bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of rust (Phakopsora pachyrhizi) on soybean yield and quality in south-eastern Queensland
Authors: Ogle HJ , Byth DE , McLean R
Published: November 2004

In a field trial conducted at the University of Queensland Research Farm, Redland Bay in 1976, plots of soybeans were protected from rust, Phakopsora pachyrhizi, with mancozeb sprays for varying periods after sowing. Seed yield losses were 60–70% in the most severely rusted plots. In a glasshouse trial, rust inoculations were commenced at regular intervals during growth, and yield was reduced by 95% in plants inoculated immediately prior to flowering. In both trials, reduced yield was associated with reductions in the number of filled pods per plant, the number of filled seeds per plant and seed weight. The oil but not the protein content of the seed was also reduced in the more severely rusted treatments in the field trial.
The inhibitory effect of light on seed and burr development in several species of Trifolium
Authors: Taylor GB
Published: November 2004

The effect of light on seed and burr development was studied in 20 genotypes from four species of Trifolium. Burrs produced from spaced laterals were enclosed in plastic tubes variously shaded to produce a range of light treatments. Light inhibited seed development to varying degrees in a range of subterranean clovers, which included strains of T. israeliticum and of all three subspecies of T. subterraneum. In four strains studied intensively the weight of seeds per burr decreased linearly with increases in the logarithm of the light intensity. Light had no effect on seed development in two other geocarpic species, T. batmanicum and T. globosum, which do not actually bury their burrs. The weight of both the pod walls (pericarps) and the sterile calyces was reduced by light in all strains of T. subterraneum. Light also reduced the weight of pod walls in T. israeliticum but had little effect on the production of sterile calyces. Variation in the pattern of light response between plants of the Seaton Park strain of T. subterraneum was found to be associated with genetically distinct lines. Four of the subterranean clover strains commonly produced twin-seeded pods in dark and low light treatments. The incidence of twinning in these strains appeared to be greater than that normally encountered in buried burrs. The ranking of strains of T. subterraneum for susceptibility to light agreed reasonably well with the ranking of the same strains, by others, for seed development above ground. Seaton Park and, to a lesser extent, Dinninup were exceptions in that they were more severely inhibited by light than by lack of burr burial. It is suggested that another factor in addition to light may be involved in the response to burr burial.
Effect of temperature on the development of two annual medics
Authors: Clarkson NM , Russell JS
Published: November 2004

Development of two annual medics (Medicago scutellata cv. Robinson and M. truncatula cv. Jemalong) was recorded under four controlled day/night temperature regimes of 12/5°, 18/11°, 24/17° and 30/23°C. Equations expressing the fractional daily increments of development as a function of daily mean temperatures were derived from the results. From these equations and field temperature data, predictions of development in the field were compared with observations from 24 serial monthly plantings at Warwick in southern Queensland. Predictions were satisfactory for all stages from planting to first mature pod for cv. Robinson and for all stages except flowering for cv. Jemalong. Inclusion of a vernalization constraint with daily minimum temperatures improved the prediction of flowering, but unknown factors delayed this stage in plantings of cv. Jemalong from January to April.
The effect of residual grain on the utilization of sweet lupin stubbles and concurrent changes associated with lupinosis, in particular changes in liver copper and zinc in weaner sheep
Authors: Croker KP , Allen JG , Masters HG , Petterson DS
Published: November 2004

An experiment was conducted with Merino wether weaners to examine the influence of lupin grain on the utilization of stubbles from crops of sweet, narrow-leafed lupins (Lupinus angustifolius cv. Unicrop). Sheep grazed at 25 ha-1 without additional grain or with grain (350 kg ha-1) added to the stubble gained weight over 65 days, but those with the additional grain grew faster (av. 126 v. 77 g d-1). At 50 ha-1, sheep grazed on normal stubble gained weight for only 44 days at a mean rate of 82 g d-1, while those with the additional grain (350 kg ha-1) reached a peak weight after 65 days of little growth (31 g d-1). The sheep developed lupinosis. Those grazed at 50 ha-1 suffered more liver damage than those at 25 ha-1, and liver copper levels increased while zinc levels decreased as the severity of liver damage increased. Plasma ornithine carbamyl transferase (OCT) was of minimal value in the diagnosis of lupinosis.The levels of plasma glucose were generally higher in the sheep grazed at the low stocking rate.
The digestion of barrel medic (Medicago truncatula) hay and seed pods by sheep
Authors: Denney GD , Hogan JP , Lindsay JR
Published: November 2004

Experiments were conducted to determine the digestion and utilization of barrel medic hay and pod fed separately to penned sheep. Estimates were made of intake and digestion in the whole tract. Rates of passage of digesta from the stomach and intestines were estimated by reference to radioactive markers. The organic matter of pod contained 23.8% crude protein, 5.2% long-chain fatty acids and 77.5% acid-detergent fibre including 19.9% lignin. Organic matter digestibility was only 24.3%, largely because of poor digestibility of fibre. Protein utilization was inefficient because of high loss of dietary protein in the rumen and poor digestibility in the small intestine. Only 20.3% of protein intake was absorbed from the small intestine. High loss of protein in the rumen was verified by high rumen ammonia levels, 52 mg nitrogen/100 ml rumen liquor. Long-chain fatty acids present in the pod diet, mainly in polyunsaturated form, were extensively hydrogenated in the stomach. Although only a small loss of fatty acids occurred in the stomach, 72% of the intake was absorbed from the small intestine. Pods provided only small amounts of nutrients, derived mainly from the digestion of seeds. However, energy derived from pods should be used efficiently, as a high proportion of absorbed nutrients consisted of long-chain fatty acids and amino acids. Barrel medic hay had an organic matter digestibility of 65% and contained 16.9% crude protein. Digestibility of organic matter in the stomach and intestines resembled that of lucerne, and it was concluded that barrel medic hay was similar in nutritive value to good quality lucerne hay.
A study of sheep grazing a belah (Casuarina cristata)–rosewood (Heterodendrum oleifolium) shrub woodland in western New South Wales
Authors: Leigh JH , Wilson AD , Mulham WE
Published: November 2004

