bluuebunny/crossref_metadata_2025 huggingface dataset:
The utilization of spear grass (Heteropogon contortus). III. The influence of the level of dietary sulphur on the utilization of spear grass by sheep
Authors: Kennedy PM , Siebert BD
Published: November 2004

The effect of additions of sulphate to a spear grass diet fed to sheep with or without urea supplements was studied. With spear grass (0.39 g nitrogen/100 g dry matter), sulphate additions did not improve intake or digestion, but nitrogen retention was improved. With urea-supplemented spear grass, sulphate additions caused an increase in intake, digestion, and nitrogen retention. Nitrogen retention reached a plateau of about 2.5 g nitrogen per day. Sulphate added in excess of that required for microbial synthesis was excreted mainly as urinary sulphate. Nitrogen and sulphur in blood, rumen liquor, urine, and faeces were determined and the interrelationships between these variables are discussed. The differences between results of this experiment and results previously reported are discussed in relation to the variation in nitrogen content of mature spear grass between years, and to nutrition of the grazing ruminant.
Diallel analysis and cross prediction in common bread wheats
Authors: Bhatt GM
Published: November 2004

An eight-parent diallel set of crosses among spring wheats together with parents were used for studying the yield potential of the crosses in the F2 generation. The results of diallel analysis in the F1 generation performed on yield-determining characters, as well as analysis on yield performance in the F2 progeny, were considered for employing various methods of cross prediction. The prediction methods used gave consistent results with regard to preselection classification of the hybrids for yield. Further handling of the potential high-yielding crosses is outlined.
Temperature influences on the in vitro digestibility and soluble carbohydrate accumulation of tropical and temperate grasses
Authors: Wilson JR , Ford CW
Published: November 2004

Thirteen tropical or subtropical and 11 temperate grasses were grown in controlled environment under daylnight temperatures of 21/13, 27/19, and 32/24�C. Each plant was harvested 2 days after the fifth leaf on the main stem reached maximum length; other plants of Panicum maximum var. trichoglume and Lolium perenne cv. S.24 grown under the same conditions were also harvested 4, 8, 12, and 18 days after this stage of development. There was a consistent decline in the in vitro digestibility of most of the temperate grasses with increase in temperature from 21/13 to 32/24�C. This decline averaged about 5 digestibility units and was associated with a fall in the percentage of soluble carbohydrates. In contrast, temperature had little effect on the digestibility of most of the tropical grasses. However, in later harvests of Panicum the digestibility at 27/19 and 32/24� was consistently lower than at 21/13�. This was attributed to the more advanced growth stages at the higher temperatures. The temperate grasses accumulated much higher concentrations of soluble carbohydrate than the tropical grasses.
Bos indicus and Bos taurus crossbred dairy cattle in Australia. II. Effect of calf removal and prolactin treatment
Authors: Hayman RH
Published: November 2004

Some 70 % of filial generation Red Sindhi x Jersey and Sahiwal x Jersey crossbred animals were discarded from the dairy herd on the F. D. McMaster Field Station, CSIRO, because of failure to continue in lactation when separated from their calves. This well-known characteristic of Bos indicus cattle, generally referred to as 'maternal instinct,' has been assumed to emanate from the dam's sense of loss on separation from her offspring. Observations on animals in the Field Station herd suggested that this separation causes the dam to cease producing secretory hormones with consequent cessation of lactation. Two systems of management, in one of which the calf was separated from its dam within 24 hr of birth while in the other the dam and offspring were allowed to run together for 10 days, both failed to overcome the problem. Injections of oxytocin after separation were also unsuccessful. Some success was obtained by daily injections of 250 i.u. of prolactin for the 10 days immediately following the separation of dam and offspring, and it was concluded that the presence of the calf stimulated prolactin secretion by the pituitary. Continuation of injections over a period of 7-10 days enabled some animals to continue their lactation without the stimulation afforded by the calf.
The influence of temperature and density on the growth of communities of subterranean clover (Trifolium subterraneum L. cv. Mount Barker)
Authors: Cocks PS
Published: November 2004

The influence of temperature on the growth of high and low density communities of subterranean clover (Trifolium subterraneum L. cv. Mount Barker) was studied at four temperatures ranging from 12�C day/7�C night to 27�C day/22�C night. The response to temperature depended on leaf area index (LAI). When the LAI was low (0.2), growth rate increased with increasing temperature to a maximum at 22� day/ 17�C night. This agreed with the temperature response of single plants of the same species previously reported. However, when the LAI was 3 the growth rate was not influenced by temperature within the range tested. At a still higher value of LAI (5.5), the response in growth became negative with increasing temperature, communities at the highest temperature growing at only half the rate of those at the lowest. The frequency distribution of plant size in the dense communities was measured, at eight times during the experiment. The distribution was influenced by both temperature and the total dry weight of the community. At low temperature it was approximately symmetrical, but at high temperature it rapidly became asymmetric as total dry weight increased, the amount of skewness being greatest at the highest temperature and dry weight. Plant death was greatest at the high temperature. The communities were divided into five equally populated groups of ascending plant size. At high temperature the largest plants increased in size throughout the experiment, but each of the groups of smaller plants reached a maximum size, subsequently losing weight. At lower temperatures only the groups of smaller size lost weight, the number of groups losing weight depending on temperature. The distribution data were used to try to explain the interaction between temperature and LAI. It was proposed that community growth rate was best when canopy cover was complete and the distribution of plant weight was not strongly skewed.
Heat therapy of virus-infected cultures of the cultivated mushroom Agaricus bisporus
Authors: Nair NG
Published: November 2004

