bluuebunny/crossref_metadata_2025 huggingface dataset:
Adaptation and seed yield of cool season grain legumes in Mediterranean environments of south-western Australia
Authors: Siddique K. H. M. , Loss S. P. , Regan K. L. , Jettner R. L.
Published: November 2005

A range of cool season grain legume species have shown considerable potential
for soils unsuitable for the production of narrow-leafed lupin
(Lupinus angustifolius L.) at limited sites in the
Mediterranean-type environments of south-western Australia. In this study the
adaptation of these grain legume species was compared by measuring crop
phenology, growth, and yield in field experiments at a total of 36 sites over
3 seasons, with the aim of identifying species with suitable adaptation and
seed yield for specific environments.
The grain legumes examined appeared to fall into 3 categories:
(i) field pea (Pisum sativum L.),
faba bean (Vicia faba L.), common vetch
(Vicia sativa L.), and narbon bean
(Vicia narbonensis L.) clearly had superior seed yield
to the other species over a wide number of sites and years across
south-western Australia (mean 1.0–2.3 t/ha);
(ii) albus lupin (Lupinus albus
L.), desi chickpea (Cicer arietinum L.), and
Lathyrus cicera, L. sativus, and
L. ochrus produced seed yields of 1–1.3 t/ha;
and (iii) red lentil
(Lens culinaris L.), bitter vetch
(Vicia ervilia), and kabuli chickpea
(Cicer arietinum L.) generally produced the lowest
yields (0.6–1.0 t/ha). There were clear species × environment
interactions. At low-yielding sites (<1.4 t/ha), field pea was the
highest yielding species, while faba bean often produced the highest seed
yields under more favourable conditions at high yielding sites. Lentil, bitter
vetch, Lathyrus spp., and desi chickpea showed average
response to increasing mean site yield. Soil pH and clay content and rainfall
were the environmental factors identified as the most important in determining
seed yields. Soil pH and clay content appeared to be especially important in
the adaptation of lentil, narbon bean, bitter vetch, and kabuli chickpea, with
these species performing best in soils with pH >6.0 and clay contents
>15%. Seed yields were positively correlated with dry matter
production at maturity across a number of sites
(r2 = 0.40,
P < 0.01). Future improvements in seed yield of these
species are likely to come from management practices that increase dry matter
production such as increased plant density and early sowing, and through the
development of genotypes with greater tolerance to low winter temperatures,
and more rapid phenology, canopy development, and dry matter production than
existing commercial cultivars.
Measuring yield loss in cereals caused by root lesion nematodes (Pratylenchus neglectus and P. thornei) with and without nematicide
Authors: Taylor S. P. , Vanstone V. A. , Ware A. H. , McKay A. C. , Szot D. , Russ M. H.
Published: November 2005

Yield loss caused by root lesion nematodes
(Pratylenchus neglectus and
P. thornei) was measured using the nematicide aldicarb
(Temik 150GTM) or by correlating yield with initial or
final nematode densities. In 1996, rotation trials (1
P. neglectus and 1 P. thornei)
were established with susceptible and moderately resistant wheat varieties and
resistant barley and triticale varieties. An intolerant oat variety (cv.
Echidna) was planted over all plots in 1997. Nematode densities were
90% (P. neglectus) or 95%
(P. thornei) lower in oat plots following the resistant
triticale (cv. Tahara) relative to the susceptible wheat (cv. Machete). In
1997, a significant, negative correlation between both initial and final
nematode density and yield was obtained. In wheat variety trials (3 sites) in
1997, a significant, negative correlation was also obtained between mean
variety yield and mean final P. neglectus density or
mean P. neglectus multiplication rate. Yield loss of up
to 20% was calculated from the regression. In all trials, cereal
varieties that were more resistant were also more tolerant. In 1996, aldicarb
rate trials (1 P. neglectus and 1
P. thornei) were established to assess the affect of
rate and timing of aldicarb application on yield of 2
susceptible/intolerant wheat varieties (cvv. Machete and Janz). Lower
rates of aldicarb (≤1.5 kg a.i./ha) gave inconsistent nematode control
and did not significantly increase yield. Rates ≥2.5 kg a.i./ha reduced
nematode densities by 70–90%, resulting in up to 23%
greater yield for Machete. The magnitude of yield loss caused by
P. neglectus or P. thornei
determined with or without nematicide was similar between trials.
Detection and differentiation of phytoplasmas in Australia: an update
Authors: Schneider B. , Padovan A. , De La Rue S. , Eichner R. , Davis R. , Bernuetz A. , Gibb K.
Published: November 2005