A 5-year study (1969–1974) was made of the effects of the different grazing pressures on animal productivity and the vegetation of a belah (Casuarina cristata Miq.)–rosewood (Heterodendrum oleifolium Desf.) shrub woodland set-stocked by Merino wethers at three stocking rates (0.16, 0.25, and 0.5 sheep/ha). Most of the pasture species were short-lived and the plant biomass present fluctuated considerably from year to year (200–2000 kg/ha), depending on the amount of rainfall received. The two principal components of the pasture were Stipa variabilis Hughes and Sclerolaena diacantha (Nees) Benth., both of which were dependent on seedling recruitment rather than on perenniality for their continued existence within the pasture. The animals preferred forbs and green grass when these were available; at other times Sclerolaena spp. became the major part of the diet. There were few species that were unacceptable to the sheep. Analyses of extrusa collected from fistulated animals showed that the nitrogen content of the diet was generally 2% or above, and in vitvo digestibility within the range 52–67%, falling below that range only when forage availability was lower than about 50 kg/ha. Wool production reached a peak in spring of 16–18 g clean wool per day with a plateau of 12–14 g/day at other times, unless influenced by low levels of forage availability. Of the three stocking rates imposed, only the low rate (0.16 sheep/ha) proved capable of sustaining the animals at a satisfactory level of production throughout the 5-year period. At 0.25 sheep/ha, it was considered that the sheep could be maintained satisfactorily for extended periods, whilst at the high rate (0.5 sheep/ha) productivity could only be maintained for relatively short terms. Despite the difference in grazing pressures, few permanent differences were observed in the vegetation composition. The data suggest that it is unlikely that any form of sheep management other than the traditional continuous grazing would result in higher, or more stable, animal productivity or be of any permanent benefit to the pasture.
Milk replacers containing isolated groundnut protein for preruminant lambs: the effect of protein concentration and energy intake on the requirement for lysine
Authors: Phillips DD , Walker DM
Published: November 2004

Preruminant male crossbred lambs, aged 2-5 days at the start of the experiment, were fed on milk replacers that contained groundnut protein isolate as the sole source of protein, supplemented with graded levels of L-lysine hydrochloride. A series of 6x 6 change-over designs with 4-day dietary periods was used in experiments 1 and 2, and a conventional 14-day nitrogen balance in experiment 3. Estimates were made of the minimum intake of lysine coincident with the maximum animal response (MIMR)-measured as maximum nitrogen balance (NB) or minimum plasma urea nitrogen (PUN) concentration. In experiment 1 three diets with different protein concentrations (0.11, 0.18 and 0.25 of total energy as protein) were compared at a controlled intake of gross energy (0.88 MJ/day per kg0.73). At each protein concentration the response to six graded levels of L-lysine hydrochloride was measured. In experiment 2 a diet of constant protein energy concentration (0.25) was offered at three different intakes of energy (0.63, 0.88 and 1.13 MJ/day per kg0 73). At each level of energy intake the response to six graded levels of L-lysine hydrochloride was measured. In experiment 3 a milk replacer containing 0.25 protein energy was offered at a constant intake of 0.88 MJ gross energy/day per kg0 73 and, as in the previous experiments, the response to SIX graded levels of L-lysine hydrochloride was measured. The MIMR for lysine (expressed as a percentage of dietary protein) decreased curvilinearly with an increase in protein concentration, but was unaffected by an increase in the intake of energy. Estimates based on PUN were similar to those based on NB, but the errors associated with the estimates were greater at the lowest protein concentration in experiment 1 and at the lowest intake of energy in experiment 2. Estimates of MIMR in experiments 1 and 3 were in close agreement.
Suppression of take-all by some Australian soils
Authors: Wildermuth GB
Published: November 2004

Soils with 17 different cropping histories in Australia and overseas were tested in a pot bioassay for suppression of take-all. Of the 10 that were partially or fully suppressive, only two were from under continuous wheat. The most suppressive soils were from under pasture, although not all pasture soils were suppressive. Most natural or fumigated soils without take-all inoculum but planted to wheat were non-suppressive. However, where live inoculum of Gaeumannomyces granzinis (Sacc.) Arx & Olivier var. tritici Walker either as oat grain inoculum or as mycelium was added to fumigated soil, with or without wheat plants, suppression was induced.
Effects of shading on the growth and nitrogen content of green panic and Siratro in pure and mixed swards defoliated at two frequencies
Authors: Wong CC , Wilson JR
Published: November 2004

