bluuebunny/crossref_metadata_2025 huggingface dataset:
Chilling at 0 deg C in air induces ethylene production in Fuji and Lady Williams apples
Authors: Jobling J , McGlasson WB
Published: March 2005

Fuji apples have low rates of ethylene production at commercial harvest maturity, whereas Lady Williams apples, which are harvested commercially in late autumn, produce large concentrations of ethylene. We investigated whether chilling at 0�C, which has previously been shown to stimulate ethylene synthesis in preclimacteric Granny Smith apples, would stimulate Fuji and Lady Williams fruit as well. Preclimacteric Fuji and Lady Williams apples were stored in air at 0�C and were removed at intervals to 20�C. Ethylene production remained low in Fuji apples held continuously in air at 20�C. Fruit held for 32 days at 0�C accumulated 1-aminocyclopropane-1-carboxylic acid (ACC) and developed ACC oxidase activity. On return to 20�C these fruit had a high and sustained level of ethylene production. ACC accumulated in all chilled Lady Williams apples at 0�C but decreased to low levels within 2 days after transfer to 20�C. A sustained increase in ACC was not found until 15 days at 20�C in fruit chilled for 32 days. A distinct temporary increase in internal carbon dioxide (CO2) concentration was observed in Fuji apples but not in Lady Williams apples following chilling. Chilling for 32 days was required to stimulate sustained levels of CO2 in Lady Williams apples.
Chemical and biological control of Rhizoctonia solani on potato seed tubers
Authors: Wicks TJ , Morgan B , Hall B
Published: March 2005

Chemical and biological treatments for the control of tuber-borne inoculum of R. solani on potatoes were evaluated by testing the viability of sclerotes removed from treated tubers. This technique showed that most sclerotes adhering to the tuber surface were devitalised when tubers were dipped for 20 min in a 2% solution of formaldehyde. Dusting tubers with toclofos-methyl, or spraying them with fenpiclonil or pencycuron, gave control equal to formaldehyde, whereas a sodium hypochlorite dip was ineffective. A spore suspension of Verticillium biguttatum applied to tubers as either a dip or a spray devitalised >90% of treated sclerotes, whereas similar treatments of other organisms such as Bacillus, Gliocladium, and Trichoderma were ineffective.
Pasture management in semi-arid tropical woodlands: effects on herbage yields and botanical composition
Authors: McIvor JG , Gardener CJ
Published: March 2005

The effects of pasture management options (introduced legumes and grasses, superphosphate, timber treatment, cultivation before sowing, stocking rate) on the yield and botanical composition of pastures were measured from 1982 to 1992 at 2 sites, Hillgrove (extractable phosphorus, 50 mg P/kg) and Cardigan (extractable P, 6 mg/kg), near Charters Towers, northeastern Queensland. Despite generally poor establishment and growing conditions, some sown species (Stylosanthes hamata, S. scabra, Cenchrus ciliaris, Urochloa mosambicensis) established and persisted at both sites. The initial sown grass populations were small but yields increased markedly towards the end of the experiment. There were no yield responses by the native pastures to superphosphate, but the sown pastures responded at Cardigan, although not at Hillgrove. There were large yield responses to tree killing. The percentage increase in herbage yield following tree killing increased as the available water in the soil during the growing season decreased, and was greater at the higher fertility Hillgrove site. Overall, the native pastures were dominated by perennial grasses, but annual grasses and forbs increased on plots with live trees and high stocking rates towards the end of the trial. sown grasses, particularly C. ciliaris, became dominant (and are likely to remain so) at Hillgrove and on plots with superphosphate at Cardigan, especially where the trees were killed. Productive, mixed pastures with reasonable proportions of both grass and legume were maintained under live trees.
Effect of ensiling whole barley grain with pasture on silage quality and effluent production, and the performance of growing cattle
Authors: Jacobs JL , Morris RJ , Zorrilla-Rios J
Published: March 2005

Pasture was ensiled with increasing amounts of whole barley in stacks [0, 75 (SLB), 150 (SMB) kg/t fresh pasture] or in 200-L drum silos 10, 75 (DLB), 150 (DMB), 225 (DHB) kg/t fresh pasture]. All silages were well fermented with low pH values and low ammonia concentrations. The addition of barley significantly (P<0.05) increased the dry matter content of the resultant stack silages by 29% (SLB) and 54% (SMB) and significantly (P<0.05) increased residual water-soluble carbohydrate levels in the SMB silage compared with untreated stack silage. Incorporation of barley with pasture in 200-L silos significantly (P<0.001) increased the dry matter of the resultant silages and significantly (P<0.01) reduced effluent production by 55, 93, and 100% for DLB, DMB, and DHB compared with the untreated silo silage. Dry matter, nitrogen, and lactic acid concentrations in effluent did not differ significantly, although total losses of these components were significantly (P<0.01) higher in the untreated silage.| The stack silages were fed to beef steers (293 kg) and compared with silage diets containing equivalent levels of rolled barley mixed with untreated silage at feeding. Irrespective of method of feeding barley, animal performance improved compared with feeding a silage-only diet. At equivalent levels of barley inclusion, liveweight gains were higher and feed conversion ratios lower with the rolled barley diets. The results indicate that the addition of barley to low dry matter pasture during ensiling can reduce effluent production and the loss of soluble nutrients; however, it is likely that the grain will need to be processed to maximise subsequent animal production.
Predictors of yield of Lupinus angustifolius (cv. Gungurru) seedlots from different sources in Western Australia
Authors: Tapscott HL , Cowling WA
Published: March 2005

