bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthetic Approaches to the Angucycline Antibiotics. A Route to C-Glycosidic Benz[a]anthraquinones
Authors: Andrews Fleur L. , Larsen David S. , Larsen Lesley
Published: September 2002

3-Deoxy-6′-hydroxy-13-norurdamycinone B (32a) and
3-deoxy-13-norurdamycinone B (32b) have been synthesized in eight steps from
5,8-dimethoxynaphthalen-1-ol (9) both in 28% overall yield. The key
step in this approach is the boron trifluoride diethyl etherate promoted
β-C-glycosylations of (9) and
1,3,4,6-tetra-O-acetyl-2-deoxy- and
1,3,4-tri-O-acetyl-2-deoxy-D-arabino-hexopyranoses
(13) and (19). The solvent, acetonitrile, was essential for the success of
these reactions. Acetylation of the
C-glycosyl-5,8-dimethoxynaphthalen-1-ols (16) and (20)
followed by oxidation with ceric ammonium nitrate gave
C-glycosyl-5-acetoxy-1,4-naphthoquinone derivatives (21)
and (23) in 63 and 49% overall yields from (9). Selective deacetylation
of the C 5 acetoxy groups of (21) and (23) was achieved by treatment with
boron trifluoride etherate in dichloromethane to give
3,4,6-tri-O-acetyl- 2-deoxy- and
3,4-di-O-acetyl-2,6-dideoxy-β-D-arabino-hexopyranosyl-5-hydroxy-1,4-naphthoquinones
(24) and (25) respectively. The tetra-O-acetyl diborate
promoted Diels–Alder reactions of (24) and (25) with
(±)-(E)-1-acetoxy-3-(2-methoxyvinyl)cyclohex-2-ene
(8) each gave a 1 : 1 mixture of diastereoisomeric cycloadducts which, upon
treatment with 1,8-diazabicyclo[5.4.0]undec-7-ene gave
(1R*)-1-acetoxy-9-(3,4,6-tri-O-acetyl-2-deoxy-β-D-arabino-hexopyranosyl)-
and
(1R*)-1-acetoxy-9-(3,4-di-O-acetyl-2,6-dideoxy-β-D-arabino-hexopyranosyl)-8-hydroxy-1,2,3,4-tetrahydrobenz[a]anthracene-7,12-dione
(30a) and (30b) respectively. Sequential deacetylation and photochemical
oxidation of (30a) and (30b) gave the targets (32a) and (32b) respectively.
Modified Linearized Poisson-Boltzmann Theory. Dynamic and Thermodynamic Properties of 1 : 1 Electrolytes
Authors: Kaya Tuncer
Published: September 2002

Theoretical electrolyte conductivity and osmotic and activity coefficient
relationships that work well over a large range of concentrations, up to 1 mol
l–1, are derived from a hypothetical modified
linearized Poisson–Boltzmann distribution function. The distribution
function is expressed in terms of modified Debye parameter κ and
normalization constant α. Both of these parameters are evaluated in
terms of concentration and ion-size parameter, d, by the
help of moment conditions. The modified Debye parameter κ is also
expressed as a function of the usual Debye parameter
κD. Also considered is the short-range part of the
pair potential crucial to obtain at least qualitative agreement with
experimental results of electrolytic solutions, and it is assumed that the
short-range part of the potential is discontinuous at ion-size parameter
Formal Synthesis of Both Atropomers of Desertorin C and an Example of Chirality Transfer from a Biphenyl Axis to a Spiro Centre and its Reverse
Authors: Baker Robert W. , Kyasnoor Rekha V. , Sargent Melvyn V. , Skelton Brian W. , White Allan H.
Published: September 2002

In connection with the synthesis of
4,4′,7,7′-tetramethoxy-5,5′-dimethyl-6,8′-bicoumarin
(desertorin C) (11) in enantiopure form, the diastereomeric ratios of the
products of the reactions between 2-isopropyloxy-6-methoxy-4-
methylphenylmagnesium bromide (24) and
(4S)-4-isopropyl-2-(2,3,5-trimethoxyphenyl)-4,5-dihydrooxazole
(23), between 2,4-dimethoxy-6-methylphenylmagnesium bromide (37) and
(4S)-4-isopropyl-2-(2,3-dimethoxy-5-methylphenyl)-4,5-dihydrooxazole
(36), and between
2,4-dimethoxy-6-(t-butyldimethylsilyloxy)methyl-phenylmagnesium bromide (46)
and the oxazole (36) were explored. The major product of the last mentioned
reaction was converted into
(S,4S)-4-isopropyl-2-(2′-hydroxymethyl-4′,6,6′-trimethoxy-4-methyl-1,1′-biphenyl-6-yl)-4,5-dihydroxazole
(49), the axial configuration of which was confirmed by single crystal X-ray
structural determination. The similar product
(S,4S)-2-(2′,4′,6-trimethoxy-4,6′-dimethyl-1,1′-biphenyl-6-yl)-4,5-dihydrooxazole
(43) was converted into
(S)-1-(2,4′,6′-trimethoxy-4,6′-biphenyl-2-yl)ethanone
(57) which furnished
(S)-1-(2′,4′,6-trimethoxy-4,6′-dimethyl-1,1′-biphenyl-2-yl)acetamide
(58) (43%) and
(S)-2,7′-dimethoxy-3′,5′,6-trimethylspiro[cyclohexa-2,5-diene-1,1′-(1H)isoindole]-4-one
(61) (30%) on Schmidt rearrangement. The dienone (61) on reduction and
methylation regenerated the ketone (57). The methodology of Lipschutz was
adapted for the synthesis of both enantiomers of
1,1′-(2′,4-dihydroxy-6,6′-dimethoxy-2,4′-dimethylbiphenyl-3,3′-diyl)bisethanone
(32) and (83) which constitutes a formal synthesis of both enantiomers of
desertorin C.
A Unique Toxic Peptide from the Larvae of the South American Sawfly, Perreyia flavipes.
Authors: MacLeod John K. , Braybrook Carl , Simmonds Peta M. , Oelrichs Peter B.
Published: September 2002