A study was made of the effect of illumination at 100, 60 and 40% of sunlight on the growth of Macroptilium atropurpureum cv. Siratro and Panicum maximum var. trichoglume cv. Petrie (green panic) in pure and 50150 mixture swards, dcfoliated every 4 (D4) 01 8 (D8) weeks. The plants were grown without nitrogen fertilizer on a soil of moderate nitrogen status. Shading to 60 and 40% of full sunlight increased the shoot yield of green panic in pure sward by 30 and 27% respectively in the D8, but reduced it in the D4 treatment by 3 and 14%. Shade (40% full sunlight) reduced the shoot yield of Siratro in pure swards by 38 and 33 % in the D4 and D8 treatments. Nitrogen accumulation in green panic was markedly improved by shading: the increase in shoot nitrogen yield in pure sward under 60 and 40% light levels was 29 and 32% for the D4 and 45 and 76 % for the D8 treatment. All plant fractions of green panic increased in percentage nitrogen with increasing shade. The nitrogen yield of Siratro in pure sward declined with shading in proportion to dry weight. Shaded green panic swards had a higher leaf area index, better distribution of leaf area with height, and lower light extinction coefficients. The individual leaves had greater photosynthetic activity than those from the full sunlight swards. Shade-grown Siratro swards had a lower leaf area index and their leaves had a lower photosynthetic potential than in the full sunlight treatment. Nodulation was reduced under shade. Competition between green panic and Siratro was most severe in relation to shoot yield, and was accentuated by shading, frequent defoliation, and time. The proportion of Siratro in the mixture declined from 40 % initially to as low as 4-6 %. The extra competitiveness of the tropical grass, green panic, under shade in this experiment was due to a substantially increased ability to accumulate nitrogen and also to changes in canopy structure. In soils of markedly different nitrogen status or with nitrogen fertilizer the shade response might be modified.
Variations in morphine, codeine and thebaine in the capsules of Papaver somniferum L. during maturation
Authors: Hofman PJ , Menary RC
Published: November 2004

During the 1978-79 season, changes in the straw from a commercial and glasshouse-grown crop of Papaver somniferum L. were monitored. The percentage morphine and codeine reached their maximum values of 1.57 % and 0.10% respectively 5 weeks after full bloom under field conditions. Their contents changed little until the 11th week; thereafter losses of 35% and 32% in the morphine and codeine concentrations occurred over a 2 week period. This coincided with comparatively high rainfall and relative humidity, which permitted heavy fungal growth and a 28% decrease in the dry weight per sample of straw. There was a rapid decrease in thebaine concentration during the second week after full bloom, followed by a more gradual decrease up till 13 weeks after full bloom. A total loss of 58 % was recorded over the 13 week period, but there was no rapid loss during the 11-13 week period. Under glasshouse conditions morphine and codeine concentrations increased until the eighth and seventh weeks after full bloom respectively. The morphine concentration after this period showed little change, while that of codeine varied slightly. Their maximum detected concentrations were 1 .89 % and 0.16 % respectively. The thebaine concentration decreased rapidly during the first 5 weeks after full bloom from its highest detected value of 0.59% at week 2.
The incidence of grapevine yellow speckle disease in Australian grapevines and the influence of inoculum source on symptom expression
Authors: Shanmuganathan N , Fletcher G
Published: November 2004

Field observations and indexing indicated a high incidence of grapevine yellow speckle disease (GYS) in grapevines grown in Victoria. GYS showed symptoms in 38 % of the cultivars examined in the field and was detected in a further 24% by indexing cultivars not showing symptoms in the field. Indexing confirmed the presence of GYS in a random sample of vines showing GYS symptoms, while glasshouse tests showed that grapevine fanleaf virus and grapevine yellow vein virus were absent in such vines. Bud-graft inoculations of three indicator varieties, Cabernet franc, Mataro and Mission Seedling 1, with GYS from six different sources established that the source of inoculum had a significant effect on the intensity and pattern of symptoms produced, which suggests the existence of strains of the GYS pathogen. Evidence is presented which suggests that GYS is spreading in the field. Attempts to transmit the disease via contaminated pruning tools were unsuccessful.
Rapid spot test for glutathione peroxidase activity: comparison with a spectrophotometric procedure and assessment of the test as a measure of selenium in the blood of grazing ruminants
Authors: Langlands JP , Donald GE , Bowles JE , Smith AJ
Published: November 2004

The activity of the seleno-enzyme glutathione peroxidase in ovine and bovine blood was measured by using spot and spectropholometric assays, and was used to predict the selenium content of blood. Sources of error were examined in three experiments. In the first, the time from sampling and temperature at which samples were stored, the quantity of heparin used, the temperature of the assay and exercise of the sheep immediately preceding sampling were varied. In the second, relationships were calculated between blood selenium content and glutathione peroxidase activity assayed by the spot test and with a spectrophotometer. In the final experiment sources of variation in the spot assay were examined as affected by variation between animals, operators and days. Changes in glutathione peroxidase activity with time following sampling were small, and activities of samples stored at 3� and -28�C were similar; freezing samples in liquid nitrogen reduced the activity, which was also sensitive to the temperature of the assay. Exercise and the quantity of heparin used did not affect activity. Allometric relationships were calculated between blood selenium content and glutathione peroxidase activities determined by both spot and spectrophotometric assays. The latter was more precise. Differences between operators and between ewes and wethers in enzyme activity were not significant; variation between animals in blood selenium content increased with mean blood selenium content. It was concluded that the spot test would be satisfactory for identifying animals which could respond to selenium supplementation and would be particularly useful when equipment was not available for automated selenium determinations.
Diet selection and liveweight performance of steers on Stylosanthes hamata-native grass pastures
Authors: Gardener CJ
Published: November 2004