The growth and yield of 97 seedlots of Gungurm narrow-leafed lupins (Lupinus angustifolius L.) from Western Australia were assessed to identify geographical source or nutritional and physical parameters in the seed that can be used to predict the yield potential of a seedlot. Seedlots were obtained from the 1990 harvest on farms in the south-western cropping region of Western Australia, with up to 7 seedlots from each of 14 crop variety recommendation areas. Each seed lot was assessed for seed size (mean 144 mg), germination percentage (mean 87%), cucumber mosaic virus seed infection (mean 0.11%), and several seed nutrients. Seedlots were sown at 100 kg/ha (without adjusting for germination or seed size) at 4 sites in Western Australia in 1991. Plant density, shoot dry weight (at 6 weeks), and grain yield varied significantly among seedlots, with average grain yield ranging from 951 to 1478 kg/ha (l.s.d. = 240 kg/ha at P = 0.05). Seed size influenced (P<0.001) stand density (r = -0.33) and shoot dry weight (r = 0.58) but not grain yield (r = 0.09, n.s.). No seed nutrient was more than weakly associated with grain yield, nor was there an association of seedlot yield with geographical source of seed. High germination percentage and low cucumber mosaic virus infection were the main predictors of high grain yield in this experiment, but accounted for only 40% of the yield variance among seedlots.
Effect of rotation with barley and oats on crown rot of wheat in the northern wheat belt of New South Wales
Authors: Nelson KE , Burgess LW
Published: March 2005

We investigated the incidence of Fusarium graminearum Group 1 (infection, stem colonisation) and crown rot in 3-year crop sequences of 1 or 2 years of barley, oats, or mown oats followed by wheat, compared with 3 years of wheat. Seed was sown into the stubble of the previous crop. Stubble production was estimated for each cereal treatment. Plants of each cereal were infected by the crown rot pathogen. Oats were susceptible to infection but did not express symptoms of crown rot in 2 years of the trial. Oats can, therefore, be considered a symptomless host that may contribute to the maintenance of inoculum. The overall mean incidence of infected plants increased from 12% in 1987 to 81% in 1989. The various treatments did not significantly reduce the incidence of infected wheat plants in November of the final year. The incidence of crown rot of wheat in 1989 was greatest after 2 prior wheat crops and lowest after 1 or 2 years of mown oats. The 3 species produced a similar amount of straw by weight; however, mown oats produced significantly less. Oat straw decomposed more rapidly than that of other cereals in controlled conditions.
Influence of orchard production system and cultivar on early productivity of sweet cherry (Prunus avium): effects on tree growth and fruit production and quality
Authors: Boucher WD , Adams G
Published: March 2005

This experiment assessed 3 orchard production systems [Tatura trellis, 1-m within-row tree spacing; palmette trellis, 2-m within-row spacing; freestanding, multiple leader (vase), 3-m within-row spacing] and 2 cultivars of sweet cherry (Prunus avium) (Van, Lambert) to establish the horticultural merits of high density, sweet cherry production. The combination of high tree densities and shallow duplex soils reduced vegetative vigour by 32% compared with the lowest tree density production system. Production systems at the highest tree densities produced the highest cumulative yields to year 7 for both cultivars. Fruit size was not affected by orchard production system; however, the extent of rain-induced fruit splitting may be affected by production systems. Cultivar influenced both yield and susceptibility to rain-induced fruit cracking. Van was earlier to bear fruit than Lambert on all production systems and more resistant to rain-induced fruit splitting.
The importance of long-term trials in understanding sustainable farming systems: the Rothamsted experience
Authors: Poulton PR
Published: March 2005

This paper gives examples of how long-term experiments can be used t o improve our understanding of sustainable farming systems. Rothamsted conducts more than 20 long-term (>20 years) experiments in south-eastern England; several were started in the middle of the last century. Some have continued with minor changes, others have been modified considerably t o ensure their continuation and relevance. Examples are given of the effect on soils and crop yields of organic matter, the availability of P, and acidification. The use of archived material in addressing problems not even considered when the experiments began is also discussed. Long-term experiments are essential in determining the factors affecting soil fertility and sustainable production. In many cases, effects may only be observed or interactions become apparent over an extended time. Full use should be made of existing experiments and data; in particular, those on different soil types and under different climatic conditions should be compared so that the information is valuable to farmers, advisers, legislators, and other scientists in both the local and wider community.
Trends in wheat yields and soil organic carbon in the Permanent Rotation Trial at the Waite Agricultural Research Institute, South Australia
Authors: Grace PR , Oades JM , Keith H , Hancock TW
Published: March 2005

