bluuebunny/crossref_metadata_2025 huggingface dataset:
Biological studies of soils in paired old and new land sites growing sugarcane
Authors: Blair B. L. , Magarey R. C. , Bull J. I. , Johnson E. J.
Published: August 2004

Summary. The growth of sugarcane in soils from land
monocultured with sugarcane, and from land which had either never been cropped
with sugarcane, or just recently cropped, was compared under glasshouse
conditions. In general, cane growth in new land soils was greater than in
monocultured soil (shoot growth 7.4%, root growth 21.4%).
Responses to soil pasteurisation were investigated in some soils and were
greater in monocultured soils suggesting that root growth constraints were
larger in the monocultured soil (210% response in monocultured soils
v. 64% in new land soils). Assays for sugarcane
root pathogens suggested that Pachymetra chaunorhiza was
a major contributor to the old/new land growth responses, but it is
unlikely that Pythium spp. were factors in the growth
differences. Monitoring of other groups of organisms in soil from one site
suggested that sugarcane monoculture may affect populations in the broader
biological community.
Relationships between temperament and growth in a feedlot and commercial carcass traits of Bos indicus crossbreds
Authors: Burrow H. M. , Dillon R. D.
Published: August 2004

Summary. Two cohorts of
Bos indicus crossbreds were studied to determine the
relationships between temperament and growth in a feedlot and commercial
carcass characteristics. Prior to entry to the feedlot, one cohort received
intensive, short-term training at weaning but minimal handling before and
after weaning, while the second cohort received similar training at weaning
and also experienced a 4-month period of relatively intense handling
immediately before entering the feedlot. Both cohorts entered the feedlot at
similar ages. Temperament was recorded as the animal’s flight speed,
which is the time taken for the animal to cover 1.7 m after leaving a weighing
crush, with fast times indicating animals that have poor temperaments.
Average flight speed scores of animals in the 2 cohorts differed
substantially, with 51 and 12% of animals in cohorts 1 and 2
respectively having fast flight speed scores. Conversely, 23 and 69% of
animals in cohorts 1 and 2 respectively had slow flight speed scores and could
therefore be regarded as docile. In the first cohort, animals with slow flight
speeds gained weight more rapidly (P<0.05) to achieve
heavier slaughter and carcass weights (P<0.05) than
animals with fast flight speeds. The relationship between flight speed and
growth in the feedlot in the second cohort was not significant, although
animals with the fastest flight speeds in that cohort had the lowest
liveweight gains. Docile animals in both cohorts had comparable liveweight
gains in the feedlot. These results suggest that animals with slow flight
speed scores (good temperaments) may grow faster in a feedlot than animals
with faster flight speed scores (poorer temperaments), regardless of whether
the favourable scores result from intensive, long-term handling or because the
animals are naturally docile. There was no relationship in either experiment
between flight speed and fat thickness or carcass bruising, when bruising was
scored simply as presence or absence of bruising. A negative relationship was
evident between flight speed score and dressing percentage in the second
cohort (P<0.05). The relationship between flight
speed and dressing percentage was not significant in the first cohort.
It is suggested that feedlot operators could select potential feedlot animals
on the basis of temperament before entry to the feedlot to improve performance
in the feedlot.
Long-term persistence of subterranean clover Trifolium subterraneum L.) cultivars at three sites in south-western Victoria
Authors: Clark S. G. , Li J. , Johnson A. M. , Ward G. N. , Chin J. F.
Published: August 2004

Summary. The seed banks of 6 subterranean clover
(Trifolium subterraneum L.) cultivars were sampled at 3
abandoned cultivar evaluation experiments in south-western Victoria (Hamilton,
Macarthur and Timboon). Two were var. yanninicum
(Trikkala and Larisa) and 4 were var. subterraneum
(Denmark, Goulburn, Karridale and Leura). Seed was sampled in late
summer–early autumn 1993, between 6 and 10 years after the sites were
established and between 3 and 7 years after the sites were abandoned. The
collected seed was separated into black and white seed, and a sample of the
black seed was grown in a glasshouse and identified as either belonging to the
sown cultivar or belonging to another cultivar/genotype. All white seed
was assumed to belong to the sown cultivar. The aim was to determine if these
widely used cultivars were persisting under farm management conditions and
competition from perennial grass, other subterranean clover and annual weeds.
With some variation between sites all cultivars were found to be persisting
satisfactorily. Over the 3 sites, white-seeded cultivars averaged 460
kg/ha and 6640 seeds/m2; black-seeded cultivars
averaged 260 kg/ha and 5590 seeds/m2.
Contamination with other subterranean clover cultivars/ecotypes was
generally low, except at Macarthur where the white-seeded cultivars were
heavily contaminated (Trikkala 39% pure; Larisa 57% pure) with
black seeds highlighting the poor adaptation of var.
yanninicum to light soil types. Of the black seeds, over
the 3 sites, average contamination level was 13% and ranged from
41% (Goulburn at Macarthur) to 1% (Leura at Timboon).
The study indicates that in south-western Victoria, all the recently released
cultivars are likely to persist and be productive, and that the small-plot
evaluation techniques used to identify potential new cultivars are likely to
be adequate if replicated in space and if the clovers are sown in mixed swards
with perennial grass.
Satellite derived maps of pasture growth status: association of classification with botanical composition
Authors: Vickery P. J. , Hill M. J. , Donald G. E.
Published: August 2004