Diet selection in S. hamata-native grass pastures was studied over 25 months at Lansdown, north Queensland, In oesophageally fistulated steers. The results were uscd to interpret the relationship between winter rainfall and liveweight gain of steers on pastures with and without S. hamata. Steers selected green grass leaf early in the wet season (December-February), but preferred S. hamata in March when stem elongation and flowering occurred in the native grasses. They then continued to eat a high proportion of legume during the dry season until rain fell. At Lansdown, this may occur from 4 to 23 weeks after the pastures hay off. After the rain, the steers ignored the large bulk of mouldy dry legume, selecting instead both green and dry grass. Seed and green leaf of S. hamata made their greatest contribution to the diet at the end of the wet season when retained on the standing plant and easily accessible to cattle. Small amounts of seed and dried leaf were licked off the ground before rain fell. The nitrogen content of the diet in the S. hamata-native grass pastures rose to a peak in April and did not fall below 1.0% during the study. The level in July was twice that recorded for the native pasture. Cattle gained weight during the wet season at a similar rate for all pastures. After March steers on S. hamata-native pasture continued to gain weight longer onto the dry season than those on native pasture in three out of four years. Much of the additional weight gains of steers on S. hamata were lost with the advent of winter rain, especially at the high stocking rate from which the perennial grass component had been lost. The value of S. hamata cv. Verano in the greatly differing climatic environments existing in northern Australia is considered.
Development of the grape berry. II. Changes in diameter and deformability during veraison
Authors: Coombe BG , Bishop GR
Published: November 2004

Berries of Vitis vinifera, cvv. Muscat Gordo Blanco and Doradillo, were measured at close intervals (during the day or daily) sequentially while on the vine. Measurements of berry diameter and deformability showed that : (a) There were large diurnal fluctuations due to a decrease in diameter and an increase in softening during the day, both recovering by nightfall. (b) There was a prolonged and steady increase in diameter of 0.043 mm day-1, which was ended by a spurt of growth (an increase of about 0.25 mm during one day), followed then by a second prolonged increase at a new rate of 0.090 mm day-1. (c) Softening, as revealed by deformability, which was initially low, was heralded by a sudden increase followed by a steady daily increase for more than a week. (d) The increase in deformability usually, though not always, preceded the increase in diameter, the median difference being 6 days. (e) There was no evidence of a relationship between the time of softening and vascular proximity of berries on the bunch.
Associated growth of wheat and annual ryegrass. 1. Effect of varying total density and proportion in mixtures of wheat and annual ryegrass
Authors: Rerkasem K , Stern WR , Goodchild NA
Published: November 2004

A field study was undertaken in which wheat (T. aestivum L.) cv. Gamenya and annual ryegrass (Lolium rigidum Gaud.) cv. Wimmera were grown at total densities of 33, 100,300 and 900 plants m-2 in pure cultures and in mixtures in the proportions 33W : 67R, 50W : 50R, 67W : 33R. In densities of 100 and 900 plants m-2, five sequential harvests were made for total dry matter of each species in each pure culture and proportion. Interactions between proportion and density at the first and some subsequent harvests were noted, while at others these treatments behaved independently. At maturity, all plots were sampled for dry matter of each species, grain yield in wheat and seed production in ryegrass. With respect to dry matter and seed numbers, there was no interaction between density and proportion, but a main effect of density was noted. Seed numbers in ryegrass were between 31,000 and 45,000 m-2, and increasing the proportion of wheat had little effect on ryegrass seed production. An examination of the yield components of wheat (ears per plant, spikelets per ear and grains per spikelet) showed that intraspecific competition replaced interspecific competition as density rose. Although in pure cultures the two species had a similar growth pattern, the results showed that the effects of the species on one another were not identical and at final harvest, relative yield totals (RYT) > 1.0 were recorded in some treatments. The results are discussed in terms of inter- and intraspecific competition. From the practical point of view, this study shows that increasing either the density or proportion of wheat does not reduce the seed production of ryegrass to any great extent, and therefore its potential as a weed in wheat crops.
Variation in the nutrient content of leaves and fruit with season and crown position for two apple varieties
Authors: Haynes RJ , Goh KM
Published: November 2004

