bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of response to sulfur by established Siratro/grass pastures in south-eastern Queensland
Authors: Rayment GE
Published: March 2005

Dry matter responses by component species of 18 established, commercial Macroptilium atropurpureum cv. Siratrolgrass pastures to gypsum topdressing treatments (0 or 25 kg S/ha) were assessed from field experiments conducted over a four-year period in south-eastern Oueensland under rain-grown conditions. The objective was to establish diagnostic criteria for the assessment of sulfur status by relating pasture yields to agronomic attributes and soil and plant chemical tests. Beneficial responses to gypsum were small (maximum of 32% in Siratro) and restricted to fewer than 25% of sites, whereas at disadvantaged sites (28% of total), grass yields were more severely depressed than Siratro yields. It was not possible to predict these effects from past sulfur fertilizer history, Siratro percentage in the pasture, or pasture age. Significant correlations between Siratro relative yields (100 x yield without sulfur/yield with sulfur applied, attenuated at 100 for model fitting) and both soil sulfate and plant sulfur concentrations confirmed the predictive value of these laboratory data. For Siratro, best prediction of responsiveness was provided by sulfur concentrations in either whole tops (R2 = 0.65) or diagnostic samples (tips of runners back to the fifth to sixth fully expanded leaf; R2 = 0.65). Critical value for diagnostic samples was 0. 16% S while for whole tops of Siratro the value varied with mathematical model from 0.13 to 0. 15% S. Phosphate-extractable sulfate was the most effective soil test but irrespective of sampling depth, it accounted for less than 50% of the variation in Siratro relative yields. Whether sampled at 0- 10 cm or 0-90 cm, a critical range of 3-5 ppm phosphate-extractable sulfate was indicated for the Siratro component. Grass and total pasture relative yields were not correlated with the chemical tests employed.
Resistance of lucerne lines at different stages of plant growth to spotted alfalfa aphid and blue-green aphid
Authors: Lloyd DL , Franzmann BA , Hilder TB
Published: March 2005

The relative resistances of lucerne (Medicago sativa) lines to the spotted alfalfa aphid (SAA) ( Therioaphis trifolii (Monell) f. maculata) and the blue-green aphid (BGA) (Acyrthosiphon kondoi Shinji) are generally assessed as seedlings and not as mature plants. To determine if the orders of resistances dre maintained, two separate glasshouse experiments assessed the relative resistances of 11 and 12 lucerne lines after infestation by SAA and BGA respectively at these stages: seedling, regrowth after cutting, and mature growth. Relative resistance between growth stages was compared by measuring aphid populations, percentage plant mortality and percentage yield reduction of surviving plants, and correlating the ranking for those indices. There was no change in the order of resistance to SAA between growth stages. Plants of both mature-age growth stages were, however, more tolerant of SAA than were seedlings. The technique employed in the experiment did not discriminate for resistance to BGA, though the yield of all lines was reduced by BGA. The implications of these findings are briefly discussed.
Effect of superphosphate application on the phosphorus status of breeding cattle grazing Townsville stylo based pastures in northern Queensland
Authors: Loxton ID , Murphy GM , Toleman MA
Published: March 2005

The performance of Brahman crossbred cows grazing annual grass plus Townsville stylo (Stylosanthes humils) pasture with or without superphosphate fertilizer was monitored over a two year period. The animals were introduced to the experimental areas as yearling helfers and remained until weaning of their first calf. Levels of phosphorus In rib bone varied between 145 and 172 mg/ml. At weanlng, levels were higher on the fertilized than on the unfertilized pasture (172 vs. 157 mg/ml). Calcium levels in rib bone varied between 329 and 362 rng/ml and paralleled bone phosphorus levels. Pasture nitrogen levels were similar on both pastures but phosphorus levels were higher on the fertilized area. Faecal analyses reflected this same pattern with faecal nitrogen levels being similar on both pastures, and faecal phosphorus levels higher on the fertilized pasture. Liveweight changes of cows and calf weaning weights were greater in groups grazing the fertilized pasture. It is hypothesized that this superior performance is a function of increased feed intake resulting from increased phosphorus intake on the fertilized area although the possible contribution of sulfur cannot be overlooked.
Sowing time effects on the development, yield and oil characteristics of irrigated sunflower (Helianthus annuus) in semi-arid tropical Australia
Authors: Garside AL
Published: March 2005

The effect of sowing time on development, yield and oil characteristics of irrigated sunflowers was studied in an experiment at the lrrigation Research Station, Ord lrrigation Area (15� 30'S, 128� 43'E), Western Australia in 1978. Sunflower cultivars Hysun 10, Hysun 30, Sunfola 68-2 and Polestar were sown at monthly intervals between mid-February and mid-August. Delay in sowing from February to June increased the period from sowing to physiological maturity by between 10 d (Hysun 10) and 24 d (Hysun 30), due mainly to an increase in the period from emergence to bud visible. Results showed that May sowing of the late maturing hybrid Hysun 30 was the best combination, with a seed yield of 2.3 t/ha. Oil content and quality (% linoleic acid) were highest with April sowing, 47.0 and 57.0%, respectively. Sowings from April to July gave acceptable yields (1.8-2.0 t/ha) and oil contents (45-47%). However, oil quality, although responding to sowing date, was always lower than the accepted level of 60% linoleic acid. Seed yields, which were considerably lower than those recorded for irrigated sunflower in southern Australia, are discussed in terms of the environmental limitations of the region
Effects of ethephon on ripening, red colour, and storage performance of Jonathan and Delicious apples
Authors: Brohier RL , Faragher JD
Published: March 2005

