces with short wool and proportionally diluted in the fleeces with long wool. Concentrations of heavily medullated white fibres from white-spotted coats of the crossbred lambs showed that ewes that reared multiple lambs had greater transfer while the day of birth after the start of lambing and the extent of coat colour on the lambs were both negatively related to transfer of these fibres. Side samples collected from the same 26 ewes at weaning and 3.5 months after weaning revealed declines in contaminant fibres greater than could be explained by dilution by new wool growth after weaning, implying physical loss from the fleece. However, the residual contaminant fibres after 3.5 months' delay in shearing remained excessive for Merino wool. Wool samples from the sheep's side produced similar concentrations of contaminant fibres as the fleece grid sample.
Blackheart development following chilling in fruit of susceptible and resistant pineapple cultivars
Authors: Stewart R. J. , Sawyer B. J. B. , Robinson S. P.
Published: September 2002

Smooth Cayenne, a widely grown commercial cultivar of pineapple
(Ananas comosus L. Merr.), is susceptible to the
internal browning disorder known as blackheart (also referred to as endogenous
brown spot or internal browning). This disorder is induced by chilling and
results in browning of the flesh and core of the fruit due to the oxidation of
phenolic substances by the enzyme polyphenol oxidase. The hybrid pineapple
cultivar Hawaiian Gold (53-116) is reported to be resistant to blackheart.
Fruit of both Hawaiian Gold and Smooth Cayenne were stored for 14 days at 0,
2, 4, 6, 10 and 23˚C, followed by 7 days at 23˚C. Blackheart
symptoms were observed in the flesh of Smooth Cayenne fruit chilled at
10˚C and they were progressively less severe at lower chilling
temperatures, with no symptoms observed in the flesh of fruit chilled at
0˚C. Increased blackheart symptoms were observed in the core of the fruit
at temperatures below 6˚C. Blackheart symptoms were not observed in the
flesh of Hawaiian Gold fruit chilled at any of the temperatures tested, but
some symptoms were observed in the core tissue at temperatures between 0 and
6˚C. Increased polyphenol oxidase activity was induced by chilling in the
flesh of Smooth Cayenne fruit but not in the flesh of Hawaiian Gold. The
levels of phenolics and juice pH were similar in the 2 cultivars. The results
indicate that Hawaiian Gold fruit are resistant to blackheart in the flesh, at
chilling temperatures of between 0 and 23˚C. The unexpected observation
that blackheart symptoms were restricted to the core of both Smooth Cayenne
and Hawaiian Gold fruit following chilling at 0˚C may have useful
implications for the pineapple-processing industry.
Economic impact of Vulpia in temperate pasture systems in south-eastern Australia
Authors: Vere D. T. , Dowling P. M. , Jones R. E. , Kemp D. R.
Published: September 2002

An increasing incidence of annual grasses is considered to be a primary cause of decline in the productivity of Australia's temperate pasture systems. In particular, Vulpia (silver grass) comprises a significant proportion of the biomass of many temperate pastures and can seriously affect livestock productivity. The main economic effects of Vulpia include reducing pasture carrying capacities, contaminating produce and competing with more desirable pasture species. This paper presents the results of an economic evaluation of the costs of Vulpia and the long-term benefits of improving Vulpia management in the high-rainfall areas of south-eastern Australia. The evaluation used an integrated economic modelling system that determined the grazing system and livestock industry impacts of Vulpia and translated these into measures of economic welfare change that enabled the benefit-cost analysis of various levels of Vulpia management to be undertaken. With a focus on wool, the analysis established the high annual costs of Vulpia to wool producers and consumers, together with substantial long-term economic benefits that could potentially result from reducing the incidence of Vulpia in pastures. Total annual costs to the wool industry in the temperate pasture zone of New South Wales and Victoria ranged between A$7 and $30 million, while the potential discounted net benefits to the Australian and international wool industries were between $32 and $287�million over a 15-year period at a real discount rate of 5%. These estimates provide a strong economic basis for promoting improved management strategies for reducing Vulpia incidence in pastures.
Feed intake, liveweight and wool growth rate in Merino sheep with different responsiveness to low- or high-quality feed
Authors: Adams N. R. , Blache D. , Briegel J. R.
Published: September 2002

