bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of delayed film wrapping and waxing on the shelf life of avocado fruit
Authors: Joyce DC , Shorter AJ , Jones PN
Published: March 2005

Film wrapping and waxing are both known to extend the shelf life of harvested avocado fruit. However, the effect of delays in film wrapping and waxing on shelf life has not been reported. Early, mid, and late season avocado cv. Hass fruit were wrapped in 'Glad Wrap' or waxed in 'Avocado and Passion-fruit Wax' at intervals of up to 96 h after harvest. Compared with untreated control fruit, both wrapping and waxing delayed softening and colour change at 22�C by about 50%. Loss in fruit weight during ripening was reduced more by wrapping than by waxing. Delaying wrapping or waxing by up to 48 h after harvest was not associated with consistent differences in shelf life. There was, however, significant (P<0.05) shortening of both time to colour and time to soften if treatment was delayed to 96 h. Accordingly, wrapping or waxing avocado fruit is advisable within 48 h of harvest to realise maximum treatment benefits. Early colouring within 3-4 days of harvest, but not early softening, was characteristic of late season fruit.
Blackleg disease on oilseed Brassica in Australia: a review
Authors: Salisbury PA , Ballinger DJ , Wratten N , Plummer KM , Howlett BJ
Published: March 2005

Blackleg, caused by the fungus Leptosphaeria maculans, is the major disease of canola (Brassica napus) in Australia. The development of blackleg-resistant B. napus varieties has been a major factor in the resurgence of the industry nationwide. The main sources of resistance used in Australian public breeding programs are Japanese spring varieties and French winter varieties. In these programs, all early generation material is screened in field blackleg nurseries sown on, or adjacent to, infested canola stubble from the previous season. Little is known about the genetic control of resistance, and the mechanisms responsible for generating pathogenic variability of L. maculans isolates in Australia is largely uncharacterised. Australian B. napus varieties are the most blackleg-resistant spring varieties in the world. Apart from growing blackleg-resistant varieties, other strategies that minimise infection and delay any breakdown in varietal resistance include growing canola on the same area only once every 3 years, destroying stubble, and eradicating volunteer plants between cropping seasons. Additionally, strategic use of chemicals can provide effective control to supplement varietal resistance in areas prone to severe blackleg infestation.
Perceptions and knowledge of measurement in selection programs: a survey of stud Merino breeders in Australia
Authors: Butler LG , Corkrey SR , Knox IJ , Hannan G , Thomson RP
Published: March 2005

A total of 329 (25%) stud Merino breeders returned a survey designed to evaluate their knowledge of, and attitudes to, objective measurement in sheep breeding and performance recording. The data were analysed by log-linear regression techniques. There was overwhelming agreement that performance records were not as valid as traditional methods, but there was general agreement that measurement improves accuracy of selection, increases genetic gain, assists ram buyers and breeders, and increases flock earnings. There is a significant concern regarding the accuracy of fleece tests. Most respondents (60%) intend to increase their use of measurement, although the common attitude was that measurement only gives back-up to visual assessment. Some answers demonstrated a lack of understanding of the principles of applying measurement. There appears to be a difference between breeders and those more closely involved with technical genetics in interpretation of the term 'breeding objective'. Department of Agriculture Officers and Stock Agents rated poorly as sources of information. Rural newspapers and magazines are confirmed as useful media for awareness. It was concluded that a number of barriers to adoption of objective measurement and performance recording need to be overcome, including suspicion about the accuracy of the fleece tests, and the ram age at which testing can be conducted with confidence.
Large-scale trapping of sheep blowflies in the northern North Island of New Zealand using insecticide-free traps
Authors: Dymock JJ , Forgie SA
Published: March 2005

Large-scale trapping of sheep blowflies (Diptera: Calliphoridae) was undertaken on a mixed farming property in the north of the North Island of New Zealand over 3 consecutive summers. Traps were placed at a density of 1 trap110 ha and baited with fresh sheep offal every 2 weeks. No insecticide was used in the 150-L traps. The most effective bait trialled was sheep offal <2 weeks old. There was no significant effect of trap colour or trap site on the number of blowflies caught. A 95% decline in the principal flystike blowfly, Lucilia cuprina, was recorded. Flystrike incidence at the site was low during the study so that the effect of trapping on sheep myiasis could not be determined.
Effective barley grass (Hordeum spp.) control in annual medics with 2,2-DPA herbicide
Authors: Wallace A , Evans PM , Bowran D
Published: March 2005