Phytoplasmas were found in 33 plant species that were not described as host
plants in an earlier Australian survey. Plants displayed characteristic
symptoms of little leaf, proliferation, and floral abnormalities. Restriction
fragment length polymorphism analysis revealed 13 different restriction
patterns. The majority of phytoplasmas showed a restriction pattern identical
to that of either the tomato big bud (TBB) or sweet potato little leaf V4
(SPLL-V4) phytoplasma. Phytoplasmas from 6 plant species showed a restriction
pattern similar to that of the pigeonpea little leaf (PLL) phytoplasma. One
phytoplasma from garden bean displayed a restriction pattern identical to that
found in papaya dieback and Australian grapevine yellows (AGY) phytoplasmas.
Seven new restriction fragment patterns have been detected and sequence
analysis of the 16S/23S spacer region revealed that 3 of these
phytoplasmas are related to the faba bean phyllody (FBP) group. The spacer
region of a graminaceous phytoplasma was most similar to phytoplasmas from the
sugarcane white leaf group. Another graminaceous phytoplasma was identical to
a phytoplasma from Indonesia. The spacer region of a phytoplasma from
poinsettia (PoiBI) was identical to the western X-disease phytoplasma from
North America and Europe. The spacer region of a phytoplasma in stylosanthes
contained no tRNAIle. Full-length 16S rRNA gene
sequences from selected new phytoplasmas were determined to corroborate
results obtained from the spacer region analyses. Three of these phytoplasmas
(galactia little leaf, vigna little leaf, and stylosanthes little leaf) are,
along with the PoiBI phytoplasma and the graminaceous phytoplasmas, members of
phytoplasma groups that have not been reported before in Australia.
Dry matter accumulation and distribution in five cultivars of maize (Zea mays): relationships and procedures for use in crop modelling
Authors: Birch C. J. , Hammer G. L. , Rickert K. G.
Published: November 2005

The ability to predict accurately dry matter (DM) accumulation, partitioning,
and thus final grain yield is crucial in crop simulation models. The
objectives of the study were to measure radiation interception and radiation
use efficiency, to quantify the distribution of DM among the various plant
parts, and to develop improved methods of modelling DM accumulation and
partitioning among plant parts. Five cultivars of maize differing widely in
maturity and adaptation were planted in October 1993 in south- eastern
Queensland, and grown under non-limiting conditions of water and plant
nutrient supplies. Data on DM accumulation, light interception, and canopy
development were collected. The light extinction coefficient
(k) did not differ among the cultivars. Radiation use
efficiency was constant in each cultivar until close to physiological
maturity, when a small decline was observed. Partitioning of DM between leaves
and stems (until 90% of leaf tips had appeared) was described by a
linear relationship between the proportion of DM allocated to leaves and the
number of leaves present. Ear growth was described by a thermal-time-dependent
equation from 150 degree-days (base temperature 8˚C) before silking to
115 degree-days after silking. Predictions of accumulation of grain yield by
either components of yield (grain number per plant and individual grain
weight) or daily increase in harvest index were assessed, but neither was
entirely satisfactory, the former because of inaccurate prediction of grain
number per plant, and the latter because of differences among cultivars in the
daily increase in harvest index and terminal harvest index. Thus, the use of
genotype-specific coefficients remains necessary. Throughout crop life, DM in
stems can be predicted by difference, once DM is allocated to other plant
parts. The relationships presented where leaf number mediates DM partitioning
before silking simplify modelling of DM accumulation and partitioning in
maize.
Distribution and incidence of necrotic and non-necrotic strains of bean yellow mosaic virus in wild and crop lupins
Authors: Cheng Y. , Jones R. A. C.
Published: November 2005

A new strain of bean yellow mosaic virus (BYMV), a non-necrotic strain, was
found in south-west Western Australia. It differs from the original necrotic
strain of BYMV in that it does not kill
Lupinus angustifolius (narrow-leafed lupin) plants, but
causes symptoms of mottle and stunting, or dead growing points, fleshy
expanded leaves, and stunting. A survey of
L. angustifolius crops during September and October 1997
compared the distribution and incidence of the necrotic strain with that of
the non-necrotic strain. Based on 1000 plants inspected at the edge of each
crop, the necrotic strain was found in 100 of 102 crops while the non-necrotic
strain was found in 64 of them. Incidences ranged from 0.3 to 56%
(necrotic strain) and 0.1 to 7% (non-necrotic strain) of plants
counted. Both strains were present over the whole range of the survey. Wild
L. angustifolius and L. luteus
(yellow lupin) populations were also inspected. The necrotic and non-necrotic
strains were found in 31 and 9 of the 34
L. angustifolius populations examined, respectively.
Incidences ranged from 0.1 to 28% (necrotic strain) and 0.1 to
3% (non-necrotic strain) of plants counted. BYMV was found in 9 of 11
wild L. luteus populations with incidences ranging from
0.3 to 7% of plants counted. In a separate survey in which samples of
L. angustifolius crops, with necrotic symptoms suspected
of being caused by Colletotrichum gloeosporioides (lupin
anthracnose disease), were examined, 37 of 130 samples had typical necrotic
BYMV symptoms. Samples with these necrotic symptoms also came from northern
and eastern wheatbelt areas not normally associated with BYMV infection. When
8 BYMV isolates cultured by sap inoculation in
Trifolium subterraneum (subterranean clover) were tested
by aphid transmission to L. angustifolius plants in 1994
and again in 1997, the isolates of the 2 strains behaved the same on both
occasions causing only necrotic (3 isolates) or non-necrotic (5 isolates)
symptoms. Thus, despite repeated subculture by sap inoculation over a 3.5-year
period, the 2 BYMV strains still remained distinct. An isolate collected from
wild L. luteus in 1997 produced only non-necrotic
symptoms in L. angustifolius. The non-necrotic strain
caused symptoms typical of BYMV in hosts other than
L. angustifolius, reacted strongly with BYMV antiserum,
and failed to react with antiserum to clover yellow vein virus. In a
BYMV-infected lupin crop, grain yields of individual
L. angustifolius plants infected early with the
non-necrotic strain were decreased by 95%. Shoot weights, seed number,
and seed size were also greatly decreased. Widespread occurrence of the
non-necrotic strain of BYMV is cause for concern for the lupin industry.
Responses of broilers to sodium bicarbonate supplementation of diets containing varying arginine : lysine ratios
Authors: Balnave D. , Brake J.
Published: November 2005