Leaves and fruit of Golden Delicious and Granny Smith apple trees, pruned by the Hawkes Bay tree-training method, were sampled at 2-weekly intervals from bloom time to leaf fall from the bulk of the top, middle and bottom thirds of the tree crown. Levels of calcium and magnesium per unit leaf area showed a general increase as the leaves aged, while nitrogen, phosphorus and potassium contents stayed relatively constant. With decreasing height in the crown, tree leaves had a markedly lower dry weight per unit area and lower contents of nitrogen, phosphorus, potassium, calcium, magnesium, chlorophyll and soluble carbohydrates per unit area, but the area per leaf was not significantly affected. The trends were more pronounced in the upright, bush-like Golden Delicious than in the spindly, open-centred Granny Smith trees. On a dry weight basis, differences in leaf nutrient content with crown height were not consistent or clear-cut, and therefore unlikely to affect leaf sampling for diagnostic purposes. The dry weight per fruit and the amounts of all nutrients per fruit increased throughout the season. With decreasing crown position, there was a decrease in fruit size, dry matter content and soluble carbohydrate concentration and an increase in green coloration, total nitrogen and free a-amino nitrogen concentration. The increased size of fruit from the upper crown position resulted in greater amounts of nitrogen, phosphorus, potassium, and magnesium per fruit in Golden Delicious but not in Granny Smith. Thus the self-shading nature of the Hawkes Bay training method may be detrimental to the production of large, highly coloured fruit. The largest dry weight and nutrient accumulation of both leaves and fruit was in the middle crown position of the trees followed by the lower and then the upper regions. The quantities of nutrients removed in the fruit crop at harvest time, as calculated from 2 years' data, were (kg ha-1 year-1): Golden Delicious: nitrogen, 23; phosphorus, 4; potassium, 120; calcium, 5; magnesium, 4; for Granny Smith: nitrogen, 13; phosphorus, 3; potassium, 57; calcium, 3; magnesium, 2. The quantities of nutrients returned to the orchard floor at leaf fall were (kg ha-1 year-1): Golden Delicious: nitrogen, 35; phosphorus, 3; potassium, 26; calcium, 45; magnesium, 7; Granny Smith: nitrogen, 35; phosphorus, 2; potassium, 25; calcium, 34; magnesium, 6.
Effects of sheep grazing Astrebla grassland in central western Queensland. 1. Effects of grazing pressure and livestock distribution
Authors: Orr DM
Published: November 2004

The effects of grazing pressure on plant responses and livestock distribution in Astrebla grassland were determined from paddocks subject to commercial grazing by sheep at light, medium or heavy grazing pressure. Increased grazing pressure reduced the projected foliage cover of Astrebla spp., the basal area of which was similar under light and medium grazing pressure, and was reduced under heavy grazing pressure. Differences in the density and size of Astrebla spp. tussocks were apparent under the three grazing pressures. Other perennial grasses, notably Aristidu latifolia and A. leptopoda, were most frequent under light grazing pressure. Numerical classification of the sampling sites, which were arranged on a regular grid, allowed the grazing pattern to be established. Heavy utilization was shown to be associated with wind direction, shade availability and watering facilities.
Genotype as a source of variation in selenium concentration and glutathione peroxidase activity of whole blood from grazing sheep and cattle
Authors: Langlands JP , Bowles JE , Donald GE , Ch'ang TS , Evans R , Hearnshaw H , Post TB
Published: November 2004

Selenium and glutathione peroxidase activities in whole blood were measured in a herd of 213 cattle containing Bos indicus and Bos taurus heifers and their crosses grazed at Rockhampton, Qld, and in a herd of 125 pregnant cows containing Hereford, Friesian x Hereford, Brahman x Hereford, and Simmental x Hereford genotypes, which was grazed at Grafton, N.S.W. Similar measurements were made on a flock of 18 Suffolk and 24 Cheviot lambs, and on a flock of 358 ram and ewe lambs of the Dorset Horn, Merino and Corriedale breeds and their reciprocal crosses. All lambs grazed at Armidale, N.S.W. Genotype was a significant source of variation in blood composition in all herds and flocks; there were differences between Bos indicus and Bos taurus cattle, between Bus indicus x Bos taurus cattle and Bos taurus cattle, between breeds of sheep and between sire groups within breeds. Heterosis was identified in blood selenium concentrations and glutathione peroxidase activities of blood from Dorset-Merino lambs. Other significant sources of variation were nematode and tick infestation in cattle and single versus twin births in sheep.
Effects of various rehydration procedures after a long journey on liveweight, carcasses and muscle properties of cattle
Authors: Wythes JR , Shorthose WR , Schmidt PJ , Davis CB
Published: November 2004

After a long journey of 1420 km, bullocks were watered without feed for 0, 3.5, 7, 28 or 32 h or watered with feed for 32 h prior to a 16 h preslaughter fast (no water and feed). The 108 bullocks in the first three treatments (36 per treatment) were slaughtered after resting for 1 day and the remaining 108 after resting for 2 days. Bullocks lost 10.4% of initial liveweight (656 kg) in transit. Mean liveweight of 588 kg on arrival increased when bullocks had access to water, so that after 3.5 h on water the net liveweight loss was reduced (P < 0.05) to 6.0 % of initial liveweight and after longer periods the loss varied from 6.8 to 7.3%. The net loss of the group also offered lucerne hay was 6.7%. More importantly, re-hydration increased (P < 0.01) gross hot carcass weight from 369 kg to 383 kg when bullocks were watered for 3.5 and 7 h, 381 kg after 28 h on water alone and 379 kg after 32 h on water and feed. However, this increment was not maintained, since the carcasses of bullocks on water alone for 32 h averaged 376 kg and were lighter (P < 0.05) than those of other bullocks on water. The water content of fat-free muscle reflected the same pattern as carcass weight (P < 0.01), although muscle water content peaked at 78.16% when bullocks were watered for 28 h compared with 76.01 % for those bullocks not offered water. Resting bullocks for 2 days rather than 1 day reduced (P < 0.01) the pH values of the M. longissimus dorsi 24 h post mortem from 5.64 to 5.57.
The fate of radioactive sulfur applied to grazed irrigated lucerne
Authors: Devaud E , McFarlane JD
Published: November 2004