A previous field trial using 30 sheep from each of 3 strains of Merino sheep (designated F, M and B) found that wool growth rate in strain B changed less throughout the year, compared with the other 2 strains. The present study examined components of liveweight loss on dry pasture with low protein and low digestibility to detect underlying relationships with the subsequent responsiveness of wool growth rate to young green pasture. Strain B lost less liveweight when grazed on dry (poor-quality) pasture, but lost more liveweight on sparse green pasture, than the other 2 strains. The rate of liveweight loss was not related to fatness on dry pasture, but was related to fatness on green pasture. The plasma concentration of leptin at the start of winter was related to clean-fleece weight (P<0.01). A second study examined the role of voluntary feed intake in strains M and B, offered low (56%�digestibility) and then high (70% digestibility) quality feed ad libitum in individual pens. Wool growth rate increased (P<0.001) on the better feed and tended to increase more (P = 0.06) in strain M. Feed intake increased (P�= 0.01) more in Strain M when offered good-quality feed. Fatness affected feed intake similarly in both periods. The results indicate 2 mechanisms that differed between feed conditions. First, sheep differed in their capacity to increase wool growth on high-quality feed, associated with the capacity to increase feed intake. Second, fatness was associated with the differential liveweight response to good or poor quality feed, although it was not clear whether it acted through appetite. It is hypothesised that the capacity to increase wool growth rate on good feed may be associated with a greater decrease in protein synthesis rate on poor quality pasture. This may result in a lower drive to eat and so a greater liveweight loss on poor pasture.
The potential of near-infrared reflectance spectroscopy for soil analysis — a case study from the Riverine Plain of south-eastern Australia
Authors: Dunn B. W. , Batten G. D. , Beecher H. G. , Ciavarella S.
Published: September 2002

Environmental management in agricultural systems must be maintained while controlling costs and increasing productivity. To obtain a better response from inputs in agriculture, cost-effective soil analysis is needed to enable site-specific applications. Near-infrared reflectance spectroscopy (NIRS) technology has the potential to provide a rapid, low-cost analysis enabling within field variability to be identified. NIRS was evaluated for its ability to predict a range of soil properties in the Riverine Plain soils of southern New South Wales. Over 550 topsoil (0-10�cm) and 300 subsoil (40-50 cm) samples from a range of soil types were air dried and ground before scanning with a NIRSystems model 6500 scanning spectrophotometer. The Partial Least Squares (PLS) regression procedure was used to determine the best correlation (i.e. calibration) between the chemical reference data and spectral data for both topsoil and subsoil samples. A validation set of samples was used to test the predictive ability of NIRS for a number of soil properties. The results demonstrated that NIRS can successfully determine some soil properties in both the topsoil and subsoil. In the topsoil, cation exchange capacity (CEC), exchangeable Ca and Mg, pH and Ca : Mg ratio were predicted with a high level of accuracy and organic carbon and exchangeable sodium percentage (ESP) with an acceptable level of accuracy. In the subsoil, CEC, exchangeable Na, Ca, Mg, ESP, pH and Ca : Mg ratio were all predicted with a high degree of accuracy. The predictive ability of NIRS for many soil constituents may make it suitable for use in agricultural soil assessment for site-specific agriculture in the Riverine Plain soils of southern New South Wales.
Economics of increasing the persistence of sown pastures: costs, stocking rate and cash flow
Authors: Scott J. F. , Lodge G. M. , McCormick L. H.
Published: September 2002

Poor persistence of sown pastures, trends of
low pasture resowing rates and a substantial decline in carrying capacity of
non-crop areas bring into question the basis of the philosophy of pasture
improvement by sowing pasture species. If graziers are to adopt grazing
strategies or stocking rates that are more ecologically sustainable, then
clearly they must also be cost-effective in either increasing income or
reducing costs so that they are economically sustainable. This paper describes
the use of an interactive spreadsheet model developed to assist graziers and
their advisers with assessing the long-term profitability of pasture
management and/or improvement (and therefore pasture persistence). The
model provides a comparative cash flow for different levels of inputs
(fertiliser, herbicides and feed supplements) over a 15-year period. Results
clearly show that at the same stocking rate, different animal enterprises have
markedly different profitabilities over a 15-year period. Further, for native,
improved and sown pastures, the most profitable pastures are those that can
sustain increased stocking rates for long periods of time, without the need
for resowing.
Productivity of pasture legumes and chicory in central New South Wales
Authors: Kemp D. R. , Michalk D. L. , Goodacre M.
Published: September 2002