Interactions of sodium bicarbonate (NaHCO3) with dietary
arginine : lysine (arg : lys) ratios at thermoneutral (21˚C) and high
(31˚C) temperatures were investigated with 21–42-day-old broilers
fed diets containing increasing concentrations of arginine to produce arg :
lys ratios of 1.05, 1.15, 1.25, and 1.35, with and without 16 g
NaHCO3/kg. Consistent positive relationships were
observed between increasing dietary arg : lys ratios and improved food intake
and weight gain at 31˚C with broilers fed diets without NaHCO3. The
primary response to increasing dietary arg: lys ratio in broilers receiving
NaHCO3 was increased food intake. This gave
corresponding increases in weight gain at 31˚C, but not at 21˚C.
Increases in dietary arg : lys ratio increased plasma arginine, ornithine, and
arg: lys ratio but had little effect on plasma lysine concentrations.
NaHCO3 alone had no direct effect on plasma amino acid
patterns but was important in potentiating the elevated plasma arg : lys ratio
responses observed at 31˚C in broilers receiving
NaHCO3 in their diet. The results indicate important
interrelationships exist between dietary amino acids and electrolytes, and the
existence of a nutritional requirement for bicarbonate at high temperatures.
Glucosinolate profiles of Australian canola (Brassica napus annua L.) and Indian mustard (Brassica juncea L.) cultivars: implications for biofumigation
Authors: Kirkegaard J. A. , Sarwar M.
Published: November 2005

The glucosinolate (GSL) profiles in root, shoot, and seed tissues of 22
Australian canola (Brassica napus) and 15 Indian mustard
(Brassica juncea) entries were measured in the field.
The Indian mustard lines included 12 low seed GSL lines from a breeding
program aimed at producing canola-quality B. juncea
cultivars and 3 high seed GSL condiment cultivars. The aromatic glucosinolate,
2-phenylethyl GSL, was the major GSL found in the roots of both species
although Indian mustard also contained 2-propenyl GSL in the roots. The
concentration of glucosinolates in the roots varied from 5 to 35
µmol/g in B. napus, from 2.5 to 25
µmol/g in low seed GSL B. juncea, and from 10
to 21 µmol/g in high seed GSL B. juncea, but
was not correlated with seed glucosinolate concentrations in either species.
Breeding for low seed GSLs in Indian mustard reduced the concentration of
2-propenyl GSL in both root and shoot tissues, but levels of 2-phenylethyl GSL
in the roots were unaffected. The results indicate that high yielding and
agronomically adapted varieties of both species could be developed with higher
levels of root GSL for enhanced biofumigation potential without compromising
seed quality. The GSLs which liberate isothiocyanates on hydrolysis were found
primarily in the taproot and larger lateral roots (>2 mm) of both species,
whereas younger fine roots (<2 mm diameter) had higher levels of indolyl
GSLs. Correlations between root GSLs and susceptibility of brassicas to root
pests and pathogens will need to take account of these differences in GSL
profiles among different root classes.
Genetic improvement of early vigour in wheat
Authors: Rebetzke G. J. , Richards R. A.
Published: November 2005

Grain yield potential of Australian wheat crops is often limited because of
inadequate water for crop growth and grain filling. Greater early vigour,
defined here as the amount of leaf area produced early in the season, should
improve the water-use efficiency and yield of wheat crops grown in
Mediterranean-type climates such as occurs in southern Australia. In order to
maximise selection efficiency for early vigour in breeding programs, the
magnitude and form of genetic variation for early vigour and its components
was investigated for 2 contrasting wheat populations. The first population
comprised 28 Australian and overseas wheat varieties evaluated in a serial
sowing study in Canberra. The second population contained 50 random F
2:4 and F 2:6 families derived
from a convergent cross of elite CIMMYT wheat lines evaluated in Canberra, and
in the field at Condobolin, New South Wales.
For the first population, environmental effects on leaf breadth and length,
and to a lesser extent, phyllochron interval, produced significant
(P < 0.05) changes in leaf area. Large and
significant (P < 0.05) differences were observed
among Australian and overseas wheats for early vigour and its components.
Australian varieties were among the least vigorous of the lines tested, with a
number of overseas varieties producing about 75% greater leaf area than
representative Australian wheats. Increased leaf area was genetically
correlated with increases in leaf breadth and length, and a longer phyllochron
interval. Significant (P < 0.05) genotype ´
environment interaction reduced broad-sense heritability (%) for early
vigour (H ± s.e., 87 ± 26) compared with leaf breadth (96
± 25) and length (97 ± 27).
Narrow-sense heritability (%) in the second population was small for
leaf area (h2 ± s.e., 30 ± 6) and plant
biomass (35 ± 7), but high for leaf breadth (76 ± 14) and length
(67 ± 16). Genetic correlations were strong and positive for leaf area
with plant biomass, leaf breadth and length, specific leaf area and coleoptile
tiller frequency, whereas faster leaf and primary tiller production were
negatively correlated with leaf area. The high heritability for leaf breadth
coupled with its strong genetic correlation with leaf area
(rg = 0.56-0.57) indicated that selection for
leaf breadth should produce genetic gain in leaf area similar to selection for
leaf area per se. However, the ease with which leaf
breadth can be measured indicates that selection for this character either by
itself, or in combination with coleoptile tiller production, should provide a
rapid and non-destructive screening for early vigour in segregating wheat
populations. The availability of genetic variation for early vigour and
correlated traits should enable direct or indirect selection for greater leaf
area in segregating wheat populations.
Spray-topping annual grass pasture with glyphosate to delay loss of feeding value during summer. III. Quantitative basis of the alkane- based procedures for estimating diet selection and herbage intake by grazing sheep
Authors: Dove H. , Wood J. T. , Simpson R. J. , Leury B. J. , Ciavarella T. A. , Gatford K. L. , Siever-Kelly C.
Published: November 2005