The Permanent Rotation Trial at the Waite Agricultural Research Institute in South Australia was established on a red-brown earth in 1925, with predominately cereal-long fallow rotations on 34 adjacent plots. The trial was upgraded in 1948 to include a greater proportion of pasture leys in the rotations and currently contains 11 treatments. The trial is unreplicated; however, each phase of a sequence is represented each year. Seven of the original rotations have remained in an unbroken sequence since 1925: continuous wheat (W), wheat-fallow (WF), wheat-peas (WPe), wheat-pasture-fallow (WPaF), wheatoats- fallow (WOF), wheat-barley-peas (WBPe), wheat-oats-pasture-fallow (WOPaF). For the 11 rotations, soil organic carbon (SOC) in the top 10 cm declined from 2.75% in 1925 to a mean value of 1.56% in 1993. One plot, which had reverted to permanent pasture in 1950, showed the smallest decline with an SOC content of 2.46% in 1993. The greatest declines in SOC were in the 4 original rotations that included fallow phases in the sequence (mean value of 1.22%). In the WF rotation the SOC content had declined from 2.75 to 1.04% during 68 years of cropping. Associated yield decreases showed that the treatment could not sustain production. Soil organic C declined linearly with increasing frequency of fallows and decreasing frequency of pasture in the rotations. Average grain yields (1925-93) in the 7 original sequences ranged from 2.64 t/ha in WOPaF to 0.89 t/ha in the continuous W plot. The linear decline in yields for WBPe, WPaF, WPe, and WOF treatments indicate a convergence in the 1990s under current management, with an average yield of 1.54 t/ha in 1993 and average SOC in the top 10 cm of 1.32%. We hypothesise that the gradual increase in grain yields from the continuous W plot since the 1960s is the result of a gradual build-up of light fraction organic material, which assists in the maintainence of structure and nutrient availability.
Long term investigations of the effect of tillage practices on crop production at Wagga Wagga, New South Wales
Authors: Pratley JE
Published: March 2005

Three seedbed preparation methods were compared from 1977 to 1989 to evaluate their effects on crop production. Treatments were conventional cultivation (CC, at least 3 workings pre-sowing), reduced cultivation (RC, 1 cultivation plus knockdown herbicide pre-sowing), and direct drilling (DD, no pre- sowing cultivation, knockdown herbicide only). Wheat (Triticum aestivum) was sown for the first 8 years of the experiment and lupins in 1985 and 1988. In 9 of the 11 years wheat grain yield was significantly better with DD, averaging 15% more than CC and 10% more than RC. Weed populations were generally greater where cultivation occurred; particularly fumitory (Fumaria spp.) and eyespot lodging (Tapesia yallundae) had greater impact on wheat in the CC and RC treatments.
Long-term effects of tillage, stubble, and nitrogen management on properties of a red-brown earth
Authors: Fettell NA , Gill HS
Published: March 2005

Differences in soil organic carbon (C), total nitrogen (N), and pH resulting from 14 and 15 years of different tillage, stubble, and fertiliser N management practices were measured for a red-brown earth at Condobolin in western New South Wales. The 5 main treatments comprised stubble burning or retention in factorial combination with cultivation and direct drilling, and stubble incorporation combined with cultivation. Two rates of N fertiliser (0 and 40 or 50 kg/ha) were applied annually, and wheat was grown each year. There were no significant differences between tillage and stubble treatments for soil organic C, total N, or pH. Fertiliser N application caused small but significant increases in organic C and total N but decreased the pH of the surface 2.5 cm of soil by 0.4-0.5 units compared with the nil fertiliser rate. The study indicates that direct drilling and stubble retention with continuous wheat have had little long-term effect on soil organic C and total N in this low rainfall environment.
Use of a network of long-term experiments for analysis of soil carbon dynamics and global change: the North American model
Authors: Paustian K , Elliott ET , Collins HP , Cole CV , Paul EA
Published: March 2005

Soils contain a large proportion of the carbon (C) in the terrestrial biosphere, yet the role of soils as a sink or a source of net atmospheric C flux is uncertain. In agricultural systems, soil C is highly influenced by management practices and there is considerable interest in adapting management systems to promote soil C sequestration, thereby helping to mitigate atmospheric CO2 increases. Long-term field experimental sites represent a unique source of information on soil C dynamics, and networks of such sites provide a key ingredient for making large-scale assessments of soil C change across ranges in climate and soil conditions and management regimes. Currently, there are collaborative efforts to develop such site networks in Australia, Europe, and North America. A network of long-term experiments in North America was established to provide baseline information on the effects of management (i.e. tillage, crop rotations, fertilisation, organic amendments) on soil organic matter. Historical data on soils, primary productivity, climate, and management were synthesised by scientists from the individual field sites, representing a total of 35 long-term field experiments. An additional cross-site soil sampling campaign was carried out to provide uniform comparisons of soil C and nitrogen (N), both within and across sites. Long-term field experiments are a principle component necessary for regional assessments of soil C dynamics. We describe a general methodology for combining long-term data with process-oriented simulation models and regional-level, spatially resolved databases. Such analyses are needed to assess past and present changes in soil C at regional to global scales and to make projections of the potential impacts of changes in climate, CO2, and landuse patterns on soil C in agroecosystems.
Modelling water, nitrogen, and crop yield for a long-term fallow management experiment
Authors: Probert ME , Keating BA , Thompson JP , Parton WJ
Published: March 2005