A procedure for elimination of viruses by heat treatment of virus-infected isolates of the cultivated mushroom Agaricus bisporus has been perfected. A minimum treatment time of 3 weeks at 33�C was required. The effect of heat treatment was assessed in terms of increased growth of the isolates in vitro and absence of virus particles. Growth rate was not always a good measure of effective heat treatment. Some virus-infected isolates were found which can act as symptomless carriers. The effect of heat treatment appeared to depend on the pre-treatment which the isolates had received. Elimination of viruses did not occur when the isolates were grown at 25� prior to heat treatment. It appears, therefore, that thermal inactivation of viruses is not complete in mature mycelium.
The effect of the androgen status of rams on sexual activity and fructose concentration in the semen
Authors: Knight TW
Published: November 2004

Sexually active and sexually inhibited rams had similar concentrations of fructose in their semen. The injection of 40 mg testosterone propionate every alternate day did not stimulate sexual activity in the sexually inhibited rams, nor did it increase the libido of rams which were already sexually active. The only effect the injections of testosterone propionate had on the semen was to increase the concentration of fructose in the seminal plasma.
The influence of nitrogen nutrition of Desmodium uncinatum on seed production
Authors: Gibson TA , Humphreys LR
Published: November 2004

Desmodium uncinaium cv. Silverleaf was grown in simulated swards well supplied with water and basal nutrients. Nodulated control swards yielded 179 g m-2; whole plant nitrogen accretion was 25 g m-2. The rate of nitrogen uptake decreased during seed maturation and redistribution of nitrogen from leaf, stem, and raceme was inadequate to meet the nitrogen demand of maturing seeds. Ammonium nitrate applied at 16.9 kg nitrogen ha-1 wk-1 from the immediate pre-floral initiation stage or at later development stages increased seed yield by 21 to 31 % according to timing. Applied nitrogen increased the number of racemes differentiated per runner and the size of seeds, and decreased the number of seeds formed per floral node. Components of seed yield such as raceme number per runner, floral nodes per raceme, seeds per node, and seed weight were influenced by position on the plant. The greater part of the ammonium nitrate response was due to increased seed production from the secondary racemes on the larger primary runners.
Isotopic studies on the uptake of nitrogen by pasture plants. V. 15N balance experiments in field microplots
Authors: Vallis I , Henzell EF , Martin AE , Ross PJ
Published: November 2004

Recovery of 15N from labelled fertilizers was measured in open microplots on pastures at three sites in southern Queensland. Very little 15N was recovered from plants growing further than 15-30 cm from the area of application. Most of the 'N found in soil and roots was in the top 15 cm of the profile. The following total recoveries of 15N (with their standard errors) were recorded: 83.0�2.7% from ammonium sulphate applied to Rhodes grass; 76.6 �3.7 % from potassium nitrate on a Townsville stylo-spear grass pasture; and 97.9�6.7% from urea applied to a Nandi setaria pasture. The weather during the three experiments was relatively dry, and it is unlikely that any ISN was leached below the depth of sampling. The advantages and disadvantages of open and enclosed microplots are discussed in some detail. It is suggested that while open microplots are satisfactory for some purposes, the use of plots enclosed by steel cylinders pressed into the soil is probably the most accurate technique available for 15N balance studies in the field.
Productivity of vegetable crops in a region of high solar input. II. Yields and efficiencies of water use and energy
Authors: Sale PJM
Published: November 2004

Details are given of final yields and size gradings of three potato crops grown under conditions of high solar input and high temperatures in the Murrumbidgee Irrigation Areas of New South Wales. Total yields were up to 50 t ha-l. Differences resulting from different irrigation treatments were surprisingly small, although mean tuber weight was slightly less in the drier treatments. Water use was about 300 g for each 1 g dry weight produced, and efficiency was slightly greater in the wetter irrigation treatments. Reductions of 21 %and 34 % of the total solar input, using shade covers, markedly reduced yields, and there was no statistical interaction with irrigation treatment. Tuber numbers also decreased with decreasing solar input, though not as much as yields, and mean tuber size was greatest on unshaded plots, least under 34% shade. Tuber moisture percentage at harvest was not affected by the different irrigation treatments, but was reduced in two experiments as shading increased. There were only small differences in plant and stem numbers per unit area between any of the treatments, though stem numbers decreased significantly as shading increased. High crop growth rates were achieved especially during the tuber bulking periods, when up to 22.8 g m-2 day-1 of dry matter were produced in each of two experiments, achieved with conversion efficiencies of photosynthetically active radiation of 3.5 % (spring-planted crop) or 6.1 % (summer-planted crop). The results are in agreement with the hypothesis that assimilation in the potato depends primarily on the 'sink' strength of the developing tubers, which is determined in the 2 or 3 weeks following the onset of initiation. The main effects of differences in solar input appear to be determined in this period. It is suggested that a practical approach to increasing yields in this region may be to increase the numbers of tubers which develop per unit area by increasing plant density and encouraging early haulm growth.
Outcrossing rates in Australian populations of subterranean clover
Authors: Marshall DR , Broue P
Published: November 2004

