bluuebunny/crossref_metadata_2025 huggingface dataset:
Productivity of Hereford, highgrade Simmental and Belmont Red beef herds in central Queensland 5. Liveweights and carcass traits of steers
Authors: Tierney TJ , Burns BM , Mayer DG , Esdale CR , Webber RJ
Published: March 2005

Postweaning liveweights and carcass traits of Hereford, 1/4 Simmental-3/4 Hereford crossbreed, first-cross Simmental-Hereford, highgrade Simmental, and Belmont Red steers were compared from 3 cohorts bred at Brigalow Research Station, Theodore, Queensland. One half of each breed was grown and fattened at Brigalow Research Station, and the other half at a different site in southern Queensland, for each of 3 cohorts. When the mean liveweight of the Hereford steers reached 450 kg, a random selection of all breed groups was slaughtered (light group), while the remainder was slaughtered when the Hereford steers reached 550 kg liveweight (heavy group). Highgrade Simmental steers had higher (P<0.05) liveweights than 114 Simmentals and Herefords at each site in each year at all ages. While highgrade Simmentals were usually heavier than first-cross Simmental-Herefords and Belmont Reds, differences were not always significant. First-cross Simmental- Hereford and Belmont Red steers were usually heavier (P<0.05) than Herefords. Response to higher nutritional levels from provision of forage crop varied according to breed, with highgrade Simmentals showing the greatest liveweight response (268 kg by 27 months) and Belmont Reds the least (164 kg) over contemporaries grazing pasture only. Highgrade Sirnmental steers had the heaviest (P<0.05) carcasses in both slaughter groups (274 and 340 kg, respectively), and there were no significant (P>0.05) differences between Belmont Red and first-cross Simmental-Hereford steers (light group, 263 and 258 kg; heavy group, 318 and 327 kg). The 114 Simmental steers had heavier (P<0.05) carcasses than Hereford steers in both slaughter groups (light, 244 v. 235 kg; heavy, 307 v. 295 kg). Belmont Red carcasses had the greatest rib fat depth for both slaughter groups (6.6 and 8.4 mm), and highgrade Simmental carcasses were leanest (3.3 and 4.1 mm; P<0.05). Carcasses from 114 Simmental and from Hereford steers had similar rib fat depth in both slaughter groups (light, 5.0 and 5.1 mm; heavy, 6.8 and 6.8 mm), while the fat depths on first-cross Simmental-Hereford carcasses were 4.3 and 6.0 mm. Although highgrade Simmental steers yielded the heaviest carcasses, the lack of subcutaneous fat cover may reduce the value of these carcasses, on a unit weight basis. By contrast, Belmont Red carcasses were more likely to meet the range of market specifications for grass-fed carcasses.
Genotypic variation in response to high temperature at flowering in common bean (Phaseolus vulgaris L.)
Authors: Agtunong TP , Redden R , Mangge-Nang MA , Searle C , Fukai S
Published: March 2005

In controlled temperature glasshouses, 5 cultivars of Phaseolus vulgaris L. (cv. Actolac, and 4 Mexican cultivars: M 650, 659, 674, 685B) were subjected to super-optimal temperature (34/29�C day/night) stress pre-flowering (T2), pre- and post-flowering (T3), and post-flowering (T4). The stress treatments increased bud and flower production and dramatically increased abscission of buds, flowers, and pods compared with controls at 24-19�C. Actolac was the most sensitive to heat stress, while the Mexican cultivars displayed varying degrees of partial tolerance. For pod and seed production, M 674 was the most tolerant under T2, and M 685B the most tolerant under T4, with grain yields nearly equal to the control. This was achieved despite reduced seed weight, through increased seed set. Under T3 no cultivar produced seed. Cultivar M 659 was intermediate in stress reaction between Actolac and M 674 under T2, and M 650 was intermediate between Actolac and M 685B under T4. The data indicate that optimum growth temperatures for M 674 and M 685B may be greater than that for Actolac.
Performance of steers fed grain sorghum (Sorghum bicolor) of varying sorghum midge (Contarinia sorghicola) resistance
Authors: Strachan DB , Dillon RD , Henzell RG
Published: March 2005

This experiment examined the association between the level of sorghum midge resistance of a grain sorghum hybrid and its ultilisation by cattle. Twenty-five Hereford steers were placed in individual pens and fed a feedlot ration (80% grain) for 8 weeks containing 1 of the following grain sorghum hybrids: Pacific 810, DK55plus (susceptible to midge); Barrier (low resistance to midge); AQL39/QL36, DK470 (moderate resistance to midge). There was no significant (P>0.05) difference between the hybrids in dry matter intake, liveweight gain, feed conversion efficiency, apparent nitrogen digestibility, and digestibility of the dry matter. No tannins were detected in the grain of any of the hydrids. It was concluded that the development of grain sorghum hybrids resistant to sorghum midge will not affect the utilisation of the grain in steers.
Evaluation of resistance to potato leafroll virus in selected potato cultivars under field conditions
Authors: Wilson CR , Jones RAC
Published: March 2005