A major toxic component of the South American sawfly larvae,
Perreyia flavipes (Pergidae), has been shown to be a
heptapeptide with the structure (1). The unique features of this peptide,
which has been named pergidin, are the presence of five unnatural D amino
acids and a phosphoseryl residue.
5-Deoxy, 12-Deoxy, 5,12-Bisdeoxy, and 4,5,12-Trisdeoxy Anthracyclines: Synthesis of New Analogues of Daunorubicin and Doxorubicin by Controlled Deoxygenation of the C-Ring.
Authors: Cameron Donald W. , Feutrill Geoffrey I. , Griffiths Peter G.
Published: September 2002

Hydrogenation of the anthracyclines daunorubicin (1) and doxorubicin (2) gave
selective deoxygenation at position 5. Hydride reduction of (1) and (2) gave
complementary regiocontrol, leading to 12-deoxygenation or 5,12-
bisdeoxygenation. This chemistry allows retention of the 7-glycoside and the
side-chain carbonyl groups. It has led to new anthracycline families
possessing all of the stereochemical and most of the spatial characteristics
of the parent compounds (1) and (2). These are typified by 5-deoxy (12), (15);
12-deoxy (22), (23); 5,12-bisdeoxy (34), (35); and 4,5,12-trisdeoxy systems
(36). All possess high anticancer activity.
Fragmentation Reactions of All 64 Deprotonated Trinucleotide and 16 Mixed Base Tetranucleotide Anions via Tandem Mass Spectrometry in an Ion Trap.
Authors: Vrkic Ana K. , O'Hair Richard A. J. , Foote Simon
Published: September 2002

The gas-phase fragmentation reactions of the
[M–H]– ions derived from all 64
trinucleotides and 16 isomeric tetranucleotides each containing adenine,
thymine, guanine and cytosine were examined using multistage mass spectrometry
(MS/MS and MS3) collision-induced dissociation in an
ion trap mass spectrometer. The initial fragmentation pathway involved neutral
base loss predominantly from the 5´ terminus, along with minor 3´
and internal base loss in the order A > T > G > C to form
[M–H–BH]–
‘non-sequence’ ions. The resultant
[M–H–BH]– ions often
fragment via intramolecular proton transfer with concomitant cleavage of the
3´ C–O phosphodiester bond to yield an ion–molecule complex,
which undergoes either direct dissociation or proton transfer to yield the
w-type or (a–B)-type ‘sequence’ ions respectively.
Isomorphous Lanthanide Complexes of a Tripodal N4O3 Ligand
Authors: Bernhardt Paul V. , Flanagan Bernadine M. , Riley Mark J.
Published: September 2002

The heptadentate ligand
2,2¢,2¢¢-tris(salicylideneimino)triethylamine
(H3trensal) has been complexed with the lanthanides Sm
III , Eu III , Tb
III and Er III . The resulting
[Ln(trensal)] complexes are isomorphous. We demonstrate that the
method of preparation of these complexes is important in ensuring structural
homogeneity across the Ln III series.
Relationships between kernel oil content, fruit removal force and abscission in macadamia.
Authors: Trueman S. J. , Richards S. , McConchie C. A. , Turnbull C. G. N.
Published: September 2002

Delayed or extended fruit abscission in many cultivars of macadamia,
Macadamia integrifolia (Proteaceae), necessitates
multiple harvests from the orchard floor. However, it is not known whether
there is a link between fruit maturation and timing of abscission. In this
study, relationships between kernel oil content, nut size, removal force and
abscission were investigated in 2 commercial orchards, one in Queensland
(24˚S) and one in New South Wales (29˚S). Abscission lasted 6 months
(March–September) at both sites due to differences in timing of
abscission between cultivars and extended abscission within cultivars.
Abscission was consistently associated with declines in fruit removal force,
from more than 2 kgf in early March towards 1 kgf at the peak of abscission.
Later abscission in cvv. A16 and 246, compared with cvv. 344 and 741, was
correlated with more gradual declines in removal force. Fruits containing
small nuts and kernels tended to possess lower removal forces and these fruits
were often heavily represented in the population of fruits that abscised
earliest. There was little or no difference in kernel oil content between
fruits of different removal force or between sample dates for any cultivar,
either for samples taken from the tree or from the orchard floor. Attainment
of maximal oil content and onset of fruit abscission are therefore independent
processes in macadamia. If abscission can be accelerated, it may be possible
to advance the harvest of late-abscising cultivars such as A16 and 246 which
retain mature nuts on the tree up to several months after maximal oil
accumulation.
Environmental effects on the fatty acid composition of subcutaneous beef fat
Authors: Kelly M. J. , Tume R. K. , Newman S. A. , Thompson J. M.
Published: September 2002

This paper describes the effect of location and level of nutrition before
finishing on the fatty acid composition of subcutaneous beef fat. Interactions
between location and nutritional treatments, finishing regime and market
category were also examined. The effect of level of nutrition on the fatty
acid composition of beef fat during the period from weaning until feedlot
entry was small but significant. The lowest level of nutrition had the highest
percentage of C18:0 at slaughter, which was offset by reductions in C16:0 in
cohort 93-1 and C18:1c9 in cohort 94-2. Location had a large effect on the
fatty acid composition of subcutaneous beef fat. At a common slaughter weight,
cattle grown in a tropical environment were older, fatter and had higher
percentages of saturated fats, including C16:0 and C18:0, than cattle grown
out in a temperate environment.
Nutritional and developmental effects on the intrinsic properties of muscles as they relate to the eating quality of beef
Authors: Oddy V. H. , Harper G. S. , Greenwood P. L. , McDonagh M. B.
Published: September 2002

