bluuebunny/crossref_metadata_2025 huggingface dataset:
Some effects of nitrification inhibitor (2-chloro-6(trichloromethyl)pyridine) on the use of fertilizer nitrogen and the growth of two wheat varieties
Authors: Osborne GJ
Published: March 2005

A glasshouse experiment was done at Wagga Wagga, New South Sales to assess the value of a nitrification inhibitor2-chloro-6-(trichloromethyl)-pyridine ('N-serve' (R)) as a means of slowing down the rate of nitrification of ammonium added to a red earth soil. The effect of this chemical on the growth of a standard height and a semi-dwarf wheat variety was also assessed. The results indicate that a concentration of only 5 p.p.m. of the inhibitor in this soil slowed down the rate of nitrification of ammonium for up to 140 days. Although 'N-serve' was apparently phytotoxic to volunteer ryegrass and clover at the 5 p.p.m. level, the yield of wheat dry-matter after 60 days and grain at harvest were not significantly affected by concentrations of up to 10 p.p.m. in the soil. However, at the 10 p.p.m, level of inhibitor maturity was delayed.
Techniques for long-term storage of table grapes
Authors: Hedberg PR
Published: March 2005

Table grape storage experiments were conducted in 1974 and 1975 with Nyora grapes to enable the extension of marketing periods. Grapes were packed in half-bushel (450 mm x 290 mm x 135 mm) boxes and stored in a standard cool room with various treatments. In 1974 two-stage SO2 generators, polyethylene liners and tight or loose packing were compared using grapes treated with field benomyl sprays. SO2 generators proved very effective in maintaining grape quality, particularly when used with polyethylene liners and a loose pack, enabling a storage life of four months. In 1975 the best treatment was reassessed in both wooden boxes and the cheaper cardboard box. Unwaxed cardboard boxes were inferior to wooden boxes for storing grapes. Field benomyl sprays were marginally beneficial in controlling moulds in storage. In 1975 benomyl treated grapes packed loose with a polyethylene liner and two-stage SO2 generators, were kept in an acceptable condition for six months.
The relationship between protein, essential amino acids and energy requirements of broiler chickens fed practical diets
Authors: Guirguis N
Published: March 2005

The relationship between dietary protein, essential amino acids (EM) and energy was examined in two experiments using male broiler chicks fed practical diets to eight weeks of age. All diets contained a balanced proportion of ten EAA which was maintained over various treatments. Growth of birds was closely related to the EAA content of the diet and poorly related to dietary protein content. When the dietary concentration of ten EAA was treated as a combined unit and expressed as proportion of diet, 7.6 per cent EAA in an 18 per cent protein starter diet and 5.8 per cent EAA in a 16 per cent protein finisher diet were adequate to support maximal growth of male birds to eight weeks of age. Feed intakes were reduced as energy concentrations increased in diets regardless of protein content of diets.
Pedigree investigation using biochemical markers: the wheat cultivar Gabo
Authors: Wrigley CW , Shepherd KW
Published: March 2005

Biochemical tests for characterizing genotype were used to investigate the pedigree of the important Australian wheat Gabo. Although its registered pedigreeis (Bobin Selection x Gaza) x Bobin Selection, there have been suggestions that the recurring parent is Gular, not Bobin. Phenol reactions (grain and glume) and electrophoresis/isoelectric focusing patterns (gliadins) were obtained for a number of different accessions of Gabo, Gaza, Bobin and Gular. Gabo and Gaza samples were uniform; Bobin and Gular samples were not. The characteristics of most Bobin and Gular samples were inconsistent with their being a parent of Gabo. The results indicated that a sample called 'Bobin Selection W39' was the parent used in the cross with Gaza to produce Gabo, and that this selection was probably not Bobin, but a sample of Gular similar to that accessioned as 634 at the Waite Agricultural Research Institute.
Milk yields of cows fed maize and molasses supplements to tropical pastures at two stocking rates
Authors: Cowan RT , Davison TM
Published: March 2005

Twenty-four Friesian cows grazing green panic (Panicum maximum var. trichoglume)-glycine (Glycine wightii cv. Tinaroo) pastures at 2 or 4 cows ha-1 were fed no supplement, 2.4 kg maize or 3.0 kg molasses cow-1 day-1. The experiment was a randomized block design and of six months duration. Milk yield and composition were similar for cows fed maize and molasses and these supplements increased average milk yield from 10.3 to 11.8 kg cow-1 day-1 (P < 0.05). Increased stocking rate reduced milk yield from 12.7 to 9.8 kg cow-1 (P < 0.01). Interactions of stocking rate with type of supplement were not significant (P > 0.05). The level of supplement intake and yield of pasture on offer accounted for 52 per cent of the variation in average milk yields (P < 0.01). Of the variation in milk yields between paddocks only 5 per cent was unaccounted for by this relationship.
Genetic improvement of meat sheep. 5. Heritability of post-weaning weight and gain in Dorset and Border Leicester sheep
Authors: Gregory IP , Roberts EM , James JW
Published: March 2005