To test the resistance of potato cultivars to potato leafroll luteovirus (PLRV) in the field, small plots each containing 3 rows of 3 plants of the same cultivar were planted next to a row of infector plants. Harvested tubers were tested for PLRV infection by enzyme-linked immunosorbent assay. Most of the PLRV spread (85%) was sequential rather than random (i.e. related to distance between test and infector plants). Twenty-six potato cultivars were screened for resistance to PLRV in 6 trials during 3 years at 3 locations. Summer, autumn, or winter plantings were made. There were significant differences between cultivars in the degree of PLRV resistance and susceptibility, independent of location, season, or year. Of the cultivars included in at least 2 trials each, the most resistant were Delcora, Omega, Spunta, and Whitu. Most susceptible were Cadima, Denali, Elliot, Renova, Russet Burbank, and Tor. Contrary to earlier reports, Spunta was resistant, while Delaware was relatively susceptible. Four Australian-bred cultivars (Cadima, Elliot, Geographe, and Tor) that were tested for the first time had little or no resistance, and 2 (Bremer and Toolangi Delight) were intermediate. The incomplete (quantitative) nature of resistance to initial infection with PLRV by viruliferous aphids was demonstrated in a seventh field trial where aphids were more abundant and all plants became infected, including resistant cultivars Delcora and Omega.
Lupins, barley, or barley plus virginiamycin as supplements for sheep at different feeding intervals
Authors: Godfrey SI , Rowe JB , Speijers EJ , Toon W
Published: March 2005

This experiment compared the efficiency with which lupins, barley, and barley plus virginiamycin were used as supplements for sheep when fed at daily, twice weekly, weekly, and fortnightly rates. Merino wethers, about 1 year of age and 35 kg liveweight, were penned individually in 12 groups of 17 animals. There was a 3-week introduction to grain, followed by 10 weeks of supplement feeding. There was an interaction (P<0.05) between type of grain and feeding interval, for liveweight gain, wool growth, and wool strength. The linear response between liveweight gain, wool growth, or wool strength and the interval of feeding was significantly (P<0.05) different for sheep supplemented with barley and those supplemented with lupin grain. Increasing the interval of feeding reduced the efficiency of grain utilisation; the effect was more pronounced when untreated barley was fed. Over the period of supplement feeding, there was no significant (P>0.05) difference in liveweight gain between sheep supplemented with lupins and those suppplemented with barley plus virginiamycin. The addition of virginiamycin (34 g/t) resulted in a significant (P<0.01) reduction in the incidence of diarrhoea in sheep supplemented with barley plus virginiamycin compared with sheep fed barley alone. This effect may be of importance in reducing the incidence of breech strike in sheep fed cereal grains.
Effect of granulated magnesium oxide on the production and composition of milk by cows fed cereal grain and either conserved fodders or pasture
Authors: Valentine SC , Bartsch BD , Carroll PD , Chirnside IJ
Published: March 2005

Milk production and composition were measured in 54 Holstein-Friesian dairy cattle fed 8.4 kg DM crushed barley grain daily and either supplemented or not with granulated magnesium oxide (MgO). The supplement was offered for 2 sequential test periods of28 days. During the first test period, cows were offered conserved pasture, conserved cereal crops, and grazed pasture. During the second test period they were only grazed on pasture. In the first period MgO had no effect (b0.05) on milk production or composition. During the second period, more (P<0.05) milkfat was produced by cows offered the MgO supplement than by unsupplemented cows (0.73 v. 0.69 kg/day). During this period the breakeven net milkfat price was calculated as $A1.23/kg.
Compensation for reduction in seed set due to sorghum midge (Contarinia sorghicola) in midge-susceptible and midge-resistant sorghum (Sorghum bicolor)
Authors: Franzmann BA , Butler DG
Published: March 2005

The relationship between percentage seed set on grain sorghum (Sorghum bicolor) panicles damaged by sorghum midge, Contarinia sorghicola (Coquillett), and percentage compensation (percentage increase in weight) of undamaged seed was examined in 11 experiments covering a wide range of environmental variation and incorporating various sorghum midge susceptible and resistant genotypes. In contrast to previous findings where negative compensation was found after sorghum midge damage, compensation was generally positive, but the slope of the response with respect to seed set changed from positive to negative as seed set increased to >30-50%. Expression of the relationship was similar for susceptible and resistant genotypes. The slope of the relationship for seed sets above the point of maximum compensation was -0.51 for sorghum midge susceptible hybrids, -0.42 for resistant genotypes (various lines and hybrids), and -0.38 for resistant hybrid ATx2755/RTx2767. The pooled slope was -0.45.
Clonal selection and evaluation to improve production of Cabernet Sauvignon grapevines in South Australia
Authors: Cirami RM , McCarthy MG , Nicholas PR
Published: March 2005

The field performance of selections of Cabernet Sauvignon was evaluated from 1958 to 1988, with the aim of improving yields by visual selection of healthy, vigorous, productive clones from aged, productive vineyards within a district, and by systematic comparison of these clones with candidates from other districts, States, and countries. There were 9 clonal comparison trials, with reference clones provided by results from preceding trials. High yield (5-10 kg/vine) had little effect on juice composition, and performances of high-yielding selections in a range of areas were identified. These clones (SA 125, BVRC 17, G9V3, LC 10 and CW 44) have been established in Registered Source Areas and their cuttings distributed to the grapegrowing industry through the South Australian Vine Improvement Program. Single-vine plots with 10-20 replicates were suggested for more rigorous statistical separation of clones. It is desirable to test clones in the districts where they were selected and where they are to be planted.
Non-odorous characteristics of lychee (Litchi chinensis) and carambola (Averrhoa carambola) pertaining to fruitpiercing moth susceptibility
Authors: Fay HAC , Halfpapp KH
Published: March 2005