Seven experiments were established across a range of environments (latitude
33°S) in central New South Wales to evaluate 52 legume cultivars and
lines against currently recommended cultivars. Plots were grazed by either
sheep or cattle after each harvest. Criteria for inclusion were that lines
were either commercially available or in the process of being registered.
Three experiments also included chicory. Sites had from 600 to 900 mm annual
rainfall and were at altitudes of 440–1000 m. The 4-year program
included the dry summer of 1990–91. White clover and subterranean clover
were the most productive species over time. Among subterranean clovers, the
subspecies subterraneum cultivars were more productive
than the yanninicum or
brachycalycinum subspecies. Other species such as
balansa, Persian, strawberry, red and crimson clovers, lotus major and murex
medic were more variable in production. These legumes often grew well in the
establishment year, but failed to persist. Lucerne was in general, not as
productive as white or subterranean clover. Caucasian clover and yellow
serradella should be evaluated further as conclusive judgements could not be
formed. Chicory was often the most productive species in the experiments,
especially over the warmer 6 months of the year. It persisted under a 6-week
harvest regime and during the drought year. The newer subterranean clover
cultivars, Leura, Goulburn and Denmark all exceeded the production from the
previously recommended cultivars, Woogenellup and Karridale, even though no
major disease was evident in the later group. The lines 89820D and 89841E were
sufficiently productive to warrant further evaluation and possible development
as cultivars. In contrast, while Huia, Tahora, Bonadino and Tamar were often
as productive as the recommended white clover cultivar Haifa, they were not
consistently better. Where summer rainfall occurs and the annual rainfall
exceeds 650 mm, the greater potential yield of white clover compared with
subterranean clover justifies its use. However, no white clover cultivars
survived the summer drought in 1990–91 as intact plants. Further work is
needed to develop more drought-tolerant cultivars.
Time to converse: the importance of language, conversation and electronic media in agricultural extension
Authors: Fell L. R.
Published: September 2002

One aspect of the complex communication involved in agricultural extension
that is only discussed indirectly is the language we use. There is a saying
that words are cheap and only actions count. In this paper, a new development
in communication theory arising from cognitive science is briefly reviewed as
a basis for suggesting that our use of words is a particular kind of action
with subtle and profound consequences that are easily underestimated. This new
cognitive science supports a changing philosophy and style of agricultural
extension that leans more towards cooperative learning. Certain patterns of
word usage that occur in institutionalised agricultural extension (directives
and dogma, technical jargon, hiding behind formality, empty words, criticism,
planning terminology and motherhood statements) are exposed as barriers to
effective communication. Increasing reliance on e-mail and the World Wide Web
has possible benefits associated with a more informal and personally
responsible use of language. Growing awareness of the biology of communication
points to the need to establish strong personal connections, of heart as well
as head, for agricultural extension to continue to thrive and improve.
The impact of agricultural extension on adoption and diffusion of lupins as a new crop in Western Australia
Authors: Marsh S. P. , Pannell D. J. , Lindner R. K.
Published: September 2002

The growth of the sweet white lupin industry in Western Australia is a classic
case of the adoption and diffusion of a new innovation in agriculture. In
1979, following the release of the cultivar Illyarrie, and the development of
effective agronomic practices, the Western Australian Department of
Agriculture (Agriculture Western Australia) commenced a major extension
campaign to promote lupins. Between 1978 and 1987, the area of lupins grown
increased from 39 000 to 877 000 ha. However, the pattern of adoption varied
widely between regions, with differences in starting time, rate and ceiling
levels of adoption. In this paper, we examine regional differences in the
start time of the adoption process, and estimate the impact of various factors
by using multivariate regression analysis. Results suggest that both
Agriculture Western Australia extension activities and the presence of private
consultants contributed to earlier start times of the adoption process.
Increasing lamb output by crossing commercial Merino ewes with South African Meat Merino rams
Authors: Cloete S. W. P. , Durand A.
Published: September 2002