The ability of 2,2-dichloropropionic acid (2,2-DPA) to control annual grasses was examined in a 4-year-old medic (Medicago polymorpha var. brevispina cv. Circle Valley) pasture. Six rates of 2,2-DPA with and without spray adjuvants (1% spray oil + 0.25% wetting agent) were used: 0.37, 0.56, 0.74, 1.11, 1.48, 2.22 kg a.i./ha. The pasture was sprayed in July at the 4-true-leaf stage of the medic, after identifying and counting grasses and medics. Plants were counted again after spraying and grass seed heads were counted in spring. At the end of the season, medic seed yields were obtained. Nine annual pasture legumes were later evaluated for their tolerance to 2.22 kg 2,2-DPA/ha at 3 growth stages [post plant, pre-emergence (PPPE); 3-5-true-leaf stage; flowering] under weed-free conditions. A rate of 1.11 kg 2,2-DPAJha was found to reduce barley grass density by 85%. Efficacy was improved, however, with higher rates and/or the addition of spray adjuvants. Because of low silvergrass (Vulpia spp.) and ryegrass (Lolium rigidurn) plant numbers, it was not possible to assess whether 2,2-DPA controlled these species effectively. There was no effect of herbicide on medic seed yields, seed weight, seed number per pod, or seed germination. Medic seed yields were well correlated with plant density of medic but not with herbicide rates. There was a wide variation in biomass production of the 9 pasture legumes in the evaluation of tolerance, when assessed by visual rating and seed yield, with significant biomass and yield reductions at all timings of application of 2,2-DPA. Subterranean clover (Trifoliurn subterraneum L.) was the most severely affected. Generally, medic species tolerated 2,2-DPA well. Serena was the most susceptible medic cultivar at any treatment time, with seed yield reductions at the first 2 times of application. The results suggest that 2,2-DPA could be used safely on annual medics for the control of barley grass, and possibly other annual grasses.
Effect of lupins and location on soil acidification rates
Authors: Dolling PJ
Published: March 2005

The effect of years since clearing, frequency of lupin crops, and location on soil acidification rates was determined on a deep yellow sand in the northern wheatbelt of Western Australia. The study involved soil sampling of 87-89 sites at each of 2 locations (Mingenew, East Chapman) representing a range of years (3-40) since land clearing and frequency of lupin crops (0-11). The sites were sampled to a depth of 80 cm in 10-cm increments, and measurements included soil pH, pH buffering capacity, and bulk density. The rate of acidification for the profile at Mingenew (400-450 mm rainfalljyear) in a rotation without lupins (3-4 years pasture and 1 year wheat) was 0.42 kmol H+/ha . year requiring 21 kg CaCO3/ha. year to neutralise. When a lupin-wheat rotation was grown at Mingenew, the net acidification for the profile was 0.62 kmol H+/ha. year (or 31 kg lime/ha. year). The main causes of acidification were organic anion removal and nitrate leaching. At East Chapman (325-375 mm rainfall/year), the acidification rate depended on years since clearing. For 8-14 years since clearing the acidification rate was negative, and for 15-4oyears since clearing it was positive: in year 8 the rate for the profile was -0.39 kmol H+/ha. year; in year 15, 0.04 kmol H+/ha. year; and in year 40, 1.58 kmol H+/ha. year (79 kg CaCO3/ha.year). The main causes of acidification were organic anion removal, nitrate leaching, and ammonium-based nitrogen fertiliser use. There was a significant difference in initial pH (pH of the uncleared sites) of the soil samples from the 2 locations; at East Chapman the initial pH was 0.2-0.3 units higher than at Mingenew, and the rate of pH decline was greater at East chapman.
Some factors affecting the development and biocontrol of cotton seedling disease
Authors: Ogle HJ , Stirling AM , Dart PJ
Published: March 2005

The effects of temperature and cultivar on disease development in cotton were investigated in addition to the duration of susceptibility to infection and the timing of infection by Pythium ultimum and Rhizoctonia solani. Symptom development was also monitored. Disease was more severe at day/night temperature regimes of 20/15, 25/20, and 30/25�C than at 35/30�C. Disease development differed significantly between cotton cvv. Deltapine 90 and Siokra 1-4 at 30/25�C and 35/30�C. In glasshouse trials in field soil, both R. solani and P ultimum were isolated from seeds as early as 2 h after inoculation, although most seeds were not infected with P. ultimum until 10 h after inoculation and with R. solani until 24 h after inoculation. Increasing the duration of exposure to inoculum increased the number of seeds infected and reduced the number of plants surviving. Seedlings were resistant to P. ultimum infection by 14 days after sowing but were not resistant to infection by R. solani until 28 days after sowing.
Use of airshear technology to reduce chemical spray rates for thinning of apples
Authors: Oakford MJ , Bound SA , Jones KM , O'Rielly L
Published: March 2005

An experiment at the Grove Research Station in southern Tasmania compared the efficacy of low spray volume (LV) treatments of NAA applied by an airshear sprayer with that of the industry standard, airblast sprayer, high volume (HV) application of 4000 L/ha at 10 mg NAA/L to thin Red Delicious apple trees. By adjusting the concentration of NAA, the LV treatments of 100, 200, 400, and 800 L/ha were each applied at 4 rates of NAA representing 25, 50, 75, and 100% of the HV rate of 40000 mg/ha. All treatments were applied at full bloom and 9 days after full bloom. All chemical rates except 25% reduced crop load significantly compared with the control. Fruit weight and size improved in most cases at the 100, 75, and 50% chemical rates. Fruit numbers and mean fruit weight were fitted to polynomial models. This work shows that airshear technology is effective at volumes as low as 100 L/ha, which represents a major saving in spraying time. It also indicates that with effective spraying systems, chemical application rates can be reduced to 50-75% of label rates. This should give the apple industry the confidence to reduce rates and still produce crops of high quality fruit.
Effect of weather station logging interval on the precision of degree-day estimates
Authors: Watson DM , Beattie GAC
Published: March 2005