Two models that differ markedly in how they represent the crop-soil system have been used to simulate soil processes and crop production in the long-term experiment at Hermitage Research Station, Warwick, Queensland. The experiment was designed to examine the effects of tillage, stubble management, and nitrogen (N) fertiliser on the productivity of a winter cereal-summer fallow cropping system. it commenced in 1968 and the treatments have been maintained until the present. CENTURY operates on a monthly time step, considers all soil N transformations to occur in a single soil layer, and has a very simple crop growth routine that does not deal with crop phenology. APSIM provides a framework whereby a model of a cropping system is configured from component modules, which operate on a daily time step. For simulating the Hermitage experiment, modules to represent the dynamics of soil-water, N, surface residues, and growth of a wheat crop were used. The water and N modules deal with a multi-layered soil, whilst the wheat module develops leaf area, intercepts light, and accumulates and partitions dry matter in response to weather, soil-water, and N. Both models were specified to simulate the whole experimental period (1969-92) as a continuous run. The ability of these models to simulate grain yields, soil-water and drainage, nitrate-N, and soil organic matter were examined. Both models predict, in agreement with the observed data, that for this continuous cereal cropping system there has been a decline in soil organic matter for all the treatments and a reduction through time in the capacity of the soil to mineralise and accumulate nitrate during the fallows. CENTURY performed better than APSIM in predicting the relative yields of the N treatments but was less satisfactory than APSIM for absolute grain yield, soil-water, and drainage. Yield predictions with APSIM were sensitive to carry-over errors in the water balance from one season to the next, so that in some seasons large errors occurred in the predicted relative yields. Both models reproduced the observations well enough to indicate their suitability for providing useful insights into the behaviour of cropping systems where the focus is on depletion of soil fertility.
An appraisal of soil phosphorus testing data for crops and pastures in South Australia
Authors: Reuter DJ , Dyson CB , Elliott DE , Lewis DC , Rudd CL
Published: March 2005

Data from more than 580 field experiments conducted in South Australia over the past 30 years have been re-examined to estimate extractable soil phosphorus (P) levels related to 90% maximum yield (C90) for 7 crop species (wheat, barley, oilseed rape, sunflower, field peas, faba beans, potato) and 3 types of legume-based pasture (subterranean clover, strawberry clover, annual medics). Data from both single-year and longer term experiments were evaluated. The C90 value for each species was derived from the relationship between proportional yield responsiveness to applied P fertiliser rates (determined as grain yield in crops and herbage yield in ungrazed pastures) and extractable P concentrations in surface soils sampled before sowing. Most data assessments involved the Colwell soil P test and soils sampled in autumn to 10 cm depth. When all data for a species were considered together, the relationship between proportional yield response to applied P and soil P status was typically variable, particularly where Colwell soil P concentration was around C90. When data could be grouped according to common soil types, soil surface texture, or P sorption indices (selected sites), better relationships were discerned. From such segregated data sets, different C90 estimates were derived for either different soil types or soil properties. We recommend that site descriptors associated with the supply of soil P to plant roots be determined as a matter of course in future P fertiliser experiments in South Australia. Given the above, we also contend that the Colwell soil P test is reasonably robust for estimating P fertiliser requirements for the diverse range of soils in the agricultural regions of the State. In medium- and longer term experiments, changes in Colwell soil P concentration were measured in the absence or presence of newly applied P fertiliser. The rate of change (mg soil P/kg per kg applied P/ha) appeared to vary with soil type (or soil properties) and, perhaps, cropping frequency. Relatively minor changes in soil P status were observed due to different tillage practices. In developing P fertiliser budgets, we conclude that a major knowledge gap exists for estimating the residual effectiveness of P fertiliser applied to diverse soil types under a wide range of South Australian farming systems.
Evaluation of soil biological properties as potential bioindicators of soil health
Authors: Pankhurst CE , Hawke BG , McDonald HJ , Kirkby CA , Buckerfield JC , Michelsen P , O'Brien KA , Gupta VVSR , Doube BM
Published: March 2005

Two long-term field trials in South Australia were used to detect and characterise changes in soil biological properties that were a consequence of different agricultural management. The properties examined were total bacteria, fungi, and actinomycetes; total pseudomonads; cellulolytic bacteria and fungi; mycorrhizal fungi; plant root pathogens (Gaeumannomyces graminis var. tritici, Rhizoctonia solani, Pythium irregulare); bacterial-feeding protozoa; soil mesofauna (collembola and acari); earthworms; microbial biomass; C and N mineralisation; in situ CO2 respiration; cellulose decomposition; and soil enzyme activity (peptidase, phosphatase, sulfatase). The sensitivity of these biological properties was assessed to tillage (no-tillage v. conventional cultivation), stubble management (stubble retained v. stubble harvested), crop rotation (continuous wheat v. wheat-sown pasture), and N fertilisation (nil v. 80 kg N/ha applied during the crop phase). Tillage, stubble management, crop rotation, and N fertilisation significantly (P<0.01) affected C mineralisation and microbial biomass. Tillage with stubble management significantly affected root pathogenic fungi, protozoa, collembola, earthworms, and cellulose decomposition. Crop rotation affected mycorrhizal fungi, protozoa, and soil peptidase activity, and N fertiliser had a significant effect on mycorrhizal fungi, protozoa, and cellulose decomposition. As these biological properties are responsive to agricultural management, they may have potential as bioindicators. Total bacteria, fungi, and actinomycetes, cellulosedecomposing bacteria and fungi, soil phosphatase and sulfatase activity, and N mineralisation were less affected by these treatments and may therefore have limited potential as bioindicators.
Estimating the actual annual production and utilisation of dry matter from a highly productive improved pasture: a community-based approach
Authors: King KL , Hutchinson KJ
Published: March 2005