Ethephon, at concentrations of 125- 1000 ppm, was applied to Jonathan and Delicious apple trees 3-4 weeks before the anticipated harvest date for untreated apples. Ripening of Jonathan, as measured by increases in red colour and flavour score, was advanced by 6, 10, and 15 d by 250,500 and 1000 ppm ethephon respectively. Softening was not affected. Fruit drop was increased by 1000 ppm only, to 14% of the crop. In Delicious, red colouring and flavour development were advanced by up to 6 d with 1000 ppm ethephon, but yellowing and softening were advanced more, by 7- 14 d with 250 ppm and up to 10- 17 d with 1000 ppm. Softening did not reach unacceptable levels, but three weeks after treatment, yellowing and water core reached unacceptable levels. Red colouring, as measured by anthocyanin concentration or area of red skin, was increased up to two-fold in Jonathan with 1000 ppm, and by up to 50% in Delicious with 1000 ppm. Ethephon also advanced the rise in susceptibility of both cultivars to storage disorders, breakdown and brownheart, in air or controlled atmosphere cold storage. However, if the treated apples were harvested when ripe, 7- 15 d before the controls, their quality after storage was the same as that of controls harvested later.
Application of piggery waste to soils in pots: effect on dry matter yield and uptake of nitrogen, potassium, calcium and magnesium by ryegrass and white clover
Authors: Reid R , Douglas LA , Chalk PM
Published: March 2005

The effect of piggery waste application on the yield and uptake of nitrogen, potassium, calcium and magnesium by ryegrass (Lolium perenne) and white clover (Trifolium repens) growing in three soils was studied in pot culture. Waste was applied six times during a 108-d growth period. The total waste applied to different treatments was equivalent to 0,5.3,9.4, 12 2 and 18.0 t dry matter (DM)/ha. Application of waste resulted in significant increases in the yield of ryegrass on all soils, and white clover on one soil. There was no significant decrease in yield at the highest application rate, indicating the absence of an excess soluble salt effect. Application of waste at 9.4 t DM/ha corrected a dietary deficiency of potassium in ryegrass and clover growing on a potassium-deficient podzolic soil. However, application of waste at 5.3 t DM/ha caused the K: (Ca + Mg) ratio of ryegrass growing on an alluvial soil and a red brown earth to exceed 2.0, considered to be an index above which grass tetany may develop in ruminants. Application of waste to ryegrass at 18 t DM/ha or clover at greater than or equal to 9.4 t DM/ha caused the plant tissue nitrate concentration to exceed 0.2% N, which is pitentially toxic to farm animals.
Purification of corynetoxins from galls of annual ryegrass infected with Corynebacterium rathayi
Authors: Vogel P , Golding H , McWilliam A , Carlin J
Published: March 2005

An improved, rapid and efficient purification procedure of corynetoxins, the causal agents of annual ryegrass toxicity, is described. The method relies upon bacterial gall concentration from crude seedhead material and the use of Sep Pak 'Florisil' cartridges and 'short column' chromatography to purify corynetoxinsfrom crude extracts. Extracts were monitored for toxicity using a recently developed bacterial inhibition assay.
Dimethoate dipping of Kensington mango against Queensland fruit fly
Authors: Swaine G , Melksham KJ , Corcoran RJ
Published: March 2005

Dipping mangoes (Mangifera indica) for 0 5 or 3 min. in solutions of dimethoate (nominally 375 or 500 mg/litre, see below) was highly effective against infestations of Queensland fruit fly, Dacus tryoni (Froggatt), with more than 99.9% mortality. Residual dimethoate from dipping fruit for 3 min in dimethoate solution (nominally 500 mg/litre) was below the Australian maximum residue limit of 2 mg/kg. The procedure is not a replacement for fumigation with 1,2-dibromoethane in all circumstances but should be acceptable for all but very high risk markets. Differences between calculated (nominal) and actual strengths of dimethoate dip solutions could not be accounted for by hydrolysis.
Survival feeding of cattle with molasses. 1. Feeding non-pregnant heifers with molasses plus urea and roughage
Authors: Gulbransen B
Published: March 2005

Twelve groups, each of four yearling Hereford heifers of mean � s.e. initial fasted liveweight of 211 � 6.5 kg, were fed solely on molasses either with or without roughage for 23 weeks in a 2 x 3 x 2 factorial experiment. The experiment examined the effects on liveweight change of molasses allowance (2.0 or 3.2 kg/animal per day), type of molasses mixture (undiluted; molasses 80%; water 20%; molasses 80%; water 17%; urea 3%; all w/w) and roughage allowance (nil or 0.3 kg/animal per day). Increasing the molasses allowance improved growth rate from -0.25 to -0.12 kg/animal per my (P<0.01); including urea in the molasses improved growth rate from -0.22 to -0.11 kg/animal per day (P<0.01). 'Molasses toxicity' was not a problem even in the absence of roughage, and dilution of molasses with water did not affect animal performance.
Ram mating performance in Border Leicesters and related breed types. 1. Pen test performance and measures of testis diameter
Authors: Barwick SA , Kilgour RJ , Gleeson AC
Published: March 2005