The relationship between data-logging intervals and degree-day estimates was examined to determine the longest interval giving equivalent information to estimates based on 12-min intervals and, so, the most efficient interval for estimation of degree-days
DNA profiling techniques for plant variety identification
Authors: Morell MK , Peakall R , Appels R , Preston LR , Lloyd HL
Published: March 2005

The unambiguous identification of plant varieties is important in many areas of agriculture and plant biology research. New techniques based on DNA profiling provide novel approaches to varietal identification which offer advantages over traditional morphological comparisons. These advantages include great potential resolving power, data that can be analysed objectively, testing at all stages of development, and cost effectiveness. In this review, the advantages of recently introduced polymerase chain reaction (PCR) based methods are compared with the well-established restriction fragment length polymorphism technique. Two approaches to PCR-based DNA profiling (random amplification of polymorphic DNA, sequence-tagged sites analysis) are compared and contrasted, and statistical methods for the analysis of data are described. The potential use of these techniques for Plant Breeders Rights registration in Australia is outlined.
A review of trends in wheat yield responses to conservation cropping in Australia
Authors: Kirkegaard JA
Published: March 2005

Trends in wheat yield responses to conservation cropping in Australia were analysed using data from 33 medium-term (3-5 year) and long-term (>5 year) agronomic experiments. The overall effect of tillage (direct drilled v. cultivated) was small in all regions (-0.18 to +0.06 t/ha), while stubble retention (stubble retained v. stubble burnt) reduced yield in all regions (-0.31 to -0.02 t/ha). There was large year-to-year variation in the yield response to both tillage and stubble retention at all sites, but no consistent relationship between yield variation and amount or pattern of seasonal rainfall based on monthly totals. There was also little evidence that the yield of direct-drilled and stubble-retained treatments increased relative to cultivated or stubble-burnt treatments with the duration of the experiments, despite the improvement in soil conditions reported at many sites. The factors thought responsible for the year-toyear variation in yield response varied within and between regions, although some consistent effects emerged. Reduced early seedling growth of directdrilled crops was considered a major factor underlying the yield response at most sites, and this was rarely associated with the availability of water or nitrogen. High soil strength and increased severity of rhizoctonia root rot were responsible for these effects at some sites, but at others the cause remains unclear. Stubble retention influenced yield in many ways but the significance of the allelopathic effects of stubble, suspected by many authors to influence crop growth, is poorly understood. Adoption of direct drilling and stubble retention is likely to remain low in areas where no long-term yield benefit can be demonstrated and where greater management flexibility is offered by systems of reduced cultivation and late stubble burning-incorporation. Further research should identify and develop strategies to overcome the constraints to yield in conservation farming systems, particularly stubble retention, and assess the sustainability of recent innovations incorporating minimum disturbance and partial stubble retention. The more rapid adoption of such intermediate strategies will hasten the move of the grains industry toward sustainable production.
Biological farming for sustainable agricultural production
Authors: Penfold CM , Miyan MS , Reeves TG , Grierson IT
Published: March 2005

In 1989, funding was provided to establish a large-scale (16-ha), long-term trial at Roseworthy campus. The trial aims to compare organic, biodynamic, integrated, and conventional broadacre farming systems for attributes of sustainability. It is overseen by a 13-member management committee comprising farmers with experience in each practice, agronomists, and soil scientists. Through the monitoring of indicators such as soil physical, chemical, and biological changes, product quality, economics, crop water usage, and energy requirements, the comparative advantages or disadvantages of each system are being evaluated in terms of productivity, profitability, and environmental sustainability. After 6 years, significant differences between systems are apparent in economic returns and soil available phosphorus (P) levels. The biodynamic treatment has the highest gross margins, followed by conventional, organic, and integrated. Conversely, available P levels on the biodynamic and organic treatments have declined 12 and 9%, respectively, since the start of the trial, while both the integrated and conventional treatments have increased soil P levels. In summary, it is too early in the trial to state categorically that any one system is more sustainable than another, although trends are now emerging. Weed management remains the main impediment to high production levels on the organic and biodynamic treatments, while input costs, variable yields, and low returns for grazed pastures are major constraints to high economic returns on the integrated and conventional systems.
Crop production in a rotation trial at Tarlee, South Australia
Authors: Schultz JE
Published: March 2005

A crop rotation trial was established in 1977 on a hard-setting red-brown earth at Tarlee, South Australia, to monitor the long-term effect of intensive and traditional rotations on soil properties and crop production. The rotations involve wheat alternating with cereals, grain legumes, pasture, and fallow. There are 3 stubble + tillage treatments: remove stubble + cultivate, retain stubble + cultivate, retain stubble + no tillage. Three rates of nitrogen (0,40, 80 kg N/ha as ammonium nitrate) are applied to the wheat. Grain yield varied with seasonal conditions, and water use efficiencies were up to 10 kg/ha. mm. In the more productive rotations, wheat grain yields expressed as a percentage of potential yield tended to increase over time. The best wheat yields were always in rotations that included a grain legume or legume pasture, with additional yield increases in all rotations coming from the use of N fertiliser. By comparison with rotation and N fertiliser effects, there was little effect of the stubble + tillage treatments on grain yield. Most of the yield variations were related to differences in tiller density or grains per ear, with grain weight remaining relatively constant over all seasons. There was a tendency for grain legume yields to decrease over the latter years of the trial, and this was attributed to the build-up of plant diseases through growing the same species on the same plot every second year. Overall, faba beans were the highest yielding grain legume, and the wheat-beans rotation, with 80 kg N/ha on the wheat, gave highest total grain production. Data for residue remaining after harvest indicate that in some years there is less than the desired minimum levels to give adequate protection against erosion, so any grazing of the residues must be carefully managed.
Decline in soil organic carbon and total nitrogen in relation to tillage, stubble management, and rotation
Authors: Heenan DP , McGhie WJ , Thomson FM , Chan KY
Published: March 2005