Quantitative estimates were made of the extent of cross-pollination in four populations of subterranean clover. Estimates of outcrossing varied from 0 to 0.22% with a mean of 0.15%, indicating that subterranean clover consistently outcrosses at a low rate in Australian environments.
Association of a small coryneform bacterium with the ratoon stunting disease of sugar-cane
Authors: Teakle DS , Smith PM , Steindl DRL
Published: November 2004

When fibrovascular sap extracts of sugar-cane plants affected by the ratoon stunting disease (RSD) were centrifuged and the resuspended pellets negatively stained and examined in an electron microscope, cells of a small bacterium were always observed. The bacterium could be distinguished readily from other bacteria present by its small size (usually 1.0–2.5 µm long by 0.15–0.32 µm wide), the coryneform (club-shaped) morphology of some cells, and its permeability to negative stain revealing a thin cell wall surrounding a cytoplasmic membrane and coiled mesosomes. Since the small bacterium was never observed in fibrovascular extracts of RSD-free sugar-cane plants, it is a possible causal agent of RSD.
Comparisons of diets of sheep and cattle grazing together on sown pastures on the Southern Tablelands of New South Wales by principal components analysis
Authors: Dudzinski ML , Arnold GW
Published: November 2004

The botanical and chemical composition of the diets of oesophageal fistulated wether Merino sheep and cattle (mainly yearlings and dry cows) were compared when they grazed together on sown pastures varying widely in yield and botanical composition. Sheep diets were consistently different from cattle diets, independent of pasture conditions, in having lower normal-acid fibre contents (3.8 units lower), and higher water-soluble carbohydrates (1 unit) and in vitro digestibility (4.4 units). Differences in nitrogen content and in botanical composition of the diet were related, in part, to the botanical composition of the pasture being grazed. It is suggested that differences in composition of the diet arise from differences between sheep and cattle in their mechanical ability to be selective. Use of the principal components technique allowed reasonable biological conclusions to be drawn from multivariate intercorrelated data.
The effect of level of calcium intake on the utilization of phosphorus by the pre-ruminant lamb
Authors: Hodge RW
Published: November 2004

Four groups of lambs received liquid diets providing 50, 250, 450, and 650 mg calcium/kg liveweight/day between 5 and 70 days of age. Phosphorus balance measurements were made during two 32-day periods to determine the retention and apparent availability of phosphorus. Retention was also estimated by the comparative slaughter technique. The apparent absorption of phosphorus/kg liveweight was similar at all levels of calcium intake in the first period, but was reduced at the two higher levels of calcium intake in the second period. Mean apparent availability of phosphorus was 96 %for the lower level of calcium intake and 86% for the highest level in the first period. The corresponding values in the second period were 90 and 64%. The faecal excretion of phosphorus (mg/kg liveweight) was positively related to the level of calcium intake and was also greater, at each level of calcium intake, forthe older lambs. The excretion of phosphorus in the urine (mg/kg liveweight) was inversely related to the level of calcium intake and was reduced in the older lambs. The retention of phosphorus/kg liveweight gain increased as the level of calcium intake was raised. These results, calculated from the balance studies, were supported by the slaughter analyses.
Simulated frosting of tropical grasses
Authors: Hacker JB , Forde BJ , Gow JM
Published: November 2004

Ranking order for leaf damage was determined in six varieties of the tropical grass setaria after frosting in a controlled environment and was found to be similar to known field response. A frost temperature of –2.5°C provided good discrimination between populations subjected to three successive frost cycles of 4 hr under programmed conditions which closely simulated field conditions. Further experiments were carried out to investigate: (a) The relative frost tolerance of a range of varieties in the genera Setaria, Digitaria, Paspalum, and Lolium; (b) the effect of vapour pressure deficit (VPD) during frosting and rate of temperature change into the frost period on leaf damage; (c) the effect of temperatures preceding frosting and duration of frost on leaf damage; (d) the relationship of concentration of alcohol-soluble carbohydrates to susceptibility to frost. The most tolerant tropical grass tested was Paspalum dilatatum. Significant variation in frost tolerance in Setaria was related to altitude of origin, whereas in Paspalum plicatulum latitude of origin appeared to be the controlling factor. Frost tolerance was slightly increased by pre-hardening for 3 days or by growing at a lower night temperature. Frosting at a VPD of –3 mb resulted in less damage than frosting at a VPD of zero, when visible frost formed on leaf surfaces. Extending the duration of the frost resulted in an increase in leaf damage. Ranking order for frost tolerance was not attributable to differences in concentration of alcohol soluble carbohydrates and was not affected by environmental conditions either preceding or during the frost period.
Variation in Australian and European collections of Trifolium glomeratum L. and the provisional distribution of the species in southern Australia
Authors: Woodward RG , Morley FHW
Published: November 2004