Sexual activity, serving capacity, mean number of mounts per serve and mean testis diameter were measured in 286 Border Leicester, BLI (a 'high fertility' sheep related to the Border Leicester) and BLI x Border Leicester rams at 1.5, 2.5 or 3.5 years of age. Rams were allowed two 20-minute introductory periods with spayed oestrous ewes, and then were given two 1-h pen mating tests during which their serving capacity (the mean number of serves in the two tests) and mounts per serve were counted. Rams which commenced mounting in introductory or 1-h tests were classed as sexually active. Among 1-5 and 2.5-year-old rams, 68.9 and 65.4%, respectively, were sexually active, while all 3.5-year-old rams were active. Mean testis diameters for inactive rams were smaller (P<0.05) than for active rams in both 1.5- and 2.5-year-old rams. There were breed type differences in activity, serving capacity and mean testis diameter at 1.5 years of age, but not at other ages. BLIs were less active at 1.5 years than other types, but BLIs and Border Leicesters did not differ in either their serving capacity or testis diameter. BLI x Border Leicesters generally had greater (P<0.05) serving capacities and testis diameters than other types, suggesting possible advantages for these rams at early joinings. Sire effects for serving capacity were not significant, but were significant (P<0.05) for mounts per serve, and for testis diameter at 1.5 years old. Activity status was highly repeatable (0.83) between 1.5 and 2.5 years and testis diameter was moderately repeatable (0.41). Repeatabilities for serving capacity and mounts per serve, in active rams, were not significant. Correlations between serving capacity and testis diameter were not significant for active rams, while serving capacity and mounts per serve were generally negatively related. Mean testis diameter was significantly (P<0.05) correlated with liveweight at 1.5 years but not at other ages. Liveweight at 2.5 years was positively (P<0.05) related to mounts per serve and negatively (P<0.05) related to serving capacity.
Performance of North American and Australian lucernes in the Queensland subtropics. 1. Field reaction to important root and crown diseases
Authors: Gramshaw D , Langdon PW , Lowe KF , Lloyd DL
Published: March 2005

Twenty-three lucernes from North America and five Australian lines were assessed for their sensitivity to root rot (Phytophthora megasperma f. sp. medicaginis), anthracnose/ crown rot (Colletotrichum trifolii) and root canker (Rhizoctonia solani). Plantings were spray irrigated or raingrown on sites representative of the major lucerne environments in southern Queensland. Ratings for each disease discriminated generally the same most susceptible and resistant lines across plantings, although significant sitexline interactions occurred, these being most pronounced for anthracnose. Nevertheless, mean ranking for reaction to each disease conformed to previous assessments conducted under more controlled conditions. For root rot, many of the North American lines showed resistances superior to those of the Australian lines Hunter River, Siro Peruvian and Paravivo, but not to Falkiner and HS Gen 3 Composite. None, however, were rated as having better resistance to anthracnose than Hunter River. Few of the introduced lines had better than moderate levels of combined resistance to root rot and anthracnose, a combination considered important for superior adaptation in the subtropics.
The growth of improved pastures on acid soils. 1. The effect of superphosphate and lime on soil pH and on the establishment and growth of phalaris and lucerne
Authors: Horsnell LJ
Published: March 2005

The response of improved pastures to the application of superphosphate is low on the acid sedimentary soils, of the Southern Tablelands of New South Wales, which contain high levels of exchangeable aluminium. An investigation was made into the effect of surface-applied fertilizers on soil pH and on the establishment and growth of lucerne and phalaris on these soils. At 6 weeks after the application of gypsum, superphosphate, or superphosphate plus potassium sulfate, soil pH (H2O) had decreased markedly. This effect extended to a depth of 20 cm, but decreased with time. Initially, lime application increased the pH of the surface soil only. When superphosphate was applied with lime the pH of the soil under the lime layer decreased to the same level as that found in the soil treated with superphosphate alone. Lime, however, had penetrated into the subsoil 102 weeks after application and substantially more so after 13 years. Soil pH (0.01 M CaCl2) was not depressed by the application of fertilizers. Growth and persistence of both species in the first summer were poor, but growth responses to phosphorus, lime and nitrogen increased after the first year. Lucerne showed large growth responses to lime, greater than those found on plots receiving nitrogen fertilizer. Lime reduced aluminium levels both in lucerne plants and in soil. It is suggested that the slow penetration of lime into the soil, the relatively quick effect of superphosphate in increasing subsoil acidity, and high soil aluminium levels are together responsible for the poor persistence and slow growth of both lucerne and phalaris in the early stages. The subsequent large dry matter responses of lucerne to lime are possibly related to increased nitrogen fixation and a lowering of plant and soil aluminium levels. It is suggested that the lime responses of phalaris are also related to lower aluminium levels.
Nutritional quality of grain of Australian cultivars of lablab bead (Lablab purpureus)
Authors: Lambourne LJ , Wood IM
Published: March 2005