Commercial Merino ewes were randomly allocated
to 1 of 2 groups, which were joined either to commercial Merino or South
African Meat Merino rams during October 1996 and 1997. Merino rams were
involved in 161 joinings, and South African Meat Merino rams in 157 joinings.
The proportions of ewes that lambed were independent of the breed of the sire
when expressed relative to the number of ewes joined (0.809 and 0.801 in ewes
joined to South African Meat Merino and Merino rams, respectively). The
proportion of multiple lambs was similarly not affected by the breed of the
service sire. Lambs sired by South African Meat Merino rams were on average (
s.e.) heavier (4.17 0.07 v. 3.86 0.07 kg;
P<0.01) at birth. They also tended to have a better
(0.69 v. 0.59; P<0.10) survival
to weaning, and were heavier (26.9 0.6 v. 22.8 0.6 kg;
P<0.01) at weaning than purebred Merino
contemporaries. The combined effect of the tendency towards an improved
survival rate as well as the increased lamb weaning weight resulted in a
36% increase (P<0.01) in lamb output in Merino
ewes joined to South African Meat Merino ewes compared with ewes joined to
Merino rams. Higher (P<0.01) proportions of ram lambs
sired by South African Meat Merino rams reached slaughter weight (about 40 kg)
before the onset of the dry Mediterranean summer than purebred Merinos.
Two-tooth ewes sired by South African Meat Merino rams were heavier
(P<0.01) at 2-tooth age (53.0 0.6
v. 52.0 0.6 kg) than purebred Merinos. The 2-tooth
greasy fleece weight of South African Meat Merino sired 2-tooth ewes were
lower (3.85 0.08 v. 4.66 0.09 kg;
P<0.01), with a lower (66.8 0.6
v. 70.5 0.7 %; P<0.01)
clean yield than that of purebred Merinos. This resulted in a marked
difference in clean fleece weight between the 2 types (2.56 0.06
v. 3.28 0.06 kg, respectively). Wool produced by South
African Meat Merino sired 2-tooth ewes was generally broader (21.8 0.3
v. 20.3 0.3 m; P<0.01) and
shorter (87.3 1.3 v. 96.4 1.4 mm;
P<0.01) than that of their purebred Merino
contemporaries. The coefficient of variation of fibre diameter as well as
staple strength was independent of the breed of the sire. Liveweight of adult
ewes and wool traits were independent of the breed of the service sire.
Efficacy of Ridomil MZ and protectant fungicides to control white rust (Albugo candida) and their effect on seed yield, oil content and fatty acid composition in mustard
Authors: Khangura Ravjit K. , Sokhi S. S.
Published: September 2002

Ridomil MZ alone or Ridomil MZ followed by protectant fungicides was tested to
manage white rust (Albugo candida) (Pers. ex Lev.)
Kuntze on Brassica juncea L. var. RL-1359, sown at the
normal time in 1989–90 and 1990–91 and under delayed sown
conditions in 1990–91 at 2 different geographical locations of the
Punjab state. Two spray applications of aqueous suspension of Ridomil MZ at
450 g a.i./ha or 1 foliar application of Ridomil MZ at 450 g a.i./ha,
followed by another spray of Dithane M-45 at 600 g a.i./ha or Blitox-50 at
375 g a.i./ha at 15- or 20-day interval to a 70-day-old crop significantly
reduced both foliage and floral infections. These treatments significantly
increased the seed yield over control and other treatment combinations,
without having an adverse affect on the oil content and fatty acid composition
of the oil. The same fungicide regime was effective to control white rust when
applied to a 50- or 60-day-old crop under delayed sown conditions. The seeds
harvested from the plots treated twice with Ridomil MZ exhibited no detectable
residue of metalaxyl and mancozeb. The timing of application of these
fungicides may be critical in the control of white rust, particularly in the
late sown crop.
Changes in fallow weed species in continuous wheat in northern New South Wales 1981-1990
Authors: Wicks G. A. , Felton W. L. , Murison R. D. , Martin R. J.
Published: September 2002

Four experiments in northern New South Wales comparing fallow management
treatments of no-tillage, cultivated with the stubble retained, and cultivated
with the stubble burned, from 1981 to 1990, were sampled for weeds between
wheat harvest and seeding on a number of occasions during this period. Eighty
weed species were identified, 23 of which were found at all 4 sites but only
13 were recorded in the samples taken. These were dwarf amaranth, wild turnip,
spear thistle, Australian bindweed, fleabane, bladder ketmia, prickly lettuce,
turnip weed, variegated thistle, common sowthistle, dandelion, wild oats and
native millet. The density of weeds during the fallow period decreased by
97% from 1981 to 1990 with some species eliminated, probably because of
the herbicides used, particularly glyphosate and chlorsulfuron. These included
Boggabri and redroot amaranth, button grass, caustic weed, dense crassula, fat
hen, legumes, common peppercress, hedge mustard, London rocket,
shepherd’s purse, wild mustard, sorghum-almum, paradoxa grass, wild
zinnia, and wireweed. Twenty-four weed species were classified as a problem or
a potential problem in the future at 1 or more sites. Seventeen weed species,
including perennial grasses, often were tolerant to glyphosate at the rates
used. The densities of common sowthistle and wild oat were reduced after 10
years, but still remained at all 4 sites. Plant density of species with
wind-blown seeds was greater in no-tillage plots than stubble-retained or
stubble-burned plots. Weeds whose seeds are dispersed by wind and weeds
tolerant to glyphosate were the most troublesome. The perennial grass native
millet increased at all 4 sites.
Water-use efficiency on irrigated dairy farms in northern Victoria and southern New South Wales
Authors: Armstrong D. P. , Knee J. E. , Doyle P. T. , Pritchard K. E. , Gyles O. A.
Published: September 2002