Seventy-four lines of Trifolium glomeratum L. from a wide range of Australian and European environments were grown in a glasshouse at Canberra. Time to flower, growth habit, leaf markings, stipule colour, floret colour and dry matter production varied among collections, and within some lines. Numbers of flowers per plant, leaf: stem ratio, and dry matter yields were correlated with days to flower. The variation within the European collection was similar to that within the Australian collection. Time of flowering has probably been important in natural selection in this species, since the date of flowering at Canberra was strongly correlated with date of the end of the growing season (defined by effective rainfall) at the collection site of each ecotype. A survey during 1970 through New South Wales, Victoria and South Australia showed the western limit of spread of T. glomeratum to be through Garah, Burren Junction, Coonamble, Euabalong,Booligal, Moulamein, Beulah, Lake Hindmarsh, Mannum and Jamestown. Extrapolation of climatic restrictions to Western Australia indicated that the species could exist west of Lake Biddy, and possibly north and east to Geraldton and Esperance. The distribution appears to be controlled by the shortest length of growing season in which the species can germinate, grow, and set viable seed.
Biological control of Eutypa armeniacae. II. Studies of the interaction between E. armeniacae and Fusarium lateritium, and their relative sensitivities to benzimidazole chemicals
Authors: Carter MV , Price TV
Published: November 2004

Fusarium lateritium, a saprophyte sometimes associated with apricot trees, inhibits in vitro germination and growth of Eutypa armeniacae. The amount of inhibition increases with the age of the F. lateritium colony and in the presence of nutrients. The inhibitor is non-volatile, diffusible and produced in amounts proportional to the age of the colony. In the field, F. lateritium sporulated abundantly at the pruned sapwood surfaces of apricot trees a few days after inoculation. Application to pruned surfaces of suspensions containing 104 macroconidia per ml, or more, gave significant protection against E. armeniacae. Growth of F. lateritium was mainly restricted to a zone of sapwood within 2 cm of the pruned surface. The tolerance of F. lateritium to benzimidazole chemicals in vitro is about 10 times as great as that of E. armeniacae, and its macroconidia germinate and produce sporulating colonies on sapwood of excised apricot stems when these are inoculated with spores in water suspensions containing up to 400 ppm benomyl or thiabendazole.
Behaviour of Phytophthora cinnamomi in soils suppressive and conducive to root rot
Authors: Broadbent P , Baker KF
Published: November 2004

Suppression of root rot in avocados caused by Phytophthora cinnamomi was demonstrated in soil from a grove at Tamborine Mt., Queensland. The addition of P. cinnamomi inoculum in amounts sufficient to cause severe root rot of plants in other soils, untreated or steam-air treated at 60°C for 30 min, produced little or no damage in the suppressive soil. Suppressive soil was found to have higher populations of bacteria and actinomycetes than soils conducive to root rot. Few sporangia were formed by P. cinnamomi and P. citrophthora in suppressive soil or soil leachate. The suppression of sporangium formation was found to be microbial and not related to the nutrient level of the soil leachate. Mycelium of P. cinnamomi grew through untreated conducive soils, but developed poorly in untreated suppressive soils. The fungus grew readily through all soils steam-air treated at 49, 60 and 100�C for 30 min. After 6 weeks the isolation frequency of P. cinnamomi had declined in the suppressive soil treated at 49 or 60°C for 30 min. Exchangeable calcium and magnesium, nitrogen, and organic matter were higher in soils suppressive to root rot than in conducive soils. Rain-forest soil, where the pathogen is not damaging, was comparable in this respect to the suppressive soil.
Effects of Trichostrongylus colubriformis (Nematoda) on the nutrition and metabolism of sheep. II.* Metabolism of urea
Authors: Roseby FB , Leng RA
Published: November 2004

The effect of infection with Trichostrongylus colubriformis on the rates of production, excrehon and recycling of urea was studied in 24 Merino lambs. The production rate of urea was estimated as the irreversible loss rate of [14C]urea given as a single injection. The feed intake of all sheep was maintained at 540 g/day throughout the experiment. Parasitized sheep had a higher plasma urea concentration than their paired controls 15–35 days after they were infected. This was associated with an increase in the rate of irreversible loss and the rate of urinary excretion of urea. The additional urea lost in urine is apparently produced from ammonia released from amino acids in the tissues or in the digestive tract.