Nutritional studies using rats have shown that the grains of Rongai and Highworth, the current commercial cultivars of lablab bean in Australia, and of CPI41222, a white-seeded accession, have low nutritive value. Diets containing raw beans of the three accessions at levels up to 12% crude protein led to severe weight losses of up to 0.89 g/day compared with weight gains of up to 2.8 g/day with autoclaved soybean meal. Autoclaving for 20 min or boiling the grain improved growth rates only marginally. Increasing the period of autoclaving reduced the feeding value; extraction of the grain with saline solution or treatment with formaldehyde failed to improve it. These results are consistent with previous reports of the presence in lablab beans of a heat-labile phytohaemagglutinin. Blood haemoglobin levels were signifycantly depressed on diets which contained Highworth beans. The proteins of all accessions contained low levels of the sulfur-containing amino acids; a deficiency of methionine was confirmed by feeding trials. The level of histidine in the lablab protein was about 50% higher than in soybean and, in supplementation trials, additions of histidine reduced growth rates. In two feeding trials, there were good correlations (R2=0.85 and 0.92) between weight gains and digestible dry matter intake, indicating that the differences in growth rates were primarily the result of differences in intake. Intakes of digestible dry matter and digestible crude protein and the digestibilities of dry matter and crude protein were all significantly lower with Rongai than with the other two accessions. These differences do not appear to be associated with the quality of the protein as shown by amino acid analyses or by the responses to supplementation with essential amino acids. They also do not appear to be associated with seed coat colour, seed size or crude protein content of the grain.
Residual 1,2-dibromoethane in mango, capsicum, passionfruit and papaw after fumigation against Queensland fruit fly, Dacus tryoni (Froggatt)
Authors: Melksham KJ , Munro HE
Published: March 2005

Residual 1,2-dibromoethane (EDB) was measured in mango, capsicum, passionfruit and papaw following treatment with biologically effective levels of EDB. Post-fumigation forcedairing periods, storage conditions and times of storage were varied. The duration of the forced-airing period after fumigation had no significant effect on the rate of dissipation of EDB from mango. Fumigated mango required storage at 21� for at least 3 days before EDB levels fell to the maximum residue level (MRL) of 0.1 mg/kg. Cool storage of mango extended the time required for the EDB level to fall to the MRL to at least 6 days. Fumigated capsicum stored at 21�C required 2 days for EDB levels to fall to the MRL while, with fumigated papaw, this took at least 4 days. Even after storage for 7 days, EDB levels in fumigated passionfruit exceeded the MRL so the fumigation procedure was unsuitable for use with passionfruit. A kinetic model was proposed which explained the behaviour of EDB in the various trials and in other literature reports. All samples were analysed by X-ray fluorescence spectrometry (X-RF) and many results were confirmed more specifically and more sensitively by gas chromatography-mass spectrometry. Comparison ofresults by these two methods, including the results of samples spiked with low levels of EDB, helped remove doubts about the suitability of X-RF for the determination of residual EDB.
Honeybee pollination of loganberries (Rubus loganobaccus L.H. Bailey)
Authors: Langridge DF , Goodman RD
Published: March 2005

The role of honeybees (Apis mellifera) in the pollination of loganberries was studied in an experimental planting at Knoxfield, Victoria. When plants were enclosed in cages to exclude bees and larger insects, there was no difference in the total numbers and weight of fruit harvested. Quality rather than quantity of fruit benefited from honeybee activity. The number of reject fruit on enclosed plants was 49.9% of the total as compared with 7.8% on open plants, corresponding respectively to 35 5% and 3- 3% by weight. The farm gate value of fruit harvested per plant was $A2.39 on open plants and $A1.28 on enclosed plants. After deducting cost of hiring bees this was computed to nett an extra return to the grower of $A1876 per hectare. Honeybees comprised 98.6% of all insect visitors to the flowers. Concentrations of airborne pollen 'were greater inside the cages than outside.
Soil treatment, plant species and management effects on improved pastures on a solodic soil in the semi-arid subtropics. 2. Cattle liveweight gains
Authors: Russell JS
Published: March 2005

Increased and sustained beef cattle liveweight gains were obtained during 1974-79 on improved pastures in an experiment on a solodic soil at Kogan in southern Queensland. Annual liveweight gains of almost 100 kg/ha and 160 kg/steer were obtained at a stocking rate of 0.62 steers/ha on Rhodes grass fertilized with nitrogen; Rhodes grass and medics; and Rhodes grass, medics and siratro. The latter two pastures received an initial application of hydrated lime and gypsum (HLG). Medics responded markedly to HLG and this resulted in a 54% increase in liveweight gain per hectare on the Rhodes grassmedic pasture. However, the capacity of Rhodes grass-legume pastures to sustain higher stocking rates was much less than Rhodes grass fertilized with nitrogen. Rate of liveweight gain varied seasonally. There was a marked depression in late autumn and early winter, a steady increase in spring, a minor depression in late spring and early summer, and a minor increase in late summer and early autumn. Comparison of animal production with a long term experiment at Narayen on a low-fertility soil showed similarities, except for the poor performance of siratro at Kogan in terms of productivity and persistence. The main differences in the soils (both Alfisols) were the presence of levels of exchangeable sodium exceeding 40% in the subsoil, and poorer physical properties of the Kogan soil. Although the experiment has shown potential for increased animal production from improved pastures in this environment, factors limiting sustained high production are high liveweight losses in the cool months, rainfall variability and pasture instability. Conservative pasture management is needed if improved species are to be retained in pastures on these soils.
Summer forages under irrigation. 2. Forage composition
Authors: Muldoon DK
Published: March 2005