Previous papers in this series have demonstrated that, when annual pastures
were sprayed at seed head emergence with low rates of the herbicide
glyphosate, the nutritive value of the sprayed herbage was improved. Housed
sheep preferred sprayed herbage to unsprayed herbage and, within sprayed
herbage, appeared to have a preference for stem material. The housed sheep ate
more of the sprayed material and their weight gains were improved. If such
responses occurred in grazing animals, they could result in substantial
improvements in animal liveweights or wool production. The present paper
describes the alkane-based procedures used to investigate diet selection and
herbage intake in grazing animals, with the emphasis placed on methodological
and statistical issues. The alkane concentrations in the plant fractions
(leaf, leaf sheath, stem, seed head) of sprayed and unsprayed herbage are
reported. Similarly, the alkane concentrations in extrusa samples collected by
oesophageally fistulated sheep given access to the grazed areas, and in the
faeces of sheep grazing the areas, are reported. Patterns of alkane
concentrations in extrusa and faeces were similar and indicated that, in the
short term, oesophageally fistulated animals consumed a diet of similar
composition to that selected by the animals resident on the plots. Using these
data for alkane concentrations, multivariate statistical analyses are
presented which provide an objective basis for selecting the alkanes to be
used in the estimation of diet selection. The results of the first of 4
grazing periods are presented, as an example of the application of the
alkane-based procedures for estimating herbage intake and, in particular, diet
composition. Use of these techniques indicated that, when given access to
sprayed senescent pasture, sheep consumed more digestible dry matter and
selected more of it from the stem fraction than was the case with unsprayed
herbage. These results are similar to those found with housed animals and
demonstrate that patterns of herbage and faecal alkane concentrations can be
used to estimate diet composition of grazing animals in terms of the plant
parts on offer
Spray-topping annual grass pasture with glyphosate to delay loss of feeding value during summer. IV. Diet composition, herbage intake, and performance in grazing sheep
Authors: Leury B. J. , Siever-Kelly C. , Simpson R. J. , Gatford K. L. , Dove H.
Published: November 2005

We report the effects of spray-topping annual grass pasture with glyphosate
(180 g a.i./ha as Roundup CT, at the seed head emergence stage) on the
nutritive value of herbage and on subsequent performance of grazing sheep.
Eight 1-ha plots, consisting of 4 sprayed and 4 unsprayed (control) plots,
were set-stocked with Merino wethers (18 months old, 12 sheep/ha) from 8
days after anthesis in the control plots (late spring) until 165 days after
anthesis (mid-autumn). In 4 periods (15–20, 36–41, 71–76,
and 99–104 days after anthesis; Periods 1–4, respectively) sheep
were dosed with synthetic alkanes and herbage and faecal samples were taken,
in order to estimate diet composition (in terms of plant parts), faecal
output, herbage intake, and the digestibility of the whole diet. As described
in our earlier papers, spray-topping reduced the yield of pasture dry matter,
but also slowed the loss of water-soluble carbohydrate (WSC) and digestibility
during pasture senescence. The present paper shows that as a result, sheep
grazing sprayed herbage in Periods 1 and 2 consumed significantly more organic
matter (OM) and digestible OM (DOM) than sheep grazing the control pasture.
Their diet contained a higher proportion of stem with a higher WSC
concentration than that of the sheep grazing the control plots. The
proportions of different plant parts (leaf blade+sheath, stem, seed head)
in the diet of both the plot sheep and oesophageally fistulated (OF) sheep,
which grazed treatments for short periods, differed significantly between
treatments in all periods. However, the compositions of the diets selected by
plot and OF sheep were similar. These results confirmed diet preferences
measured using housed sheep and demonstrate the usefulness of alkane-based
procedures for quantifying diet composition and intake in grazing animals. As
a result of their higher intake of DOM, sheep grazing sprayed herbage had a
significantly higher liveweight gain over the first 2 periods (40 g/day).
In Period 3, sheep grazing sprayed herbage consumed more OM than sheep grazing
control herbage. However, DOM intakes from sprayed or control plots were not
significantly different in either Period 3 or Period 4, and were lower than in
Periods 1 and 2. Sheep grazing both treatments lost liveweight at a similar
rate over this time. Wool growth in sheep grazing sprayed herbage was improved
by 10% during the experimental period; wool strength was also improved
significantly. The implications for the management of sheep grazing
spray-topped pastures over summer are discussed.
Gradients of pH, ammonium, and phosphorus between the fertiliser band and wheat roots
Authors: Zhang Xike , Rengel Zdenko
Published: November 2005