No abstract available.
Effect of legume-wheat rotation on the water balance, nitrogen dynamics, and soil acidification in Western Australian soils
Authors: Fillery IRP , Dolling PJ , Murphy DV , Sparling GP , Dunin FX , Smettem KRJ
Published: March 2005

No abstract available.
Superphosphate and grazing pressure: effects on soils, pastures, and wool production
Authors: Cayley JWD , Lescun CL , Saul GR
Published: March 2005

No abstract available.
Steam-flaked lupins for preruminant calf rations
Authors: Hoang CC , Hosking BJ , Holmes JHG
Published: March 2005

Steam-rolled lupins were studied as a cheaper alternative to complex and expensive commercial calf rations for rearing dairy calves. Four diets were fed to 4 groups of 6-8 calves: diet 1, 100% commercial pelletted calf ration (CR), 0% steam-flaked lupins (SFL); diet 2, 67% CR, 33% SFL; diet 3, 33% CR, 67% SFL; and diet 4, 100% SFL. A multimineral salt block and fresh water were available. Calves received milk-replacer (MR) in week 1, MR plus experimental diets in weeks 2-5, then experimental diets plus a small amount of straw in weeks 6-10. Calves grazed fresh pasture in weeks 11-15. Blood and rurnen contents were sampled in weeks 2 (blood only) 4,6 (diets 1-4), 8 and 10 (diets 1-3). In weeks 2-5, calves fed diet 4 ate less than calves fed diets 1, 2 and 3 (SFL 0.38 v. 0.50 kg dry matter (DM)/day, MR 0.47 v. 0.49 kg DM/day; P<0.05), grew less rapidly (0.58 v. 0.66 kg/day, not significant) and lost appetite in weeks 5-7. Feeding diet 4 was abandoned and CR, barley and hay were fed in weeks 8-10. In weeks 6-10, calves ate 2.49 kg DM/day of diets 1, 2 and 3 and grew 0.99 kg/day. Growth rates did not differ, at 0.59 kg/day in weeks 11-15; thus calves fed diet 4 seem to have sustained no permanent injury. Plasma glucose was higher in calves fed diet 4 in week 6 (P<0.05) but otherwise did not differ between diets or ages. Ruminal volatile fatty acids differed between diets only in week 6, when diet 4 resulted in a lower concentration than diets 1, 2 and 3 (95 v. 118 mmol/L), with 54.6 v. 49.9% acetic, 31.0 v. 34.1% propionic, and 8.0 v. 10.7% butyric acids. Plasma acetate increased steadily from 0.23 mmol/L at week 2 to 0.58 mmol/L at week 10 (P<0.05), with no difference between diets. We conclude that SFL can be a satisfactory component of the diet of young calves at up to 67% of the ration, producing calves with sufficiently developed ruminal digestion to permit unsupplemented grazing after 10 weeks of feeding.
Performance of crossbred progeny of Trangie Fertility Merino and Booroola Merino rams and Poll Dorset ewes. 3. Reproduction, liveweight and wool production of adult ewes
Authors: Fogarty NM , Hall DG
Published: March 2005

Reproduction, liveweight and wool production are reported for 4 cohorts of 377 Trangie Fertility x Dorset (TD) and 261 Booroola x Dorset (BD) ewes over 6 years. The BD ewes were 3-4 kg lighter (P<0.001) and had a higher ovulation rate prior to joining in February-March (2.37 � 0.03 v. 1.65 � 0.03) than TD ewes. This resulted in a higher litter size (2.07 � 0.03 v. 1.66 � 0.04) and number of lambs born per ewe joined (1.92 � 0.04 v. 1.56 � 0.04) for the BD ewes. Lamb survival was lower from BD than TD ewes (0.71 � 0.02 v. 0.85 � 0.02), so that the 2 ewe strains weaned the same number of lambs. The growth rate of lambs was lower from the BD ewes and overall they weaned 3.8 kg less (P<0.001) weight of lamb than TD ewes. Chill (index of environmental conditions at lambing), litter size and average birth weight of lambs in the litter (linear and quadratic) affected (P<0.001) lamb survival. At moderate levels of chill there was little difference in survival of single and twin lambs from BD and TD dams when birth weight was 4-5 kg, but survival declined more rapidly for progeny of BD ewes at lower birth weight. Under severe lambing conditions survival was depressed more for lambs born from BD ewes than TD ewes. Almost all ewes expressed oestrus over the 3, 6-week periods, December-January, January-February and March (joining). There was significant variation (P<0.001) in incidence of oestrus due to year and age (linear and non-linear), but not liveweight at joining, and there was little difference between ewe strains. Similarly, for post-lambing oestrus (to fit 8-monthly joining) and post-lambing anoestrous interval, there was little difference between strains, but year and age were highly significant (P<0.001). BD ewes had a lower (P<0.001) greasy fleece weight (3.76 v. 3.86 kg), than TD ewes. BD ewes were classified as either carriers (F+) or non-carriers (++) of the FecB gene, which was significant (P<0.001) for ovulation rate (+1.14 ovulations), litter size (+0.8 lambs), lamb survival (-18%), lambs born per ewe joined (+0.64 lambs) and total weight of lamb born per ewe joined (0.5 kg, P<0.01). The effect of the FecB gene was non-significant for lamb survival when litter size and lamb birth weight (P<0.001) were included in the model. Repeatability estimates based on over 3 records per ewe were about 0.2 for lambs born, weight of lamb born, lambs weaned and weight of lamb weaned per ewe joined. Component traits ranged from 0.27 for litter size to 0.10 for lamb survival, with fertility intermediate (0.15). Greasy fleece weight (0.72) and ovulation rate (0.41) had high repeatabilities with post-lambing anoestrous interval being low (0.11). Repeatability for ovulation rate was reduced to 0.34 when F+ ewes were excluded.
Supplementary feeding pattern and rate of liveweight gain in winter-spring affect wool production of young Merino sheep on the south coast of Western Australia
Authors: Doyle PT , Plaisted TW , Love RA
Published: March 2005