Summer forages, including Sorghum bicolor hybrids, S. sudanense, S. bicolor x S. sudanense hybrids, perennial sorghum, maize and Pennisetum and Echinochloa millets, were grown on an alkaline clay soil at Trangie, New South Wales. Primary growth was sampled every 3 weeks and the plant components analysed for nitrogen, sulfur, sodium and in vitro dry matter digestibility. Whole plants were analysed for calcium, magnesium, phosphorus, potassium and chloride content. Fresh leaf samples were analysed for potential hydrocyanic acid (HCN) yield. The quality attributes were regressed on time in order to describe accurately the quality of a forage at different times in its growth. Sorghum species, particularly the sweet sorghum hybrids and perennial sorghum, had high HCN potentials (0.15 and 0.14, respectively, at 8 weeks). They had low contents of sulfur, especially in the stem fraction and this decreased with time. Hence the nitrogen:sulfur ratio was always marginally high or, in sweet sorghum hybrids and perennial sorghum, above the recommended optimum of 15:1 for animal nutrition. Furthermore, they were deficient in sodium, particularly in the leaf fraction, while digestibility decreased rapidly with age. Nevertheless, Piper Sudangrass had a low HCN potential, which would allow it to be grazed early when digestibility was high (70% at 7 weeks). Maize had a negligible HCN potential, a nitrogen: sulfur ratio consistently below 15: 1 and a sodium content intermediate between sorghum and millet species. Millets had a negligible HCN potential and high sodium content, particularly Echinochloa utilis. This species also had a high sulfur content and hence very low nitrogen: sulfur ratio; it is recommended for early grazing to obtain high quality forage.
Effects of iprodione and vinclozolin seed treatments on germination, emergence and plant growth in onion
Authors: Wicks T , Philp B
Published: March 2005

Iprodione or vinclozolin dusted on White Spanish and Goldberg onions, at 100g a.i./kg of seed, reduced germination by at least 40% and severely stunted the growth of seedlings nated on moistened filter paper. Similar rates of vinclozolin severely reduced field emergence and retarded the growth of White Spanish and Goldberg seedlings whereas the same rate of iprodione reduced field emergence and growth of Goldberg, but not White Spanish. Poor field emergence of treated seed could have been a germi consequence of inhibition of germination, stunted seedling growth or a combination of both factors.
Growth and yield of rice under sprinkler irrigation on a free-draining soil
Authors: Blackwell J , Meyer WS , Smith RCG
Published: March 2005

A line-source sprinkler irrigation system was used to study rice growth under irrigation on a free-draining soil in the Murrumbidgee Irrigation Area of New South Wales. Ponded rice was grown on the same soil for comparison. Seven levels of sprinkler water application were examined, ranging from 26 to128% of Class 'A' pan evaporation. Apparent efficiency of water use ranged from 3.4 kg of grain/mm for the highest yielding sprinkler treatment to 1.85 kg of grain/mm for the highest yielding ponded treatment. Excellent weed control was achieved by herbicides applied through a sprinkler system.
Effect of stubble management during different fallow periods on nitrogen nutrition of wheat on an irrigated black earth
Authors: White PJ , Saffigna PG , Vallis I
Published: March 2005

A series of field experiments was conducted on a black earth of the Darling Downs, in south-eastern Queensland, to examine nitrogen availability to irrigated wheat (Triticum aestivum) after stubble of the previous crop had been either removed, mulched, or incorporated. Three crop sequences were considered: S-W, sorghum (Sorghum bicolor), short (3-month) fallow, wheat; W-W, wheat, normal (7-month) fallow, wheat; LFW, sorghum, long (15-month) fallow, wheat. The effect of stubble management on the availability of nitrogen to the test crop of wheat in each sequence was assessed by the response of the test crop to urea applied at planting (0, 25, 50, 75, 100 and 150 kg N/ha). Soil mineral nitrogen was measured at the beginning and end of the fallow during the experiments. There was a little evidence that stubble management influenced plant growth in any of these cropping sequences. Responses to nitrogen were very large in the S-W sequence, moderate in the W-W and very slight in the LFW sequence. Apart from a slight effect in the S-W sequence, measured soil mineral nitrogen concentrations were unaffected by stubble treatments.
The use of tritiated gypsum for estimating individual intakes of pelleted or unpelleted supplement by lambs fed individually or in groups
Authors: Dove H , Freer M
Published: March 2005

Grazing lambs, fed either individually or in groups, received daily supplements of 400 g/lamb of pelleted or unpelleted sunflower meal (SFM), labelled with tritiated gypsum. For pelleted SFM, individual and group intakes, estimated from the accumulation of tritium in the body water pool, were 1.5% and 3-5% less respectively than measured intakes. However, for unpelleted SFM, estimated intakes were 3-24% less than measured intakes. In a second experiment, lambs were individually fed labelled, unpelleted SFM indoors to examine possible losses of radioactive label which might account for the discrepancies observed in experiment 1. Loss of label in water bowls and in SFM adhering to the food bins reduced the effective specific activity of the food consumed by only 0.2%. Estimated intakes were closely related to known intakes by a regression in which the slope did not differ significantly from 1.0 nor the intercept from zero. It is concluded that the low estimates of unpelleted SFM intake in the first experiment are real and reflect wastage of supplement. It follows that the tritiated gypsum technique is equally applicable to pelleted and unpelleted supplements, and may be of greater use with the latter where wastage may be greater.
Effect of burr burial on seed production of Trifolium subterraneaum subsp. brachycalycinum and other annual legumes
Authors: Bolland MDA , Collins WJ
Published: March 2005