Radioactive gypsum (Ca35S04.2H20) was applied on thirteen 1 m2 plots in each of four 1025 m2 lucerne paddocks, which were rotationally grazed by 15 first-cross wethers. Sampling was from two paddocks only: soil, lucerne and wool samples were collected immediately prior to each grazing of these paddocks over a period of 551 days after the application of radioactive sulfur. Under the conditions of the study sulfur was found to cycle in an equilibrated and almost closed system. During the experiment 8.4% of the applied radioactivity was removed by plants and transferred by sheep to the unlabelled parts of the paddocks. One year after application of the fertilizer, the transferred 35S was the source of up to 94% of the cycling radioactive sulfur. By this time 3.6 % of the applied 35S was still cycling, which was 43.1 % of the total radioactivity extracted by plants. The amount of sulfur involved in the cycle was estimated to be 366 kg ha-1. Sulfur inputs were estimated as 1.6 kg sulfur ha-1 and 11 .9 kg sulfur ha-1 in rain and irrigation water respectively. Sulfur output was estimated as 6.4 sulfur ha-1 in wool and sheep. Soil total sulfur remained relatively constant through the experiment, but extractable sulfates decreased as a fraction of total sulfur, which suggested a big increase in the organic sulfur fraction.
Inheritance of resistance to rust (Phakopsora pachyrhizi) in soybeans
Authors: McLean RJ , Byth DE
Published: November 2004

A study was conducted to determine the inheritance of resistance to soybean rust in three soybean accessions-PI200492, Tainung 3 and Tainung 4. The results suggest that PI200492 and Tainung 3 contain the same single dominant gene for resistance, and that Tainung 4 contains two dominant genes for resistance, one of which is identical with that in PI200492 and Tainung 3.
Effects of anthelmintic treatment on weight gain of weaned dairy calves on the Atherton Tablelands
Authors: Hutchinson GW , Cook LA , Colditz P , Copeman DB
Published: November 2004

The effects of repeated anthelmintic treatment with levamisole on body weight gain of grazing calves on the Atherton Tablelands are reported. On six farms, calves treated up to 10 times at 3-week intervals with 1.9 mg/kg or 7.5 mg/kg levamisole injected subcutaneously gained up to 37 and 59 kg more than untreated calves grazing the same pasture. Significant differences ( P < 0.05) were found in cumulative weight gains of calves given high doses of levamisole from 18 weeks and at low dosage from 24 weeks compared with untreated controls. The helminths mainly responsible for the reduced weight gain were Haemonchus placei, Oesophagostomum vadiatum and Coopevia species (C. pectinata and C. punctata). Seasonal incidence of nematode egg counts showed an increase in the proportion of H. placei eggs following wet and warm conditions, and O. vadiatum eggs following wet and cool conditions. Untreated calves developed natural resistance to helminth infection as measured by reduced faecal nematode egg counts after 6 months of natural challenge. One-quarter recommended dose of levamisole at 3-week intervals resulted in approximately half the weight gain advantage produced by full dose treatment except in the drier areas of the Tableland, where a higher advantage was recorded at this level.
Bivalent formation and chromosome dynamics in hexaploid triticate and rye crosses
Authors: Mohapatra SS , Chauhan KPS
Published: November 2004

Twelve hexaploid triticale lines were crossed with diploid rye (Secale ceveale L.) to study the extent and pattern of bivalent formation in hybrid and F2 generations. The number of bivalents in hybrid plants ranged from four to seven. This was used as a criterion to determine the number of D-chromosomes substituted for R-chromosomes in triticale parents. The implications of R/D chromosome substitutions in triticale breeding are discussed. Observations on the number of bivalents and their segregation pattern in seven F2 plants indicated recovery of tetraploid triticale types in later generations.
Ammonia and nitrous oxide losses following applications of ammonium sulfate to flooded rice
Authors: Freney JR , Denmead OT , Watanabe I , Craswell ET
Published: November 2004

Ammonia volatilization from applications of ammonium sulfate to a wet season crop of flooded rice in the Philippines was measured directly by a micrometeorological technique. Prior to transplanting the rice, ammonium sulfate (80 kg nitrogen ha-1) was broadcast over the flooded soil and incorporated by harrowing. A further 40 kg nitrogen ha-1 was broadcast at the panicle initiation stage. The soil pH was 6.7, while the pH of the floodwater varied from 7 . 5 to 9.5 during the course of the experiment. Loss of ammonia was detected immediately after application of ammonium sulfate and continued for approximately 7 days. Ammonia volatilization rates were highest in the middle of the day and declined each evening following the diurnal variations in water temperature and wind speed. More ammonia was lost from the fertilizer applied at the panicle initiation stage (10.6%) than from the pre-planting application (5.1 %). The overall measured loss of ammonia was small and amounted to approximately 7 % of the total nitrogen applied to the crop. Nitrous oxide losses, measured with a chamber system, amounted to only 0.1 % of the nitrogen applied as ammonium sulfate.
Early weaning of lambs: effect of various preweaning factors on voluntary food intake before and after weaning
Authors: Walker DM , Hunt SG
Published: November 2004