Di-ammonium phosphate (DAP) band application generally improves phosphorus (P)
fertiliser use efficiency but can cause ammonia toxicity to plants. We used
specially constructed pots to study P and ammonium
(NH4+) gradients between the DAP
band and plant roots grown in 2 soils. The pots were with or without a 30-mm
nylon mesh between the roots and the fertiliser band, and had a movable side
to enable sampling of soil layers at various distances from the fertiliser
band and/or plant roots. After 28 days, ammonia toxicity symptoms occurred
in plants grown in Lancelin soil in both mesh and no-mesh pots with the band
placed 1 cm from the seed. Smaller root and shoot dry weights and a shorter
root length were measured in both soils in no-mesh pots when the banding
distance from the seed was 1 cm compared with 2.5 cm. In contrast, no
differences in root and shoot dry weight occurred when direct contact between
the roots and the fertiliser band was prevented in mesh pots; however, roots
were shorter in mesh pots when fertiliser was banded 1 cm, compared with 2.5
cm, from the seed. The highest values for pH,
NH4+ concentration, and
bicarbonate-extractable P level occurred 4–5 cm from the seed in mesh
pots, and in the layer between the fertiliser band and the seed in no-mesh
pots. Phosphorus concentration in shoots was greater when plants were grown in
Lancelin than in New Norcia soil, and when grown in no-mesh compared with mesh
pots. In conclusion, large gradients of pH, ammonium, and
bicarbonate-extractable P existed around plant roots when DAP and ammonium
sulfate were banded in the vicinity of the seed. The frequently employed
practice of growing plants in mesh pots to characterise nutrient gradients in
soil close to roots, including the rhizosphere soil, results in plants with
altered growth and nutrient accumulation characteristics in comparison to
plants with no physical restriction for root growth within the pot.
Effects of superphosphate fertiliser and stocking rate on the nutritive value of perennial ryegrass and subterranean clover herbage
Authors: Saul G. R. , Kearney G. A. , Flinn P. C. , Lescun C. L.
Published: November 2005

The effect of superphosphate fertiliser on digestible dry matter (DDM) and
crude protein (CP) percentages of perennial ryegrass and subterranean clover
was assessed on a long-term, grazed experiment in western Victoria. CP of both
species increased significantly (3–6 units) where long-term average
phosphorus (P) applications were 33 kg/ha.year compared with 1
kg/ha.year. CP of herbage was also greater on paddocks grazed at higher
(9–23 ewes/ha) than lower (5–13 ewes/ha) stocking rates
(1–3 units). DDM of subterranean clover significantly increased
(8–10 units) with higher superphosphate applications but there was
little effect on the DDM of perennial ryegrass. Long-term applications of
superphosphate were associated with larger increases in both DDM and CP than
if the same rate was applied in autumn of the year of measurement. For
subterranean clover, 30 kg/ha of P applied to infertile soils (Olsen P 5
mg/kg) in autumn increased the DDM of herbage collected in September by
only 4–6 units. The nutritive value of most volunteer pasture species
also increased with higher superphosphate applications but the DDM of these
species was usually inferior to perennial ryegrass. The results highlight the
importance of monitoring nutritive value, pasture composition, and herbage
production to quantify fully the likely effect of fertiliser applications on
animal production.
Evaluation of white clover (Trifolium repens L.) populations for summer moisture stress adaptation in Australia
Authors: Jahufer M. Z. Z. , Cooper M. , Bray R. A. , Ayres J. F.
Published: November 2005

A genetic experiment was conducted using 80 full-sib families in irrigated and
dryland treatments under the summer moisture stress conditions of the Northern
Tablelands of New South Wales, over 3 years. This paper reports on the effects
of climatic and soil moisture conditions, the genetic variation for stolon
attributes and seasonal herbage yield, and the development of new recombinant
genotypes in relation to the association between stolon attributes and herbage
yield.
Large components of variance were estimated for
genotype-by-environment-by-year interactions for the attributes stolon
density, number of branches, number of nodes, number of rooted nodes, stolon
thickness, root diameter, internode length, and summer herbage yield. The
combined analysis of variance across environments and years indicated the
presence of genetic variation for the stolon attributes stolon density, number
of branches, number of nodes, stolon thickness, internode length, and herbage
yield.
Crossing of the morphologically contrasting cultivars El Lucero × Tahora
× Duron, and Barbian × El Lucero, resulted in generating genotypic
recombinants with new associations between herbage yield and stolon density,
number of branches, number of nodes, and number of rooted nodes. Evaluation of
the full-sib families and check cultivars (cvv. Haifa and Huia) identified 5
full-sib families with relatively higher herbage yield, stolon density, number
of branches, number of nodes, and number of rooted nodes than cultivars Haifa
and Huia.
Response of field-grown maize to applied magnesium in acidic soils in north-eastern Australia
Authors: Aitken R. L. , Dickson T. , Hailes K. J. , Moody P. W.
Published: November 2005