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*Part I, Aust. J. Agric. Res., 24: 947 (1973).
A sand culture experiment to compare the effects of sulphur on five wheat cultivars (T. aestivum L.)
Authors: Archer MJ
Published: November 2004

A glasshouse sand culture experiment was conducted to determine the effects of sulphur supplied at 10,375 and 875µM concentrations on total dry matter production per plant (TDM), grain yield, harvest index (HI), yield components, nitrogen, sulphur and phosphorus levels in herbage and grain samples of two vitreous grained (Stockade and Gabo) and three non-vitreous grained (Insignia, Olympic and Summit) wheat cultivars (T. aestivum L.). Pelshenke doughball fermentation tests were done on wholemeal samples from all treatments.Stockade and Gabo had higher TDM than Insignia, Olympic and Summit at 10µM sulphur concentration, but relatively lower harvest indices. At 375µM sulphur, TDM increased for all cultivars; Gabo and Stockade continued to have relatively higher TDM, but Stockade produced only half the increase of any other cultivar. However, Stockade doubled its HI which, in turn, was double the increase recorded by Olympic and Summit. Insignia failed to increase its HI. Only Stockade showed increased TDM at 875µM sulphur. Olympic had the highest HI values at both 375 and 875µM sulphur. Similar grain yield increases for all cultivars were largely attained by differential grain number-grain size combinations. The higher sulphur supplies therefore stimulated the translocation of photosynthates to the developing grains and/or shifted the location of most rapid cell division from vegetative to reproductive sites. Stockade and Gabo had relatively higher percentages of grain sulphur at 10µM sulphur than the other cultivars and Stockade continued to have the highest percentage of grain sulphur at 375 and 875µM concentration. Except for a marked fall by Insignia, an increasing sulphur supply did not affect the distribution of sulphur within the plants as the indices for percentage sulphur remained largely unchanged. However, the distribution of nitrogen and phosphorus from straw to grain were both stimulated. Stockade and Gabo had relatively larger increases in their indices of percentage nitrogen, but the non-vitreous grained cultivars showed relatively larger increases in the percentage of nitrogen in the grain. Comparatively poor Pelshenke results, especially for Stockade, at I0µM sulphur, indicate an adverse affect of sulphur deficiency on grain quality. The experiment has shown that variation in sulphate sulphur supply differentially affected the biological and physico-chemical mechanisms controlling the optimum phenotypic expression of five wheat genotypes (cultivars). Part of these mechanisms involves close interrelationships and interactions between the uptake and/or metabolism of sulphur, phosphorus and nitrogen anions. Stockade was a particularly responsive cultivar to sulphur, while Insignia was relatively insensitive.
Tomato big bud, legume little leaf, and lucerne witches' broom: three diseases associated with different mycoplasma-like organisms in Australia
Authors: Bowyer JW
Published: November 2004

The pathogens (presumed to be mycoplasma-like organisms) causing tomato big bud, legume little leaf, and a 'mild' form of lucerne witches' broom disease could be distinguished by differential symptomatology and incubation periods in tomato (Lycopersicon esculentum) and Datura stramonium. They were regarded as reference 'type strains' of the Australian yellows disease agents. Incubation periods of the tomato big bud and legume little leaf agents in the leafhopper vector Orosius argentatus were similar, but the pathogen causing mild lucerne witches' broom was not transmissible by this insect. Six species of plants with yellows disease symptoms (shoot proliferation, small leaves, chlorosis, virescence) were collected from northern and southern Queensland. The pathogens were transmitted by O. argentatus to D. stramonium. From symptoms produced in this host, the various isolates were characterized as either the original big bud or little leaf reference strains. An isolate causing 'severe' lucerne witches' broom could not be distinguished from the legume little leaf type strain.
Phosphorus homeostasis in sheep. II.* Influence of diet on the pathway of excretion of phosphorus
Authors: Tomas FM
Published: November 2004

Urinary phosphorus excretion by sheep given diets of coarse or finely ground roughage to vary their salivary flow rates, was studied. A 3 x 3 Latin square design was used in which three Merino ewes with rumen fistulas were given nutritionally complete diets in which the roughage component consisted of oat hulls (diet A), finely ground oat hulls (0.8 mm screen) (diet B), and finely ground oat hulls with added polyethylene flakes (diet C). Daily rumination time was used as an index of relative saliva flow rate and varied from 7.59?0 .47 and 6.83?1.12 hr/day for diets A and C respectively, to 1.92?0.39 hr/day for diet B. Similar changes were observed for the daily number of chews. When the sheep were given diet B, the pH of the rumen fluid, the concentration of inorganic phosphorus in the rumen fluid and the total inorganic phosphorus content of the rumen were reduced relative to diets A and C. Each of these effects points to a reduced rate of saliva flow. The inorganic phosphorus levels of the plasma were unaffected by the dietary treatments except that in the 6 hr following feeding, the levels fell for treatments A and C, but rose for treatment B. Urinary phosphorus excretion, which was significantly increased by diet B, was 356.6, 472.7 and 373.5 mg/day for diets A, B and C respectively. Urinary and faecal excretions of phosphorus were significantly correlated (r = –0.86) as were the urinary excretion and rumen content of phosphorus (r = –0.88). The data are discussed in relation to the role of salivary secretion of phosphorus in the balance between faecal and urinary excretion of phosphorus in sheep.