Fifty-two crossbred lambs were used in four experiments to study the relative importance of such factors as birth weight, sex, age of weaning, provision of extra salt, and restriction of milk intake, on the intake of solid food (pellets) both before and after weaning, and on the growth check after weaning. Experiment I was a 2 x 2 x 2 factorial (sex x birth weight x weaning at 21 or 42 days) with 24 lambs. All lambs were given milk to appetite until they had made an estimated gain of 23 MJ; milk intake then restricted to a maintenance level. Twelve lambs were weaned at 21 days and the remainder were given milk sufficient for maintenance up to 42 days, when the experiment was terminated. Three out of six lambs that weighed less than 2.7 kg at birth died when weaned abruptly off milk at 21 days. Lambs that were heavy at birth (> 3.4 kg) survived weaning at 21 days but had a growth check of 11 � 5 days. Both the heavy and light birth weight lambs that were given a restricted intake of milk daily from 22 to 42 days ate similar amounts of pellets between 22 and 42 days, but less than those eaten by the heavy birth weight lambs weaned at 21 days. There was no effect of sex on pellet intake or on the length of the growth check. In experiment 2 the provision of a block of salt from 10 days of age had no significant effect on pellet intake before or after weaning at 28 days. In experiments 3 and 4 the milk intake of half of the lambs in each experiment was restricted to a maintenance level for 7 days before weaning. In experiment 3 the lambs weighed more than 3.6 kg at birth and were weaned at 21 days. Restriction of milk intake was without effect either on the intake of pellets before and after weaning or on the length of the growth check. In experiment 4 the lambs weighed less than 3.2 kg at birth and were weaned at 35 days. Lambs given a restricted intake of milk from 29 to 35 days ate significantly more pellets both before and after weaning and had a significantly shorter check to growth than lambs given milk to appetite until weaning.
Sulfur and nitrogen fertilizer effects on wheat. I. Concentrations of sulfur and nitrogen and the nitrogen to sulfur ratio in grain, in relation to the yield response
Authors: Randall PJ , Spencer K , Freney JR
Published: November 2004

Grain samples from a factorial (5 sulfur x 3 nitrogen treatments) field experiment with Olympic wheat, which showed yield responses to both factors, were analysed for total sulfur and nitrogen. Sulfur application increased the grain sulfur concentration more with high than with low nitrogen treatment, but had only small effects on the nitrogen concentration in grain. Nitrogen application increased the grain sulfur concentration at high but not low sulfur and increased grain nitrogen concentration at all sulfur treatment levels. The critical grain sulfur value for yield was 0.12% in treatments adequately supplied with nitrogen, but plots with low nitrogen (sulfur-unresponsive) also had grain sulfur values below 0.12 %. Grain from sulfur-responsive plants could be distinguished from grain from unresponsive plants because the former had less than 0.12% sulfur and nitrogen/sulfur ratios wider than 17/1. Results from a glasshouse experiment with three cultivars were consistent with this. The findings suggest that seed analysis may be a useful method for diagnosis of the sulfur status of cereal crops.
Effect of low temperature on number and location of developed seed in two cultivars of French beans (Phaseolus vulgaris L.)
Authors: Farlow PJ
Published: November 2004

Seed and pod development for the French bean cv. Redlands Pioneer were both reduced at temperature treatments below 21.0�C. At temperatures greater than 13.9�C undeveloped seeds were distributed uniformly within pods, and this was attributed to failure of the female gamete. At 13.9�C restriction of developed seed to the stigmatic end of the pod was apparent, and below this temperature the number of undeveloped seeds increased significantly, with no seeds developing at 10.0�C. This cessation appeared to be due to both random failure of the female gamete and inadequate pollen tube growth. Seed development within pods of the cultivars Redlands Pioneer and Tweed Wonder was compared at 12.0�C. Tweed Wonder performed significantly better, and this was attributed to greater cold tolerance of both male and female gametes.
Variation for oil quantity and quality in linseed (Linum usitatissimum)
Authors: Green AG , Marshall DR
Published: November 2004

Significant variation in seed weight, oil content and fatty acid composition was found both between and within varieties in a diverse collection of 214 Linum usitatissimum accessions. Parent-offspring correlation analysis indicated that at least a proportion of the variation within several varieties was due to genetic heterogeneity. Lines were identified that had up to 46 % oil, compared with the 40 % present in the current Australian cultivar, Glenelg. High oil content was consistently associated with larger seeds. Oleic acid and linolenic acid varied between 13.3 and 25.2%, and 45.5 and 64.2 %, respectively, and were strongly negatively correlated within and between all varieties tested. The level of variation is insufficient to develop lines with less than 5 % linolenic acid by conventional hybridization and selection techniques. It is concluded that mutation breeding and interspecific hybridization are more promising approaches to the breeding of linseed genotypes containing low levels of linolenic acid.
The effect of plant top material on the water repellence of fired sands and water repellent soils
Authors: McGhie DA , Posner AM
Published: November 2004