The intrinsic properties (those extant at the time of slaughter) of bovine
skeletal muscle as they relate to the subsequent quality attributes of beef
are reviewed here. Attributes of bovine skeletal muscle that ultimately affect
toughness, colour, fat content, flavour, juiciness, and nutritive value of
beef are discussed. The dynamic nature of muscle development, particularly
with regard to structure and composition, is highlighted. Variation in
development of muscle structure and composition due to inherited (genetic)
factors and environment (particularly nutrient supply) are described. Examples
are given of the implications of sources of variation due to animal genotype,
age, nutrient supply, and hormonal environment on muscle cellularity and
growth, fibre type, connective tissue composition and structure as they affect
meat quality attributes.
Key intrinsic properties of muscle include muscle type, cellularity, size,
myofibre type, connective tissue composition and structure, glycogen and fat
content and proteolytic activity. Activity of the calpain system at slaughter
is seen as an important attribute. Regulation of myofibrillar and connective
tissue proteolysis in vivo are discussed together with
implications for subsequent meat quality. Amongst the on-farm environmental
factors, nutritional history and developmental pathway are identified as
factors that can be responsible for significant variation in the intrinsic
properties of muscle that contribute to variation in toughness, colour and fat
content, and thus consumer liking of beef.
Aluminium tolerance and lime increase wheat yield on the acidic soils of central and southern New South Wales
Authors: Scott B. J. , Fisher J. A. , Cullis B. R.
Published: September 2002

Acidic soils constrain wheat yield in some parts of central and southern New
South Wales. This paper describes research designed to evaluate the usefulness
of aluminium (Al) tolerance, manganese (Mn) tolerance and the interaction of
lime use and Al tolerance in improving wheat yields.
Closely related pairs of wheat lines with tolerance and sensitivity of Al and
Mn were bred. Carazinho (a Brazilian wheat cultivar) was used as a source of
Al tolerance in a backcrossing, recurrent selection program to introduce
tolerance into an Egret background (a locally adapted Australian cultivar).
Aluminium tolerance was determined using the haematoxylin root tip test and Mn
tolerance was determined using a subirrigated gravel bed system. Eight pairs
divergent in tolerance of Al were evaluated for their yield on 3 acidic soil
types in 5 field experiments. Grain yield increased in Egret-derived lines
when Al tolerance from Carazinho was introduced. Yield from the Al-sensitive
genotypes (averaged over the 8 pairs) compared with the Al-tolerant genotypes
was 0.43 to 0.98 t/ha and 0.88 to 1.38 t/ha respectively on an acid
earthy sand in central western New South Wales (Binnaway) in 2 seasons, and
1.08 to 1.96 t/ha and 1.29 to 1.88 t/ha on an acid podsolic soil in
southern New South Wales (Borambola).
On a moderately acidic red earth site (pH Ca 4.8) at
Wagga Wagga, no such advantage accrued to the Al-tolerant group with the
average yield for the sensitive and tolerant pairs being 5.00 and 4.78
t/ha, respectively. Manganese tolerance was assessed in only 1 of these
experiments (Borambola) using 6 pairs of lines tolerant of Al but with
contrasting Mn tolerance. No advantage of Mn tolerance was apparent at this
site.
At Binnaway the tolerant and sensitive lines responded to lime application
with the tolerant lines yielding on average about 0.42 t/ha of grain more
than the sensitive lines even when 5 t/ha of lime was applied. At
Borambola the tolerant lines yielded 0.59 t/ha of grain more than the
sensitive lines when no lime was applied. With lime application this
difference in performance disappeared and Al-tolerant and sensitive lines
yielded equally. At the Wagga Wagga site, the addition of lime did not affect
the yield of the sensitive lines, while the tolerant lines showed a yield
depression of 0.32 t/ha of grain with lime application.
Three different relationships between lime application and Al tolerance were
observed. While 2 relationships fit with our previous understanding, grain
yield depression resulting from the combined use of Al tolerance and lime at
our least acidic site remains poorly understood.
Comparison of four phalaris cultivars under grazing: drought survival and subsequent performance under rotational grazing versus set stocking
Authors: Culvenor R. A.
Published: September 2002

Four cultivars of phalaris were evaluated for their ability to survive a
severe drought in 1994 in an existing grazing experiment at 2 sites near
Canberra. The effect of rotational grazing and set stocking on persistence of
phalaris measured as basal cover, pasture composition in spring and animal
production from the pastures was assessed over the next 4 years.
Basal cover of all cultivars declined sharply in 1994, but had recovered by
August 1995 at a site with a relatively deep soil profile. Recovery was slower
at a site with a shallower soil profile. Sirosa declined more in basal cover
than Holdfast and Australian at the latter site. All of the cultivars survived
the drought well but Sirosa may be more sensitive to overgrazing in drought.
Compared with set stocking, rotationally grazed pastures had a higher
(P<0.001) proportion of phalaris for all cultivars 2
years after management treatments began, and a higher
(P<0.005) basal cover for 2 winter-active cultivars
after 3 years. Overall, a divergent effect of grazing management on basal
cover (management × year interaction) could only be demonstrated at
P = 0.08 because of a large effect of site
variation for another winter-active cultivar, Sirosa. Phalaris basal cover did
not decline with set stocking and it was concluded that rotational grazing was
beneficial, but not crucial, for the persistence of winter-active phalaris
cultivars in this environment. Site factors and their manipulation by
management were also important for the persistence of phalaris.
A review of the persistence of phalaris over the entire 9 years of the grazing
experiment concluded that all cultivars displayed good persistence under
conditions of reasonable soil fertility. The importance of good establishment
for a high presence of phalaris in later years was emphasised.
An evaluation of a no-tillage, unfertilised, direct-sown, wheat - rice cropping system in Korea
Authors: Cho Y. S. , Lee B. Z. , Choe Z. R. , Ockerby S. E.
Published: September 2002