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*Part I, Aust. J. Agric. Res., 25: 475-83 (1974).
Sulphur metabolism and excretion studies in ruminants. XIII.* Intake and utilizaton of wheat straw by sheep and cattle
Authors: Bird PR
Published: November 2004

The capacity of cattle and sheep to utilize wheat straw was compared, six 15-month-old Hereford steers and six 20-month-old Merino wethers being used. The addition of urea (2.0% of dry matter) to wheat straw (c. 0.3% nitrogen, 0.09% sulphur) significantly increased the intake of energy, the efficiency of digestion and the liveweight gains of both the sheep and the cattle. The addition of sodium sulphate (0.4% of the dry matter) to the ration containing urea significantly increased these responses in the sheep but not in the cattle. Cattle and sheep had a similar capacity to digest the basal straw (22 v. 23 kcal/kg W0.92 per day), but cattle were more efficient than sheep when urea alone was included in the ration (68 v. 42 kcal/kg W0.92 per day day). The further addition of sulphate decreased this disparity (75 v. 64 kcal/kg W0.92 per day) so that the sheep were then also able to derive their maintenance requirement of energy (an estimated 49 kcal/kg W0.92 per day) from the straw. Addition of urea to wheat straw significantly increased the nitrogen balance in cattle but not in sheep. The further addition of sulphate significantly increased this balance in both the sheep and the cattle. Nitrogen balance on the basal straw, straw plus urea, or straw plus urea plus sulphate was –97, –62 and 17 mg nitrogen/kg W0.92 per day respectively for sheep compared with –79, –24 and 32 mg nitrogen/kg W0.92 per day for cattle. Supplemental sodium sulphate (0.4% of the dry matter) without urea slightly decreased the nitrogen balance and tended to depress intake and digestion of feed in both sheep and cattle. Cattle require less dietary sulphur and can cope with a wider nitrogen/sulphur ratio in the feed than sheep, apparently because sulphur is recycled more effectively in cattle. Responses to urea supplementation under grazing conditions may therefore be greater with cattle.

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*Part XII, Aust. J. Biol. Sci., 26: 1429 (1973).p>
Milk yield and composition of milk and blood as indicators of energy intake by Jersey cows
Authors: Stobbs TH , Brett DJ
Published: November 2004

Jersey cows were used in a change-over design to examine the effect of three levels of energy intake (lucerne hay at 100, 75 and 50% ad lib.) on milk yield, milk composition, fatty acid composition of milk fat, and blood metabolites (non-esterified fatty acids, glucose and total ketones) to determine which measurement was the most accurate indicator of intake of energy. Milk yields averaged 9.9, 8.7 and 7.2 kg/cow/day with relative intakes of 100, 75 and 50% of ad lib. When energy was restricted the proportion of C4–C16 fatty acids in milk fat decreased (72, 69 and 59%), while the proportion of oleic acid increased (15, 18 and 26%). These changes occurred within approximately 6 days on new energy levels. Fore milk and strippings had similar fatty acid proportions. Restriction of energy reduced the solids not fat, protein and casein contents of milk, and increased its butter fat percentage. Non-esterifred fatty acid levels in blood plasma increased with restriction of feed (348, 528 and 579 µ-equiv./l). Glucose and ketone bodies of blood averaged 58 mg/100 ml and 9.1 mg/100 mi respectively, and did not vary between treatments. It is concluded that milk production is the most sensitive indicator of the intake of digestible energy where change-over designs are used. However, when individual animal variation is not removed in the analysis, the intake of energy is most closely correlated with the fatty acid composition of milk fat (r = 0.73 and –0.74 for C4–C16 acids and oleic acid respectively). Significant correlations with the protein to fat and casein to fat ratios of milk were also measured (r = 0.64 and 0.63 respectively). There was a poor relationship between energy intake and blood composition (r = –0.25 for non-esterified fatty acid content).
The use of multivariate analysis in identifying relationships among disorder and mineral element content in apples
Authors: Ratkowsky DA , Martin D
Published: November 2004

The use of principal component analysis, followed by rotation of a reduced number of component axes, and its role in the identification and interpretation of relationships between disorder and mineral content in apple research is described. The relationship among bitter pit incidence, calcium deficiency and mean fruit weight per tree is illustrated by using data obtained on Jonathan apples from potted trees. Principal component analysis must be performed on unstructured data, and emphasis is placed upon the removal of treatment and block effects when constructing the correlation matrix upon which the analysis is performed. The mathematical techniques described are applicable to a wide range of agricultural experimentation.
Epidemiology of lettuce necrotic yellows virus in South Australia. III.* Virus transmission parameters, and vector feeding behaviour on host and non-host plants
Authors: Boakye DB , Randles JW
Published: November 2004