Summary. Spectral data from the green, red and
near-infrared bands of Landsat MSS and Landsat TM satellite imagery acquired
in mid-spring were classified into 3 and 6 pasture growth classes
respectively. The classifications were compared with a site database of
botanical composition for the Northern Tablelands of New South Wales to
examine the association between spectral growth class and pasture composition.
Pastures ranged in composition from unimproved native perennial grasses
through semi-improved mixtures of native and naturalised grasses and legumes
to highly improved temperate perennial grasses and legumes. For 3 years of MSS
data, the fast growth class had a mean botanical composition of about
80% improved perennial grass and 0% native; medium growth class
averaged 46% improved perennial grass and 14% native; while the
slow growth class had about 60% native and 1% improved perennial
grass when averaged over 3 years of MSS data. For the 6 class TM data from a
single year, a predictive logistic regression of cumulative probability was
developed for percentage of ‘very fast’ growth pixels and ordered
10 percentile categories of improved perennial grass or native grass.
Differences in patch characteristics between classes with MSS disappeared with
TM reclassified to the same 3 class level. Most probable pasture type was
inferred from 3 class MSS and TM data using Bayesian probability analysis. The
resulting maps were similar in general appearance but detail was better with
the TM data. The pasture growth classification identified highly improved
perennial grass pastures and native pastures but sensitivity to intermediate
pasture types was poor. Future improvement will come from direct measurement
of biophysical characteristics using vegetation indices or inversion of
reflectance models.
Effects of modifying layer cages with perches on stress physiology, plumage, pecking and bone strength of hens
Authors: Barnett J. L. , Glatz P. C. , Newman E. A. , Cronin G. M.
Published: August 2004

Summary. This experiment evaluated the welfare of layer
hens housed in cages modified with perches. Welfare was assessed on the basis
of physiological measures of stress (corticosterone concentrations ‘at
rest’ and in response to ACTH and heterophil : lymphocyte ratios) and
immunological responsiveness, feather condition and cover, bone strength, claw
length and between-bird pecking behaviour. Factors examined were cage
modification (perches v. standard cage), tier (upper v. lower), birds (1 or 2
birds/cage) and age (commencing at 35 v. 60 weeks of age). The cages
provided a floor area of 1504 cm2 . Floor pens (2.5 by
2.5 m) with 10 birds/pen served as an external control treatment.
Perches improved the strength of the femur (P<0.05)
compared with standard cages but bone strength was still less than in floor
pens (P<0.05). There were no effects of cage
modification on any of the physiological variables or liveweight
(P>0.05). The only improvement in feather condition
and cover within cages due to the presence of a perch was in the condition of
the tail feathers which was better (P<0.05) than in a
standard cage, but not as good as tail feathers in the pen treatment
(P<0.001). Overall, feather condition and cover was
better in the pen treatment (P<0.001) and similar in
the 2 cage treatments (P>0.05). The presence of a
perch resulted in longer claws than in a standard cage and floor pens
(P<0.05), and significant
(P<0.01) perching activity compared with floor pens.
The experiment showed that perches should be considered for use in commercial
laying cages as they resulted in an improvement in bone strength; there was
also an improvement in tail feather condition, which is considered by some to
be an advantage.
Evaluation of multifrequency bioelectrical impedance data for predicting lean tissue mass in beef cattle
Authors: Thomson B. C. , Thomas B. J. , Ward L. C. , Sillence M. N.
Published: August 2004

Summary. Multifrequency bioimpedance analysis has the
potential to provide a non-invasive technique for determining body composition
in live cattle. A bioimpedance meter developed for use in clinical medicine
was adapted and evaluated in 2 experiments using a total of 31 cattle.
Prediction equations were obtained for total body water, extracellular body
water, intracellular body water, carcass water and carcass protein. There were
strong correlations between the results obtained through chemical markers and
bioimpedance analysis when determined in cattle that had a wide range of
liveweights and conditions. The r2
values obtained were 0.87 and 0.91 for total body water and extracellular body
water respectively. Bioimpedance also correlated with carcass water, measured
by chemical analysis (r2 =
0.72), but less well with carcass protein
(r2 = 0.46). These
correlations were improved by inclusion of liveweight and sex as variables in
multiple regression analysis. However, the resultant equations were poor
predictors of protein and water content in the carcasses of a group of small
underfed beef cattle, that had a narrow range of liveweights. In this case,
although there was no statistical difference between the predicted and
measured values overall, bioimpedance analysis did not detect the differences
in carcass protein between the 2 groups that were apparent following chemical
analysis. Further work is required to determine the sensitivity of the
technique in small underfed cattle, and its potential use in heavier well fed
cattle close to slaughter weight.
Exogenously supplied sucrose improves the postharvest quality of Grevillea ‘Sylvia’ inflorescences
Authors: Ligawa J. K. , Joyce D. C. , Hetherington S. E.
Published: August 2004