A no-tillage, direct-sown, unfertilised, wheat–rice relaying cropping
system has major advantages over a conventional transplanted-rice system. For
example, when rice is sown simultaneously with the wheat harvest, there are
savings in labor and costs as a result of eliminating the tillage required to
prepare the seedbed and for transplanting. A field experiment was conducted
between 1996 and 1998 at Hadong, Korea. The experiment compared the soil
microbial-N status, the soil physical and chemical characteristics, and rice
growth and yield in a long-term conventional rice system with those in a
no-tillage, unfertilised, direct-sown, wheat–rice, relay cropping
system. The wheat–rice system was imposed for 2, 4 and 7 years to
identify the time course of responses in the soil and crop. Agricultural
chemicals including fertilisers were not applied in the wheat–rice
cropping system. Rice crop yields after 2, 4 and 7 years of a direct-sown,
wheat–rice cropping system were similar to those in the conventional
rice system. Rice yields were high, ranging from 4.7 to 6.9 t/ha. Since
110 kg N/ha was applied to the conventional rice system, a large amount of
N was mineralised during the wheat–rice system. The pattern of rice
growth and yield formation, however, differed between the 2 systems. Rice in
the wheat–rice system generally had more panicles, fewer spikelets per
panicle and heavier grains. These responses reflected temporal changes in the
N content and greenness of the rice leaf and were related to soluble N levels
in the soil. Generally the soil was fertile with a high initial organic matter
content. Organic matter increased by 30% during the 7 years of
wheat–rice cropping. Other soil physical measures, bulk density and
permeability to air and water, indicated that soil structure improved in
response to wheat–rice cropping. Problems of pathogens and perennial
weeds associated with new cultural practices in the wheat–rice cropping
were minor; however, a higher rate of seeding was necessary to achieve
satisfactory seedling establishment. Benefits to weed control and soil
moisture conditions during crop establishment were derived from the increased
level of crop mulch. The wheat–rice cropping system was found to be high
yielding and sustainable over the 7-year period of experimentation.
Consumer sensory requirements for beef and their implications for the Australian beef industry
Authors: Egan A. F. , Ferguson D. M. , Thompson J. M.
Published: September 2002

Consumer sensory requirements for beef vary as a function of the market in
which the product is being sold and, within any market, they can vary also
over time. These conclusions are demonstrated using the Australian domestic
and Japanese export markets as examples. In Australian studies, consumers
buying meat for home consumption place more emphasis on leanness than do food
service operators, with whom marbling rates more highly. Both household
consumers and food service operators rate tenderness as the most important
attribute of eating quality for cooked beef. This is followed by flavour. In a
restaurant situation, marbled steaks (AUSMEAT score 2–3) have a higher
acceptability than for home consumption. In the Japanese market,
consumer-purchasing criteria are somewhat more sophisticated but tenderness is
again the most important attribute of eating quality. This is perhaps
surprising, considering the traditional cultural differences. It suggests that
intrinsic factors in the consumer requirements for of beef may be similar
worldwide.
Effect of sowing date on the severity of ascochyta blight in field peas (Pisum sativum L.) grown in the Wimmera region of Victoria
Authors: Bretag T. W. , Keane P. J. , Price T. V.
Published: September 2002

Field experiments were established at Horsham, in the Wimmera region ofVictoria, in 1987, 1988 and 1989 to compare the severity of ascochyta blightand grain yield of field peas sown in May, June and July. In each year, theseverity of ascochyta blight on all the pea cultivars studied was greatest onthe May-sown plots and least severe on the July-sown plots. The level of seedinfestation by ascochyta blight fungi was also highest in grain harvested fromthe plots sown earliest. In 1987, the average length of lesions girdling themain stem was 28.7 cm in the May-sown plots and 1.0 cm in the July-sown plots.In 1988, the average percentage of stem area affected by ascochyta ranged from 60.2% in the May-sown plots to 13.1% in the July-sown plots,while in 1989 the range was from 38.3% in the May-sown plots to5.8% in the July-sown plots. In 1988, delaying sowing until Julyresulted in a significant reduction in disease with only a small reduction inyield. However, in 1989 while July sowing reduced the severity of disease by 17%, compared to a June sowing, the later sowing also reduced grainyields by 40%.In a separate trial at Horsham in 1988, using cv. Buckley, disease progresswas most rapid on the April-sown plots and slowest on the August-sown plots.The final disease levels ranged from 100% of stem area affected (Aprilsowing) to 2% of stem area affected (August sowing). The yield lossescaused by the disease were greater the earlier the plots were sown.These studies suggest that the severity of disease in commercial crops may bereduced by delaying sowing until after mid-June, thus avoiding exposure ofyoung plants to high levels of primary inoculum.
Responses of subterranean clover and Italian ryegrass to application of lime
Authors: Bolland M. D. A. , Rengel Z. , Paszkudzka-Baizert L. , Osborne L. D.
Published: September 2002