The heritability of corrected post-weaning weight has been estimated for both Dorset and Border Leicester sheep and the heritability of corrected post-weaning gain and the repeatability of body weight for Dorset sheep. In the Dorsets, the half-sib heritabilities of corrected post-weaning weight were 0.36, 0.1 4 and 0.28 respectively for rams, ewes and pooled over sexes. The corresponding parent-offspring heritabilities were 0.17, 0.32 and 0.25 respectively. The half-sib heritabilities of corrected post-weaning gain were respectively 0.28, 0.21 and 0.32 and the corresponding parent-offspring estimates -0.31, 0.03 and -0.14. The repeatability of body weight was estimated as 0.64 for both sexes. In the Border Leicester, the half-sib heritability of corrected post-weaning weight was 0.26, 0.17 and 0.23 for rams, ewes and pooled over sexes respectively. The corresponding parent-offspring estimates were 0.09, 0.04 and 0.06. Heritabilities were estimated on a within-property basis and then pooled over properties. Two methods of pooling the half-sib heritabilities were compared: 1. pooling the sums of squares and cross products and degrees of freedom and 2, pooling by weighting each estimate by the inverse of its variance. Pooling by method 1. resulted in consistently higher estimates than did pooling by method 2. Reasons for this are discussed.
Comparative effects of calcium carbonate on growth, nodulation, and chemical composition of four Leucaena leucocephala lines, Macroptilium lathyroides and Lotononis bainesii
Authors: Hutton EM , Andrew CS
Published: March 2005

The comparative effects of CaCO3 on growth, nodulation and chemical composition were determined in four Leucaena leucocephala lines (three bred), Macroptilium lathyroides and Lotononis bainesii grown in pots of an acid soil. Calcium carbonate treatments were equivalent to nil, 250, 750, 1250 and 2500 kg ha-1 (Ca0 to Ca4). L. leucocephala is a tree, well adapted to calcareous soils. M. lathyroides and L. bainesii are herbaceous species tolerant of acid soil conditions. Total dry matter production (tops+roots) of the four Leucaena lines exceeded that of M. lathyroides and L. bainesii. However, the top DM yield of the latter two species exceeded that of Leucaena due to a low top/root weight ratio in Leucaena. The Leucaena lines gave successive total DM increases up to the Ca3 treatment, the overall increase being relatively large, especially in line 3 ;at Ca4 mean DM yieldswere below those at Ca,. Both M. lathyroides and L. bainesii had significant responses particularly at the Ca1 treatment, but at the Ca4 treatment their total DM yields were reduced below those obtained with no CaCO3 addition. In all Leucaena lines there was a significant increase in nodule DM pot-1 between the Ca0 and Ca4 treatments. However, there was a decrease in nodule DM of lines 5 and 27A from the Ca3 to Ca4 treatment. Nodule DM of M. lathyroides and L. bainesii was only affected to a limited extent over the range of treatments Ca0 to Ca3, but at Ca4 a significant reduction occurred in both species. In all species CaCO3 additions progressively increased the concentration of Ca in the plant tops. The positive DM responses were considered to be primarily due to Ca, although Al may have had a confounding effect, especially in L. leucocephala. Line 3 of L. leucocephala had the highest Ca concentration as well as the greatest reduction in Al concentration.
Effects of nitrogen and phosphorus fertilizers and gypsum on a Danthonia caespitosa-Stipa variabilis grassland. 2. Residual response
Authors: Tupper GJ
Published: March 2005

The residual effects of nitrogen and phosphorus fertilizers applied over four consecutive years and gypsum applied once only, were assessed over five years on a Danthonia caespitosa-Stipa variabilis grassland, growing on the semi-arid Riverine Plain of south-eastern Australia. Totals of 155 and 31 0 kg ha-1 of N, 100 and 200 kg ha-1 of P, and 3.34 and 6.68 t ha-1 of CaS0,. 2H2O had been added. The increase in dry matter production in response to nitrogen ceased one year after the last application of nitrogen fertilizer. After five years, grassland which had received 200 kg ha-1 of phosphorus and 6.68 t ha-1 of gypsum yielded 6500 kg ha-1 of dry matter, compared with 1300 kg ha-1 in the absence of fertilizers and gypsum. Legume growth was still suppressed five years after nitrogen fertilizer had been applied, but legumes increased production greatly in response to the previous phosphorus and phosphorus-gypsum treatments. Nitrogen content of the herbage averaged 2.1 per cent four years after the previous high level phosphorus treatment, compared with 1.6 per cent with the control after four years. It was unaffected by previous nitrogen fertilizer. Phosphorus content was reduced for the first three years after nitrogen fertilizer was last added, but was increased by phosphorus fertilizer to 0.28 per cent, compared with 0.1 8 per cent on the control, four years after phosphorus fertilizer was last added. Soil moisture characteristics, and total soil nitrogen and carbon showed no differences between treatments. The Truog phosphorus in the soil under the high phosphorus level decreased from 103 p.p.m. to 53 p.p.m., compared with the unaltered control level of 7 p.p.m, over the five year period.
Estimation by calcium analysis of the proportion of grass in oesophageal fistula samples from cattle grazing grass-stylo pastures
Authors: Playne MJ , Megarrity RG , LeFeuvre RP
Published: March 2005