Summary. Short vase life (e.g. 3–7 days) is a problem with
inflorescences of Grevillea used as cut flowers and may
be associated with depletion of respirable substrates. A series of 4
experiments addressing this hypothesis were conducted with
Grevillea hybrid ‘Sylvia’ inflorescences. In
experiment 1, the effect of leaf retention on inflorescence stems and a range
of sucrose concentrations (0–6% w/v) in vase solutions was
investigated. In experiment 2, the relationship between inflorescence maturity
(4 stages) and sucrose supply was studied. In experiment 3, the effect of
sucrose concentration as a short period pulse and pulsing duration was
determined. In experiment 4, simulated handling and transport was undertaken
to gauge the practical usefulness of sucrose pulsing to the cut flower
industry. These vase life experiments were conducted in a constant temperature
room (22 ± 2°C) at 50–80% relative humidity. All vase
solutions contained 10 mg chlorine/L to suppress microbial growth.
Three percent sucrose (w/v) was found in experiment 1 to be the best vase
solution. This treatment gave a mean vase life of 10.1 ± 0.2 days,
which was 44% longer than the control (no sucrose) treatment.
Inflorescences picked at the ‘early looping’ stage and provided
with 3% (w/v) sucrose had the best overall vase life (12.0 ±
0 days) and visual appeal in experiment 2. Sucrose pulsing (10%
w/v) for 6–24 h extended vase life by at least 1 day. The presence
of leaves shortened the vase life of both sucrose-pulsed and non-pulsed
inflorescences by about 1 day in experiment 3. Storage for 5 days at 5°C
as handling/transport simulation in experiment 4 did not shorten the vase
life of Grevillea ‘Sylvia’ inflorescences.
Sucrose pulsing (10% w/v) before simulated handling/transport
did not result in a significant increase in the vase life of
Grevillea ‘Sylvia’ inflorescences, and is
therefore not recommended. To achieve the best floral display,
Grevillea ‘Sylvia’ inflorescences should be
picked at the ‘early looping’ stage of maturity and then placed in
a vase solution containing 3% (w/v) sucrose.
Diet composition of cattle grazing Stylosanthes - grass pastures in the seasonally dry tropics: the effect of phosphorus as fertiliser or supplement
Authors: Coates D. B. , Feuvre R. P. Le
Published: August 2004

Summary. The effect of phosphorus (P) on diet selection
in cattle grazing pastures based on Stylosanthes hamata
cv. Verano andS. scabra cv. Seca in the seasonally dry
tropics was studied in 3 grazing trials on soils with inherently low P status
( 5 µg/g bicarbonate-extractable P). The contribution of
Stylosanthes (stylo) to diets was estimated at regular
intervals (approximately monthly) using carbon isotope analysis of faeces.
Feeding P supplement increased the proportion of stylo in the diet but the
effect was seasonal and variable, being most pronounced during the late wet
and early dry seasons when dietary stylo proportions are usually highest. The
results indicated that P supplement influenced diet selection through its
effect on dietary P status such that cattle with a deficiency of dietary P
select a lower proportion of stylo than those with higher P intakes.
The effect of fertiliser P on dietary stylo content was also variable. The
dominant effect was via fertiliser-induced changes in pasture botanical
composition. Higher stylo proportions in the diet of heifers grazing
unfertilised pasture compared with those grazing fertilised pasture were
associated with increasing stylo dominance in unfertilised pastures as opposed
to grass dominance in fertilised pastures. At the same time there was evidence
of a fertiliser treatment effect that was consistent with dietary P status
influencing diet composition. In the grass-dominant pastures, unsupplemented
cattle on low P pasture selected less stylo than those grazing pastures of
higher P status due to more frequent fertilising but there was no difference
where P supplement was fed. A strong seasonal preference for grass early in
the wet season, reinforced by a generally reduced preference for stylo in
cattle with diets deficient in P, probably hastened the development of stylo
dominance in unfertilised pasture where P supplement was not fed.
Performance of weaned rusa (Cervus timorensis) deer given concentrates of varying protein content with sorghum hay
Authors: Puttoo M. , Dryden G. M. , McCosker J. E.
Published: August 2004

Summary. In 2, 18-week experiments, rusa deer
(Cervus timorensis) initially weighing 22 kg, were given
sorghum hay supplemented with concentrates containing nominally 12, 17 or
20% protein. Hay was given ad libitum and the
concentrates were offered at 2.8% (experiment 1) or 2.5%
(experiment 2) of liveweight daily. Concentrate contents in the diets as
selected averaged 88 and 74% (air-dry basis) in the final 3 weeks of
experiments 1 and 2. In experiment 1, males grew faster than females (163
v. 125 g/day; P =
0.0001), and deer given the 20% protein concentrate grew significantly
(P<0.05) faster than the remainder. Stags given the
20% protein concentrate in experiment 2 grew more quickly (161
g/day), and had larger necks, greater body length and greater antler
growth. The optimum diet protein content for growth in both male and female
weaners may be 15% (dry matter basis), but higher protein contents may
give earlier pedicle initiation and faster antler growth in males.
Genetic diversity amongst Australian canola cultivars determined by randomly amplified polymorphic DNA
Authors: Mailer R. J. , Wratten N. , Vonarx M.
Published: August 2004