A glasshouse experiment evaluated dried herbage yield responses of dense
swards of subterranean clover (Trifolium subterraneum
cv. Trikkala) or Italian ryegrass (Lolium multiflorum
cv. Aristocrat) to applications of different amounts of lime (0, 2.5, 5.0,
7.5, 10 and 12.5 t lime/ha) to either a loam or a sand. Yields were
measured at 4 harvests [29, 51, 86 and 108 days after sowing (DAS)]
when ryegrass plants had 3 leaves per tiller.
Increasing amounts of lime raised the pH (1: 5, soil: 0.01 mol
CaCl2/L) of the loam by 2.7 units and that of the
sand by 2.0 units. Applications of lime significantly
(P<0.05) increased dry herbage yields, by between 16
and 53%, for: (i) clover on the loam soil at 86 and 108 DAS, and for
the sand at 108 DAS; (ii) ryegrass on the loam at 51, 86 and 108 DAS, and on
the sand at 108 DAS. Increasing amounts of lime had no effect on the
concentration of nutrient elements in dried herbage of either clover or
ryegrass, except that the concentration of calcium increased, and the
concentration of sodium, manganese and zinc (and boron for ryegrass only) all
decreased. Additions of lime had no effect on dry matter digestibility,
metabolisable energy, concentration of crude protein or water-soluble
carbohydrates in dried herbage at any of the 4 harvests.
Irrigating perennial pasture with saline water: effects on soil chemistry, pasture production and composition
Authors: Rogers M. E.
Published: September 2002

In response to a local survey that revealed that many farmers in the Goulburn
Valley region of Victoria did not adhere to recommendations for safely
applying saline irrigation water to perennial pasture, an experiment was
conducted at Tatura. Six irrigation water quality treatments, which differed
in the timing of the application of saline water, were applied to perennial
pasture plots over 4 irrigation seasons. Measurements made included soil
EC1:5, soil SAR1:5, soil ESP,
pasture dry matter production and composition, dry matter digestibility,
tissue ion concentrations and mineral ash content. After 4 seasons, in which
the winter rainfall for each season was significantly lower than the long-term
average, soil sodicity and salinity levels appeared to reach steady values.
Plots irrigated with non-saline water (0.1 dS/m, treatment 1) performed the
best in terms of lower soil salinity and sodicity levels and higher dry matter
production and pasture quality levels. However, for most of these measurements
and for most seasons, there were no significant differences between the
control plots and those irrigated with water at 1.2 dS/m (treatment 2). Soil
EC1:5 and SAR1:5 levels were
highest, and dry matter production and dry matter digestibility levels the
lowest (particularly for the clover component), in plots irrigated with water
at 2.4 dS/m throughout the season (treatment 6). There were no significant
differences in soil characteristics or biomass production between the
remaining 3 treatments (treatments 3, 4 and 5) or between treatment 2. These
treatments had the same amount of salt applied throughout the season but
differed in the pattern of salt application — whether it occurred at the
beginning or end of the season, or was alternated with fresh water throughout
the season.
This study confirmed that in the long term, there is a reduction in the yield
of perennial pastures when saline irrigation water at levels greater than
0.8–1.2 dS/m is used on the red-brown earths of the Shepparton
Irrigation Region. However, the soil and pasture were more sensitive to the
total amount of salt applied rather than to the pattern of salt application
throughout the season. It was concluded that farmers should monitor the
salinity levels of their irrigation water to avoid a build up of
Na+ and Cl– in the soil
profile and consequent long-term reductions in herbage production and quality.
Relationships between darkening of dried apricots and nutrient concentrations in fresh fruit and mid-shoot leaves
Authors: Rettke M. A. , Maier N. A. , Dahlenburg A. P. , Partington D. L.
Published: September 2002

Relationships between darkening of dried apricots in storage and nutrient
concentrations in mid-shoot leaves and fresh fruit collected at harvest were
studied. Commercial orchards were sampled for 3 growing seasons throughout the
irrigation districts of Berri, Loxton and Renmark in South Australia.
Darkening of dried apricots was assessed as the time taken for the optical
absorbance of 50% ethanolic extracts of the dried fruit to reach 0.3,
hereafter referred to as weeks to OD 0.3. Linear or quadratic relationships
were found between weeks to OD 0.3 and (i) nitrogen, calcium, magnesium,
sodium, chloride, sulfur, boron and copper concentrations in both leaves and
fresh fruit; (ii) potassium and iron concentrations in leaves; and (iii)
phosphorus and manganese concentrations infresh fruit. However, for nutrients
other than nitrogen, relationships were not found consistently in each of the
3 growing seasons. Further, although statistically significant, the
relationships were of little predictive value, with coefficients of
determination (r 2 ) as low as
0.03. Coefficients of determination for the relationships between weeks to OD
0.3 and nitrogen concentrations in fresh fruit, were 0.73 in 1992–93,
0.20 in 1993–94, 0.51 in 1994–95 and 0.61 for the 3 seasons’
data combined (1993–95). It is suggested that nitrogen concentration in
fruit at harvest is a useful tool to predict the darkening of dried apricots
during storage.
Growth response of highly tolerant Eucalyptus species to alkaline pH, bicarbonate and low iron supply
Authors: James S. A. , Bell D. T. , Robson A. D.
Published: September 2002