The influence of rotation, tillage, stubble management, and nitrogen (N) fertiliser on soil organic carbon (C) and total nitrogen (N) was studied between 1979 and 1993 in a field experiment at Wagga Wagga, New South Wales, on a red earth. The rotations included lupin-wheat (LW), subterranean clover-wheat (SW), and continuous wheat (WW) with and without N fertiliser (100 kg N/ha). At the start of the experiment the soil organic C and N in the surface 10 cm were high following many years of subterranean clover based pasture. The trends in soil organic C varied considerably between treatments from near equilibrium levels for SW direct-drilled and stubble-retained to annual losses of 400 kg/ha for WW conventionally cultivated and stubble burnt. Similarly, total soil N content over time varied from equilibrium levels to highly significant declines of 53 kg/ha. year for WW conventionally cultivated and stubble burnt. Both direct drilling and stubble retention reduced the losses of organic C and N compared with conventional cultivation and burning, with greatest loss occurring when cultivation and stubble burning were combined. SW and LW produced a similar contribution of fixed N to total N product removal, but greater benefits to following wheat crops were provided by SW rotations. Where losses of organic C and N were recorded there was no evidence of equilibrium levels being reached after 14 years.
Rotation effects on sustainability of crop production: the Glen Innes rotation experiment
Authors: Norton MR , Murison R , Holford ICR , Robinson GG
Published: March 2005

This study, which commenced in 1921, is the longest running crop rotation experiment in the summer rainfall region of Australia. The 7 rotation treatments comprise various frequencies and combinations of maize and spring oat crops with and without autumn oats and red clover ley. The maize and oat yields are analysed separately using principles described by Paterson (1964). Spline regressions are used to describe the trends of yields with time and to make comparisons amongst the rotations. Yield performance of maize and oats was improved as legume ley duration increased, although as maize cropping became more frequent this effect was reduced. Autumn-sown oats benefited both maize and spring oat yields, independent of the presence of a legume ley. Crop yields were generally maintained in those rotations containing a grazed clover ley. After alteration of ley management in the mid 1960s so that clover crops were subsequently removed as hay, crop yields in these rotations declined. The benefits of clover ley to crop productivity were considered to be primarily due to the maintenance of those soil chemical, physical, and biological properties associated with sustainable crop production.
Decline in root rot (Rhizoctonia solani AG-8) in wheat in a tillage and rotation experiment at Avon, South Australia
Authors: Roget DK
Published: March 2005

Studies of a tillage x rotation field experiment begun in 1978 at Avon, South Australia, have demonstrated a decline in rhizoctonia root rot of wheat. In direct-drilled treatments the severity of rhizoctonia root rot culminated in 1983, with patches of poor plant growth accounting for up to 46% of the crop area, and then declined to negligible levels by 1990. Disease severity was significantly less in cultivated than direct-drilled treatments. In cultivated treatments the onset of decline was more difficult to determine, but by 1990 there was negligible rhizoctonia root rot in either tillage treatment, with no increase in disease from 1990 to 1994. Decline in rhizoctonia root rot occurred largely independent of rotation, although there were significant differences in root damage and patch area between rotations, with disease generally being more severe in wheat following pasture than following peas, medic, or wheat. When inoculum of R. solani was added to soil collected from the experimental site in 1985, wheat grown in soil from direct-drilled plots had significantly less disease than wheat grown in soil from cultivated treatments, indicating a possible development of suppression.
Root-lesion nematode (Pratylenchus thornei) limits response of wheat but not barley to stored soil moisture in the Hermitage long-term tillage experiment
Authors: Thompson JP , Mackenzie J , Amos R
Published: March 2005

The cumulative effects of factorial treatments of tillage (no tillage, conventional), stubble retention (burnt, retained), and nitrogen fertiliser (0, 23, 69 kg N/ha) on yield of continuous winter cereals and on soil properties have been tested in the Hermitage fallow management experiment since 1969. Despite increased soil water stored from the combination of no tillage and stubble retention, wheat responses to the extra water were disappointing in the first 11 years of the experiment. Soil samples from the experiment were shown to be heavily infested with the root-lesion nematode (Pratylenchus thornei Sher and Allen), and therefore in 1980, the main plots were split for crop (wheat cv. Timgalen, barley cv. Clipper) and nematicide treatment (nil, aldicarb). Barley (maximum yield 3.2 t/ha) tolerated the nematodes and responded in this dry year to the extra stored water accumulated with no tillage and stubble retention, but wheat (maximum yield 1.22 t/ha) did not. Nematicide increased wheat yields by 42%. The results from the changes to the Hermitage experiment in 1980 show the importance of considering root-lesion nematodes in interpreting results from long-term experiments involving wheat and in applying those results to farms. Control of root-lesion nematodes on farms by crop rotation and by growing tolerant and resistant wheat varieties is needed to obtain full yield benefits from improved tillage practices.
Soil processes under grazed pastures: their impact on crop production
Authors: Bellotti WD , Butler JH , Grace PR , Hignett CT , Little DL , Moore AD , Reeves TG
Published: March 2005