Split-plot field experiments, with main plots consisting of various rates of
calcitic lime and single rates of dolomite, gypsum, and calcium silicate, were
conducted at each of 4 sites to determine the effect of band-applied magnesium
(Mg) on maize yield. The sites were acidic with pH values of 4.5, 4.9, 5.0,
and 6.1 and exchangeable Mg levels of 0.16, 0.10, 6.0, and 2.0
cmol(+)/kg, respectively. Magnesium significantly
(P < 0.05) increased grain yield at the 2 low-Mg
sites, both of which were strongly acidic and responsive to lime application,
but the nature of the Mg × lime interaction was different at each of the
2 responsive sites. The absence of a response to Mg at lime rates ≥1
t/ha at one responsive site was attributed to the presence of small
amounts of Mg in the calcitic lime and/or an improved root environment
enabling better exploitation of the soil Mg. Supplying a readily soluble
source of Mg in the fertiliser band also resulted in increased grain yield in
the gypsum, dolomite, and calcium silicate treatments at the 2 Mg-responsive
sites.
When the initial soil pH was strongly acidic, exchangeable Mg levels increased
with increasing lime rate, suggesting that the small quantities of Mg that
occur in the majority of liming materials may be of importance with respect to
Mg nutrition. In contrast, gypsum application exacerbated the Mg deficiency at
one site.
The relationship between grain yield response and soil Mg level across all
sites indicated that above an exchangeable Mg level of 0.27
cmol(+)/kg there would be little likelihood of a response to applied
Mg.
Effect of genotype and environment on pod wall proportion in white lupin: consequences to seed yield
Authors: Lagunes-Espinoza L. C. , Huyghe C. , Papineau J. , Pacault D.
Published: November 2005

One means of increasing seed yield in white lupin may be the modification of
the harvest index in the reproductive compartment by a reduction of the
proportion of pod walls. Genetic and environmental effects on the pod wall
proportion and yield components were evaluated. Thirty-five genotypes of
spring-sown material were sown in 6 different locations across France in 1996
and 1997, accounting for a total of 10 site × year combinations. The
existence of a genetic variation for the pod wall proportion among studied
genotypes was demonstrated (0.26–0.34). Highly significant genotypic
differences for the pod wall proportion, seed number per pod, seed weight per
pod, mean seed weight, flowering time, and seed yield were observed among
lupin genotypes. The heritability of pod wall proportion was moderate, the
phenotypic correlation between this character and seed yield was significant
and negative, and the genetic correlation was high and negative. The
environmental variance contributed a major part of the total variation. The
genotype × environment effect for the pod wall proportion was small,
which suggests that the selection of genotypes with low and stable pod wall
proportion in different environments will be possible. The strong negative
genetic correlation between pod wall proportion and seed yield supports the
feasibility of using the character as a selection criterion for a higher seed
yield.
Soil receptivity and host - pathogen dynamics in soils naturally infested with Fusarium oxysporum f. sp. cubense, the cause of Panama disease in bananas
Authors: Pittaway P. A. , Pittaway P. A. , Nasir Nasril , Pegg K. G.
Published: November 2005

Disease severity associated with the pathogen
Fusarium oxysporum is generally thought to be
proportional to the population of fungal propagules in the soil. However,
results from studies using naturally infested soil are contradictory,
implicating host predisposition to disease. In this study, soil was amended
with chicken manure to investigate the interdependence between the activity
and invasiveness of the pathogen, and the incidence of Panama disease in
susceptible banana plantlets. Two soil types naturally infested with either
race 1 or race 4 of the pathogen, and cultivars Lady finger and Grande Naine,
were used. Pathogen activity was measured by burying root tip segments for 5
days, then calculating the frequency of isolation of
Fusarium from the segments. Pathogen invasion was
measured by transplanting banana plantlets into trays of amended and unamended
soil for 4 weeks, then calculating the frequency of recovery of
Fusarium from each pseudostem. Amending both soil types
with chicken manure enhanced both pathogen invasion and disease incidence.
However, pathogen activity was not correlated with either parameter. We
postulate that the addition of chicken manure is predisposing banana plantlets
to Panama disease, by reducing the efficacy of the host wound response.
The influence of type and timing of protein supplementation on wool growth and protein synthesis in the skin of young Merino sheep
Authors: Masters D. G. , Mata G. , Liu S. M.
Published: November 2005

There is limited evidence that the response in wool growth resulting from
feeding protected protein supplements continues after the feeding has stopped.
Feeding such proteins, alternated with traditional supplements, may increase
wool growth as much as continuous feeding but at a lower cost. This experiment
aimed to determine whether the response to protected protein continued after
the sheep were switched to a cereal supplement.
Over a 2-month experimental period, 56 weaners (5 months old, weighing 26 kg)
were used in a 2 × 2 factorial experiment. Half were fed a diet
containing 25% canola meal [partially protected protein with high
concentrations of sulfur amino acids (SAA)] mixed with oaten hay, urea,
and minerals. The other half were fed the same diet but with lupin seed
(highly degradable protein with low concentrations of SAA) replacing the
canola meal. Within each of the 2 dietary treatments and in each of 2 months,
half of the weaners were fed the diet continuously, the other half were fed
the diet for 2 weeks followed by 2 weeks of a barley, oats, hay, urea, and
minerals diet. Another group of 8 weaners was fed the oats–barley diet
continuously for 2 months. All sheep were fed to lose 35 g liveweight/day.
Weaners fed canola meal grew 11% more wool during the experiment and
had a higher rate of protein synthesis in the skin than weaners fed lupins.
The response to canola meal of wool and skin was the same whether feeding was
continuous or alternated with oats–barley, indicating that the benefits
from feeding partially protected proteins continues after feeding has stopped.
Corrigendum to: IGF-I is not a useful marker for nutritional status in the growing pig under commercial conditions
Authors: Ma L. , Dunshea F. R. , Brockwell Y. M. , Inglis R. L. , Kingston D. J. , Sillence M. N.
Published: November 2005