The effects of different supplementary feeding practices in summer-autumn and management strategies on green pasture on liveweight change, wool growth rate, annual wool production and wool characteristics of young Merino wethers were examined at 2 farms. The grain feeding treatments were lupins (L) or lupins and oats (LO) fed in amounts that were adjusted to try and maintain liveweight, or lupins and oats (LOG) fed at a higher rate. The objectives of liveweight maintenance or gain were not always achieved, but liveweight patterns differed between LOG compared with L or LO during summer-autumn. The sheep used at farm 1 were aged 4.5 months and liveweight 32 kg at the start of the experiment, while those at farm 2 were 6.5 months and liveweight 39 kg. The stocking rate in summer-autumn was 8 wethers/ha at both farms. During supplementation, sheep on LOG had a higher (P<0.05) liveweight change compared with those on L or LO (farm 1, 15 v. -8 g/sheep. day; farm 2, -35 v. -51 g/sheep. day) and clean wool growth rates (farm 1, 7.1 v. 6.4 g/sheep. day; farm 2, 5.1 v. 4.8 g/sheep.day). The sheep on LOG grew broader (P<0.05) wool than those on L or LO (farm 1, 19.0 v. 18.5 �m; farm 2, 21.7 v. 20.8 �m), and at farm 1 length was also greater (P<0.05) (114 v. 111 mm), while at farm 2 staple strength was greater (P<0.01) (22.9 v. 16.4 N/ktex). There were no significant differences in annual clean wool production. There were positive (P<0.01) relationships between staple strength and liveweight change to the time of minimum liveweight in summer-autumn. After green pasture on offer reached 500 kg DM/ha in autumn, different liveweight change patterns were achieved in 2 groups (LS, lower stocking rates; HS, higher stocking rates) of sheep at each farm by adjusting stocking rates. Within a farm, the LS and HS groups were comprised of equal numbers of sheep from each replicate of the supplementary feeding treatments. There were differences (P<0.05 to 0.01) in liveweight change between LS and HS (farm 1, 93 v. 72 g/day; farm 2, 127 v. 60 g/day), the differences being more pronounced at farm 2. The differential stocking rates at farm 2 resulted in differences in clean wool growth rates (P<0.01), in clean wool production (4.22 v. 4.53 kg, P<0.05), and fibre diameter (20.8 v. 21.4 �m, P<0.01), but there were no significant effects on staple length or strength. There were no significant effects of the supplementary feeding treatments imposed in summer-autumn on the responses to the stocking rate treatments on green pasture.
Revegetation of a scalded saline discharge zone in Central Queensland. 2. Water use by vegetation and watertable drawdown
Authors: Walsh KB , Gale MJ , Hoy NT
Published: March 2005

The hydrological effect of Casuarina glauca trees established on a salt pan in East Barmoya, Central Queensland, is described. The sap flow of a single (4-year-old, 5 m tall) tree was logged with the steady-state heat balance technique at about 11 L/day. The watertable adjacent to the tree was depressed by about 130 mm relative to that 10 m from the tree, and demonstrated a diurnal oscillation of about 10 mm, consistent with an evapotranspiration rate of 1 mm/day. Infiltration was rapid in the vicinity of the tree, such -- that the watertable rose quickly (about 10 mm/h) in the vicinity of the tree after rainfall events. An apparent response of the watertable to changes in barometric pressure was also noted. The density of tree planting required to halt dryland salinity on this site was estimated, and a density trial was commenced with the aim of lowering the watertable to enable the re-establishment of pasture communities between the rows in a form of agroforestry.
Banana weevil borer control in south-eastern Queensland
Authors: Smith D
Published: March 2005

Banana weevil borer Cosmopolites sordidus (Germar) is the main insect pest of bananas in south-eastern Queensland and northern New South Wales. Four trials were conducted over 3 years to test current and new pesticides and 2 species of entomopathogenic nematode Heterorhabditis zealandica Poinar (strain 327) and Steinernemu carpocapsae (Weiser) (strain BW), in growers' plantations at Yandina and Wamuran. Nematodes were applied in a thickened aqueous solution into 200 mm deep incisions in the residual rhizomes of harvested plants usually at bimonthly intervals from November to May. The treatments were not effective possibly because of early nematode mortality caused by free water in the spike holes and/or because of the need for more frequent application. More than 1 or 2 applications a year, however, would probably be uneconomic. Prothiophos (5 g a.i./stool) was the most effective of the currently registered pesticides and bifenthrin (0.25 g a.i./stool) consistently effective among the new pesticides. Both were significantly better than all other treatments on most occasions. Efficacy was assessed using pseudostem traps (to assess beetle activity) and a sliced peripheral cut to the side of the rhizome (to assess damage by larvae). Monitoring of populations and damage by these techniques will promote the most effective and minimal use of pesticide treatments. Average beetle catches of 2 per trap and damage ratings of 2 are proposed as action thresholds for south-eastern Queensland.
Register of Australian grain legume cultivars. Lens culinaris (lentil) cv. Northfield
Authors: Ali SM
Published: March 2005