Lychee (Litchi chinensis Sonn.) and carambola (Averrhoa carambola L.) fruit, either attacked by fruitpiercing moths or undamaged, were compared on a number of occasions for weight, moisture percentage, softness, colour, �Brix, and pH, to profile fruit susceptibility in North Queensland. Height at which fruit were damaged on a tree and the tree's position in an orchard were also considered. On average 88.8% of moths inflicting damage to all fruit were Othreis fullonia (Clerck). In both crops, fruit in outer rows were more prone to attack than elsewhere in an orchard, indicating that orchard layout, trap crops, and attractive baits could all be considered to counteract these pests. No other characteristic differed significantly (P>0.05) between damaged and adjacent undamaged lychees. In damaged lychees, �Brix ranged from 11.0 to 22.8 and pH varied from 3.3 to 4.8. Highly significant (P<0.001) differences in fruit weight, colour, �Brix, and pH were recorded between damaged and undamaged carambolas; riper fruit were attacked on any individual occasion. Total soluble solids ranged from 5.2 to 11.8 �Brix in damaged carambolas and pH varied from 2.5 to 4.4. Some comparisons between cultivars were undertaken in each crop.
Effect of landuse on the composition of throughflow water immediately above clayey B horizons in the Warren Catchment, South Australia
Authors: Naidu R , Williamson DR , Fitzpatrick RW , Hollingsworth IO
Published: March 2005

The effect of landuse on composition of throughflow water immediately above the clayey B horizons in duplex soils (mostly natric and/or sodic) in the Mount Lofty Ranges, South Australia, was investigated using simple lysimeters. During July-November 1991, the pH of the first flow immediately after rainstorm under pines, native woodland, and pasture, respectively, was 5.7, 6.0, and 6.4. At each of the sites, average pH over 4 months during July-November was 5.8-5.9. Both the electrical conductivity (EC) and the amounts of total dissolved solids (TDS) were 2-3 times higher under pine than at other sites. The rate of change in EC with respect to TDS varied considerably among the sites, possibly due to the large differences in the concentration of dissolved organic compounds. Although the pH of water was >5.5, both aluminium and iron were recorded, especially under pine, where there were also high levels of dissolved organic compounds. High levels of suspended colloidal matter were recorded in the water flowing under pine, and these levels were related to dissolved organic carbon.
Comparative phosphorus requirements of Trifolium balansae and T. subterraneum measured at the same plant density
Authors: Bolland MDA
Published: March 2005

The phosphorus (P) requirement of Trifolium balansae is unknown and was measured and compared with the P requirement of T. subterraneum in 2 glasshouse pot experiments and 3 field experiments. The same density of plants was used for each species in each experiment. Requirement for P was determined from the amount reqiired to produce 90% of maximum yield of each species at each harvest. The yield produced at nil P or low levels of applied P was also used to compare the P requirement of the 2 species. As estimated from the amount of P required to produce 90% of maximum yield, 4 comparisons of P requirement were made in the pot experiments. The 2 species had similar P requirements in 2 comparisons, and T. balansae required 40% more, and 50% less, P than T. subterraneum on the other 2 occasions. In dense swards in the field experiments, T. balansae required 12-75070 more P than T. subterraneum to produce 90% of maximum yield, except for the first harvest (about 105 days after sowing) in 2 experiments when T. balansue required 20-60% less P. In one field experiment, swards of T. balansae or T. subterraneum were either uncut or cut at weekly intervals from 110 to 166 days after sowing. Compared with the uncut swards, weekly cutting reduced dry herbage yields of both species by about 5-15% for the 2 lowest levels of P applied and by 3040% for the 3 highest levels.
Subclinical selenium insufficiency. 4. Effects of selenium, iodine, and thiocyanate supplementation of grazing ewes on their selenium and iodine status, and on the status and growth of their lambs
Authors: Donald GE , Langlands JP , Bowles JE , Smith AJ
Published: March 2005

Merino ewes grazed 3 improved pastures low in selenium (Se) at 7.4 or 14.8 sheep/ha, from mating until their lambs were weaned at about 69 days of age. Treatments were arranged in a factorial design with ewes treated or not with Se pellets, an iodide drench, and thiocyanate given during gestation. Blood Se concentration, plasma thiocyanate, and thyroid hormone concentrations were monitored in ewes and their lambs. Lambs were weighed at birth and at weaning. Mean blood Se concentrations of unsupplemented ewes (Se-) and their lambs were about 0.01 �g Se/mL, and their lambs grew at 144 g/day. Lambs reared by ewes that received Se (Se+) grew at 176 g/day. Se-ewes had lower (P<0.001) circulating tri-iodothyronine (T3) concentrations and higher (P<0.05) thyroxine (T4) concentrations than Se+ ewes, and similar trends were seen in their lambs at birth. There was no evidence of clinical deficiencies of either iodine or Se in any group. Growth rates of lambs were not affected by thiocyanate supplementation of their dams during midpregnancy, but plasma T3 and T4 concentrations were depressed in ewes receiving thiocyanate. Iodide supplementation increased thyroid hormone concentrations in ewes but depressed plasma T3 concentrations in lambs.
A comparison of the persistence of Medicago truncatula cv. Paraggio with other annual medics in the Victorian Mallee
Authors: Latta RA , Quigley PE
Published: March 2005