Plasma hormone concentrations were measured in gilts after fasting, long-term
protein restriction, or supplementation. In 11-week-old pigs fasted overnight,
plasma insulin, glucagon, gastrin, urea, and glucose were increased 30 min
after re-feeding (P < 0.05), whereas IGF-I did not
change. In 16-week-old gilts fed a standard commercial diet [14.6%
crude protein (CP)], or a high-protein diet (16.7% CP) for 4
weeks, the high-protein diet increased weight gain (13%;
P < 0.05) and carcass weight (4%;
P < 0.05), but did not alter plasma IGF-I, insulin,
or glucagon. In 10-week-old gilts fed high-protein diets (19.4% and
18.3% CP), or low-protein diets (15.5% and 13.3% CP) for
12 weeks during the grower and finisher phases, respectively, the low-protein
diet decreased weight gain (18%; P < 0.001)
and carcass weight (11%; P < 0.01), with a
marked increase in plasma glucagon (P < 0.05), no
change in insulin, and only a trend towards decreased IGF-I
(P = 0.1). The pigs were more sensitive to
altered dietary protein at 10 weeks of age than at 16 weeks. Plasma IGF-I was
not responsive to the short-term effects of feeding or the long-term effects
of dietary protein. Glucagon could provide a useful marker for nutritional
status in young pigs, provided that time of feeding is taken into account.
Corrigendum to: Phosphorus efficiencies and their effects on Zn, Cu, and Mn nutrition of different barley (Hordeum vulgare) cultivars grown in sand culture
Authors: Zhu Y.-G , Smith F. A. , Smith S. E.
Published: November 2005

A sand-culture experiment was carried out in a growth chamber to investigate
the phosphorus (P) efficiencies of 8 barley cultivars that are parents of 4
mapping populations, and the effects of P nutrition on plant uptake of zinc
(Zn), copper (Cu), and manganese (Mn). Two sources of phosphate were used,
rock phosphate (sparingly soluble) and CaHPO4 (readily
available). There were significant differences in P uptake and utilisation
efficiencies between the 8 cultivars. Among the cultivars, the
Sahara–Clipper pair is of the most interest, because these 2 cultivars
had large differences in root/shoot ratios, P allocation between root and
shoot, and P uptake/utilisation efficiencies. Higher P availability
significantly reduced plant Zn uptake and tissue concentrations in all
cultivars. Shoot Zn concentrations were found to decrease significantly with P
influx to the xylem (P < 0.01), indicating that
genotypic variations in P translocation from roots to shoots may interact with
Zn accumulation in shoots. Higher P availability reduced Cu concentrations in
shoots, probably due to a dilution effect. P availability (rock
phosphate v. CaHPO4) seemed to
affect plant uptake of Mn in some cultivars, but further study is needed to
elucidate the mechanisms involved and the practical implications of this
interaction in Mn-deficient soils.
Obtaining soil hydraulic properties for water balance and leaching models from survey data. 2. Hydraulic conductivity
Authors: Smettem K. R. J. , Bristow K. L.
Published: November 2005

Regional scale application of water and solute transport models is often
limited by the lack of available data describing soil hydraulic properties and
their variability. Direct measurement over large areas is expensive and time
consuming. Physico-empirical models derived from soil survey data are
therefore an attractive alternative. If the Marshall method of estimating the
saturated hydraulic conductivity is simplified to depend primarily on the
maximum pore radius, given by the bubbling pressure, then it is equivalent to
the Campbell model of saturated hydraulic conductivity which relies entirely
on an estimate of the bubbling pressure obtained from particle size data. We
apply this simplified physico-empirical model to estimate the
‘matrix’, or textural saturated hydraulic conductivity, K
m, using estimates of the bubbling pressure derived
entirely from clay content data that are readily available in soil surveys.
Model estimates are compared with in situ measurements
on surface soils obtained using a disc permeameter with a negative pressure
head at the supply surface of 40 mm. Results appear to be satisfactory for
broad-scale water balance and leaching risk models that require specification
of a matching point for the unsaturated hydraulic conductivity function and
for modelling applications requiring generalised application of results from
experimental sites.
Yield and components of seed yield of indeterminate narrow-leafed lupin (Lupinus angustifolius L.) subjected to transient water deficit
Authors: Palta J. A. , Plaut Z.
Published: November 2005