No abstract available.
Assessment of the ability of LEACHM to simulate aldicarb movement in a Hanwood Loam soil using lysimeters
Authors: Foerster J , Milne-Home WA
Published: March 2005

No abstract available.
Seed and seedling studies of three Trifolium subterraneum var. brachycalycinum lines, in a predominantly summer rainfall environment
Authors: Lodge GM
Published: March 2005

Field experiments were conducted in a predominantly summer rainfall environment to investigate burr burial, seed production, seed characteristics, seedling emergence and survival, and the effects of time of sowing on 3 Trifolium subterraneum var. brachycalycinum lines (cv. Clare and 2 local lines). Each line produced more surface than buried burrs; surface burrs were 59% (range 56-62%) of the total number of burrs recovered and produced 59% of the total seed number. Numbers of seeds per burr were similar for surface and buried burrs, however, buried seeds were 0.97 mg heavier (P<0.05) than surface seeds. Storage for 5 months at 25/60�C decreased hardseed content of surface seed by 50% and buried seed by 70%. Surface and buried seeds stored at 25/25�C for 3 months prior to sowing in trays had a total emergence of <10%, compared with 70% emergence for seeds stored at 25/60�C before sowing. These emergence differences reflected their levels of hardseededness. Numbers of seeds recovered from the soil were not significantly different among lines, declining from about 4200 seeds/m2 after initial seed set to 150 seeds/m2 by the following winter, a 97% decrease. Seed production in the second year increased seed reserves to about 8730 seeds/m2. With no further seed production, levels had declined by 93% in June 1990 and by 99% in May 1991. These data confirm the importance of annual seed production for persistence. Total seedling emergence in summer-autumn accounted for only 10% of the estimated seed production in each year. Seedling survival in summer-autumn 1988-89 was 92.7%, more than double the survival in 1989-90. The effect of sowing time on flowering was always significant, with time to first flower being highest (196 days) for the earliest sowing in March (P<0.05), progressively decreasing (P<0.05) to 108 days for the latest sowing in July. In March, April and May sowings, inflorescence numbers on the first day of flowering were similar at about 120/m2, but increased markedly (P<0.05) for sowing in June or July. However, for the March and July sowings, number of inflorescences at the 9 November 1990 count, were lowest (P<0.05). May or June sowings had the highest number of burrs and seeds (P<0.05), indicating that these may be the best sowing times for maximum seed production in these Trifolium subterraneum var. brachycalycinum lines.
Site preparation for Pinus establishment in south-eastern Queensland. 1. Temporal changes in bulk density
Authors: Costantini A , Nester MR , Podberscek M
Published: March 2005

In south-eastern Queensland, Australia, standard site preparation practices used for Pinus plantation establishment are mounding (bedding) on poorly drained soils and blade cultivation (subsurface, wing rip) on well-drained soils. This paper reports the impacts of both site preparation treatments on soil bulk density over time. Following site preparation, the extent of bulk density reduction and the nature of bulk density consolidation was affected by soil type, soil depth and the site preparation technique used. On high strength, hardsetting soils, bulk density reductions from both mounding and blade cultivation persisted throughout the 28-month period, and contrasted with non-hardsetting soils in the plantation estate, which consolidated more rapidly and had higher bulk densities relative to precultivation levels for the period 4-28 months following site preparation. The studies reported in this paper were the first in south-eastern Queensland to investigate the impact of site preparation for Pinus establishment on the nature and longevity of bulk density reductions. Previously, plantation managers assumed that positive site preparation impacts would be relatively short-lived, and therefore developed a prudential policy of planting Pinus seedlings immediately following site preparation. For the soils studied, delays of 2-4 months, and perhaps up to 6 months, between site preparation and planting would not compromise Pinus growth, but would assist management planning.
Changes in physiology, composition and sensory characteristics of Australian papaya during ripening
Authors: Wills RBH , Widjanarko SB
Published: March 2005

Australian papaya fruit were held at 20, 25 and 30�C and physico-chemical and sensory changes occurring during ripening observed. Fruit at 20�C showed a respiratory climacteric after about 5 days at which time peel colour was 20-50% yellow. The peak in ethylene production occurred about 1 day after the climacteric. The major physico-chemical changes were increases in ascorbic acid and total carotene, and a decrease in benzyl isothiocyanate (BITC). Maximum sensory characteristics were attained 2 days after peel showed a full yellow colour. Fruit held at 25 and 30�C ripened faster, had higher concentrations of total carotene and ascorbic acid, firmer flesh texture, a lower BITC level, more intense yellow peel colour and more acceptable eating attributes. Australian papaya would therefore be more acceptable to consumers if ripened at elevated temperatures rather than at 20�C.
Significance of carry over inoculum, flower infection and latency on the incidence of Botrytis cinerea in berries of grapevines at harvest in New South Wales
Authors: Nair NG , Guilbaud-Oulton S , Barchia I , Emmett R
Published: March 2005