The annual medic Medicago truncatula cv. Paraggio has been widely sown in pastures throughout the Victorian Mallee region; however, its ability to persist in cereal pasture rotations is not known. Seed permeability and production, and plant regeneration of Paraggio, were studied in the field over 4 years, and the changes in its seed reserve were examined under 3 different cereal-pasture rotations. When compared with medic cvv. Parabinga, Harbinger, and Jemalong, Paraggio had up to twice the level of permeable seed over the summer-autumn period in 2 years (7-36% v. 2.5-19%). Paraggio produced 336-928 kg/ha of seed over 3 years, and after seed production was halted, it regenerated at densities of 150-1438 plants/m2 over the next 4 years. These results were generally the same as, or better than, the other cultivars. When seed set occurred in 1 and 2 years in the pasture phase of a 2- and 3-year rotation, respectively, Paraggio seed reserves were maintained at >4000 seeds/m2. This study demonstrated that Paraggio resulted in superior plant densities when grown in a number of typical rotations. It persisted satisfactorily and is expected to improve agricultural productivity in shor-tterm cereal-pasture rotations.
Yield of early dryland sowing of wheat with winter and spring habit in southern and central New South Wales
Authors: Penrose LDJ
Published: March 2005

The effect on yield of early sowing of wheat, and of sowing wheats with winter habit, was assessed from routine trials from 29 sites in south and central New South Wales from 1981 to 1990. Early-sown trials were largely sown from mid to late April and conventionally late trials from mid to late May. Entries in early trials consisted of winter wheats or photoperiod-sensitive spring wheats, while photoperiod-insensitive spring wheats were sown in late trials. There was a gradual change in trial entries over the period of study. Although more variable than the late-sown trials, the early-sown trials had high yields over a wider range of sowing times and displayed less risk of frost damage. On average, winter wheats had a 6% yield advantage over late-maturing spring wheats in early-sown trials. Trials yielded 15% more when sown early than late. In comparison with quick-maturing spring wheats, winter wheats did not appear to suffer a large yield penalty when sown late. Yield of early-sown trials declined with sowing before or after the optimum sowing time of late April. There was a large reduction in yield with sowings earlier than 20 April. Yield of spring wheats declined from early May almost linearly with delay in sowing date.
Early detection of dwarf off-types from micropropagated Cavendish bananas
Authors: Smith MK , Hamill SD
Published: March 2005

A method was developed for early detection of dwarf off-types from micropropagated bananas (Musa sp., AAA Group, Cavendish subgroup). Selection of dwarfs was from glasshouse-grown plants, and although differences between dwarf and normal plants could be detected as early as 3 weeks from deflasking, discrimination was most effective at week 7, when the normal plants had reached a height of 18-20 cm. In order to develop selection criteria, known dwarf off-types and normal plants were micropropagated and established in a glasshouse. Measurements included plant height, petiole - - length, lamina length and width, and distance between leaves. Petiole length, lamina length, and the petiole to lamina length ratio provided the most promising selection criteria, with the dwarfs having significantly (P<0.01) smaller petioles and leaves than the normal plants. Selection was most effective when the plants were growing vigorously and uniformly. When growth became limiting, selection was more difficult. This was particularly apparent in plants that required repotting into larger containers and in micropropagated bananas grown in nurseries under suboptimal conditions. Plants were grown in the field and observed at bunch emergence, to verify trueness to type and to eliminate the possibility that off-types may have arisen in the normal and dwarf populations. A survey of these selection criteria with other Cavendish cultivars of various statures was also completed and the results suggest that dwarf and extra-dwarf off-types could be readily separated from the taller Cavendish cultivars Williams, New Guinea Cavendish, and Grande Naine.
A micro-challenge technique for the study of resistance to Dermatophilus congolensis in Merino sheep
Authors: Sasiak AB , Raadsma HW , Brown SC , Egerton JR , Lloyd DH
Published: March 2005

The clinical response (erythema, oedema, scab formation) of sheep to a micro-challenge with zoospores of Dermatophilus congolenis is described. The effect of site preparation (wax removal), dose of zoospores applied (0, 1 x 106, 1 x 107, 1 x 109, 1 x 1010. zoospores/mL), and day of inspection after challenge (0, 2, 4, 7, 9, 13, 17, 20, 23 days) were the major factors accounting for differences in responses to challenge. At all doses, large differences were observed between sheep in the prevalence, severity, and persistence of infection. These differences were not due to the effects of flock, or to footrot resistant and susceptible phenotypes. Based on results from this work, modifications were proposed to allow large numbers of sheep to be tested to estimate genetic differences between sheep in their resistance to challenge with zoospores from D. congolensis.
Barley grass control with herbicides in subterranean clover pasture. 1. Effect on pasture in the year of spraying
Authors: Stephenson DW , Mitchell GJ
Published: March 2005