Variation in calcium (Ca) concentration in tropical grasses and Stylosanthes species growing in paddocks with and without superphosphate fertilizer was examined at six intervals over one year on whole plant tops and on hand-plucked samples. Variation in Ca concentration between plant parts was also measured on one sampling date. Extrusa samples obtained from cattle fitted with oesophageal fistulae in two grazing experiments were used to examine the relation between the Ca concentration and the botanical composition determined by the microscope-hit method. The concentration of Ca was 2.2 to 5.2 times greater in legumes than in grasses. While it decreased in legumes with increasing plant maturity, it remained relatively constant in the grasses, especially in those receiving fertilizer. Calcium concentration did not vary greatly between plant parts in the grasses, but the legume stems had lower (0.77 per cent Ca) concentrations than legume leaves (1.58 per cent Ca). The relationships found in the two grazing experiments did not differ, and the resulting combined equation describing it was : y = 128.4 - 82.0x (n = 40; r2 = 0.822; S y . x = 12.6) where y = per cent grass and x = per cent Ca.
An economic analysis of a 10 year rate of stocking trial with fine-wool
Authors: George JM , Pearse RA
Published: March 2005

Merino ewes were grazed for 10 years at stocking rates of 8, 12 and 16 ha-1, lambing in winter, spring or summer on a phalaris/white clover pasture on the Northern Tablelands of New South Wales. Wool production, wool yield and count, and lambing and weaning rates were established for the wide range of climatic conditions experienced. A spring lambing is indicated under the within-year price relationships experienced. Under a wide range of wool and lamb prices the optimum stocking rate varied from 12 to 16 ewes ha-1 depending on labour costs.
The effect of supplementation or fertilizer application on the utilization by sheep of Stylosanthes guianensis grown on sulphur deficient soils
Authors: Hunter RA , Miller CP: Siebert BD
Published: March 2005

Merino wethers held in individual metabolism crates were fed one of the following: a control diet of Stylosanthes guianensis; S. guianensis supplemented with 0.5 g sulphate-sulphur per head per day; or S. guianensis which had been fertilized with superphosphate (1 2 per cent S). The daily dry matter (DM) intakes and DM digestibilities of the three diets were 142 g, 0.203; 202 g, 0.296; 268 g, 0.352 respectively. The digestible dry matter intake of the animals supplemented with sulphate-sulphur was, therefore, double that of the controls, and that of animals fed fertilized hay, treble. The magnitude of the responses in each case were modified by the availability of other dietary constituents, notably nitrogen. In a second period DM intake of sheep supplemented with sulphate-sulphur and those fed fertilized S. guianensis was further increased by supplements of sodium chloride.
Root rot of subterranean clover in the irrigation areas of south-western Western Australia
Authors: Barbetti MJ , MacNish GC
Published: March 2005

Investigations in 1974 identified the fungi associated with the roots of subterranean clover at four irrigated sites at Wagerup, Western Australia. Two of these sites had previously had a disease problem, two were apparently healthy. A range of fungi were isolated, including Pythium irregulare, P. debaryanum, P. acanthicum, P. middletonii, Fusarium oxysporum, and Rhizoctonia spp. There was a more rapid buildup of Pythium spp. population following the initial irrigation, and an overall lower incidence of Fusarium spp., at the diseased sites. The incidence of Rhizoctonia spp. was usually low and variable at all sites. Disease index ratings rose more rapidly for diseased sites. No association was proven between disease incidence and soil water potential. The three most frequently isolated fungi; viz. P. irregulare, P. acanthicum, and F. oxysporum, were all shown to be capable, under the conditions of this investigation, of producing high levels of tap and lateral root rot, and of causing reductions in seedling emergence. In some cases the levels of both tap and lateral root rot were increased, and the plant emergence decreased, by the application of two or more fungi in combination in comparison with application of a single fungus. Overall P. irregulare was the most pathogenic of the fungi tested.
Response of beef cattle to infused supplements of urea and of urea-molasses when offered a low quality grass hay
Authors: Hennessy DW , Nolan JV , Norton BW , Ball FM , Leng RA
Published: March 2005

Eight Hereford steers, fistulated at the rumen and offered a low quality grass hay (Axonopus affinus comprised 75 per cent of the pasture) were studied in pens for 100 days to evaluate urea and urea-molasses supplements in terms of their effect on hay intake, rumen fermentation and liveweight changes. The hay contained 0.58 per cent nitrogen and had an apparent digestibility of 49.8 per cent. Supplements were made up in a liquid form and infused directly and continuously into the rumen so that on a daily basis 56 g urea with and without 500 g molasses, or 112 g urea with 500 g or 1000 g molasses was delivered. When urea alone was infused, rumen ammonia and plasma urea concentrations were increased (P < 0.05) but the urea had no significant effect on liveweight change, on digestible organic matter intake (DOMI) or on the pattern of rumen fermentation. When infusions of urea and molasses were given, total DOMI was increased (P < 0.08) and the pattern of rumen fermentation changed: total rumen volatile fatty acid (VFA) concentrations were increased (P < 0.05), with an increased (P < 0.05) molar proportion of propionate in one of the treatments. Neither urea nor urea and molasses infusions significantly increased the animal's intake of hay. Liveweight change was related (r= 0.60) to DOMI and it was estimated that steers in the experiment required 41 g DOM kg.-0.75 day-1 for maintenance of liveweight. This level of intake occurred only when supplements containing molasses were given. Overall, the results indicated that little improvement in growth of cattle or of their utilization of low quality pastures could be obtained from a urea supplement. However, there may be potential for molasses as a concentrate supplement for cattle grazing native pastures.
Effect of fasting on liveweight and subcutaneous fat depth of cattle
Authors: Truscott TG , Gilbert JE
Published: March 2005