When Hyperomyzus lactucae are given acquisition feeds of 24 hr on Sonchus oleraceus infected with lettuce necrotic yellows virus (LNYV) a temperature-dependent latent period must be completed before the virus can be transmitted. The mean duration of latent period is 18.0, 9.2 and 5.4 days at 15, 20 and 28°C respectively. On completion of the latent period, H. lactucae transmit LNYV consistently. Within 24 hr of reaching the fourth instar, nymphs which have developed on virus-infected S. oleraceus are capable of transmitting the virus, adult apterae and alatae transmit more efficiently than nymphs, and the efficiency of transmission is similar for both morphological forms of the aphid. The longer the inoculation feed by viruliferous H. lactucae, the greater are the chances for successful transmission of the virus to either S. oleraceus or lettuce seedlings. The inoculation thresholds are between 5 and 30 min on S. oleraceus and 1–5 min on lettuce. During this time stylets penetrate the epidermal layer only, which indicates that aphids can inoculate without penetrating the vascular tissue. Transovarial transmission has been demonstrated in viruliferous viviparae apterae, but the rate of passage of virus to progeny is low; out of 73 sets of progeny 5 sets acquired LNYV maternally. It appears that nymphs which acquire the virus maternally complete the latent period at or shortly after birth. At 20 and 28°, the longevity of aphids transmitting LNYV is less than that of those not transmitting. When apterous H. lactucae freshly removed from S. oleraceus are allowed to probe on lettuce they generally walk off the plant; however, the tendency to settle in a feeding position is considerably increased when they are 'pretreated' by starving them in continuous light at a lowered relative humidity of 65–70%. Salivary secretions are deposited on the leaves of both S. oleraceus and lettuce when either pretreated or untreated aphids are caged on them. Depth of probing increases with time up to 30 min on both hosts, but after this aphids feeding on lettuce tend to withdraw their stylets. Pretreated H. lactucae given access to 32P-labelled plants took up 17 times more sap from S. oleraceus than from lettuce.

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*Part II, Aust. J. Agric. Res., 22: 231 (1974).
A new method for the analysis of three-dimensional data matrices in agricultural experimentation
Authors: Williams WT , Edye LA
Published: November 2004

The analysis of three-dimensional data sets has received considerable attention in ecology, but relatively little in agriculture, in which such data sets are equally common. A model has recently been proposed for the (sites x species x times) case in marine ecology; it can be regarded as based either on Euclidean distance or on the analysis of variance. The model is recapitulated in outline, its properties are somewhat extended, and its application to agronomic experiments is discussed. A brief account is given of the use of the model in the analysis of two real-life agronomic experiments. Finally, the relationship of such methods to those of classical statistics is briefly discussed.
A study of the phosphorus responses of a wide range of accessions from the genus Stylosanthes
Authors: Jones RK
Published: November 2004

The effects of a wide range of phosphorus levels on the growth and uptake of phosphorus by 30 accessions of the legume genus Stylosanthes, representing seven species, were compared in a glasshouse experiment. The basic data from the experiment were subjected to a numerical classification, and accessions with similar patterns of response were grouped to simplify description and interpretation of the results. Differences in growth and phosphorus uptake under conditions of severe deficiency were fairly small, but there were appreciable differences between groups in the dry matter produced per unit phosphorus absorbed. With progressive improvement in the supply of phosphorus, large differences developed between the groups in growth and phosphorus uptake. One group, in which nodulation was partially or completely ineffective, responded poorly in growth and phosphorus uptake to additions of phosphorus. Other groups, however, were effectively nodulated, and appeared to differ considerably in their inherent growth rates and hence in their uptake of phosphorus during the 55 days of the experiment. At moderately high levels of applied phosphorus (equivalent to between 96 and 192 kg P/ha) accessions in several groups developed foliar symptoms resembling 'phosphorus toxicity', had depressed yields of dry matter, and accumulated phosphorus in their tops to high concentrations.
Effects of soil temperature and phosphorus supply on growth and composition of Lupinus angustifolius L. and L. cosentinii Guss
Authors: Rahman MS , Gladstones JS , Thurling N
Published: November 2004

Two Lupinus species, L. angustifolius L. and L. cosentinii Guss., were grown in pots in the glasshouse on a virgin lateritic soil, with two soil temperatures attained by immersion in water-baths at 10 and 20°C, and four rates of superphosphate ranging from 0 to 1792 kg ha-l. Air temperatures were not controlled. Dry matter, and phosphorus and nitrogen concentrations, were measured separately for tops and roots after harvest at 7 weeks. In a second experiment, the rate of early radicle elongation was measured for the two species in complete nutrient solutions at 10 and 20°.Water-bath temperature markedly influenced the growth of both roots and tops, growth with 20° being approximately double that with 10° in both species. At both bath temperatures, responses to superphosphate closely paralleled those observed previously on the same soil in the field. There was a slight positive interaction between bath temperature and superphosphate rate, but in the main the effects of the two factors were independent and additive. The results did not support the suggestion that reduced growth with low root temperature may be due primarily to reduced phosphorus uptake. Nor did they indicate reductions in nodulation, nitrogen fixation, or translocation of either nitrogen or phosphorus from roots to tops as likely causes. It is suggested that temperature may have directly affected the growth and/or metabolism of the roots, influencing their production of growth substances, which in turn influenced processes controlling top growth.
Some effects of urea and Streptomyces griseus (2-A24) on Fusarium avenaceum (Fr.) Sacc
Authors: Kollmorgen JF
Published: November 2004