A survey of 170 randomly selected, irrigated, dairy farms in northern Victoria
and 9 in southern New South Wales was conducted to examine and benchmark the
key factors influencing water-use efficiency. Water-use efficiency was defined
as the amount of milk (kg milk fat plus protein) produced from pasture per
megalitre of water (irrigation plus effective rainfall). Information on
water-use, milk production, supplementary feeding, farm size and type, pasture
management, and irrigation layout and management was collected for each farm
by personal interview for the 1994–95 and 1995–96 seasons. The
farms were ranked in the order of water-use efficiency with the average farm
compared with the highest and lowest 10% of farms.
The range in water-use efficiency was 25–115 kg milk fat plus
protein/ML, with the highest 10% averaging 94 kg/ML and the
lowest 10% averaging 35 kg/ML. The large range in water-use
efficiency indicated potential for substantial improvement on many farms. The
high water-use efficiency farms, when compared with the low group: (i)
produced a similar amount of milk from less water (387
v. 572 ML) (P<0.05), less land
(48 v. 83 ha) (P< 0.05) and a
similar number of cows (152 v. 143 cows); (ii) had
higher estimated pasture consumption per hectare (11.5
v. 5.5 t DM/ha) (P<0.01)
and per megalitre (1.0 v. 0.5 t DM/ML)
(P<0.01); (iii) had higher stocking rates (3.2
v. 1.8 cows/ha) (P<0.01);
(iv) used higher rates of nitrogen fertiliser (59 v. 18
kg N/ha.year) (P<0.05) and tended to use more
phosphorus fertiliser (64 v. 34 kg P/ha.year)
(P<0.10); (v) used similar levels of supplementary
feed (872 v. 729 kg concentrates/cow); (vi) had
higher milk production per cow (396 v. 277 kg fat plus
protein) (P<0.05); and (vii) directed a higher
proportion of the estimated energy consumed by cows into milk production (53
v. 46%) (P<0.05).
The survey data confirmed that irrigated dairy farm systems are complex and
variable. For example, the amount of feed brought in from outside the milking
area varied from 0 to 74% of the estimated total energy used by a
milking herd. There was a large range in the level of supplement input amongst
the farms in the high water-use efficiency group, and in the low water-use
efficiency group. This indicates that the management of the farming system has
a greater impact on the efficiency of water-use on irrigated dairy farms, than
the type of system.
The data from the survey provide information for individual farms, a measure
of the water-use efficiency of the industry, and an indication of the quality
of regional land and water resources.
Influence of fungal pathogens and environmental conditions on disease severity, flower fall and desiccation of harvested Geraldton waxflower. 2. Studies with commercial packages
Authors: Taylor M. N. , Joyce D. C. , Wearing A. H. , Simons D. H.
Published: September 2002

Relationships were examined between environmental conditions mediated by
packaging and handling and the deterioration of harvested Geraldton waxflower
cv. ‘Fortune Cookie’. Disease severity plus flower and leaf drop
caused by inoculation with Botrytis cinerea were reduced
by lowering handling temperatures to 0, 5 or 5/20˚C alternated daily,
versus 20˚C. They were also reduced by inhibition of ethylene action with
a silver thiosulfate pulse pretreatment. Additionally, treatments that
enhanced water loss, such as packing dry, keeping forced air-cooling holes
open and strategic placement of extra ventilation holes may also reduce
disease severity and flower plus leaf fall. Inclusion of
KMnO4 -based Bloomfresh ethylene scrubbing sachets in
packages did not reduce disease severity or lessen flower plus leaf fall.
Thus, deterioration of waxflower packaged in commercial cartons can be
minimised by keeping temperatures low, packing plant material dry, use of
cartons with strategically placed ventilation holes and/or pretreatment
with silver thiosulfate.
Environmental effects on seed composition of Victorian canola
Authors: Pritchard F. M. , Eagles H. A. , Norton R. M. , Salisbury P. A. , Nicolas M.
Published: September 2002