Two groups of British bred steers, mean liveweight 384 kg, were held off feed for 5 days with or without water and their liveweights and subcutaneous fat depth at two points determined daily. Fat depths were determined using a Scanogram. The aim was to determine the possible effect of management during marketing on some of the carcase characteristics likely to be used for market specification in Australia. The curvilinear decrease in liveweight was less in the group with water available although their mean daily consumption of water was low (61 head-1). No difference in the rate of change of fat depth between the group with water and the group without it was detected. There was no detectable change in fat depth measured at a point 2.5 cm from the edge of the eye muscle (FD2) whereas fat depth over the eye muscle (FDI) appeared to increase in the 5 day period (0.043 mm day-1). Rates of change of fat depth at the two sites were not correlated. The rate of change of FD2 was negatively correlated (r = 0.45) with initial FD2 fat depth; in animals with an initial FD2 of < 5 mm, FD2 appeared to increase with fasting ; in animals with an initial FD2 of > 5 mm, FD2 decreased with fasting.
The effects of saline irrigation water and gypsum on perennial pasture grown on a sodic, clay soil at Kerang, Victoria
Authors: Mount JH , Schuppan DL
Published: March 2005

During five consecutive irrigation seasons at Kerang, Victoria, saline effluents were used to irrigate perennial pasture grown on a heavy clay, sodic soil. The nominal effluent salinities were 6000; 4000; 2400; 1600; 800 and 100 mg l-1 total soluble salt (TSS). After five seasons there were no significant differences in pasture dry matter yields between the 100 and 800 or 1600 mg l-1 TSS effluent treatments. In the fifth season there was a significantly higher (5 per cent) dry matter yield in the 800 mg l-1 TSS treatment when compared with the 1600 mg I-1 TSS treatment. With effluents above 1600 mg l-1 TSS, the higher the salinity the lower the pasture dry matter yield. The reason for the effluent of 800 and 1600 mg l-1 TSS producing similar yields to the 100 mg I-1 TSS is probably explained by the effects of electrolytes on soil permeability. Dry matter response to gypsum was not significant in the fourth and fifth seasons. In the second and third seasons there were significant responses at 10 and 20 t ha-1 respectively. There were no significant interactions between saline irrigations and gypsum applications. Medicago sativa (lucerne) and Lolium perenne (perennial ryegrass) proved valuable species under saline and sodic conditions. The percentage of Agropyron elongaturn (tall wheat grass) increased with salinity whereas the clover content decreased.
Nitrogen and phosphorus nutrition of dryland grain sorghum at Katherine, Northern Territory. 2. Effect of rate and source of phosphorus fertilizer
Authors: Myers RJK
Published: March 2005

Field experiments were conducted at Katherine, Northern Territory, in 1970-71 and 1971 -72 to examine responses of dryland grain sorghum to applied phosphorus at different growth stages. In the first, the effect of rate of application up to 100 kg P ha-1 as triple superphosphate was investigated. Growth responses to phosphorus were noted from mid-elongation onwards, but the magnitude of response varied between seasons, being greater in the higher rainfall season 1970-71. Maximum yields of grain were 7730 kg ha-1 with 50 kg P ha-1 in 1970-71, and 4440 kg ha-1 with 100 kg P ha-1 in 1971-72, which were increases of 49 and 37 per cent respectively over the appropriate zero phosphorus treatment. These suggested an increased requirement for phosphorus over previous recommendations. Phosphorus reduced the time from emergence to anthesis from 68 to 60 and from 70 to 63 days respectively in the two seasons. About half of the plant phosphorus was taken up after anthesis. It was concluded from soil analysis that phosphate-treated plots had an enhanced supply of phosphorus throughout the period of crop growth. In the second study, four phosphorus sources (superphosphate, triple superphosphate, monoammonium phosphate, and diammonium phosphate) were compared. With 25 kg P ha-1 and with constant nitrogen, grain yield response followed the order superphosphate > monoammonium phosphate > diammonium phosphate > triple superphosphate in both years. Triple superphosphate tended to give lower dry matter yields and nitrogen and phosphorus concentrations than the other three sources.
Effects of different feeding regimes during lay of egg-type pullets fed either high or low-protein diet during rearing
Authors: Abu-Serewa S
Published: March 2005