The incidence of Botrytis cinerea was monitored at different stages in the growth of 7 grapevine cultivars in 14 vineyards in New South Wales, Australia, over a period of 10 years. The incidence of B. cinerea fluctuated during the growing season. While carry over infection from the previous season explained 70% of variation in flower infection, it only accounted for 26% of berry infection. Infection of flowers explained 78% of berry infection. Latent infection resulted in 58% of inoculum carried over to the following season. Disease prediction models were developed on the basis of these quantitative relationships so that growers can use them to measure disease risk and respond by rational application of fungicides. For instance, based on the model, a 50% incidence of B. cinerea monitored on grapevine tissues carried over from previous season can predict a 30% primary infection of flowers in the new season. This will require fungicide application during flowering so as to reduce the predicted risk of 22% berry infection at harvest.
Evaluation of electronic identification transponders implanted in the rumen of cattle
Authors: Hasker PJS , Bassingthwaite J
Published: March 2005

The performance of electronic identification transponders encased in ceramic capsules inserted into the reticula-rumen was assessed in 3 groups of cattle: 1059 two-year-old feedlot steers, 11 penned calves and 46 grazing calves. Insertion of capsules presented little difficulty and at slaughter, examination of the reticulorumen showed no visible signs of damage to the reticula-endothelium due to the capsules. The retention rate of the capsules was 100% in adults when slaughtered 55-107 days after capsules were inserted. All losses of capsules from calves occurred before calves were 21 weeks of age. Transponders were successfully read both in the live animal and in the body on the slaughter chain. All transponders in the reticulorumen of grazing calves were functioning normally up to 46 weeks after being implanted. At slaughter, capsules were recovered easily with no risk of contaminating meat or by-products. Small steel metallic objects near the capsule appeared not to affect the reading distance of the transponder.
A comparison of three techniques to determine the herbage intake of dairy cows grazing kikuyu (Pennisetum clandestinum) pasture
Authors: Reeves M , Fulkerson WJ , Kellaway RC , Dove H
Published: March 2005

Two studies were conducted to compare the precision of estimating kikuyu grass (Pennisetum clandestinum) intake by Friesian cows fed 0, 3 or 6 kg of cereal-based concentrate/cow.day, using a rising plate meter (RPM), standard energy requirements in reverse (RS) and plant wax alkanes as internal markers. Study 1 compared herbage intake estimates obtained using the RPM and RS techniques over a 45-day period. RS estimates were based on the metabolisable energy (ME) of ration components derived from in vitro organic matter digestibility (OMD) values. Pregrazing calibration equations for the RPM determined at 2-weekly intervals differed significantly (P<0.01) from postgrazing calibrations; consequently separate equations were used to determine pasture intake as the difference in pre- and post-grazing pasture mass. Estimates of total intake were lower using the RPM than the RS technique for the groups fed 0 kg (12.5 v. 14.8 kg dry matter (DM)/cow.day) and 3 kg (10.4 v. 12.9 kg DM/cow.day) of concentrate, and higher for those receiving 6 kg (10.5 v. 7.8 kg DM/cow.day). In study 2 (12 days duration), intakes derived using alkanes were compared with intakes estimated using the RS and RPM techniques. The C32/C33 alkane pair gave the closest estimate of herbage intake to that obtained using the RPM and RS techniques. Whole diet in vivo DM digestibility (DMD), determined by the alkane method, was not significantly different between the 3 groups (mean 70%), suggesting that digestibility of the kikuyu declined with increasing concentrate supplementation. The in vivo DMD of kikuyu alone (determined in the non-concentrate-supplemented cows) was considerably higher (69.5%) than the OMD determined in vitro (63.9%). By using in vivo rather than in vitro digestibilities for kikuyu in the RS calculations, the intake estimates were reduced by 17%, and for the 0 kg concentrate group, intake estimates aligned closely to predictions of the RPM and alkanes. Concentrates in the diet resulted in lower intake estimates using the RS technique compared with the RPM and alkane techniques. This was most evident at the 6 kg level of supplementation where RS predicted kikuyu intake to be 6.5 kg DM/cow.day using in vivo-derived DMD and this was substantially lower than either the RPM (12.4 kg DM/cow.day) or alkanes (9.2 kg DM/cow.day). The alkane technique provided a direct and precise method of measuring the intake of individual cows grazing tightly-managed kikuyu pasture. With the use of accurate animal production and feed quality parameters, the RS technique can provide sensible pasture intake estimates over an extended time period. The RPM technique is useful for obtaining herd estimates of pasture intake and for the determination of pasture parameters associated with intake.
Lamb carcass. 3. Describing changes in carcasses of growing lambs using real-time ultrasound and the use of these measurements for estimating the yield of saleable meat
Authors: Hopkins DL , Hall DG , Luff AF
Published: March 2005