Lens culinaris subsp. microsperma cv. Northfield was selected, from the ICARDA breeding line ILL5588 (originally collected from Jordan), for uniform height, maturity, seed type, colour and freedom from symptoms of Ascochyta lentis. Growth habit is erect becoming trailing during flowering. Plant height at maturity is slightly shorter than Aldinga but Northfield matures several days earlier. Northfield is less likely to lodge at maturity than many other cultivars making harvesting easier. Pods are bivalved, rhomboid and 2-seeded. Seeds are biconvex with a uniform red testa without marbling or speckling. Seed size is small (2.5-3.5 g per 100 seeds). It was evaluated in field trials in South Australia, New South Wales, Victoria and Western Australia over 4 years. Mean yields (1.18 t/ha) were 19% less than Aldinga (1.4 t/ha) but exceeded that of Kye (0.93 t/ha). Northfield has field resistance to A. lentis with lower levels of seed infection (1%) than Aldinga (24-48%). This results in seeds being free of blemishes, an advantage when seed is marketed whole and for seed purposes. Seed protein content of Northfield (22.2-25.2%) is similar to that of Aldinga. Northfield is less prone to seed cleaning damage than similar cultivars.
Assessment of strains of Bradyrhizobium sp. (Lupinus) for serradellas (Ornithopus spp.)
Authors: Ballard RA
Published: March 2005

Several strains of Bradyrhizobium sp. (Lupinus) were compared, in the glasshouse and field, with the Australian commercial inoculant strain, WU42.5, for symbiotic performance on serradella. Strains WSM471 and USDA3709 were more effective in nitrogen fixation (12 and 8% respectively) than WU42.5 across 10 serradella lines, although WU42.5 generally displayed good levels of effectiveness. WSM471 was a more saprophytically competent strain than WU425 in mildly acidic sandy soils, resulting in a 2.8-fold increase in the nodule score of serradella sown 32 cm from a line of bradyrhizobia established the previous year. Although WSM471, when compared with WU42.5, increased the nodulation and early production of an established sward of serradella, it did not improve total annual production of the sward. The possible replacement of WU42.5 with WSM471 in serradella inoculants is discussed.
Relationship between vigour tests and emergence of soybean when grown under a range of seedbed moisture conditions
Authors: Adkins SW , Boersma M , Law M
Published: March 2005

Laboratory vigour tests were performed on seed from 4 soybean [Glycine max (L.) Merr.] cultivars coming from commercial crops grown in eastern Australia. The seed from each cultivar had greater than 80% germination and a range in vigour. Vigour tests consisted of the accelerated aging (with or without a seed protectant, Thiram), cold, saturation and hypocotyl length tests. Results were compared with seedling emergence from the same cultivar when planted under growth room conditions (25/20 � 1�C, 14/10 h day/night) at 3 seedbed moisture levels (field capacity, -0.01 MPa; dry, -0.30 MPa; and saturated soil, soil saturated for 48 h, planted then allowed to dry to field capacity). The modified accelerated aging test with Thiram was significantly (P<0.01) correlated with emergence in all 3 seedbed moisture conditions. High vigour seed samples with high accelerated aging germinations emerged well. Overall, the vigour test which ranked the seed samples to give the best indicator of performance under a range of seedbed moisture conditions was the modified accelerated aging test with thiram.
Susceptibility of low chill peach rootstocks to Phytophthora spp
Authors: Broadbent P , Barkley MB , Sriskanthadas M , Kaldor CJ
Published: March 2005

Peach seedlings (Prunus persica L. Batsch cv. Ansbacher, Boyles, Clarke's Shanghai, Neilson (Fred Hill), Okinawa, O'Meara, Richens Nos 1,2 and 3, Tomm's Early and Tomm's Shanghai), which are commonly used as rootstocks for low chill peaches in coastal New South Wales, were all susceptible to Phytophthora cinnamomi and P. cambivora and to a lesser extent P. parasitica, P. citricola, P. cryptogea, and P. megasperma, when tested by stem inoculations in the glasshouse. Myrobalan H29C plum (P. cerasifera Ehrh.) cuttings showed more resistance than peach seedlings. Variety of seedling peach was highly significant in stem inoculation experiments, but the performance of each varied between experiments. Root inoculations in aerated nutrient solution showed all rootstocks were susceptible to P. cinnamomi, but Neilson (Fred Hill) peach was more tolerant than other seedling peaches and less tolerant than Myrobalan H29C plum. No recommendation could be made on a rootstock for low chill peaches more tolerant of root and collar rots and waterlogging.
Prediction of lifetime reproductive performance of Australian Merino ewes from reproductive performance in early life
Authors: Lee GJ , Atkins KD
Published: March 2005