The performance of two groups of pullets reared on either high or low-protein diets was compared under six feeding regimes from 20 to 68 weeks of age. Pullets fed the low-protein (10 per cent) diet from 4 to 20 weeks ate about 20 per cent less food during rearing, were significantly lighter at 20 weeks and were delayed in attaining maturity compared with pullets reared on the high-protein diet. In the period from 20 to 36 weeks of age, pullets reared on the high protein diet laid at a higher rate when fed a laying diet containing 17 per cent protein than with a diet containing 15 per cent protein supplemented with methionine, or 13 per cent protein supplemented with methionine and lysine to the N.R.C. (1971) levels. In contrast, pullets reared on the low-protein diet laid fewer eggs on the 17 per cent protein diet than on the other two diets during the same period. However, no significant rearing x laying interaction was observed in average rate of lay during the whole laying year. The low-protein group laid fewer eggs from 20 to 68 weeks than the other group of birds, but the difference in production was not significant when calculated from maturity. Average rate of lay was not affected by the level of protein in the laying diet, but egg size tended to increase with increasing the level of protein. Increasing the level of protein gradually with the advance in lay had no effect on performance relative to birds fed the 15 or 17 per cent protein diet throughout lay. Restricting the feed intake during lay to 94 per cent of that consumed by full-fed controls, or restricting the time of feeding to four hours daily, reduced egg production by 7 and 6 per cent respectively, regardless of the rearing treatment. Rate of mortality throughout the experiment was not affected by any of the rearing or laying treatments. The results of this experiment indicate that the requirement during lay of pullets reared on a low-protein diet is between 51 and 53 g protein and 900 and 1000 mg of methionine per 4.1 9 MJ (1000 Kcal) ME. This protein concentration should be increased to between 58 and 60 g protein per 4.19 MJ ME if the pullets were reared on conventional diets. Restricting feeding during lay by either of the methods used in this experiment is detrimental to egg production.
Mineral and vitamin supplementation of diets for growing pigs. 1. Wheat-based diets and the effect of preventing cross-coprophagy on the response to supplementation
Authors: Greer EB , Lewis CE
Published: March 2005

Two factorial experiments examined the effects of mineral and or vitamin supplementation on the performance of 64 growing pigs. The wheat-based diets contained either meat-and-bone meal (with some fish meal up to 32 kg liveweight) or solvent-extracted soybean meal (SBM). A basal supplement of vitamins A and D2 was added to all diets. The pigs were individually fed at restricted intakes between 18 and 73 kg liveweight and housed as mixed treatment groups. In a third factorial experiment, 32 growing pigs were restrictively fed a wheat/SBM diet from 20 kg liveweight to 75 kg or for 20 weeks. The pigs were individually housed to prevent cross-transfer of vitamins from supplemented to unsupplemented pigs by way of the faeces (cross-coprophagy). Mineral supplementation of the wheat/animal protein diet (experiment 1) did not affect pig performance, but improved the growth rate and feed conversion ratio of pigs fed the SBM diet (experiment 2) by 45 and 32 per cent respectively. Omitting the mineral supplement from the SBM diet caused loss of appetite, soft bones, joint and foot abnormalities and lameness in many pigs; 5 out of 16 pigs did not reach slaughter weight. Gilts fed the SBM diet were less tolerant of mineral deficiencies than barrows. They also stored less calcium in their bones when minerals were added to the diet. There was no response to vitamin supplementation even though both diets, but especially the SBM diet, were apparently deficient in a number of vitamins. The SBM diet provided 76, 83 and 53 per cent respectively of the pigs' estimated requirements for riboflavin, pantothenic acid and vitamin B12. In experiment 3 the SBM diet supplied 64, 80 and 28 per cent of the pigs' riboflavin, pantothenic acid and vitamin B12 requirements. As in experiment 2, there was no response to vitamin supplementation. Cross-coprophagy was thus most unlikely to have caused the lack of response to vitamin supplementation in the group-housed pigs of experiment 2. Mineral supplementation improved growth rate by 108 per cent and feed conversion ratio by 40 per cent.
Influence of water stress on yield and quality of flue-cured tobacco
Authors: McNee P , Warrell LA , Muyzenberg EWBvan den
Published: March 2005

In a field experiment with tobacco the effect of water stress at each of four times during the period of rapid growth following establishment was compared with an unstressed control. Water stress as a result of withholding irrigation was applied prior to 'budding', at 'budding', at 'early flower', and at 'full flower'. The soil moisture of the control treatment was maintained above 60 per cent of the soil moisture held at field capacity. The stress treatments ranged from 7 to 14 days and at the recommencement of irrigation the soil moisture ranged from 30-50 per cent of the soil water held at field capacity. All stress treatments were completed prior to the occurrence of either sunburn or permanent wilting. No water stress treatment applied to tobacco during the period of rapid growth following establishment improved yield or leaf quality. Depending on the timing, water stress during this growth period was shown to be detrimental to leaf yield and quality. Water stress at 'budding' reduced the harvested leaf area and cured leaf yields. Water stress during the flowering period resulted in an 'off type', 'immature' cured leaf of reduced commercial value.
The relation between sheep-time spent and egesta accumulated within an arid zone paddock
Authors: Lange RT , Willcocks MC
Published: March 2005

A small paddock on a sheep station near Whyalla, South Australia, was picked clean of egesta and marked into 30 sections. It was then stocked with 20 Merino sheep which were observed continuously for two days. The numbers of sheep in each section were scored every minute. Total accumulated egesta was recovered from each section and the relations between egesta accumulation (field weight, loose volume and oven dry weight) and sheep-time spent were examined. Regressions showed that egesta accumulation indexed sheep-time spent in the different parts of the paddock, providing a means of measuring intra-paddock stocking differences in arid-zone shrubland.
Mineral relationships in 'maturity bronzing' of banana fruit
Authors: Campbell SJ , Williams WT
Published: March 2005