In experiment 1,76 cryptorchid (n = 37) and ewe (n = 39) lambs were scanned for GR (depth of muscle and fat tissue from the surface of the carcass to the lateral surface of the 12th rib, 110 mm from the midline) and M. longissimus thoracis et lumborum (LD) depth (USB) on 4 occasions over 3 months at intervals of 28 days with a real-time ultrasound scanner. Carcass GR measurements were obtained after the final live measure at 5.5 months of age. Significant (P<0.001) changes in GR and USB were detected as liveweight increased. All changes could be best explained by linear models (P<0.001) and there was a significant (P<0.001) sex effect evident for GR indicating that this is a useful measurement for monitoring changes in carcass fatness in live lambs. The correlation (r = 0.31) between ultrasonic and carcass GR was significant (P<0.05), however, mean ultrasonic and carcass measurements of GR were significantly different (P<0.05) for ewe, but not cryptorchid lambs. A sex effect was found with the relationship between in vivo GR, liveweight and carcass GR indicating that there was no significant relationship between GR measured ultrasonically and on the carcass when liveweight and sex were accounted for. In experiment 2, 86 ewe and 84 cryptorchid lambs were slaughtered in sex groups, the ewes at 6 months of age and the cryptorchids at 8 months of age. Before slaughter subcutaneous fat depth (USFat C) over the LD and LD depth (USB) were measured using a real-time scanner. Of the carcasses, 84 (42 ewes, 42 cryptorchids) were prepared into 'trim' lamb (TL) cuts. There was a significant (P<0.001) correlation between USFat C and the carcass equivalent (Fat C) for ewes and cryptorchids respectively (r = 0.63; r = 0.47). This was also the case for USB and carcass LD depth (B) with significant (P<0.001) correlations of r = 0.53 and r = 0.56 for ewes and cryptorchids respectively. Liveweight per se was a poor predictor of Fat C and B irrespective of measurement group and was of minimal value when used in combination with USFat C or USB measurements. The amount of variation in Fat C and B that was explained by the corresponding ultrasonic measurement and liveweight ranged from R2 = 0.29-0.39. Irrespective of the measurement group considered or the yield type, measurement of USFat C significantly (P<0.001) improved the accuracy with which percentage yield could be estimated over and above liveweight and increased the amount of variation (R2) in percentage yield that was explained. However, it is recommended that if ultrasonic measurements are to be used for predictive purposes, GR and LD depth be adopted.
Evaluation of three automatic jetting races for control of the sheep body louse Bovicola ovis
Authors: Johnson PW , Dawson KL , Dixon R
Published: March 2005

Fine wool Merino sheep with short (4 mm) or long (30-80 mm) wool and moderate to heavy infestations of lice (Bovicola ovis) were treated with cyhalothrin at a concentration of 50 mg/L, applied using Alison, Aussie Dip and Boral Cyclone Superace automatic jetting races. Each machine was set up and operated by representatives of the manufacturer. With all 3 machines, arithmetic mean louse counts before and after treatment showed that in the sheep with short wool, lice numbers were reduced by > 98% at 8-12 weeks after treatment but were not eliminated. In the sheep with long wool, the maximum reductions in mean louse counts were 79, 68 and 98% for Alison, Aussie Dip and Boral Cyclone Superace machines at 7, 5 and 8 weeks after treatment, respectively. The Alison and Aussie Dip machines were each tested in alternative configurations which affected the disposition of the jetting fluid on the fleece. The distribution of live lice on the bodies of the shorn sheep after treatment using the Alison machine and 1 configuration of the Aussie Dip machine, indicated that more insecticide may have been delivered to the left side of the body than to the right. There were no significant differences between sides in sheep treated in the Boral Cyclone Superace machine. Our results suggest that the jetting races tested would control infestations of lice for at least 12 weeks in sheep treated within 2 weeks after shearing, but would be unlikely to eradicate lice from an infested flock. The machines differed markedly in their ability to control moderate to heavy infestations of lice in sheep with long (30-80 mm) wool, but in all cases there was evidence of a resurgence in lice numbers beyond 12 weeks after treatment.
Narbon bean (Vicia narbonensis L.): a promising grain legume for low rainfall areas of south-western Australia
Authors: Siddique KHM , Loss SP , Enneking D
Published: March 2005

The phenology, growth, seed yield and yield components of a number of introduced narbon bean (Vicia narbonensis L.) accessions and F9 breeding lines were compared with faba bean (Vicia faba L. cv. Fiord) or field pea (Pisum sativum L. cv. Dundale) at 3 sites in 2 seasons. All narbon bean accessions had slow development, for example all accessions reached 50% flowering 9-35 days later than faba bean or field pea depending on the accession, site and season. Dry matter production near flowering ranged from 1.0 to 2.3 tlha and the growth of the best accessions was comparable with faba bean. In general, the accession ATC 60114 collected in the Beka'a Valley, Lebanon, produced the greatest seed yield across the sites and seasons (on average 1.52 t/ha). In 1993, the best narbon bean accession produced seed yields that ranged from 59% of the faba bean seed yield at the wettest site to 121% at the driest site. In the following year, one of the driest in decades, 6 accessions produced seed yields of more than 1.0 t/ha, similar to field pea. Seed yield was negatively correlated with days to flowering, podding and maturity, suggesting that yield could be improved by selecting for more rapid development. Most accessions retained the majority of their leaves at maturity, but showed some degree of pod shattering and a moderate level of lodging at maturity. Genotypic variation in all these characters was evident. Further selection and breeding, together with appropriate agronomic packages will improve the adaptation of narbon bean to mediterranean-type environments of southern Australia. However, the adoption of narbon bean in Australian agriculture will depend on its marketability and acceptance by the stockfeed industry, and its on-farm utility.
The response of organic and conventionally grown wheat to superphosphate and reactive phosphate rock
Authors: Dann PR , Derrick JW , Dumaresq DC , Ryan MH
Published: March 2005