Summary. The rapid increase in canola production in
Australia in recent years has been associated with the release of several new
cultivars with progressive improvements in quality, yield and disease
resistance. The origin of many Australian cultivars is Canadian material that
was introduced into Australia in the late 1970s. A selection of new genetic
material has recently been introduced from diverse sources including China,
Japan and Europe. As a result, Australian cultivars now contain a much larger
gene pool and wide ranging agronomic characteristics. Cultivar identification
and discrimination has become an important issue in canola breeding programs.
This paper describes the diversity amongst 25 Australian cultivars, analysed
using the polymerase chain reaction and arbitrary primers to detect randomly
amplified polymorphic DNA (RAPD) sequences. From 19 primers, 89 bands were
detected. Six of the best of these primers, producing 27 bands, were selected
for cultivar discrimination. Cluster analysis was used to illustrate the
diversity of genetic material in Australian canola cultivars and between
individual breeding programs. Despite the common origin of Australian
cultivars, differences between individual programs are evident.
The results obtained are generally in agreement with known pedigrees. However,
RAPD provides canola breeders with a more accurate picture of similarities and
diversity among cultivars. The similarity of cultivars within individual
programs suggests RAPD discrimination may be associated with particular
cultivar characteristics and able to be used in selections in breeding
programs.
Shading material changes the proportion of diffuse radiation in transmitted radiation
Authors: Healey K. D. , Rickert K. G.
Published: August 2004

Summary. A wide range of shading materials are used by
horticulturists (to protect plants from direct light, wind and hail) and
researchers (often to simulate shading by plant canopies). All materials
reduce the incidence of direct shortwave radiation and, to varying degrees,
alter the relative proportions of direct and diffuse radiation compared with
the incident radiation outside the material. Plant responses under the shading
material would be influenced by the changes in incident radiation. This study
measures the proportion of shortwave radiation transmitted and the proportion
of diffuse radiation under 12 commercially available shading materials. Colour
of the material (white, green or black) greatly influenced the proportion of
shortwave radiation transmitted by commercial shadecloths, with transmission
highest under white shadecloth and lowest under black shadecloth. In addition,
the mean proportion of diffuse radiation increased under white shademesh,
clear solarweave, glasshouse film and dense lattice compared with incident
radiation.
Using near infrared reflectance spectroscopy to estimate the nutritive value of senescing annual ryegrass (Lolium rigidum): a comparison of calibration methods
Authors: Smith K. F. , Simpson R. J. , Armstrong R. D.
Published: August 2004

Summary. The suitability of near infrared reflectance
(NIR) spectroscopy for predicting the concentration of several quality traits
in samples of annual ryegrass (Lolium rigidum Gaud.)
herbage was assessed in 2 separate experiments.
In the first experiment, NIR calibration equations were developed for 6 traits
(water-soluble carbohydrates, dry matter digestibility, neutral detergent
solubles, neutral detergent solubles digestibility, neutral detergent fibre
digestibility and nitrogen) using 4 calibration methods. No significant
differences were found in the accuracy of NIR equations developed using either
stepwise multiple linear regression (SMLR) or partial least squares regression
(PLS) techniques when the equations were used to predict the concentration of
constituents in those samples not used during the calibration process. The
process of removing samples identified by the computer as spectral outliers
was found to improve those statistics that related NIR data to the reference
data of the samples used during calibration development (i.e. improved the
goodness of fit of the regressions). However, when the resulting equations
were used on all of the samples there was no improvement in the accuracy of
the prediction of composition, and the estimates were less accurate for 2 of
the equations.
In the second experiment, plant part-specific equations (leaf blade, stem and
leaf sheath) were developed. The specific equations were found to be no more
accurate than those developed using a subset of all samples when used to
analyse samples of the same plant part. However, using equations developed on
either stem or leaf sheath samples to predict the composition of leaf blade
samples led to inaccurate estimates of composition, illustrating the potential
for error when NIR calibration equations are used on dissimilar samples.
The similarity of the NIR estimates of decline in nutritive value and those
obtained using reference analyses was illustrated by plotting the actual and
predicted decline in nutritive value.
The results of the experiments in this paper illustrate the need to monitor
the accuracy of any NIR prediction of nutritive value. Striving for very low
standard errors of calibration either by eliminating outliers or by limiting
the plant tissues used during calibration did not lead to more accurate
predictions of the composition of samples other than those used during the
calibration process.
Effect of lock up and harvest dates on dairy pasture dry matter yield and quality for silage in south-western Victoria
Authors: Jacobs J. L. , Rigby S. E. , McKenzie F. R. , Ward G. N. , Kearney G.
Published: August 2004