Two experiments have been conducted to explore the relations between the economically important disorder 'maturity bronzing' and a number of mineral elements. Neither irrigation nor fertilizer treatments had any significant effect on the degree of bronzing. In order to eliminate the highly significant seasonal effect, analyses were carried out on deviations from the appropriate harvest means. The techniques employed were a. stepwise multiple regression, and 6, principal component analysis of the within-harvests correlation matrix, followed by varimax rotation. The results suggest that fertilizer treatments can produce profound changes in the seasonal pattern of mineral content without significantly affecting the incidence of bronzing. When the effect of season is eliminated, bronzing shows a positive association with fruit-skin Cu and leaf Ca, and a negative association with fruit-skin Ca and Mg. However, these associations are relatively weak, and the results suggest that bronzing is not a direct result of mineral imbalance.
Effect of nutrition of dairy cows in late pregnancy on milk production
Authors: Rogers GL , Grainger C , Earle DF
Published: March 2005

Three experiments were carried out to examine the separate effects of rate of liveweight gain in late pregnancy and of body weight of cows at calving on subsequent milk production. In each experiment, cows were allocated to one of two treatments about 12 weeks before calving. They were then fed so that by six weeks before calving there was a difference of about 50 kg liveweight between the animals in the two groups. In the first experiment, the two groups were then fed to gain weight at either 1.0 or 0.5 kg day-l so as to calve in similar body condition. In the second experiment, the two groups were fed to gain 1.5 kg day-1 or maintain weight so that again they calved in similar condition. In the third experiment both groups had similar rates of liveweight gain, 0.7 kg day-1 in the last six weeks of pregnancy, so that there was a difference of 51 kg at calving. In the first two experiments there were no differences due to the contrasting pre-calving nutrition in the milk production of the two groups, but in the third experiment the cows calving with the heavier body condition had a 7% greater milk yield and a higher milk fat concentration in the first 100 days of lactation. The results demonstrate that body condition of cows at calving is the important factor affecting milk production and that liveweight trends per se prior to calving were unimportant in influencing subsequent milk production. These findings offer dairy farmers alternative choices of feeding and grazing management strategies to improve cow condition at any stage during the dry period.
Effect of sowing time on the development, yield and yield components of some cultivars of Lupinus angustifolius and Lupinus luteus in northern Tasmania
Authors: Garside AL
Published: March 2005

Experiments to examine the effect of sowing time on the lupin cultivars Uniwhite, Uniharvest and Unicrop (L. angustifolius) and Weiko Ill (L. luteus) were sown in northern Tasmania in 1973 and 1974. The best yields resulted from autumn sowings in 1974 (3.7 t ha- 1) and from winter and spring sowings in 1973 (3.5 and 3.3 t ha-1, respectively). The results indicate that acceptable yields can be obtained from both autumn and early spring sowings. In addition, a number of factors are discussed that suggest spring sowing is safer and better suited to the cropping system. Yield differences between Uniwhite, Uniharvest and Unicrop were small for sowings between May and September, but Unicrop yielded better with later sowing. The yield of Weiko IIIwas poorer than the other cultivars except after very late sowing. Uniwhite and Uniharvest failed to mature when sown after late October.
Use of exchangeable potassium in assessing potassium availability in Tasmanian soils
Authors: Graley AM , Nicolls KD
Published: March 2005

Three sequential surveys of exchangeable potassium (Exch. K) in the surface 10 cm of major Tasmanian soils are presented, together with data from surface samples of profiles collected earlier. Soils with Exch. K less than 0.4 m.equiv 100 g-1 are considered to be low or marginal in potassium readily available for pasture growth. Lateritic podzolic soils were lowest in Exch. K, with four-fifths of the sample sites below 0.4 m.equiv 100 g-1 (median value 0.21 m.equiv 100 g-1). Podzols and humus podzols were similarly low. Available potassium was low to marginal in yellow podzolic soils on sandstone and solodized solonetz and solodic soils. Moderate contents were found in yellow podzolic soils on mudstone, the only soils with appreciable illite, and in organic alluvial soils. On basalt, krasnozems had moderate available potassium but black earths and prairie soils were marginal. On dolerite, non-calcic brown soils had ample potassium (median Exch. K 0.93 m.equiv. 100 g-1) but grey-brown podzolic soils had much less. Most soils showed high variability between farms and one krasnozem soil series had high variability between paddocks within farms. Coefficients of variation ranged from 42 to 58%, in agreement with corresponding values reported by other workers. The contents of Exch. K found are interpreted in terms of factors of soil formation and of land use.
Effect of time of sowing on wheat phenology in South Australia
Authors: French RJ , Schultz JE , Rudd CL
Published: March 2005

Relations between the growth intervals in wheat and meteorological variables were defined from time-of-sowing field experiments. The major factors affecting the duration of each interval were the date of sowing, the day-degrees of maximum air temperature and daylength. Equations to predict the number of days in a growth interval were tested against measurements made in other wheat growing districts. The relations between day-degrees of maximum air temperature and sowing date gave best predictions of the growth intervals in various districts. The data have application for estimating flowering dates and potential yield, and for estimating harvest dates,
Resistance to sorghum midge (Contarinia sorghicola Coquillet) in grain sorghum
Authors: Page FD
Published: March 2005