Data from advanced breeding experiments between 1985 and 1994 were used to
determine the effects of region, year and environment on the quality of canola
grown across Victoria. Estimates from these unbalanced data were made using
residual maximum likelihood. Environmental effects were large relative to
cultivar effects for oil and protein content, while the reverse occurred for
glucosinolate content.
High oil contents (and low seed protein contents) were correlated with cooler
spring temperatures and higher spring rainfall. Oil contents were lowest, on
average, in canola grown in dry years, or from the hotter regions, such as the
Mallee, and were highest in canola from the cooler, wetter regions, such as
south-western and north-eastern Victoria.
Fatty acid composition varied with year and region. Means for saturated fatty
acid content averaged 6.4 0.1%. The oleic acid content averaged 60.3
0.4% and was higher in canola grown in central Victoria and the
Wimmera, and in most years, in north-eastern Victoria compared with other
regions. Low temperatures and low rainfall reduced oleic acid content.
Linoleic acid content averaged 19.7 0.3% and linolenic acid averaged
10.4 0.3%, with the content of these fatty acids negatively correlated
with the content of oleic acid. Erucic acid levels were below 0.6% in
all regions.
The sustainability indicator industry:where to from here? A focus group study to explore the potential of farmer participation in the development of indicators
Authors: King C. , Gunton J. , Freebairn D. , Coutts J. , Webb I.
Published: September 2002

In Australia, the work being carried out on sustainability indicators has
become an industry on its own. This paper firstly provides an introduction
that reviews the literature on indicator development and use, particularly in
relation to agricultural production systems. A number of reasons for the
limited use of indicators by farmers are mentioned. Secondly, a focus group
study involving farmers from two dryland cropping areas in Queensland to
investigate sustainability indicators and sustainable farming systems is
presented. The indicators the participants identified during focus groups
included indicators that reflect (i)farming system components, (ii) the
management of these components, (iii) the management of all components and
their interrelationships at the systems level, and (iv) the external factors
that influence and interact with this systems level. Focus group analysis also
showed that the participants perceived sustainability as an on-going process
and a sustainable farming system as dynamic and emergent in nature. The
implications of these findings are discussed. Three key issues were raised (i)
the value of farmer knowledge with respect to the development of indicators
has often been ignored; (ii) there are links between indicators developed
through traditional science and those being used by farmers; and (iii)
off-farm indicators used by farmers may be very useful in policy development
at a variety of levels (e.g. catchment, regional, national, global). The focus
group method involving farmers provided a useful way to gain insights about
farmer perceptions and for farmers to learn from each other during the
research process.
Residual effect of nitrogen fixed by mungbean (Vigna radiata) and blackgram (Vigna mungo) on subsequent rice and wheat crops
Authors: Ahmad T. , Hafeez F. Y. , Mahmood T. , Malik K. A.
Published: September 2002

Annual crop legumes, grown in rotation with cereal crops, contribute to the
total pool of nitrogen in the soil and improve the yield of cereals. The
present study aimed at the quantification of nitrogen fixation by mungbean and
blackgram using 15N isotopic dilution methodology; and
the quantification of grain and nitrogen yield differences of succeeding rice
and wheat crops compared with a cereal–cereal rotation. There were 2
experiments in separate fields but with the same layout: in experiment 1, rice
followed the mungbean and blackgram varieties and in experiment 2, wheat
followed the mungbean and blackgram varieties. Nitrogen fixed ranged from 26
to 36 kg/ha in experiment 1 and from 30 to 36 kg/ha in experiment 2.
Soil nitrogen spared by legume crops ranged from 2 to 26 kg/ha in
experiment 1 and from 4 to 23 kg/ha in experiment 2. Rice paddy yields
were 0.6–1.1 t/ha higher in the legume–cereal rotation than in
the cereal–cereal sequence. Similarly, wheat grain yields were
0.5–1.1 t/ha higher in the legume–cereal rotation.
Na+/H+ exchange in the halophyte Mesembryanthemum crystallinum is associated with cellular sites of Na+ storage
Authors: Barkla Bronwyn J. , Vera-Estrella Rosario , Camacho-Emiterio Jesus , Pantoja Omar
Published: September 2002