Summary. At 2 sites in south-western Victoria, 132 plots
of predominantly perennial ryegrass pasture were randomly allocated, within 4
replicate blocks, to each of 3 lock up dates (L1, L2, L3) by 12, 12 or 9
harvest times. Harvesting commenced 2 weeks after initial treatment lock up
with L1 and L2 being harvested 12 times (weekly intervals) and L3, 9 times.
Lock up dates were 15 August (L1), 5 September (L2) and 26 September (L3) at
site 1 and 17 August (L1), 7 September (L2) and 28 September (L3) at site 2.
For each treatment and harvest date, dry matter yield and botanical
composition were determined and samples of total pasture and the ryegrass
fraction were collected and assessed for dry matter digestibility, crude
protein and neutral detergent fibre. Dry matter yield was measured from the
start of L1 (site 1, 15 August; site 2, 17 August) until the final harvest
date of L3 (site 1, 12 December; site 2, 14 December).
At site 1, L3 produced higher dry matter yields than L1 and L2 at comparable
lengths of lock up time, whilst there were no differences at site 2. Over the
total experimental period (site 1, 15 August–12 December; site 2, 17
August–14 December) there were no differences in total dry matter yield
(t/ha) between treatments at either site (site 1—L1 5.79, L2 6.43,
L3 5.94; site 2—L1 6.68, L2 5.07, L3 5.73). Treatments had little effect
on botanical composition at either site when compared at the same time after
lock up, both during the harvesting period or in the subsequent autumn.
Pasture metabolisable energy and crude protein all declined with increasing
length of lock up whilst neutral detergent fibre content increased, changes
which were similar for both the total pasture and the ryegrass fraction. The
metabolisable energy of pasture in L1 and L2 was higher than that of L3 at
least until week 8 at both sites. Initial crude protein values were higher for
L1 and L2 than for L3 at site 1, whilst at site 2, L1 had higher values than
either L2 or L3.
Although longer lock up periods produced more herbage, if conserving forage is
to be an integral component of managing surplus spring pasture, then dairy
farmers should aim to produce high quality pasture for forage conservation.
This will be achieved through shorter lock up periods and harvesting pasture
no later than early ear emergence in the ryegrass fraction of the sward. This
management will reduce dry matter yields, but allow more flexibility for
maintaining intensive grazing practices through the spring period. The
decision about when to lock up pasture will depend on both plant growth rates
and animal feed requirements.
Degradation of trifluralin in three Victorian soils —long-term field trials
Authors: Johnstone P. K. , Jolley A. V. , Code G. R. , Moerkerk M. R. , Corbett A.
Published: August 2004

Summary. The persistence of trifluralin was investigated
at 3 sites in southern Australia over 8 years. Persistence varied from
year-to-year, with the highest persistence being recorded at all sites in the
dry year of 1984. Trifluralin persistence (expressed as a percentage of the
initial measured concentration) 1 year after application was lowest at
Rutherglen (7–22%), followed by Dooen (7–26%) and
Walpeup (13–120%). Trifluralin degradation at Walpeup in 1984 was
negligible. The resultant high residue concentrations would have posed a
threat to subsequent crops. However, 1 year later after the subsequent fallow,
the residue concentration had dropped to more typical levels. Trifluralin did
not accumulate after repeated application (either 1 or 2 years apart) at all 3
sites. It was found important to measure the amount of trifluralin in the soil
immediately after application because the trifluralin concentration could not
be assumed from the rate. Soil concentrations immediately after application
ranged from 32 to 138% of that expected from the nominal application
rate. Therefore, measuring initial concentrations when comparisons were to be
made between treatments, years and sites, was essential. In addition to
studies of 1 year persistence, trifluralin concentration was also measured 2
years after application at Walpeup and Dooen. There was evidence to suggest
that the rate of degradation over the same 1 year period, was different for a
recent application when compared with weathered trifluralin residues from a
previous application. Correlations between persistence and various weather
factors indicated that the most influential factors were those that occurred
in the first 60 days after application. These included total rainfall,
effective rainfall (rainfall minus evaporation) and average maximum
temperature.
Does nitrogen fixation of commercial, dryland chickpea and faba bean crops in north-west New South Wales maintain or enhance soil nitrogen?
Authors: Schwenke G. D. , Peoples M. B. , Turner G. L. , Herridge D. F.
Published: August 2004

Summary. Nitrogen (N2 ) fixation
accords pulse crops the potential to sustain or enhance total soil nitrogen
(N) fertility. However, regional field experiments have shown that this
potential is often not realised because N2 fixation is
inhibited by the supply of nitrate N in the root zone (0–90 cm) coupled
with a low demand for N during plant growth. The objectives of this study were
to establish whether commercially grown chickpea and faba bean crops in the
northern grain belt of New South Wales were depleting, maintaining or
enhancing soil N fertility, and whether current farm management practices were
maximising the N2 fixation potential of the crops.
Fifty-one rainfed crops of chickpea (Cicer arietinum L.)
and faba bean (Vicia faba L.) were surveyed in the
Moree, Walgett and Gunnedah districts of north-west New South Wales during the
winters of 1994 and 1995. Nitrogen fixation was measured using the natural
15N abundance technique. Net N balance was calculated
for each crop by subtracting grain N harvested from fixed
N2. Soil, plant and fallow conditions with potential to
influence N2 fixation were also documented. The
percentage of crop N derived from N2 fixation
(Pfix) ranged from 0 to 81% for chickpea and 19
to 79% for faba bean. Nitrogen fixation of chickpea was uniformly low
in the 1994 drought. Total N2 fixed ranged from 0 to 99
kg/ha for chickpea and 15 to 171 kg/ha for faba bean. Net N balance
ranged from –47 to +46 kg N/ha for chickpea crops, and
–12 to +94 kg N/ha for faba bean crops. About 60% of the
difference in Pfix between chickpea and faba bean at the
average level of soil nitrate (65 kg/ha) was explained by the higher N
demand of the latter. The remaining 40% could be due to greater
tolerance of the faba bean symbiosis to nitrate effects. In addition, faba
bean had a lower N harvest index than chickpea, which meant that
proportionally less N needed to be fixed by faba bean to offset removal of
grain N. On average, Pfix needed to exceed 35%
for chickpea and 19% for faba bean to balance soil N. The equivalent
soil nitrate levels were 43 kg nitrate N/ha for chickpea and 280 kg/ha
for faba bean (extrapolated from the relationship between measured
Pfix and soil nitrate). Double-cropping chickpea into
summer cereal or grass pasture stubble provided the most consistent strategy
for achieving the low levels of soil nitrate.
Responses to grain feeding by grazing dairy cows
Authors: Robaina A. C. , Grainger C. , Moate P. , Taylor J. , Stewart J.
Published: August 2004