On sandy soil near Esperance, W.A., prevention of burr burial compared with covering developing burrs with sand drastically reduced the seed production of three subspp. of Trifolium subterraneum (brachycalycinum, subterraneum and yanninicum) and of T. israeliticum by reducing burr production and seed weight. However, T. globosum produced similar amounts of seed from unburied and buried burrs. On sandy soil at Shenton Park, Perth, W.A., prevention of burr burial also reduced seed production of T. subterraneum subspp. brachycalycinum and subterraneum, this being due to fewer burrs, fewer seeds per burr and lighter seed. For subsp. brachycalycinum, seed yields were two to five times greater from burrs which developed within loose gravel than from those developed over sand (in which fewer burrs were able to bury) as a result of increased production of burrs, more seeds per burr and heavier seed. However, for subsp. subterraneum seed yields were similar from burrs whether developed over gravel or sand.
Response of irrigated soybeans (Glycine max) to phosphorus on an alkaline cracking clay in semi-arid tropical Australia
Authors: Garside AL , Fulton MC
Published: March 2005

The primary and residual effects of phosphorus (P) fertilizer on soybeans (Glycine max cv. Buchanan) were studied at one site for three seasons on Cununurra clay in the Ord Irrigation Area. Grain yield increased (P< 0.01) with both primary and residual P in all seasons. When grain yields over the 3 years were standardized to eliminate seasonal effects, relative grain yield (RGY) was positively related to each of bicarbonate-extractable soil P (EP), applied fertilizer P (FP) and fertilizer P applied to the previous crop (PFP). Seventy-three per cent of the variation in relative yield within years could be explained by the equation: RGY = 45.44 + 0.64FP + l.84EP + 0.197PFP R 2 = 0 . 7 3 , P < 0.01 Increasing P status was associated with increased plant height, dry matter production and weight of 100 seeds and increased the number of main-stem nodes, nodules, pods per plant and days to maturity, but had no effect on number of seeds per pod and number of days until commencement and completion of flowering. Concentrations of P in the whole tops and uppermost leaf increased with increasing rate of P application. However, there was a significant P x growth stage interaction on nitrogen concentrations in whole tops and upper-most leaf, these being lower in the high-P plots early in the season. Grain protein content increased with increasing P status while oil content was reduced. The results show that rates of P application higher than those being currently used are required to maximize soybean yield on Cununurra clay.
The pattern of growth, flowering and fruiting of guava varieties in subtropical Queensland
Authors: Menzel CM , Paxton BF
Published: March 2005

The seasonal pattern of development in seven guava (Psidium guajava) varieties grown in subtropical coastal southern Queensland was investigated to test the hypothesis that the growth pattern of some varieties is more suited to this environment. Leaf initiation commenced 4 weeks after defoliation by spraying with urea dissolved in water (250 g/litre) in September and continued for 22 weeks. Floral bud emergence and fruit set began 4-8 weeks later and continued for most of the period of shoot growth. Fruit took 14 weeks to reach maturity and the last fruit was harvested in mid-June when the trees passed into winter dormancy. Varieties varied in time to maturity, although the patterns and levels of leaf initiation, flowering and fruit set were similar. Yields ranged from 68.8 to 138.7 kg/tree. Differences between the varieties in yield could not be attributed to any characteristic such as the rate, timing or duration of flowering, fruit set or fruit growth. There was no variety with a different growth pattern closely related to high yields under conditions at Nambour. However, some varieties appear more suited to this environment, since they set a heavier crop which ripened before fruit quality declines in winter.
Effects of age at harvest and irrigation near maturity on the incidence of internal brown fleck in potato tubers
Authors: Novak VJ , Mann GD , Schrodter GN
Published: March 2005

No brown fleck was observed in autumn-planted potatoes. The disorder developed every year in spring-planted crops, but only after the tubers matured and were left unharvested under hot conditions. With- holding irrigation in the few weeks prior to harvest reduced the incidence of brown fleck. Harvesting at maturity and 1 and 2 weeks after maturity resulted in 0, 15.3 and 26.7%, respectively, of the tubers being affected when the plots were irrigated until 2 weeks prior to harvest. When irrigation was discontinued 6 weeks before harvest, only 0, 3.8 and 4.4%, respectively, of tubers were affected in the same harvest treatments.
Effect of irrigation with saline water on soil properties and salinization of perennial pasture soils.
Authors: Mehanni AH , Chalmers DJ
Published: March 2005

Pasture grown on a Lemnos loam soil type, a typical red-brown earth, was irrigated with saline water of about 100, 300, 700, 1500 and 3000 mg/ litre total soluble salt. Salt accumulated in the soil during the irrigation season and was partly leached by winter rainfall. Gypsum applied annually at 5 t/ha increased infiltration of irrigation water and salt accumulation, but it also substantially enhanced leaching during winter and spring. After 4 years the soil salinities were approaching equilibrium. Any deleterious effect of sodium on physical properties was offset by the presence of electrolytes which did not leach to critical levels in winter because of low average rainfall and low soil hydraulic conductivity.
Residual value of phosphorus from superphosphate for wheat grown on soils of contrasting texture near Esperance, Western Australia.
Authors: Bolland MDA
Published: March 2005