The tolerance of 5 Eucalyptus species (E. gracilis F.
Muell., E. halophila D. Carr & S. Carr,
E. kondininensis Maiden & Blakely,
E. loxophleba Benth. and
E. platypus Hook var. heterophylla
Blakely) to alkaline conditions, bicarbonate, and low iron availability was
assessed in solution culture. All 5 species occur naturally in alkaline or
saline soils in semi-arid Western Australia. A treatment solution of pH 9 and
containing 10 mmol/L bicarbonate
(HCO3–) reduced the rate of
height increase and leaf and branch production of most species compared with a
control of pH 6 with no bicarbonate. Iron concentration within the youngest
fully expanded leaves was reduced for seedlings in the bicarbonate-pH 9
solution. Eucalyptus halophila was an exception,
responding positively to the alkaline treatment in having taller seedlings, a
greater leaf production, and maintaining a high leaf iron concentration.
Eucalyptus gracilis, E. loxophleba
and E. platypus had the highest growth rates within the
alkaline treatment, but the slow growth and sequestering of iron by
E. halophila provided this species with the greatest
potential for tolerance. The relative growth and tolerance rankings of the
species in solution culture were similar to those obtained in previous field
trials on alkaline mine processing wastes. Field selection of species from
calcareous or sodic sites, and laboratory screening under high bicarbonate
conditions can identify species with the greatest potential for the
rehabilitation of alkaline mine wastes and other damaged lands with soils of
high pH.
Effect of livestock grazing on physical properties of a cracking and self-mulching Vertisol
Authors: Taddese G. , Saleem M. A. Mohamed , Ayalneh W.
Published: September 2002

The impact of grazing on physical properties of Vertisol was studied from 1996
to 2000 in the Ethiopian highlands. The study was conducted at 2 sites with
0–4 and 4–8% slopes at Tero Jemjem watershed in Ginchi, 80
km west of Addis Ababa. The objective of the study was to compare selected
soil physical properties at different grazing pressures and slopes. The
stocking rate was moderate grazing 1.8 animal-unit months per hectare (1.8
AUM/ha), heavy grazing 3.0 AUM/ha and a control treatment with no
grazing. The result showed that heavy grazing pressure removed grass cover,
which consequently enhanced soil cracking. Effect of livestock trampling on
soil resistance to penetration (indicated by penetrometer readings) was higher
in the heavily grazed plots than in non-grazed plots. Penetrometer readings
were influenced by soil moisture content. Low moisture content was observed in
the heavily grazed plots at both sites. The infiltration of accumulated water
to the soil matrix was lower in heavily grazed plots.
An accurate and mobile weigh bin for peanuts
Authors: Krosch S. , Wright G. C. , Ashcroft S. , Shanahan P.
Published: September 2002

The design of a mobile weigh bin for use in field trials is described. The bin is designed for accurate weighing of peanut yield (pods) from large-scale (1 t) on-farm trials. It can be used with most commercially available peanut threshers and unloads pods quickly into transport trucks, resulting in minimal delay to a farmer's harvesting program.
Effects of experience on voluntary intake of supplements by cattle
Authors: Dixon R. M. , Smith D. R. , Porch I. , Petherick J. C.
Published: September 2002

Experiments examined the effects of prior experience of young cattle on their
voluntary intake of supplements, and variability among animals in intake of
supplements. Variability was measured using supplement labelled with lithium
salts. Experiment 1 examined the effects of offering a concentrate supplement
to calves before and/or after weaning on their subsequent intake of the
same supplement and of a loose mineral mix supplement. Experience of the
concentrate supplement increased acceptance and reduced variability in intake
of the loose mineral mix supplement. However, neither voluntary intake (mean
is 105 g DM/head.day) nor variability in intake of loose mineral mix
supplement was affected by prior experience. Experiments 2 and 3 examined
variability in intake of loose mineral mix supplement by weaners in larger
groups or offered molasses–urea supplement, respectively. Experiment 4
examined the effects of provision of supplements and/or exposure to human
activity and handling on subsequent intake of loose mineral mix supplement.
Supplementing grazing weaners with concentrates had a transient effect by
increasing voluntary intake of loose mineral mix supplement, but increased
exposure to supplements, and human activity and handling while held in yards
after weaning had no effects. Variability among animals in intake of loose
mineral mix supplement (CV is 52–103%) tended to be greater than
with the concentrate or molasses-based supplements (CV is
23–43%), irrespective of previous experience. There were fewer
than 1% non-eaters of concentrate supplement and 0–7%
non-eaters of loose mineral mix supplement. In experiment 5, prior experience
of loose mineral mix supplements increased intake of such supplements by
weaners during weeks 1 and 2 but not from weeks 3 to 9. In experiment 6,
intake of loose mineral mix supplement by adult cattle was not affected by
their experience as weaners of a similar supplement. In conclusion, although
prior experience of supplements by young cattle sometimes increased their
initial acceptance and voluntary intake of supplements, longer-term intake of
supplements was not affected.
Endoparasitic nematodes in cropping soils of Western Australia
Authors: Riley I. T. , Kelly S. J.
Published: September 2002

Soil samples were collected in Western Australia from cereal fields at about
harvest time to determine levels of the endoparasitic nematodes,
Pratylenchus and Heterodera. A
systematic survey in 1997 and 1998 centred on the 40 shires with the highest
proportion of cereal cropping. One hundred and eighty samples were collected
in 1997 and 227 in 1998 at 10-km intervals along north–south transects
35 km apart. A targeted survey in 1997 included 98 soil samples from fields
selected by growers as having poor productivity without an evident cause. No
Heterodera cysts were found in any survey sample but
these could be extracted from soils previously known to be infested.
Pratylenchus neglectus was most commonly detected
followed by P. thornei and
P. zeae. Populations identified as
P. brachyurus, P. penetrans,
P. scribneri, and an undescribed species similar to
P. thornei were also found. Overall
Pratylenchus was extracted from 63% of samples
(mean 1.1, median 0.3, max. 22.0/mL of soil). Maps of the data indicate
that Pratylenchus populations were aggregated with some
areas having relatively light infestations. There was a positive relationship
with the intensity of cereal cropping and a negative relationship with pulse
cropping. The findings indicate that potentially damaging
Pratylenchus numbers occur in a significant proportion
of fields and highlight the need to develop and implement strategies to lower
population densities.
Effect of different host plants on the growth of the root hemiparasite Santalum acuminatum (quandong)
Authors: Loveys Beth R. , Tyerman Stephen D. , Loveys Brian R.
Published: September 2002