Summary. Two experiments were conducted on feeding grain
supplements to dairy cows during summer. In experiment 1, dairy cows in
mid–late lactation were offered one of 2 pasture allowances (about 20
and 40 kg DM/cow.day) with and without a supplement of a grain mix (5 kg
of a 70 : 30 mixture of barley and lupins). This experiment was conducted
twice over 2 consecutive summer–autumn periods (years 1 and 2). Milk
yields were higher at the high pasture allowance and with grain feeding. The
marginal response to grain feeding (kg milk/kg grain DM consumed) was 0.7
at both pasture allowances in year 1, and 1.1 and 0.8 at the low and high
pasture allowance, respectively, in year 2. Diet had no significant effect on
milk composition. Pasture intake was reduced by supplementary feeding and the
level of substitution depended on pasture allowance.
The alkane-based and sward sampling techniques were used to estimate pasture
intake and diet digestibility. Estimates of pasture substitution, based on
measurements made with the alkane technique, were 0.3 and 0.6 kg DM reduction
in pasture/kg DM grain consumed at the low and high pasture allowance,
respectively, in both years. In year 1, the pasture substitution measured with
the pasture difference method was 1 kg pasture DM/kg grain DM at both
pasture allowances. In year 2, estimates of substitution calculated using the
pasture difference method were 0.2 and 0.5 kg pasture DM/kg grain DM at
the low and high pasture allowance respectively.
In the second experiment (year 3), the effects of level of feeding barley on
pasture intake, diet digestibility and milk production were measured during
summer. The 4 levels of grain consumed were 0, 1.8, 3.4 and 6.7 kg barley
DM/cow. day. Higher grain intake resulted in higher milk yield, higher
protein concentration and yields of fat, protein and lactose. Milk yield
responses per kilogram of barley diminished from 1.6 at the low barley intake
to 0.8 kg milk/kg barley DM at the highest barley intake. It is suggested
that higher levels of substitution and a potentially less efficient use of
grain contributed to the poorer production responses at higher levels of grain
feeding.
The proportion of individual lucerne plants resistant to Phytophthora medicaginis and Colletotrichum trifolii in Australian cultivars
Authors: Mackie J. M. , Irwin J. A. G.
Published: August 2004

Summary. Phytophthora root rot
(Phytophthora medicaginis) and colletotrichum crown rot
(Colletotrichum trifolii) are the 2 most serious
pathogens of lucerne in eastern Australia. Work reported in this paper shows
that in glasshouse tests of the 11 most commonly grown Australian lucerne
cultivars, the proportion of individual plants with resistance to both
pathogens ranges from 0 (Hunter River and Aurora) through to a maximum of
19.8% (Sequel HR). Within 9 of the cultivars, the proportion of
individual plants resistant to the 2 pathogens was <7%. Since these
2 diseases are known to cause serious losses in eastern Australia, the results
indicate further improvement in lucerne production can be obtained by
increasing the proportion of individual plants in a cultivar resistant to both
pathogens. This would be best achieved by identifying dominant sources of
resistance and incorporating this into on-going lucerne breeding programs.
Growth, seed yield and water use of faba bean (Vicia faba L.) in a short-season Mediterranean-type environment
Authors: Mwanamwenge J. , Loss S. P. , Siddique K. H. M. , Cocks P. S.
Published: August 2004

Summary. A number of studies conducted in Western
Australia have shown that faba bean has considerable potential as a pulse crop
in the low to medium rainfall cropping regions (300–450 mm/year).
However, its yield is variable and can be low in seasons when rainfall is less
than average. Traits associated with the adaptation of 10 diverse faba bean
genotypes to low rainfall, Mediterranean-type environments were evaluated at
Merredin in south-western Australia over 2 contrasting seasons. Plant density
was varied with seed size to ensure all genotypes achieved similar canopy
development and dry matter production.
Time to flowering appeared to be the most important trait influencing seed
yield of faba bean in this environment. Seed yield was significantly
correlated with time to 50% first flower in 1994 and 1995
(r2 = 0.61 and 0.82
respectively, P<0.01). In the dry 1994 season, rapid
leaf area development in ACC286 allowed a greater absorption of
photosynthetically active radiation resulting in more dry matter accumulation
than other genotypes. ACC286 also had greater root length density at
20–30 cm depth compared with Icarus and the standard cultivar Fiord.
There were no significant differences in total water use between the genotypes
examined, although the pattern of water use varied markedly. The ratio of pre-
to post-flowering water use was about 1:1 in the early flowering and high
yielding ACC286 and 2.6 :1 for the late maturing, low yielding Icarus. Seed
yield and harvest index were positively correlated with post-flowering water
use (r2 = 0.75 and 0.71
respectively). Above-average rainfall in 1995 resulted in increased yield of
all genotypes, particularly ACC286 which again produced the highest yields.
Early flowering genotypes with rapid dry matter accumulation in the seedling
stages (such as ACC286) could widen the adaptation of faba bean to low
rainfall, Mediterranean-type environments and situations where sowing is
delayed.
Diagnosis of potassium deficiency in faba bean and chickpea by plant analysis
Authors: Aini N. , Tang C.
Published: August 2004