Large differences in the water repellence were conferred on fired sand by adding the ground tops of a range of plant species. Contact angles of 75� to 90� were caused at 2% of most pasture and native species and at 5 % many gave contact angles > 95� The cereal crops gave contact angles of about 60� (2%) and 83�(5 %) and were more wettable than pasture and native species. The addition of ground Geraldton subterranean clover (Trifolium subteraneum cv. Geraldton) or brown mallet (Eucalyptus astrigens (Maiden)) to water-repellent sands increased the water repellence. Addition of clover to a water-repellent mallet-hill soil increased the water infiltration rate while the mallet did not change the slow rate. Wheat (Triticum aestivm), when added to water-repellent soils, always reduced the water repellence. Attention is drawn to the importance of the relative wettability of the soil and added organic matter, and therefore the type of plant cover. Soils sampled from beneath wheat/clover rotations of various lengths showed that water repellence increased in the pasture phase and was reduced during the cropping phase. The importance of the type, as well as the amount, of organic matter in the rotations is demonstrated.
Infectivity and effectiveness of vesicular arbuscular mycorrhizal fungi: effect of inoculum type
Authors: Abbott LK , Robson AD
Published: November 2004

Plants, inoculated with four vesicular arbuscular mycorrhizal (VAM) fungi (Glomus fasciculatus, G. monospovus and two isolates of Acaulospova laevis), were grown from 4 to 16 weeks, and the development of infection and spores was followed. Infected roots from pot cultures of different ages were used to examine the effect of mycorrhiza development on the infectivity of each fungus. The effectiveness of each fungus was assessed by measuring its ability to increase the growth of subterranean clover on a phosphate-deficient soil. For all fungi, the percentage of root length infected increased rapidly up to 10 weeks after sowing, and thereafter it either increased only slightly or decreased. Infectivity of root inocula increased with increasing percentage of root length infected in the inoculum for all fungi, except where large numbers of mature spores (24/g infected root) had been produced by one isolate of A. laevis. The infectivity of inoculum roots from pots containing mature spores of this isolate declined rapidly, although it was not decreased by the onset of sporulation by A. laevis. For all fungi, irrespective of the inoculum used, the fresh weight of tops of subterranean clover grown on a phosphate-deficient soil was very closely correlated with the percentage of its root length infected at an early stage of plant growth. That is, the effectiveness of the species of fungi examined at increasing phosphorus uptake into plants was related to the infectivity of the inoculum used.
An evaluation of different sites for measuring fat thickness in the beef carcass to determine carcass fatness
Authors: Johnson ER , Vidyadaran MK
Published: November 2004

The accuracy of a single fat thickness measurement at each of five carcass sites and at the 10th and 12th ribs in estimating side fat weight and side fat percentage was determined in 36 steer carcasses. Three sites were associated with the fat layers of the split brisket, one was located at the caudodorsal angle of M. biceps femoris and one was situated 3 .O cm lateral to the highest point of the sacral crest. All three brisket sites were poor predictors of side fat weight and side fat percentage. The other four sites were of approximately equal accuracy in predicting side fat percentage, with residual standard deviations of: M. biceps femoris, 2.81 %; sacral crest, 3.07%; 10th rib, 3.12%; and 12th rib, 2.81 %. Side fat weight was predicted less accurately by M. biceps femoris (5.42 kg) than by sacral crest (4.50 kg), 10th rib (4.98 kg) or 12th rib (4.94 kg). Chilled side weight was a valuable addition in multiple regression analyses, significantly improving the residual standard deviations of all four sites, especially M, biceps femoris, in predicting side fat weight (M. biceps femoris, 1.56 kg; sacral crest, 3.54 kg; 10th rib, 3.31 kg; 12th rib, 2.84 kg). Only in the case of M. biceps femoris did the addition of chilled side weight improve the accuracy of prediction of side fat percentage (residual standard devation = 1.75 %). The reliability of the seven sites in accurately measuring fat thickness was determined in 3215 dressed carcasses in six abattoirs. Sacral crest was clearly the most useful site. In addition to being an accurate predictor of carcass fat, it could be measured accurately in 98.3 % of carcasses (or 94.3 % of sides), compared with 10th rib (83.9 % and 71.6% respectively) and 12th rib (82.9% and 68.5 % respectively). If the measurement of fat thickness at the 12th rib is used in the Australian Beef Carcase Classification Scheme, up to 21 % of carcasses (or up to 44% of sides) in some abattoirs will require alternative procedures to describe their fat status. Sacral crest fat thickness accurately estimated side fat weight and side fat percentage, and it provided reliable measurement in all but 1.7 % of carcasses; it is conveniently located if an alternative site to the 12th rib is required.
A laboratory procedure for determining relative levels of field resistance in soybeans to Phytophthora megasperma f.sp. Glycinea
Authors: Irwin JAG , Langdon PW
Published: November 2004

A reliable laboratory assay is described which allows rapid determination of relative levels of field resistance in soybeans to Phytophthora megasperma fsp, glycinea. The expression of field resistance depended on both the inoculum level and the age of seedlings at time of saturation of the potting mix with water. At inoculum levels in the range 0.018-0.576 g dry weight of mycelium per kg dry weight of potting mix, ready differentiation in the resistance levels of the cultivars Davis (field resistant) and Semstar (field susceptible) could be made after 7 days of continuous saturation of the mix, which commenced 3 days after sowing. When inoculated by the conventional hypocotyl puncture technique, both cultivars gave susceptible reactions. The seedling assay was used to screen a range of soybean cultivars with known levels of field resistance to the fungus. Disease assessments made in the laboratory assay were similar to those expected under natural conditions of infection in the field. Possible use of the method in future soybean breeding programs is discussed.