The effect of transient water deficits on seed yield and components of seed
yield of narrow-leafed lupin was measured in plants grown in a controlled
environment under simulated field conditions. Lupins were grown in large
columns of soil and transient water deficits were induced at pod set on the
mainstem and first-order apical branches by withholding water for a 5-day
period. Soil water content, leaf water potential, turgor pressure, and leaf
conductance declined similarly during each period of transient water deficit.
Differences in these parameters were apparent 2 days after water was withheld,
and over the 5-day period, leaf water potential declined to −1.3 MPa and
leaf conductance fell to 44% of the well-watered controls. Total dry
matter per plant was reduced by the transient water deficit treatments. The
reduction resulted from less accumulation of dry matter on the first, second,
and third order apical branches. Leaf area on these branches was also reduced
by abscission of the leaves after the water deficit was released. Seed yield
per plant after each period of transient water deficit was reduced by
30–33%, relative to the well-watered controls. The reduction was
largely due to a reduction in seed yield on the branches, mainly because they
had fewer pods and seeds per pod. Seed dry weight and harvest index were not
significantly affected by each period of transient water deficit. We conclude
that differences in final seed yield between the well- watered controls and
the transient water deficit treatments resulted from differences in pod number
and seeds per pod. Low dry matter accumulation and reduction in leaf area on
the first- and second-order apical branches under the transient water deficit
were associated with the differences. Whereas the differences in pod number
generated differences in the size of the reproductive sink, the differences in
leaf area generated differences in the source capacity for assimilates for pod
set and pod-filling.
The current and future role of near infrared reflectance spectroscopy in animal nutrition: a review
Authors: Givens D. I. , Deaville E. R.
Published: November 2005

This paper aims to present an overview of the research into and application of
near infrared reflectance spectroscopy (NIRS) in relation to animal nutrition
over the last decade or so. Emphasis is placed on the developments in the
characterisation of forages, although aspects of non-forage feeds are also
considered. The changing remit of animal nutrition in relation to human food
production and the environment is placing increasing requirements on feed
characterisation to be more physiologically meaningful. How NIRS might meet
this challenge is discussed, as is the potential of NIRS for feed
identification and authentication.
Effect of grazing intensity and cultivar on morphology, phenology, and nutritive value of subterranean clover. 1. Morphology and phenology of subterranean clover during the growing season
Authors: Ru Y. J. , Fortune J. A.
Published: November 2005

The effect of grazing intensity and cultivar on plant morphology was examined
with 26 cultivars of subterranean clover during the growing season. The
cultivars were grown in 3 groups (early, mid, and late) according to their
flowering time and grazed under 2 grazing intensities (heavy and light) at a
2-weekly interval.
Heavy grazing delayed flowering time by only about 2 days for early and late
maturity cultivars without influencing flowering duration. Late and mid
maturity cultivars had more (P< 0.05) branches,
petioles, and leaves with shorter branches under heavy grazing than under
light grazing, whereas early maturity cultivars did not show any significant
differences in the numbers of plant parts under the 2 grazing intensities. The
effect of grazing intensity on the proportions of plant parts was small over
all cultivars, indicated by a 2 percentage unit increase in the proportions of
leaf in September, burr in October, and stem in November by heavy grazing.
There was a large cultivar variation in flowering duration, and the numbers,
lengths, and proportions of plant parts. The ranges of flowering duration were
24–66, 26–66, and 31–76 days and of branch length after
cessation of flowering were 12–20, 6–14, and 5–14 cm for the
early, mid, and late maturity groups, respectively. The late maturity group
had more branches, leaves, petioles, and stems, and the early maturity group
had less with the mid maturity group being intermediate. The variation in the
proportions of plant parts among cultivars was not related to flowering time
or flowering duration.
Genotype by environment interaction for grain yield and carbon isotope discrimination of barley in Mediterranean Spain
Authors: Voltas J. , Romagosa I. , Lafarga A. , Armesto A. P. , Sombrero A. , Araus J. L.
Published: November 2005

Carbon isotope discrimination (Δ) has been found to be either positively
or negatively related to grain yield of small grain cereals when grown in
contrasting environments. In order to clarify a possible association between
grain yield of barley (Hordeum vulgare L.) and Δ
of mature kernels, five 6-rowed and five 2-rowed barley cultivars were
evaluated in 22 rainfed environments of northern Mediterranean Spain. Analyses
of variance suggested that the genotypic Δ values were more consistent
across environments than the genotypic yields. Genotype×environment
(G×E) interaction for grain yield was further explored by fitting an
AMMI (additive main effects and multiplicative interaction) model. The first 2
multiplicative axes were found significant. The AMMI2 model provided more
accurate estimates of genotypic yields within environments than the
conventional unadjusted means across replicates. AMMI2 estimates were used for
input into cluster analysis, grouping environments that ranked genotypic
yields similarly. Three major groups were obtained, with average yields of
2.42 t/ha (cluster I), 3.06 t/ha (cluster II), and 5.16 t/ha
(cluster III). The genotypic ranking for Δ did not vary substantially
across clusters, but it changed for grain yield. The average genotypic yields
in the low-yielding cluster I ranked opposite to those in the high-yielding
cluster III, suggesting the existence of a crossover point at an intermediate
yield level. The association between grain yield and Δ for genotypic
means within clusters was variable. In cluster I, yield and Δ tended to
be negatively related, whereas they were positively related in clusters II and
III. Genotypes with lower Δ, i.e. with higher transpiration efficiency,
performed better in low-yielding environments (mostly those grouped in cluster
I). On the contrary, a high genotypic Δ was of advantage in medium
(cluster II) and high-yielding environments (cluster III). This observation
supports the assumption that drought tolerance and high yield potential under
non-limiting growing conditions may be antagonistic concepts in barley.
Genotypic means for kernel number per m 2 and Δ
were consistently and positively related within clusters, suggesting that a
constitutively high Δ may have been driven by a large genotypic
reproductive sink. The convenience of using Δ as a selection criterion
in areas exhibiting a considerable G×E interaction for grain yield is
discussed.