Barley grass (Hordeum spp.) in a subterranean clover pasture was controlled with herbicides in the time between the 2-3 leaf stage and flowering. The effects on subsequent pasture production and composition were measured and the interaction between grazing and herbicides was also assessed. Early removal of barley grass reduced dry matter production in winter by an average of 41%. It also allowed an incursion of Indian hedge mustard (Sisymbrium orientale L.). which was suppressed by grazing but comprised an average of 23% ground cover in ungrazed pasture. Loss of total pasture production decreased as the date of herbicide application was delayed from June to September. Broadleaf species compensated for the early removal of barley grass, so that total dry matter production in spring in herbicide-treated areas was higher than in the unsprayed pasture. Fluazifop-p at 32, 53, and 106 g a.i/ha gave, respectively, 94, 91, and 94% reduction in barley grass seedhead density when applied at the 2-3 leaf stage, and 64, 88, and 98% reduction when applied at mid jointing. Application of this herbicide at 53 or 106 g a.i/ha for barley grass control can be delayed until late winter, thereby maintaining winter feed production but avoiding declining palatability and awned barley grass seeds.
Influence of genotype, sowing date, and seeding rate on wheat development and yield
Authors: Coventry DR , Reeves TG , Brooke HD , Cann DK
Published: March 2005

A 3-year study was conducted to measure the effect of sowing time and seeding rate on the development and yield of wheat (Triticum aestivum L.) grown under high-yielding conditions in north-eastern Victoria. A range of wheat cultivars with different development responses, including 'winter' types, was used in 2 experiments in each season. High grain yields for dryland wheat were measured in the first 2 seasons (1985-86), and in 1985, near-optimal water use efficiencies (>18 kg/ha. mm effective rainfall) were obtained. In the third season (1987) grain yield was limited by adverse climatic conditions-in the me- and post-anthesis period. In each season, grain yield declined with delay in sowing time. In 1985 there was a loss of 200-250 kg grain/ha for each week's delay in sowing time. In 1987, yield loss with delayed sowing was 50-110 kg grain/ha. In each season, cultivars with late or midseason maturity development gave the highest mean yields, and the use of these maturity types allowed earlier sowing, in mid April. However, with late sowing of wheat there was a trend for early maturity types to give higher yields, and so the use of 2 wheat cultivars with distinct maturity development responses to climate is recommended. If only 1 wheat cultivar is to be used, then a late maturity type is recommended. Higher wheat yields were also obtained as spike density increased, as a result of higher seeding rates. Our data suggest that in the higher rainfall region of north-eastern Victoria, a spike density of about 500 spikes/m2 is required to optimise wheat yields.
Components of quantitative resistance to anthracnose (Colletotrichum gloeosporioides) in tetraploid accessions of the pasture legume Stylosanthes hamata
Authors: Iamsupasit N , Chakraborty S , Cameron DF , Adkins SW
Published: March 2005

Partial resistance to the anthracnose pathogen Colletotriclzum gloeosporioides was characterised in 6 tetraploid accessions and cv. Verano of the tropical pasture legume Stylosanthes hamata. Four components of resistance (incubation period, latent period, spore production, weighted infection type) were determined and compared with those of the susceptible S. scabra cv. Fitzroy. There were significant differences between the accessions for all resistance components. The mechanisms of resistance in the 3 most resistant accessions appeared to be different, with accession 55830 having a longer incubation period but higher sporulation per day than either 92715 or 92412. Spore production, weighted infection type, and latent period were significantly (P<0.05) correlated with resistance of adult plants in the field (ADPC). The weighted infection type was useful in discriminating between accessions that had similar disease severity scores. A quantitative relationship was established between 2 components, latent period and spore production per day, and the ADPC, using a multiple regression analysis (r2 = 0.9). If verified using a large number of accessions, such analysis may be used to obtain an index of resistance that may predict resistance levels in the field based on the components.
Reliability of paddock sampling for the organisms (Anguina funesta and Clavibacter toxicus) responsible for annual ryegrass toxicity
Authors: Riley IT , Stanton JM , Brown AGP
Published: March 2005

An examination of within-paddock distribution of the nematode (Anguina funesta) and bacterium (Clavibacter toxicus) responsible for annual ryegrass toxicity (ARGT) was undertaken to determine the reliability of farmer-collected samples in determining the risk of ARGT. Areas in Western Australia with a recent history of ARGT outbreaks were selected for study. The results indicate that the distribution of ARGT organisms is patchy in paddocks with low population densities, but as the populations grow they spread throughout the paddock. Populations are not likely to reach toxic levels before they become widespread in the paddock. Farmer-collected samples processed by the ARGT Testing Service procedure were found to be a reliable tool for the management of ARGT in Western Australia.
Pathogenicity of fungi associated with seedling disease of cotton
Authors: Ogle HJ , Stirling AM , Dart PJ
Published: March 2005