In recent years, the root hemiparasite
Santalum acuminatum (quandong) has become an
increasingly important commercial crop within the indigenous foods market.
Relatively little is known of the significance of the host species on quandong
growth and development. This paper presents data from a glasshouse pot
experiment showing the effect of 4 different host species on the growth of
quandong. Quandong growth, as measured by height and dry-mass accumulation,
was significantly improved when grown in the presence of a host plant compared
with being grown alone. Quandong grown with a host achieved an average height
of 45 cm, while those grown alone grew up to only 37 cm. The host species also
had an impact on the growth of quandong. Quandong had no detrimental effect on
the growth of its host plant. Quandong grown with
Myoporum parvifolium and
Atriplex nummularia accumulated a significantly greater
amount of dry biomass than quandong grown alone.
Towards sustainable temperate perennial pastures
Authors: Kemp D. R. , Dowling P. M.
Published: September 2002

Naturalised pastures across the higher
rainfall (>600 mm) perennial pasture zone of south-eastern Australia are
less productive than they were, while sown pastures fail to maintain their
initial levels of production. Several factors have contributed to this,
including lack of knowledge of suitable grazing practices, weed invasion,
increasing acid soils, rising water tables and poor management practices
during droughts. A key issue in each case is the decline in perennial grass
species which is both a cause and effect of the decline in productivity and
sustainability of these ecosystems. This paper introduces a volume devoted to
the largest collaborative study done to evaluate tactics for better grazing
management and to improve the sustainability of perennial pasture ecosystems.
Grazing practices to manage the composition of pastures have been largely
neglected in pasture research, but are an important first step in improving
pasture sustainability. This paper also outlines a new, open communal grazing
experimental design which was developed and used across 24 sites on farms in
New South Wales, Victoria, Tasmania and South Australia, to evaluate tactics
for grazing management. The general aim across these experiments was to
maintain (if adequate) or enhance (if degraded), the proportion of desirable
perennial grasses in the sward to achieve more sustainable pastures. The
results will provide the basis for building more sustainable grazing systems.
Effects of sheep grazing management on cocksfoot herbage mass and persistence in temperate environments
Authors: Avery A. L. , Michalk D. L. , Thompson R. P. , Ball P. , Prance T. , Harris C. A. , FitzGerald D. W. , Ayres J. F. , Orchard B. A.
Published: September 2002

Cocksfoot
(Dactylis glomerata L.) is among the most important
perennial grass species sown in temperate Australia. Newly sown cocksfoot
pastures were established on 5 commercial farms (sites), in the temperate
high-rainfall (>600 mm annual rainfall) zone of eastern Australia.
Experiments were located on these commercial farms, and were measured from
September 1993 to August 1996, to compare the effect of seasonal sheep grazing
management strategies with continuous grazing (control treatment) on cocksfoot
herbage mass and plant frequencies. Each experiment had 8 common grazing
treatments and up to 5 local treatments, with 2 replicates and 2 years of
start for treatments.
Cocksfoot herbage mass under continuous grazing declined at 2 sites, remained
stable at 2 sites and increased at 1 site. No single grazing strategy had a
significant linear (time) effect on cocksfoot herbage mass across sites and at
the completion of monitoring in 1996 there were few treatments with a
significant increase in fitted values for cocksfoot herbage mass compared to
the continuously grazed control.
Under moderate grazing pressure (8–10 dry sheep equivalents) cocksfoot
pastures appeared to be relatively stable and unresponsive to grazing
management and therefore continuous grazing seems to be appropriate. High
grazing pressure in summer (herbage mass below 1000 kg/ha) can reduce
cocksfoot persistence and in drought stock should be removed from cocksfoot
pastures. Summer seasonal closure increased cocksfoot frequency at all sites,
except Four Mile Creek and Dundee. These studies have shown it is possible to
improve cocksfoot herbage mass through the implementation of strategic grazing
practices, particularly over summer and early autumn.
Honeybee pollination of buckwheat (Fagopyrum esculentum Moench) cv. Manor
Authors: Goodman R. , Hepworth G. , Kaczynski P. , McKee B. , Clarke S. , Bluett C.
Published: September 2002

The role of honeybees (Apis mellifera) in the
pollination of buckwheat cv. Manor was studied in a commercial planting at
Smeaton, Victoria. Honeybees comprised 80% of all insect visitors to
this crop. Other insects included ladybirds
(Coccinella transversalis and
C. undecimpunctata), hoverflies
(Meangyna viridiceps), drone flies
(Eristalis sp.), blowflies (Calliphoridae), cabbage
white butterflies (Pieris rapae), small bush flies and
native bees. The activity of honeybees and other insects increased seed
production from 91.5 g/plot (plots closed to insects) to 180.4 g/plot
(plots open to insects).
Intelligent support systems in agriculture: how can we do better?
Authors: Lynch T. , Gregor S. , Midmore D.
Published: September 2002