Summary. Critical potassium (K) concentrations for the
diagnosis of K deficiency were determined in various shoot parts of faba bean
(Vicia faba L. cv. Fiord) and chickpea
(Cicer arietinum L. T1587) plants grown at K rates of
0–240 mg K/kg in a K-deficient soil in the glasshouse. Shoot growth
of both species increased with rates of K applied and with plant age but faba
bean was more responsive to K application than chickpea. Potassium
concentrations in plant parts greatly increased with increasing K supply. In
faba bean, K concentrations in all shoot parts decreased with plant age
irrespective of K supply while in chickpea K concentrations in leaves of
K-deficient plants increased with plant age but those in stems decreased. For
both species, young leaves had higher K concentrations than old tissues,
especially in K-deficient plants. A greater proportion of leaf K was stored in
the petioles when K supply was adequate than when K was deficient.
Critical K concentrations were determined using the hand-fitted curve and
Mitscherlich model at 90% maximum shoot weight and the 2-phase linear
model. The critical concentrations varied between plant parts and among the
methods used. Critical values decreased with leaf age and were higher in leaf
petioles than in leaf blades. Critical K concentrations, developed from
hand-fitted curves, in the 1st plus 2nd and 3rd plus 4th leaf blades of faba
bean, and leaf petioles below the youngest fully expanded leaf (YFEL) of
chickpea were similar between days 48 and 73 for faba bean and between days 55
and 80 for chickpea. It is recommended that the critical values for the
diagnosis of K deficiency at 7–8-leaf stages are 1.3–1.5%
in YFEL, 1.1–1.2% in the 1st plus 2nd leaf blades below the YFEL
and 1.8–2.0% in whole shoot of faba bean, and
1.4–1.5% in YFEL, 2.7–2.8% in the 1st plus 2nd leaf
petioles and 2.1–2.2% in whole shoot of chickpea. The gradient of
K concentration between young and old leaves occurred before a decrease in
shoot growth and may be used for the prognosis of K deficiency.
The use of repeated measurements analysis for the evaluation of seasonal variation in the dry matter yield and nutritive value of perennial ryegrass (Lolium perenne L.) cultivars
Authors: Smith K. F. , Kearney G. A. , Culvenor R. A.
Published: August 2004

Summary. Seasonal variation in herbage yield, and in the
concentrations of water-soluble carbohydrates, crude protein,
in vitro dry matter digestibility, neutral detergent
fibre, acid detergent fibre and lignin in the herbage was measured for 5
perennial ryegrass (Lolium perenne L.) cultivars grown
in 3 contrasting environments. Two separate trials were sown in one of the
environments. The yield and nutritive value data were subjected to
antedependence analyses to detect the presence of serial correlations between
data from different harvest dates. Significant
(P<0.05) antedependence was found in 2, 3, 3 and 6 of
the 7 variables in the 4 experiments respectively. It was shown that serial
correlations between harvest dates had the potential to cause the
overestimation of the significance of cultivar effects in ANOVA of data from
individual harvest dates, and in harvest and cultivar × harvest effects
in combined ANOVA across all harvest dates unless statistical procedures
appropriate for use with repeated measurements data were adopted.
Effect of partial pressure infiltration of calcium into ‘Kensington’ mango fruit
Authors: Shorter A. J. , Joyce D. C.
Published: August 2004

Summary.‘Kensington’ mango fruit harvested
at the mature green stage were partial pressure (vacuum) infiltrated with
calcium (4 g Ca 2+/L as CaCl2)
at 3 reduced pressure levels (–33, –66 and –99 kPa).
Concentrations of Ca2+ in unripened calcium-treated
fruit were about 1-, 2- and 3-fold higher, respectively, than
Ca2+ concentrations in the skin and flesh of control
(untreated; i.e. not vacuum infiltrated) fruit. For example, skin tissue
Ca2+ concentrations of control fruit and of those
treated at –33, –66 and –99 kPa were 1.51, 1.93, 3.42 and
5.01 mg Ca2+/g dry weight, respectively.
Concentrations of Ca2+ in the skin of both control fruit
and of Ca2+ -treated fruit were consistently higher, by
about 2-fold, than those in the fruit flesh. Compared with the –33 kPa
infiltration treatment, Ca2+ levels in the fruit flesh
were increased by only about 2-fold by further reductions in the partial
pressure infiltration levels to –66 or –99 kPa. Infiltration of
Ca2+ into mango fruit was apparently via lenticels and
along xylem conduits open at the cut pedicel. These infiltration pathways were
revealed by inclusion of Brilliant Blue dye in the Ca2+
solution. Undyed and dyed lenticels were separately excised for
Ca2+ analysis. Dark (dyed) lenticels had higher
Ca2+ concentrations (1.86 ± 0.11 mg
Ca2+/g dry weight) than light (undyed) lenticels
(0.83 ± 0.19 mg Ca2+/g dry weight). Partial
pressure infiltration of Ca2+ at any of the 3
subatmospheric pressure levels did not result in shelf life extension. Fruit
infiltrated at –66 and –99 kPa exhibited injuries, which included
exacerbated lenticel blackening and anaerobic off-odour and taste evident at
the end of shelf life. In comparison, both control (untreated) mango fruit and
those infiltrated with Ca2+ at –33 kPa ripened
normally.
A survey on the effect of management techniques and pasture composition and quality at harvesting on silage quality on dairy farms in western Victoria
Authors: Jacobs J. L.
Published: August 2004