The effects of urea on the pathogenicity of Fusavium avenaceum (Fr.) Sacc, to wheat and of Steptomyces griseus (2-A24) and urea on the survival of F. avenaceum were examined. In pot experiments, urea amendments increased the severity of symptoms and reduced the dry weight and height of infected seedlings. Survival of F. avenaceum in oaten straw artificially infected with the fungus was studied in gamma-irradiated soil and in gamma-irradiated soil recontaminated with the original microflora. Over the test periods of 17 and 34 weeks, a urea amendment reduced survival only in the recontaminated soil, whereas S. griseus (2-A24) did so in both soils, the reduction being greater in the absence of other microflora.
Effect of abomasal infusions of methionine, casein, and starch plus methionine on the wool production of Merino wethers fed on lucerne or wheaten chaff
Authors: Dove H , Robards GE
Published: November 2004

Merino wethers received daily abomasal infusions of (a) 2.6 g DL-methionine, (b) 80 g casein protein or (c) 2.6 g DL-methionine plus 87 g maize starch, while consuming either lucerne chaff or wheaten chaff. Responses in wool growth, nitrogen metabolism and body weight were measured. Sheep fed on lucerne chaff had a higher urinary nitrogen excretion and nitrogen retention than those fed on wheaten chaff regardless of the presence or type of infusion. The infusion of methionine did not markedly alter these parameters from their original levels on either diet. On both diets, casein infusion led to increased urinary nitrogen excretion and nitrogen retention. Compared with sheep given starch plus methionine infusions, those given casein had higher urinary nitrogen excretion and nitrogen retention. Changes in fleece-free body weight gain followed a similar pattern. There were no pronounced differences in faecal nitrogen excretion. Regardless of the presence or type of infusion, sheep fed on lucerne grew more wool than those on wheaten chaff. On both diets, all infusions were accompanied by higher wool growths than on the basal diet alone. The effect of the casein infusion, compared with methionine infusion, was apparent only in sheep on wheaten chaff. Wool growth rates in sheep infused with starch plus methionine were not higher than the rates in the same sheep infused with methionine alone. The results suggest that the wool production of sheep will show a greater response to abomasal supplements of sulphur amino acids or casein if they are consuming a high quality diet such as lucerne chaff, compared with a low quality diet such as wheaten chaff. The apparent failure of starch infusion to stimulate wool growth above the level obtained with methionine infusions alone is discussed in relation to the interaction of protein and energy in the growth of wool.
Population control in the Australian sheep blowfly, Lucilia cuprina, by the release of female-borne chemosterilant. I. Female to male transfer of chemosterilant during mating
Authors: Smart P , Gilmour D
Published: November 2004

N,N'-tetramethylene-bis-(1-aziridinecarboxamide), applied topically, sterilized male and female Lucilia cuprina (Wiedemann) at a dose of 10 µg per fly. Females tolerated 800 µg per fly. A female 'booby-trapped' with 400 µg of sterilant could transfer a sterilizing dose to a male during copulation. Booby-trapped females were sexually attractive and sterile males were as sexually vigorous as fertile males. The introduction of either booby-trapped females or sterilized males into cage populations caused a greater drop in fertility than expected, but the effect was probably due more to unspecific contact between flies than to mating contacts.
Studies of grain production in Sorghum bicolor (L. Moench). V.* Effect of planting density on growth and yield
Authors: Fischer KS , Wilson GL
Published: November 2004

Growth analysis was applied to grain sorghum (cv. RS610) grown at low, medium and high population densities, i.e. 14,352, 143,520 and 645,836 plants ha-1 respectively. The medium densities had two arrangements of plants, square (S) and rectangular (R). Crop growth rates, inflorescence growth rates, leaf area indices, net assimilation rates and leaf growth rates were calculated from growth functions of plant dry matter and leaf area over time. Differences in crop growth rate between populations in the early stages were attributed to leaf area development—specifically to the initial leaf area (dependent on seedling number) and not to differences in leaf growth rates. Peak crop growth rates were 15.0, 27.5, 26.0 and 45.8 g m-2 day-1 for the low, medium (S), medium (R) and high populations respectively.The large difference between the growth rates of the medium (S) and the high populations was not explained by differences in the amount of radiation intercepted. Although leaf area indices were 4.6 and 10.2 respectively for the two populations, both canopies intercepted almost all of the noon radiation. Light extinction coefficients were 0.45 and 0.29 respectively. The relationship between net assimilation rate and leaf area index was such that for comparable leaf area indices above 2, plants at higher densities showed greater improvement in yield per unit increment in leaf area index. A maximum grain yield of 14,250 kg ha-1 was obtained at the high population density as a result of higher dry matter production, but a similar harvest index to that of the crops grown at the other densities. Inflorescence growth rate (g m-2 day-l) slightly exceeded crop growth rate in the latter part of grain filling, which indicated that there was some retranslocation to the grain of previously assimilated material. The maximum grain yield represents an efficiency of utilization of short-wave solar radiation during crop life of 2.5 x 10-6g cal-1.

*Part IV, Aust. J. Agric. Res., 26: 25 (1975).