The lifetime reproductive performances (5 annual cycles) of 2105 Merino ewes from a multiple bloodline flock (15 separate bloodlines) were used to determine the association between reproductive performance in early life (either at 2 or 3 years of age, or the combined information from both years) and later performance. Early life fertility was indicative of both the fertility and the rearing ability of ewes in later life. The relationship of the combined weaning performance at the first and second annual reproductive cycles with reproductive performance in later life suggested gains were possible in the current flock from culling with emphasis on low fertility and rearing ability. Ewes that were dry at 2 and 3 years of age subsequently reared only half as many lambs as ewes that had reared lambs at 2 and 3 years of age.
Effects of dietary phosphorus deficiency in pregnant and lactating ewes
Authors: Ternouth JH , Budhi SPS
Published: March 2005

Maiden ewes were offered barley straw-based diets ad libitum containing very low (VLP), low (LP), medium (MP) and high (HP) levels of phosphorus (P) so that their intakes ranged from 14 to 118 mg P/kg LW.day. Dry matter intakes of ewes offered the VLP diet were 14 and 22% lower than those offered the HP diet in pregnancy and lactation, respectively. Plasma inorganic P (PIP) levels were significantly lower (<30 mg/L) in ewes offered the VLP diet in late pregnancy and throughout lactation. At the end of the experiment, the liveweight of ewes offered the VLP diet was 12% lower, rib bone P concentration 27% lower and the calcium: P ratio 37% higher than those offered the HP diet. Lamb liveweight gains of 30-70 day and tritiated water studies strongly suggest that the milk secretion was related to P intake and that most ewes were in negative balance in lactation. Using 32P as a marker, it was found that dietary P absorption was closely related to P intake. The coefficient of P absorption was low (0.52-0.56) in ewes offered the VLP diet, but high in all others (0.84-0.89). Endogenous faecal losses of P (19-45 mg/kg LW.day) were related either to P intake, or PIP and DMI. There was no difference between pregnancy and lactation in the gastrointestinal kinetics of P. Ewes offered the low P diets had similar high rates of reabsorption of P from the bones and soft tissues in both pregnancy and lactation so the lactating ewes were in more negative balance.
Chlorsulfuron residues are not accumulating in soils of southern Queensland
Authors: Walker SR , Robinson GR
Published: March 2005

Chlorsulfuron persistence was measured in soils (to a depth of 150 cm) at 4 sites in the winter cereal region of southern Queensland. The residual herbicide had been applied 6-14 times in the previous 7-14 years. Residues here measured using a bioassay based on suppression of root growth of maize (Zea mays cv. GH5010). Less than 3% of the total applied chlorsulfuron (96-210 g a.i./ha) was detected 6-12 months after the last application, and residues were <0.7 ng/g soil in the surface 30 cm, and <0.3 ng/g below 30 cm. The limited vertical movement of residues was associated with the herbicide being applied in early winter, several months before leaching rains. Changes in residue concentration with time were also measured at a site in central Queensland, and in a fallow management experiment in southern Queensland. Persistence was greater at the cooler, drier site in southern Queensland than in central Queensland; 4544% compared with 3 4 % of applied dose remained 3 months after application respectively. Stubble retention had no effect on persistence, but tillage during the summer fallow increased persistence slightly. There was no evidence of chlorsulfuron residues accumulating and only limited leaching in these alkaline agricultural soils of southern Queensland. Persistence within a season was influenced by soil and climatic factors.
Genetic diversity of Kensington mango in Australia
Authors: Bally ISE , Graham GC , Henry RJ
Published: March 2005

The genetic diversity of Kensington mangoes (Mangifera indica L.) was investigated using random amplified polymorphic DNA (RAPD) analysis. DNA was extracted from leaves of 27 'Kensington Pride', 2 'R2E2' and 1 seedling. RAPD analysis with 10 oligonucleotide primers allowed the scoring of 107 markers. The R2E2 trees (20% dissimilarity) and the seedling (10% dissimilarity) were distinct from the Kensington Pride. However, there was very little evidence of significant genetic variation within Kensington Pride selections. Fifteen of the selections were identical in all 107 markers. Only 2 selections, WEAN2 and ML2N1, differed by more than 5%. These plants provide the best options for use in genetic improvement of the Kensington Pride mango. Many of the differences found in Kensington mango orchards may be due to environmental factors not genetic variations.
A method of using a genetic algorithm to examine the optimum structure of the Australian sheep breeding industry: open-nucleus breeding systems, MOET and AI
Authors: Horton B
Published: March 2005

A genetic algorithm was evaluated as a means of using a computer model to determine the optimum structure of the Australian sheep breeding industry. The model simulates an open-nucleus 3-tiered sheep breeding system to investigate the benefit of strategies such as multiple ovulation and embryo transfer (MOET) and artificial insemination (AI) in terms of both genetic improvement and dollar values. The model indicated that both MOET and non- MOET systems benefit from an open nucleus, and both could also benefit from the promotion of some ewes from the commercial flocks. However, MOET systems require a relatively large number of rams, whereas non- MOET systems should have a smaller number of rams despite the much larger number of ewes needed. Under the conditions studied here, there was only limited advantage of MOET over non-MOET schemes. The optimum structure of the MOET, non-MOET and closed systems differ substantially. A genetic algorithm is a simple method for considering a single change (such as reproductive rate, or open v. closed) that may require major changes in the industry structure to achieve the full benefits. The method could also be of value in many other situations requiring optimisation of complex models.