In 1991 and 1992 wheat was sown on adjacent properties at Ardlethan in southern New South Wales to assess its response to superphosphate (SP) and reactive phosphate rock (RPR) under conventional and organic management systems. Five rates of P (0, 10, 20, 30, 40 kg/ha) were applied as SP and RPR. No response to RPR was recorded in terms of crop growth or grain yield. However, in both years and on both sites, SP significantly increased plant dry weight at tillering and anthesis, the number of tillers and spikes per plant and grain yield. Superphosphate also increased the P content of grain and the amount of P exported. SP (40 kg P/ha) increased the level of cadmium in the grain, although not beyond permitted maximum concentrations. The use of SP reduced the level of colonisation by vesicular-arbuscular mycorrhizal fungi (VAM). The data indicate that the choice of the organic farmer, not to use SP, incurs a large yield penalty.
Relationship between sunflower development and the onset of stem rot induced by Sclerotinia minor
Authors: Burgess DR , Porter IJ , Parbery DG
Published: March 2005

Sclerotinia stem rot, caused by Sclerotinia minor, has not been reported in sunflower (Helianthus annuus) during vegetative growth. During an investigation of disease development in the highly susceptible inbred line, PacF2582, the disease was first observed in the field at bud development. In glasshouse studies with inoculated soil, onset of disease was delayed until late vegetative growth. Direct inoculation of roots with disks of mycelium or with pregerminated sclerotia confirmed that sunflowers are susceptible to infection during the vegetative growth stages. Root measurements found that the rate of increase in root dry weight was maximum between the early and midbud stages in field-grown plants (230%/week) and between the 6- and 10-leaf stages in glasshouse plants (240%/week). Synchronisation of disease onset with proliferation of lateral roots suggests that active root growth is required to initiate infection.
Assessment of soybean seed vigour tests for eastern Australia
Authors: Boersma M , Law M , Adkins SW
Published: March 2005

Vigour testing was undertaken on seed from 4 soybean [Glycine max (L.) Merr.] cultivars taken from field trials in eastern Australia. The seed from each cultivar exhibited moderate to good germination and a range in vigour. Vigour tests consisted of the controlled deterioration and modified versions of the accelerated aging test. Accelerated aging was carried out in 4 ways using 2 periods of incubation (76 and 96 h), with or without the seed protectant Thiram to control saprophytic fungi. Results were compared with seedling emergence from the same seed samples when planted in a controlled environment glasshouse. A combination of 2 day/night temperatures, cold (18/13�C), warm (33/28�C), and 3 soil moisture regimes, dry (-0.3 MPa), field capacity (-0.01 MPa) and saturated soil, produced a total of 6 different environments. Emergence was also recorded under a moderate daylnight temperature of 23/18�C in soil at field capacity. The standard germination test and modified accelerated aging test with a 72-h incubation period with Thiram were significantly (P<0.01) correlated with emergence from all 7 soil environments. A 96-h period of accelerated aging (with or without Thiram) tended to suppress germination and there was no correlation with emergence from most soil environments. The controlled deterioration test correlated with seedling emergence from most soil environments except for dry soil. The vigour test which gave the best indicator of performance under a range of different seedbed moisture and temperature conditions was the modified accelerated aging test using a 72-h incubation period with Thiram.
Detection of Fiji disease virus in sugarcane by ELISA
Authors: Wagih MW , Adkins SW
Published: March 2005

A direct double antibody sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the detection of Fiji disease virus (FDV) in sugarcane (Saccharum spp. hybrid) cultivars NCo310 and CP44-101. Optimal results were obtained when Dynatech microplates, coated with 2 �g/mL FDV-specific immuno-gamma globulin (IgG) coupled with alkaline phosphatase-lgG conjugate at a concentration of 1/1000, were used. The test could detect FDV in crude extracts (fresh or frozen) of gall and gall-free infected tissues with an end point dilution of 1/5000 and 1/1000, respectively. The FDV antibody showed a high degree of specificity and failed to react with 3 other field-associated sugarcane viruses. When the distribution of FDV within the plant was studied, the highest titre was found in the basal axillary buds decreasing towards the top of the plant and into the roots. However, the apical meristem produced a virus titre significantly higher than any adjacent axillary buds. The ELISA was well suited for large-scale screening programs and its potential was further extended to quarantine work since it could be used to identify the virus in frozen, non-galled tissues.
A triazole compound extends the vase life of Geraldton waxflower
Authors: Joyce DC , Shorter AJ , Jones PN
Published: March 2005

A triazole compound, triadimenol, and metluidide were evaluated as vase solution ingredients for Geraldton waxflower. It was anticipated, on the basis of published literature, that these chemicals might induce endogenous abscisic acid (ABA) accumulation and associated stomatal closure, thereby providing an improved water balance. Triadimenol (10 mg/L) generally extended both foliage and flower vase life for the 3 cultivars of Geraldton waxflower studied. However, the increased longevity was associated with greater, rather than less, vase solution usage. Therefore, stomatal closure was not induced, and the beneficial effect was evidently not a function of significantly increased endogenous ABA levels. Mefluidide did not extend the vase life of Geraldton waxflower.