Fungi associated with cotton seedling disease were isolated directly from a vertisol at Narrabri, New South Wales, in which cotton had failed to establish, and from cotton seedlings grown in the same soil and seedlings grown in 7 Queensland cotton-growing soils (also Vertisols). Fusarium spp., Penicillium spp., Trichoderma spp., Rhizoctonia solani, Pythium vexans, I unidentified pythiaceous fungi, and a number of miscellaneous unidentified fungi were isolated from soil or soilborne plant debris. Pythium ultimum, R. solani, Fusarium spp., and unidentified pythiaceous fungi were isolated from lesions on seedling hypocotyls. The pathogenicity of the fungi was investigated using cotton seedlings grown in steamed potting mix; 93% of seedlings survived in the absence of fungal inoculum. Of the fungi isolated from the Narrabri soil, P. ultimum and R. solani were most pathogenic, reducing seedling survival at 14 days after inoculation to 33%. Isolates of P. vexans and Fusarium spp. reduced seedling survival to 64% and 73-87%, respectively. Isolates of R. solani or P. ultirnum from the Queensland soils completely prevented seedling emergence in most cases, while isolates of Fusarium spp. were not pathogenic. Isolates of both R. solani and P. ultimum varied significantly in pathogenicity.
Evaluation of must composition and wine quality of six clones of Vitis vinifera cv. Sauvignon Blanc
Authors: Ewart AJW , Gawel R , Thistlewood SP , McCarthy MG
Published: March 2005

The evaluation of 6 clonal selections of Sauvignon blanc grapes grown at McLaren Vale in South Australia identified 2 significantly (P<0.05) higher yielding clones, F4V6 and F14V9. F4V6 and F14V9 had significantly lower total soluble solids TTS) in the years where all clones were harvested together. In 1 year, F4V6 and F14V9 were harvested 9 days later than the remaining clones. Their TSS values were not significantly different, The titratable acidities of F4V6 and F14V9 were lower due to lower tartrate and malate levels. The pH of F4V6 was higher than that of any other clone at a similar maturity level. (Clones F4V6 and F14V9 had greater yields per vine in all 3 years.
Review of perspective, issues, and trends in soil and plant testing in the United States of America
Authors: Jones JB Jr
Published: March 2005

This paper briefly reviews the developments that have occurred in the United States of America regarding farmer and grower provided soil testing and plant analysis services from the early 1990s to the present. Significant changes have occurred in terms of the type of laboratory providing these services, methodology, and instrumentation. Developing environmental implications related to soil testing and plant analysis will begin to impact the number and types of tests that will be mandated, and those who will be qualified to conduct these tests, as well as requirements for laboratory accreditation and certification. The results of a 1991 survey of soil testing and plant analysis laboratories are given.
Plant sampling: a review
Authors: Robinson JB
Published: March 2005

The steps involved in collecting and handling samples for plant analysis are described under the following headings: purpose for which the sample is collected; sampling statistics; sampling strategies; choice of tissue; sample handling; special sampling techniques. In any application of plant tissue analysis close attention should be given to the approaches which are used to develop the critical values or ranges that are used. In diagnostic and prognostic use of plant analysis the statistics of the sampling procedure should be well understood, so that a sample which properly represents the crop or planting can be collected. When diagnosis is the primary objective the sampling unit may be as small as a single plant. It is important that contamination of the sample with nutrient sprays or other materials is understood and recorded. Washing may not be possible, particularly when samples are collected by unskilled people at a site distant from the analytical laboratory. Although washing with detergents or weak acids can remove contamination, there will remain some doubt as to the efficiency of the washing procedure. Samples which are to be used for sap tests immediately after collection for nitrate-nitrogen should be handled more carefully than those destined after drying for multi-element analysis at a remote laboratory. Ideally the respiratory loss of dry weight from samples should be minimised when the samples are destined for conventional multi-element analysis. Where certain aspects of sample handling are critical to the success of the test they should be emphasised to potential users. A wide range of plant tissues other than the commonly collected leaves and petioles has been used for assessment of mineral nutrient status, including juice, fruit, and shoot tips. Each of these presents different problems in sample collection handling and storage. Tests based on enzyme activity and other biochemical or physiological indicators probably present the most difficult sample handling problems, but these tests are not widely used. A number of sampling issues which arise from the author's experience with commercial tissue analysis services are raised. These include such matters as the extent of training of the personnel who do the sampling, contamination and transport to the laboratory. Although more attention to these issues is needed in practice, plant tissue analysis continues to be a most valuable tool in the hands of the informed manager.
Prime lamb production in relation to time of mating
Authors: Freer M , Donnelly JR , Axelsen A , Dove H , Fowler DG
Published: March 2005