Standardized levels of infestation of sorghum midge Contarinia sorghicola Coquillet were used to compare the levels of resistance in sorghum cultivars (Sorghum bicolor) in glasshouse experiments at Biloela in Central Queensland. Sorghum heads were reduced to 250 florets and ten female midges were caged over each head on three consecutive days during anthesis. Two breeding lines from the U.S.A., IS 12608C and IS 12664C were superior (P < 0.01) to Alpha and KS 19 in percentage seed set and number of midge progeny produced. The percentage seed set was 50, 54, 22, 12 for IS 12608C, IS 1664C, Alpha and KS 19, respectively. The Indian line Q 13828 was susceptible. Testing with a standardized level of infestation is a useful technique for screening parents in a breeding program aimed at incorporation of midge resistance into agronomically useful hybrid cultivars.
Beef production from native pastures sown to fine-stem stylo in the Burnett region of south-eastern Queensland
Authors: Bowen EJ , Rickert KG
Published: March 2005

At Gayndah, south-eastern Queensland, a native Heteropogon contortus pasture, sown to fine-stem stylo (Stylosanthes guianensis var. intermedia), and invaded by red natal grass (Rhynchelytrum repens), was grazed by weaner steers from June 1 in three treatments : heavy and light put-and-take grazing for five years from 1971, and set-stocked at 1.37 animals ha-1 for two years from 1974. Weight gains in the put-and-take treatments were not significantly different. The mean annual liveweight gain was 167 kg animal-1 at a mean equivalent stocking rate of 1.47 animals ha-1. Over the same period unsown native pasture, cleared of timber, gave a gain of 62 kg animal-1 at 0.62 animals ha-1. In all seasons except summer, weight gains declined linearly with stocking rate and in 1972-73, with a mean equivalent stocking rate of 2.66 animals ha-1, the annual gain was almost halved. When equivalent stocking rates were 0.9, 0.9, 1.8 and 1.2 animals ha-1 in winter, spring, summer and autumn, the respective gains were 4, 73, 65 and 45 kg animal-1. The set-stocked treatment had a mean annual gain of 147 kg animal-1. At another site 116 km north-west of Gayndah, two paddocks of Heteropogon contortus and fine-stem stylo were set-stocked with weaners over four years. One paddock had four applications of superphosphate of 250 kg ha-1. The mean annual liveweight gains were significantly different, being 154 and 143 kg animal-1 in the fertilized and unfertilized paddocks at mean stocking rates of 0.83 and 0.74 animals ha-1, respectively. In a grazing protection experiment the density of fine-stem stylo declined exponentially with an accumulation of pasture dry matter in spring and summer. Heavy continuous grazing, an annual hay cut and an accidental fire all increased the density of fine-stem stylo. Management options to maintain the density of fine-stem stylo and the relative importance of the legume and grass to animal production are discussed.
Oestrus, ovulation and ovum transport in young Merino ewes
Authors: Blockey MAde B , Holst PJ , Makin AW , Cahill LP
Published: March 2005

Three groups of Merino ewes were studied to determine the effect of age of ewe (1 1/2 vs 2 1/2 years) and parity (0 vs 1) on the oestrus-ovulation relation and on the rate of ovum transport through the oviduct. Parity rather than age increased duration of oestrus from 11.6 hours in nulliparous I 1/2-year-olds to 17.4 hours in primiparous 2 1/2-year-old ewes (P < 0.01). As a result, 65% of primiparous ewes were still in oestrus by 15 hours before ovulation (the optimum time for conception) compared with 28.5% of the nulliparous ewes (P < 0.05). Ovum transport through the oviduct in the 48 hours after ovulation was similar in all groups. The study provides supportive evidence for the hypothesis that nulliparous 1 1/2-year-old ewes have higher ovum wastage than older, parous ewes because of their shorter duration of oestrus.
A comparison of four pasture types for the wheat belt of southern New South Wales
Authors: FitzGerald RD
Published: March 2005

Four pasture types: subterranean clover/annual grass, subterranean clover/phalaris, lucerne/ subterranean clover, and lucerne/phalaris/subterranean clover were grazed by dry ewes at two stocking rates (8.9 and 13.3 sheep ha-1) from August 1969 until May 1973. Sheep on pasture containing lucerne were an average 2.4 kg heavier than sheep on subterranean clover with phalaris or annual grass. The difference increased to as much as 7 kg in summer and was usually maintained over the winter. Sheep on subterranean clover/phalaris pastures were heavier in favourable seasons and lighter in poorer seasons than those on subterranean clover/annual grass. Generally, these liveweight effects were reflected in wool production.
Water use of sunflower crops
Authors: Anderson WK
Published: March 2005

The potential, or energy-limited evapotranspiration, and the actual, or soil water-limited evapotranspiration functions of sunflower were estimated by lysimetry and field soil water measurements. The functions show that peak water demand by the crop is in the immediate post-anthesis period and that sunflower is capable of restricting its water use when some 70% of the maximum available water remains in the root zone. With the aid of these functions, weekly estimates were made of the water use of thirteen commercial sunflower crops in northern New South Wales. Estimated water use ranged from 150 to 320 mrn and water use efficiencies from 1.9 to 10.5 kg seed mm-1 water used. Highest yields and water use efficiencies were associated with a combination of high total water supply (soil water at sowing plus rainfall during growth of 380 mm or more) high water use (220 mm or more) and low evaporative demand (below 780 mm of pan evaporation). Based on the water use characteristics of the crop the optimal sowing time in most areas is mid summer. However, spring sowings may be preferable for winter rainfall areas where soil water storage capacity is high and there is only a small component of summer rain. Crops sown in spring, even with high stored soil water (up to 200 mm) failed to yield as well as those sown in summer with much lower soil water storage.
The herbage intake, eating behaviour and calf production of beef cows grazing improved pastures on the Northern Tablelands of New South Wales
Authors: Hennessy DW , Robinson GG
Published: March 2005