The residual value for wheat of phosphorus (P) from superphosphate was measured in field experiments on two texture-contrast (duplex) soils near Esperance, Western Australia. Superphosphate was applied to previously untreated plots once only, in 1980, 198 1, 1982 or 1983. The residual value of this P was measured in 1983 relative to P applied in 1983. Results were similar for both soils. Superphosphate applied in previous years did not produce the same yield as superphosphate applied in the current year. As calculated from yield response, relative effectiveness was 65, 42 or 32% after 1, 2 and 3 years, respectively. Yield depended on P content of plant tops, and this relationship was independent of time of P application. As the period of contact of P with the soil increased, less P was taken up by the plants, and this limited yield. As calculated from the P content of plant tops, relative effectiveness was 60, 30 or 23% after 1, 2 and 3 years, respectively. The amount of P extracted from the soil by 0.5M sodium bicarbonate decreased by about 54% from day 210 to day 575 after application of superphosphate, by a further 35% from day 575 to day 940, and by 15% from day 940 to day 1305. Bicarbonate-extractable P determined on soil samples collected mid January 1983 gave a good prediction of yields measured in the spring of that year
Granular reactive apatite rock phosphate is not an effective phosphorus fertilizer in the short term on lateritic soils in south-western Australia.
Authors: Bolland MDA , Weatherley AJ , Gilkes RJ , Bowden JW
Published: March 2005

The effectiveness, as a phosphate fertilizer, of granular reactive rock phosphate (carbonate substituted apatite from North Carolina, U.S.A.), granular triple superphosphate and partly powdered Duchess non-reactive rock phosphate (low carbonate apatite from north-eastern Australia) was compared in three field experiments on different soil types in different climatic regions of south-western Australia. Calciphos (finely ground calcined crandallite rock phosphate from Christmas Island) was included in one experiment. The rock phosphates were incorporated into the soil and their effectiveness was compared with both topdressed and incorporated superphosphate. Different species were grown at each site (barley, triticale and subterranean clover). As determined on the basis of relative amounts of fertilizer required for constant yield, the effectiveness of all the rock phosphates relative to incorporated superphosphate was very low at each site throughout the growth of each species. Fertilizer effectiveness of rock phosphates was about one-fifth that of superphosphate for barley, and one-tenth for triticale and clover. The maximum yield obtained from rock phosphate was generally 88-100% that obtained from superphosphate. Incorporation did not greatly affect the effectiveness of superphosphate.
Growth and carcass composition of ram and wether lambs fed at two levels of nutrition
Authors: Lee GJ
Published: March 2005

This experiment examined the effects of two levels of nutrition on growth rate and fat deposition in the subcutaneous, kidney plus channel, omental and mesenteric depots of ram and wether second-cross lambs. Growth rates to slaughter were higher (P< 0.001) in lambs fed at the higher level of nutrition (170 � 5 v. 88 � 3 g/day; mean � s.e.). There was no difference in growth rates between ram and wether lambs at the levels of nutrition imposed. The level of nutrition did not influence fat depots when the comparison was made at the same carcass weight. Ram lambs had less subcutaneous fat than did wethers, the difference increasing (P = 0.06) at heavier carcass weights (1 00 v. 20 1 g increase in subcutaneous fat/kg increase in carcass weight, for rams and wethers respectively). A similar trend was evident in GR tissue depth; consequently, the distribution of fat scores of wether carcasses was closer to the high (fat) end of the range than was the distribution for ram carcasses (P < 0.05). The levels of total solvent-extractable fat in the carcass did not differ between sexes or levels of nutrition.
Productivity of early-weaned lambs fed high-grain diets of wheat, oats or barley with or without lupin grain
Authors: Kenney PA
Published: March 2005

Poll Dorset x (Border Leicester x Merino) lambs were weaned at 6 weeks and fed ad libitum diets of whole wheat, oat or barley grain with 0, 15, 30, 45,60 or 75% lupin grain, or all lupin grain, for 11 weeks. All diets included 10% hay. The lambs adapted to diets containing barley and wheat more quickly than to diets containing oats. Digestibilities of grain DM with hay alone were: wheat 83%, oats 73%, barley 75%, and lupins 83%. Inclusion of lupins in wheat-based diets had no effect on digestibility or intake of feed or weight gain of lambs. Inclusion of lupins with oats increased digestibility ( P < 0.05) and intake of feed (P< 0.05) and caused a slight rise in feed intake:liveweight gain ratio, but greatly reduced feed intake:carcass gain ratio (P< 0.05). Inclusion of lupins with barley increased digestibility and intake of feed (P< 0.05), and caused a slight fall in the feed intake:liveweight gain ratio (P<0.05) and a large fall in the feed intake:carcass gain ratio (P<0.05). Responses to lupins were generally most pronounced as lupin content increased from 0 to 30%. Liveweight, carcass weight, wool growth, abdominal fat and muscle depth at rib 12 were all linearly related to intake of digestible DM (P<0.05). Dressing percentage increased up to a maximum as daily intake of digestible DM increased to 0.55 kg/sheep and then fell (P<0.05). Liveweight was greater, but dressing percentage less, for lambs fed oats than for those fed barley or wheat (P<0.05). Carcass weights of lambs fed different grains were therefore similar at the same intakes of digestible DM.
Effect of establishment method on field performance of Stylosanthes guianensis lines
Authors: Miles KW
Published: March 2005