Over 3 years, we examined the possible benefits of moving the joining date from mid March to early February for the productivity of a prime lamb system based on Border Leicester x Merino ewes on the southern tablelands of New South Wales. The proportion of ewes with >1 lamb (fertility) was affected more by year and by age of ewe than by joining date. The mean proportion of fertile ewes with >1 lamb (fecundity) was reduced from 0.28 to 0.15 at the earlier date, while immunisation against androstenedione increased fecundity at both mating times to 0.42 but significantly reduced fertility in the earlier group. Over the 3 years, the earlier joining produced 12 fewer lambs per 100 ewes mated and immunisation increased lamb number by 17, but flushing (for 3 weeks with sunflower meal) had no significant effect. Immunisation did not have a consistently greater effect at the earlier joining. Groups of these ewes, balanced for fetus number, grazed at 6.5, 10, or 13 per ha on pastures based on phalaris and subterranean clover. Ewe liveweight after lambing, lamb birth weight, and perinatal mortality were not affected by joining date, but mean daily weight gain by later born lambs over the first 90 days of life was 44 g greater than for earlier born lambs. However, earlier joining enabled 17 more lambs per 100 ewes to reach a marketable weight of 31 kg within the pasture season. Twins grew more slowly and relatively few reached sale weight. With a mean 1.4 lambs per ewe, the optimum stocking rate on these pastures appeared to be 6.5-10 ewes/ha. Superphosphate application to half of the experimental area, after 17 years without treatment, increased pasture weight, lamb growth rate, and numbers sold. The increase was such that a treated pasture could have carried an extra 3 ewes/ha without depression in individual productivity, relative to an untreated pasture. Supplementation of ewes in late pregnancy and early lactation benefited only twin lambs at the higher stocking rates. The results suggest that a prime lamb system in this environment is more likely to succeed with the earlier joining date. The lower lambing percentage, resulting from a decrease in fecundity, is likely to be of benefit, rather than detriment, to the efficiency of a system in which single- and twin-bearing ewes and their lambs are given equivalent treatment.
Characterisation of naturalised strains of Trifolium subterraneum var. brachycalycinum cv. Clare in northern New South Wales
Authors: Lodge GM
Published: March 2005

Burrs were collected from paddocks on 3 properties in northern New South Wales where the age of the Trifolium subterraneum var. brachycalycinum cv. Clare swards varied from 19 to 28 years. At 1 site burrs were also sampled from swards sown 2 and 10 years previously. Twenty seedlings from these burrs and 20 plants of certified cv. Clare were grown as spaced plants in a nursery. These were assessed for vegetative and floral characters, flowering time, number of seeds per burr, seed weight, and percentage hardseed after storage at 25/25�C for 6 months and 25/45�C for a further 6 months. For most plants the mean number of days from sowing to first flower was similar to that of Clare. Compared with the naturalised strains, Clare had the lowest (P<0.05) mean number of seeds per burr: about 25% below the mean of the strains (2.7 seeds per burr). While the lowest mean seed weights of the strains were not significantly different from those of Clare, the seed weights of plants from 3 sites were higher (P<0.05) than those of Clare. After storage for either 6 or 12 months, hardseed levels were also lowest (P<0.05) for Clare. Plants from the 2-year-old sward had the same median number of seeds per burr (2.0) as Clare. As sward age increased, the median number of seeds per burr increased to 2.8. Hardseed percentages were lowest for plants of Clare and for those from the 2-year-old sward after 6 months, and for Clare after 12 months. These studies indicated the presence of divergent strains in old swards of Clare in a summer rainfall environment. Natural selection among variability within Clare is the most likely reason for the development of these strains in an environment marginal for the long-term persistence of this softseeded cultivar. Although strains had the same vegetative and floral markings as Clare, differences in ecologically important characters such as number of seeds per burr, seed weight, and hardseededness may result in plants that are better adapted to the environment in which they evolved. From these studies 23 plants of T. subterraneum var. brachycalycinum were selected for further evaluation.
Initial activity of atrazine and chlorsulfuron residues is greater in the grey clays than in the black earths of southern Queensland
Authors: Walker SR , Marley JMT , Robinson GR , Hargreaves PA
Published: March 2005

Commercial experience is that soil type appears to be a major factor influencing initial weed control from soil applications of atrazine and chlorsulfuron. We tested this by collecting 26 soils from the major cropping areas in southern Queensland. Initial activity was determined by measuring the dose required for 50% inhibition (ID50) of seedling growth in Wimmera ryegrass in controlled environment cabinets. The mean ID50 for atrazine and chlorsulfuron in black earths was 3 and 4 times greater, respectively, than in grey clays. Lower activity in the black earths was probably due to higher clay and cation contents and, consequently, greater adsorption of the herbicides. These results suggest that application rates of atrazine and chlorsulfuron can be adjusted for differences in initial activity between soil types.
Effects of saline irrigation water on soybean yield and soil salinity in the Murrumbidgee Valley
Authors: Beecher HG
Published: March 2005

The effect of saline irrigation water on soybean (Glycine max cv. Chaffey) growth and yield is not known for southern Australia. Soybeans were grown on hills, on a transitional red-brown earth, with moderately saline irrigation water (0.25, 0.5, 1.0, 1.5, 2.0 dS/m) for 2 seasons. Grain yield was significantly reduced when soybeans were irrigated using water with salinity >0.25 dS/m in the first year and >1.5 dS/m in the second year. The salinity of the upper 75 cm of the soil profile increased with increasing salinity of applied treatments. Salinity levels at depth indicate increased flow beyond the rootzone with increasing salinity of applied water. The use of water >0.5 dS/m is not recommended for soybean cv. Chaffey on sites where soybeans have not previously been grown.
Growth, development, and yield of three oilseed Brassica species in a water-limited environment
Authors: Lewis GJ , Thurling N
Published: March 2005