The tonoplast Na+/H+ exchanger is involved in sequestering Na+ in plant vacuoles, providing solutes for osmotic adjustment while avoiding cytoplasmic Na+ toxicity. As such it is assumed to be one of the key mechanisms involved in salt-tolerance in plants. In this study, we measured tonoplast Na+/H+ exchange in roots and different leaf tissues of adult Mesembryanthemum crystallinum L. plants to determine if activity of the exchanger follows the gradient from roots to leaves previously observed for Na+ and pinitol accumulation. Na+/H+ exchange was absent from roots of control and NaCl-treated plants. In contrast, leaves showed constitutive Na+/H+ exchange that was enhanced by growth of the plants in NaCl. Highest activity was measured in the epidermal bladder cells in agreement with the highest concentrations of Na+ found in this tissue. Tonoplast H+-translocating ATPase activity was also greatest in this tissue, as were protein levels for myo-inositol-O-methyltransferase, a key enzyme in the pinitol biosynthesis pathway. The strong correlation between Na+/H+ exchange and Na+ accumulation confirms the role of this transporter in vacuolar sequestration of Na+ and plant salt tolerance.
Creationists and their critics in Australia: an autonomous culture or 'the USA with Kangaroos'?
Authors: Numbers Ronald L.
Published: September 2002

No country outside the United States has given creationism a warmer reception than Australia, which has spawned an internationally successful creationist ministry and at times even welcomed creation science into the classrooms of state-supported schools. A half-century ago, however, when organized anti-evolutionism first appeared in Australia, it attracted virtually no attention, and for over three decades thereafter it remained isolated on the far margins of Australian society, too obscure and impotent to warrant public concern. As late as 1984 one of the best informed students of Australian fundamentalism predicted that `because of the different national traditions and educational systems, the [creationist] controversy is not likely to become as intense in Australia as in USA�.The following decade proved him a false prophet. The most intense creation-evolution debates in the world have occurred on Australian soil, and Australian creationists have insinuated themselves into the religious, scientific, educational, and political life of the country.
In this brief history of creationism and anti-creationism in Australia during the past half-century or so, I highlight two distinctive (though not unique) characteristics of the Australian encounter: the efforts of both sides to tar the other with a `made in America� brush and the contribution of anti-creationists to the success of the creationists. Paradoxically, by hounding and ridiculing creationists, the critics significantly boosted the visibility and viability of creationism in Australia.
The larvae of the weevil tribe Eurhynchini and the phylogeny of the Brentidae (Coleoptera : Curculionoidea)
Authors: Oberprieler Rolf
Published: September 2002

The larvae of Eurhynchus laevior (Kirby) and
Aporhina australis (Heller) are described, representing
two of the three extant genera of the small Australian–New Guinean
weevil group Eurhynchini. The description of the
E. laevior larva verifies the limited account of
eurhynchine biology available so far. The patchy knowledge of the biology of
these two species is summarised. The larva of E. laevior
tunnels in woody branches of Persoonia (Proteaceae), and
that of A. australis develops in slightly swollen twigs
of Litsea (Lauraceae). An undescribed species of
Xanthocryptus Cameron (Ichneumonidae) is recorded from
the larval chamber of A. australis. The eurhynchine
larvae display the greatest similarity to brentine larvae, but exhibit several
less derived character states. A phylogenetic analysis of 33 larval characters
is conducted for 20 brentid species spanning Eurhynchini, Brentini, Cyladini,
Antliarhinini, Tanaini, Apionini, Nanophyini, Ithycerini and Microcerini, with
Curculionidae added as the indicated adelphotaxon of brentids and Caridae as
the outgroup. Microcerini are excluded from Curculionidae: Brachycerinae, and
included in Brentidae because of numerous character state agreements with the
latter. The results suggest a monophyletic family Brentidae with three to four
major clades: Ithycerinae, Brentinae and Apioninae, and Microcerinae either as
a fourth or included in Brentinae. Eurhynchini consistently cluster as
adelphon of Brentini, while Antliarhinini group in Apioninae. Larval
characters can be problematic in phylogenetic analyses because of parallel
reductions, but they can also show relationships more clearly than imaginal
features, which are often adaptive and convergently evolved.