Forage genotypes are often tested in evaluation trials established with transplanted seedlings or cuttings, whereas commercial pastures are usually direct seeded. Eleven Stylosanthes guianensis accessions were established by direct seeding (DS), transplanted seedlings (TS), or transplanted rooted stem cuttings (RC) in a space-planted field experiment to determine the effect of establishment method (EM) and particularly the magnitude of the genotype-establishment method (G-EM) interaction for dry matter forage yield, plant height and radius, and flowering abundance. Data were taken on 12 harvest dates covering 1 18 weeks from field planting. The large initial EM differences for yield (60.9, 99.4, or 92.7 g/ plant for DS, TS, or RC, respectively, at first harvest) diminished rapidly. The deviation of DS mean yield from the experiment mean increased linearly from the second to the 12th harvest, while that of TS decreased. EM effect on plant size closely paralleled that of yield. Initial EM differences in flowering abundance (RC > TS > DS) disappeared by 42 weeks from planting. While a significant G-EM effect was detected at some harvest dates, this was invariably much smaller than genotype or EM effects and did not materially affect genotype ranking. At 138 weeks following field planting, diameter of the largest root below 7 cm depth was greatest for DS while RC had the greatest number of roots. Agronomic evaluation of S. guianensis genotypes should not be greatly affected by EM when a common EM is used for all genotypes and when plants are allowed to establish well in the field before evaluation commences.
Biology and control of cereal cyst nematode in northern New South Wales
Authors: McLeod RW , Wong PTW , Southwell RJ
Published: March 2005

Cereal cyst nematode, Heterodera avenae Woll., has been found on four farms in the northern, summer-dominant rainfall, region of New South Wales. Studies on the relationship of its life cycle to season indicate a pattern similar to that in southern, winter-dominant rainfall regions. Eggs collected from the field in January hatched best at low temperatures (5, 10�C). We suggest that this low temperature requirement prevents wasteful hatching after rain in summer in the north. Fungal parasitism of eggs and larvae was observed in the field but its significance in the ecology of the nematode in the north remains to be investigated. Five wheat and a barley cultivar resistant to H. avenae in the south resist the northern population; this suggests that the pathotype is the same as that in the south. The nematode produces large numbers of cysts on all wheats grown widely in the region; two of five barleys, and all of three oat cultivars showed some resistance. Control of H. avenae in a nematicide trial on one of the region's main soil types (black earth) increased yield of wheat (cv. Kite) by 45-68%. The nematode's potential effect on wheat production in northern Australia is discussed.
Tolerances of barley cultivars to post-emergence herbicides
Authors: Lemerle D , Kidd CR , Read BJ
Published: March 2005

Sixteen spring barley cultivars were tested in southern New South Wales for their tolerances to 12 post-emergence herbicides applied at the recommended rates and at three times those rates. Examples of unsafe combinations of cultivars and herbicides (at recommended rates) that have a risk of crop damage in this environment include: Shannon with bromoxynil at 0.42 kg/ha; Panvan with bromoxynil plus MCPA at 0.42 + 0.42 kg/ha; Bandulla, Beecher, Clipper, Malebo, Panvan and Weeah with dicamba at 0.08 kg/ha; and Clipper, Galleon, Lara and Shannon with dicamba plus MCPA at 0.11 + 0.48 kg/ha. Severe damage occurred to barleys from diclofop-methyl at 0.56 kg/ha and from chlorsulfuron at 0.01 8 kg/ha. Cultivars which showed tolerance were Grimmett, Lara, Stirling and Shannon with chlorsulfuron, and Shannon and Weeah with diclofop-methyl. The use of rates three times those recommended by the manufacturers in these experiments identified the susceptibility of additional cultivars which could be at risk of crop damage from overdosing, incorrect timing of application, or adverse environmental conditions. For example, Lara and Corvette with bromoxynil at 1.26 kg/ha; Corvette and Shannon with bromoxynil plus MCPA at 1.26 + 1.26 kg/ha; Corvette, Cutter, Galleon, Lara, Panvan, Schooner, and Shannon with dicamba plus MCPA at 0.33 + 1.44 kg/ha. The grain yields ofall cultivars were unaffected by both rates of difenzoquat, diuron, linuron, methabenzthiazuron or 2,4-D. The risks of crop damage v. the benefits of weed control are discussed. Seasonal variation was observed in the herbicidexcultivar interactions and this variation was sometimes of a greater magnitude than the differences between the cultivars. An interaction was observed between the incidence of barley leaf scald (Rhynchosporium secalis) and treatment with chlorsulfuron or diclofop-methyl. Routine screening of herbicides and crop cultivars for dangerous interactions is recommended, and we need a greater understanding of the effects of environmental factors on plant responses to herbicides.
Effect of season, trash and fungicides on fungi associated with subterranean clover
Authors: Barbetti MJ
Published: March 2005

In field studies we monitored the effects of time of season, trash and fungicides on the populations of fungi associated with leaves and petioles of newly sown subterranean clover, particularly in relation to the development of disease symptoms. These effects were compared with the fungal population changes occurring in a nearby established subterranean clover pasture. A range of fungi, notably Leptosphaerulina trifolii, Phoma medicaginis and Stemphylium globuliferum, were found to colonise subterranean clover cotyledons, leaves and petioles readily throughout the growing season from as early as 1 week after emergence. The incidence of L. trifolii and S. globuliferum was reasonably consistent throughout the growing season. Alternaria spp., Cladosporium spp., Myrothecium verrucaria, P. medicaginis and Trichoderma spp. were more prevalent later in the season. Fusarium avenaceum and other Fusarium spp. were more prevalent early in the season, while Pithomyces chatarum and S. botryosum were more prevalent midseason. The fungi isolated showed no ability, under the conditions of this investigation, to cause disease, and there was no correlation between fungi isolated and disease symptoms observed. The incidence of several fungi, especially L. trifolii and P. medicaginis, was greatly increased by the presence of trash from the previous season but was greatly decreased by regular applications of fungicide.