Representative lines of Brassica napus, B. campestris, and B. juncea were compared at East Beverley in the central wheatbelt of Western Australia on the basis of agronomic and physiological characters known to affect seed yield. Seed yield of B. juncea line 81794 was 32% higher than the locally adapted B. napus cv. Wesbrook (76 g/m2). Yields of B. napus cv. Eureka and the 2 B. campestris populations were not significantly different from Wesbrook and were lower than 81794. The higher yield of 81794 was due to higher dry matter production, particularly after first open flower. Yield superiority of 81794 was not associated with any single yield component. Under the water-stressed conditions of this experiment, seed yield had a strong positive correlation with dry matter production after first open flower. Differences in dry matter production during this period were due to variation in crop growth rates among the lines, not to variations in duration of the period. There was no relationship between flowering time and seed yield in this experiment, suggesting earlier reproductive development is not obligatory for high yield of oilseed Brassicas in low rainfall mediterranean environments. Total water use throughout the season differed little among populations, but there were differences in water use patterns over time. The greater rate of dry matter accumulation of 81794 is due to its ability to extract more water from the soil profile after anthesis; postanthesis water use of 81794 was 20% higher than that of Wesbrook. Water use efficiency of 81794 was also higher than that of Wesbrook, because soil evaporation comprised a smaller proportion of evapotranspiration. Further increases in seed yield of oilseed brassicas in this environment should be possible if higher postanthesis water use could be combined with lower soil evaporation and improved water use efficiency.
Soil treatment, plant species, and management effects on improved pastures on a solodic soil in the semi-arid subtropics: 3. Improving cool season plant and cattle productivity
Authors: Russell JS
Published: March 2005

Seasonal analyses of grasses and legumes in a long-term experiment on a solodised solonetz soil (Natrustalf) in southern Queensland showed that the large liveweight losses of steers in the cool months (June-August) appeared to be broadly correlated with low plant nitrogen (N), phosphorus (P), and potassium (K) concentrations. Annual variation in the N, P, and K percentages of Rhodes grass (Chloris gayana) and volunteer grasses [medics (Medicago spp.) and siratro (Macroptilium atropurpureum)] as affected by soil and plant treatments were examined by fitting a Fourier series to the data. Cool season liveweight losses of steers ranged from 391 glday with sown grasses alone to 11 g/day with sown grasses and medics plus lime and gypsum. The N content of volunteer and sown grasses ranged from 0.56 to 0.70% in the cool months, which is below the accepted N requirement of 1%. The P concentration of volunteer grasses was only 0.08%, but where P fertiliser was applied, concentrations in Rhodes grass were 0.10-0.11%. Potassium levels were also low in the cool months, with values of 0.23-0.43% in grasses. Exchangeable magnesium (Mg) and sodium increased from 1.3 and 0.48 mLJ100 g at 0-10 cm depth to 8.5 and 5.2, respectively, at 40-70 cm. Exchangeable calcium decreased from 2.5 mL/100 g at 0-10 cm to 0.40 at 40-70 cm. The Mg levels in siratro (0.58-0.60%) were higher than those in Rhodes grass (mean 0.12%). Medics responded markedly to lime, resulting in a 54% increase in steer liveweight gains on Rhodes grass-medic pastures. The use of lime on solodic soils for reducing both surface soil acidity and exchangeable aluminium increased plant and steer productivity. The cost of lime transportation can be high in inland areas, but small limestone deposits have been identified on the Darling Downs and these merit closer attention.
Residual effects of phosphorus fertiliser in a stylo-native grass pasture on a duplex red earth soil in the semi-arid tropics of North Queensland
Authors: Shaw KA , Gilbert MA , Armour JD , Dwyer MJ
Published: March 2005

A field experiment was established to define the phosphorus (P) requirement for establishment and maintenance of a mixed legume pasture (Stylosanthes scabra cv. Seca, S. hamata cv. Verano, S. guianensis cv. Graham, Macroptilium atropurpureum cv. Siratro) introduced into a native grass pasture on an infertile duplex red earth. Rates of 0, 5, 10, 20, and 40 kg P/ha were applied to separate plots in year 1 (1982), 2, and 3. In year 5 (1986 growing season), half of each plot that had received 20 and 40 kg P/ha in year 3 was refertilised at the original rate to ensure that maximum yields were defined. Bicarbonate- or acid-extractable soil P concentrations of 8 mg/kg were sufficient for 80% maximum legume yield. The residual value of applied P in the surface soil, as measured by soil analysis, decreased exponentially, but an initial application of 40 kg P/ha was still sufficient to produce near-maximum legume yield after 5 years. Phosphorus application increased the dry matter yield of legume. During the establishment phase (years 1 and 2 after planting) yields reached maximum at 10 and 20 kg P/ha, respectively, but increased linearly in subsequent years. When the original rates were reapplied in year 5, peak yield occurred at 20 + 20 kg P/ha, and there was no difference between this yield and that from plots receiving 40 kg P/ha in year 1. Native grass yields increased with P application only in years 4 and 5 of the experiment. Stylos demonstrated good tolerance to low P supply. In year 1, 80% of the total legume yield consisted of Graham stylo and Siratro, whereas in subsequent years, Seca and Verano made up 70 and 20%, respectively, of the total, irrespective of treatment. Yield of legume at nil P, relative to maximum, increased from 5% in year 1 to 42% in year 5.