Summary. Factors associated with silage quality were
investigated on 140 dairy farms in western Victoria. The management factors
measured were date of lock up, date cut, length of lock up, duration of
wilting, raking and tedding during wilting period, rainfall during wilting
period and the type of silage made. Pasture variables measured at harvesting
included percentage composition (ryegrass, legume, other grasses and weeds),
dry matter of pasture, metabolisable energy, crude protein, neutral detergent
fibre and water-soluble carbohydrate of the pasture, and dry matter yield of
the pasture.
The average lock up time of pasture for silage was mid September, although the
range was from late July to early November. The length of lock up varied from
16 to 91 days with a mean value of 49 days and pastures were on average
harvested in early November. Ryegrass on average accounted for 61%,
legumes and other grasses accounting for a further 15% each and weeds
about 5%. The range in quality of pasture at harvesting was highlighted
by the range in metabolisable energy (8.9–11.3 MJ/kg DM) and crude
protein (10.2–20.4%) values. Wilting times varied from 0.5 to 15
days with the biggest range being observed in pastures used for baled silage.
All factors were regressed against final silage metabolisable energy and crude
protein. Factors which had the greatest effect on final silage metabolisable
energy were date of cutting, length of lock up, type of silage, the
interaction between type of silage and length of lock up, length of wilting
and mechanical treatment during the wilting period. Final silage crude protein
was most strongly associated with date of cutting, crude protein content of
the pasture and mechanical treatment during the wilting period.
Mechanical treatment during the wilting period had the greatest influence on
silage quality. Other options to improve silage quality such as cutting
earlier or reducing wilting periods may not be possible or economically
viable.
Suitability of clovers (Trifolium species and cultivars) as hosts of spotted clover aphid, a biotype of Therioaphis trifolii (Monell) (Hemiptera : Aphididae)
Authors: Milne W. M.
Published: August 2004

Summary. The performance of the spotted clover aphid, a
biotype closely related to the spotted alfalfa aphid
Therioaphis trifolii (Monell) f. maculata, was assessed
on 18 accessions, all of which were cultivars of clover
(Trifolium spp.) commonly grown in improved pastures in
Australia. Aphids were reared on excised trifoliate leaves on agar containing
a soluble fertiliser. Parameters measured were initial host acceptance by
apterous adults, survival of first generation nymphs, incidence of alate
adults produced, and the 4-day fecundity of apterous adults. A host
suitability index was calculated for each of the cultivars tested. Most of the
accessions were readily accepted by spotted clover aphid and nearly all proved
to be suitable hosts. Mortality and alate production were generally low and
fecundity of F1 apterae averaged more than 5 offspring
per day on all cultivars in the 4-day fecundity study. Spotted clover aphid
performed particularly well on 9 of the 10 cultivars of subterranean clover.
The white clover cultivar Irrigation was the least suitable host. Spotted
clover aphid has the potential to be a serious threat to improved pastures in
Australia where clover is a major component.
Faba beans and other legumes add nitrogen to irrigated cotton cropping systems
Authors: Rochester I. J. , Peoples M. B. , Constable G. A. , Gault R. R.
Published: August 2004

Summary. Legumes have become common rotation crops in
cotton cropping systems in northern New South Wales. Levels of nitrogen
fixation and yield achieved on-farm were measured in commercial faba beans and
other winter and summer legume crops sown after cotton over 3 years to assess
the relative inputs of fixed nitrogen (N) into this system. Faba bean crops
fixed up to 350 kg N/ha, removed up to 160 kg N/ha in harvested grain
and contributed up to 270 kg fixed N/ha to soil N after harvest. Grain
yields, N2 fixation and dry matter production were
reduced in late-sown crops and those water-stressed during pod-filling, but
most faba bean crops fixed almost 3 times as much N as was removed in grain.
Below-ground legume N, determined with 15N shoot feeding
techniques, accounted for 40% of the total crop N at peak biomass, or
about 100 kg N/ha for the average faba bean crops. Residual fixed N after
harvest was predicted from crop dry matter and grain yield, and this could be
used to assess the contribution to soil N from faba beans. Amounts of nitrogen
fixed by other legume crops ranged from 20 kg N/ha for adzuki bean and
droughted lablab to more than 450 kg N/ha by irrigated soybean. Soybean,
peanut and Dolichos lablab contributed more fixed N to the soil than adzuki
bean, mung bean or pigeon pea under irrigated conditions. Winter crops
including field peas, lentils and lupins and green-manured pasture species
fixed up to 240 kg N/ha.