The effects of grazing pressure on herbage intake and grazing performance of Hereford breeding cows were studied during 1974-75 at Glen lnnes on the Northern Tablelands of New South Wales. The objective was to identify a grazing pressure that allowed a high output of weaner liveweight per unit area without deleterious effects on cows or pastures. Grazing pressure was expressed through stocking rate equivalents of 0.93 (L), 1.22 (M) and 1.49 (H) cows ha-1 for two replicated groups, which contained five cows and one oesophageally fistulated heifer. Measurements were taken each month from August to November of the characteristics of the pastures and of the grazing performance of the cows. Overall there was less herbage available to cows in the second year but at the L and M grazing pressure there was no significant difference between cow performance. Cows were lighter (P < 0.01) and weaned lighter calves from the H grazing pressure in both years even though a hay supplement was given during lactation (September-October). Intake of digestible organic matter (DOMI) by pregnant cows decreased from autumn to winter at all grazing pressures. This coincided with a decrease in the availability of pasture dry matter (PDM) in the winter. With the onset of calving in late winter (August), cows increased DOMI by 43% due partly to increased grazing times (28% longer) and partly due to the ability of cows to ingest more of the available herbage (86% more DOM kg-1 PDM). This altered grazing pattern apparently was an attempt by cows to obtain their requirements for lactation from the low PDM in late winter. The mean 200 day weaning weight of calves of 187 kg suggested that cows and calves in L and M were successful in compensating, whereas the 165 kg weaners in H indicated that these cows and calves were less so. The results indicate that under similar conditions to the experiment a stocking rate of 0.93-1.22 cows ha-1 would permit a high output of weaner liveweight per ha without deleterious effects on cows or pastures. However, with these stocking rates it was suggested that calving should be delayed for 2 to 4 weeks to best match cows' energy demands for lactation to the Spring growth of highly digestible herbage.
A comparison of the forage value for sheep of buckwheat and sorghum stubbles grown on the Southern Tablelands of New South Wales
Authors: Mulholland JG , Coombe JB
Published: March 2005

Two grazing experiments were conducted to evaluate buckwheat and sorghum stubbles as forage for sheep. The stubbles were stocked by young crossbred wethers at 10 and 20 ha-1 for 55 days on the buckwheat and 81 days on the sorghum. Measurements were made at regular intervals of the availability and composition of plant material, diet selection, the intake of digestible organic matter (DOM) and liveweight change, while wool production was measured over each experimental period. More than one-third of the sheep grazing buckwheat stubble were affected by fagopyrism (buckwheat poisoning) and this probably reduced both liveweight gain and wool production. Buckwheat residues had a similar nitrogen content to sorghum (1 .0% vs 0.87%), but a lower organic matter digestibility (43.7% vs 57.1%). Mature buckwheat plants were not eaten readily. Mean liveweights of sheep on buckwheat stubble declined throughout the experimental period and overall changes were -3.8 and -7.0 kg for the low and high stocking rates, respectively. Corresponding values for sheep on sorghum stubble were 0.3 and -4.6 kg, although weight losses at the higher stocking rate did not occur until after 40 days grazing. For the same length of grazing as the buckwheat (55 days) the liveweight changes for sorghum were 0.2 and -1.2 kg, respectively. Wool growth rate was low for both stubbles but was more than 60% higher for sheep on the sorghum. Values for each stocking rate were 3.86 and 2.67 (g clean dry wool day-1) for the buckwheat, and 5.39 and 4.33 for the sorghum. It was concluded that sorghum stubble is a useful source of grazing for sheep on the Southern Tablelands but buckwheat stubble, because of its low acceptability, poor nutritional value and the risk of fagopyrism, is of very limited value.
Evaluation and calibration of an automated rising plate meter for estimating dry matter yield of pasture
Authors: Earle DF , McGowan AA
Published: March 2005

An automatic rising plate meter called the Ellinbank Pasture Meter (EPM) was constructed and evaluated at the Dairy Research Institute (Ellinbank) for measuring the dry matter present on a pasture dominated by green perennial rye grass. The meter readings of pasture height were found to correlate linearly with pasture yield, and the coefficient of variation of calibrations on any one date averaged about 13%. When the data from a large number of calibrations from separate dates were pooled, the coefficient of variation increased to about 18% (RSD 370 kg ha-1). Although there was a high level of repeatability of readings within operators, a substantial degree of variation existed between operators. The diurnal variation in dry matter percentage of pasture had only small effects on the meter readings. The EPM has an advantage over other pasture measuring methods in that its automatic function enables up to one hundred pasture measurements to be made in five minutes. In direct comparison with a manual rising plate meter and a two probe electronic capacitance meter, it was found that there was no significant difference in accuracy between the three meters but the advantages of the EPM are discussed. On perennial rye grass/white clover pastures in an actively growing vegetative state, the EPM has been found to be accurate enough for research purposes yet simple enough for use by farmers and their advisers as an aid to pasture management.