There has been considerable effort and money spent in the development of
intelligent support systems (decision support systems and expert systems) for
use by farmers, but few systems appear to be adopted for regular use. An
examination of the conceptual issues concerning the adoption of innovations,
with particular reference to software products, identifies major factors that
appear to influence the adoption of these systems by farmers. The conceptual
frameworks used for this analysis include Rogers’ diffusion theory, the
perceived usefulness and ease-of-use of software, software development methods
with a focus on the adopter-based approach to technology, and user involvement
in the development of an innovation. As a result of this approach, we argue
that the low adoption rate of intelligent support systems is understandable
and could have been predicted. Different approaches are needed if we are to do
better in the future. These include participatory approaches, using
‘softer’ systems methodologies that acknowledge the importance of
involving the user early in the development process and that pay attention to
the decision-making styles and social context of potential users.
Mango stem-end rot (Botryosphaeria dothidea) disease control by partial-pressure infiltration of fungicides
Authors: Plan M. R. R. , Joyce D. C. , Ogle H. J. , Johnson G. I.
Published: September 2002

The in vitro efficacy of several fungicides against Botryosphaeria dothidea (syn. Dothiorella dominicana) and their in vivo efficacy in controlling mango cv. Kensington Pride stem-end rot on partial-pressure infiltration v. dip treatment of green mature fruit was evaluated. In vitro sensitivity of B. dothidea to Benlate (benomyl), Sportak (prochloraz) and Scala (pyrimethanil) at 10 dilutions of the manufacturer's recommended rate was first determined at typical cold (13partial-pressure infiltration and conventional hot (52evaluated using the commercially recommended rate for each fungicide. In vitro, Benlate and Sportak prevented the growth of B. dothidea at both storage temperatures and at all concentrations, while Scala partially controlled growth of the pathogen. Benlate was the most effective fungicide for stem-end rot control. Sportak and Scala resulted in stem-end rot control when applied by partial-pressure infiltration, but not as dips. Partial-pressure infiltration holds promise for enhancing the efficacy of otherwise less effective but alternative fungicides for control of stem-end rot diseases.
Effect of virginiamycin and sodium bicarbonate on milk production, milk composition and metabolism of dairy cows fed high levels of concentrates
Authors: Valentine S. C. , Clayton E. H. , Judson G. J. , Rowe J. B.
Published: September 2002

Milk production and composition were measured for 63 days in 153
Holstein–Friesian cows offered either 7, 10 or 13 kg/day (as fed) of
a rolled, 74% barley/26% lupin grain mixture together with
either no feed additive, 300 mg/day of virginiamycin (VM) or 300
mg/day of virginiamycin plus 200 g/day of sodium bicarbonate (VM
+ NaHCO3). All cows were fed 1 kg/day of a
pelleted mineral supplement containing the additives. The cows were grazed as
a single herd on perennial ryegrass–subterranean clover pasture with
pasture silage available during periods of pasture shortage.
Rumen fluid was analysed for pH and volatile fatty acids, blood for plasma
glucose, beta-hydroxy-butyrate, urea and D- and L-lactic acid, faeces for dry
matter and pH, and both urine and milk for urea and sodium.
The incidence of grain bloat in all treatments was low. There was no main
effect of dietary additive treatment on grain intake, but at the highest grain
level, cows offered VM or VM + NaHCO3 ate more
grain than those offered no dietary additive.
There were no significant differences between the dietary additive treatments
in milk production, milk composition, cell count, liveweight and condition
score. Mean daily covariance-corrected yields of milk and protein (kg), and
milk protein content (g/kg) respectively, were significantly
(P<0.01) greater for cows fed 11 (28.0, 0.86, 30.6)
and 14 kg/day (28.7, 0.88, 31.0) of concentrate compared with those fed 8
kg/day (26.4, 0.78, 29.7). Mean milk fat content (g/kg) was
significantly (P<0.01) lower in milk from cows fed 14
kg/day (32.0) of concentrate compared with those fed 8 (35.9) or 11 (34.7)
kg/day. There were no significant differences between concentrate feeding
levels in milk fat yield or milk somatic cell count. Covariance-corrected
liveweight and condition score were significantly
(P<0.01) higher for cows fed 14 kg/day of
concentrate compared with cows fed at the lower concentrate levels. There were
no significant interactions between concentrate level and dietary additive for
all milk production parameters.
No significant differences were recorded between the different levels of
concentrate in the concentration of total rumen volatile fatty acids, or in
blood plasma concentrations of glucose and L-lactate. The rumen molar
proportions of acetate and butyrate were significantly
(P<0.01) lower, and propionate and valerate
significantly (P<0.01) higher at the higher levels of
concentrate offered. The molar ratio of acetate plus butyrate to propionate
was significantly (P<0.01) higher in cows fed 8
kg/day of concentrate compared with cows fed 11 and 14 kg/day.
It was concluded that the inclusion of virginiamycin, or virginiamycin
together with sodium bicarbonate, in high grain rations cannot be recommended
for improving milk production in grazing dairy cows already adapted to high
levels of barley and lupin grain.
Review of vehicle inspection historical data as a tool to monitor the entry of hosts of Queensland fruit fly Bactrocera tryoni (Froggatt) (Diptera : Tephritidae) into a fruit fly free area
Authors: Dominiak B. C. , Campbell M. , Cameron G. , Nicol H.
Published: September 2002

Historical records from Victorian fruit fly roadblocks were analysed to
identify past trends. A model using month of year and time of day accounted
for most of the variance in travellers carrying fruit at the Euston, Barham,
Kyalite and Wentworth sites in 1980–81. Different sites had different
characteristics and pooling of results across sites is likely to be invalid.
Tomatoes were found to make up 49.3% of infested fruit during the
7-year period between 1976–77 and 1982–83. Travellers originating
from Sydney carried 69.3% of the infested fruit. The proportion of the
3 origins carrying infested fruit did not vary significantly during the 7-year
period. The interceptions were not evenly distributed with 50% of the
detections occurring in 2 of the 7 years.