bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluating dairy sires for conformation of their daughters: use of first classification records
Authors: Meyer K , Burnside EB , Hammond K , McClintock AE
Published: November 2004

Type classification records for 18 132 Australian Holstein-Friesian heifers were analysed. These consisted of 27 traits scored in three or six categories, from three rounds of classification between 1981 and 1983. Only first lactation, first classification records were considered. The model of analysis included herd-round-classifier subclasses as fixed and sires as random effects, fitting age at classification as a linear and quadratic covariable within subclasses. Herd-round-classifier effects explained between 18% and 37% of total sums of squares. Age accounted for 5.8-2.4% for traits related to body size and for 1.6% or less for the other traits. Heritability estimates obtained using a Restricted Maximum Likelihood procedure ranged from 0.44 for total score, 0.42 for stature and 0.40 for dairy character, to 0.10 or less for feet and legs, rear heel, rear legs set, bone quality and rear teat placement. On average, values were higher than corresponding 'all-lactation' estimates. Covariance components between all traits were obtained. The resulting genetic variance/covariance matrix was then forced to be positive semi-definite before calculating genetic and phenotypic correlations. Breeding value estimates for all sires and traits were determined using a univariate Best Linear Unbiased Prediction procedure for the above model. In addition, the relationship matrix between males was incorporated. There were 2 597 sires with an average of 23.2 effective daughters, and 474 sires without daughter records included as male ancestors. The association between breeding value estimates for different traits was examined by multiple regression. Sire-son regressions were determined and compared with their expectations. Australian Breeding Values for production were obtained for a subset of sires and contrasted to the type proofs. There seemed to be little correlation between genetic merit for type and milk production.
The effect of time and sowing and row spacing on the maturity and yield of three groundnut cultivars under irrigation
Authors: Muldoon DK
Published: November 2004

White Spanish, Red Spanish and Virginia Bunch cultivars of Arachis hypogaea L. were sown at two row spacings (30 and 60 cm) and two times (29 October and 3 December) on an alkaline clay soil in western New South Wales. The crops were furrow irrigated between raised beds 1 m wide. Maximum oven dry pod yields were 3.0, 2.3 and 3.3 t ha-1 for white Spanish, Red Spanish and Virginia Bunch respectively. Corresponding shelling percentages were 65, 68 and 57%. White Spanish and Virginia Bunch matured 180-190 days after early sowing and Red Spanish after 210 days when frost stopped growth. The late sown crop failed to mature before the frosts, and yielded 15-25% less than the early sowing. The late crop had a shorter period for the production of pods and also a slightly lower rate of pod production because of reduced shoot growth; kernel weight per pod was similar at both sowings. Differences between cultivars were accounted for by differences in the rate of pod filling and hence ultimate kernel weight per pod, and furthermore, the harvest index differed among cultivars. White Spanish or Virginia Bunch sown in 30 cm rows before December can be recommended for irrigated groundnut production in western New South Wales.
Effects of soil modification and treading on pasture growth and physical properties of an irrigated red-brown earth
Authors: Kelly KB
Published: November 2004

Lemnos loam, a red-brown earth used extensively for pasture production in northern Victoria, and its exposed subsoil (topsoil removed) were both subjected to surface cultivation and total profile modification. Total profile modification consisted of excavating and mixing the top 1.1 m of soil and incorporating gypsum (10 t ha-1), superphosphate (4.5 t ha-1) and ammonium nitrate (0.5 t ha-1) . A white clover-perennial ryegrass pasture was established. Treading by cattle was superimposed over these soil treatments. Exposure of the subsoil, as often occurs with laser landforming, reduced pasture growth by 30% compared with a normal soil profile. Modification of the exposed subsoil negated this effect. Modification of the normal soil profile had little effect on pasture production but did influence pasture composition. Treading had a cumulative effect with time, reducing pasture production by 6, 9 and 12% in 1981, 1982 and 1983, respectively. This occurred despite the precaution of allowing grazing only when the soil was dry. Profile modification resulted in increased pore space and root growth, and lowered bulk density and penetrometer resistance at depth. Treading increased surface soil bulk density, with penetrometer studies showing that this effect was confined to the top 0.15 m.
The occurrence of herbicide cross-resistance in a population of annual ryegrass, Lolium rigidum, resistant to diclofop-methyl
Authors: Heap I , Knight R
Published: November 2004

A population of L. rigidum, which is known to have developed resistance to one of the diphenyl-ethertype of herbicides, diclofop-methyl, was tested for cross-resistance to three other herbicides of the same type, namely fluazifop-butyl, oxyfluorfen and the experimental herbicide CGA 82725. The population was also tested for cross-resistance to two sulfonylurea-type herbicides - chlorsulfuron and the experimental herbicide DPX-T6376. A population susceptible to diclofop-methyl was used as the controls in the tests. The two populations were treated with various rates of the herbicides during germination and at the two-leaf stage. The results show that the diclofop-methyl-resistant biotype was cross-resistant to fluazifop-butyl, CGA 82725, chlorsulfuron and DPX-T6376 but not to oxyfluorfen.
Variability in the total and component galactosyl sucrose oligosaccharides of Lupinus species
Authors: Saini HS , Gladstones JS
Published: November 2004

The oligosaccharide compositions of 33 lupin seed accessions and cultivars, from 10 species, are reported. Seed weights varied from 3.8 to 66.6 g/100 seeds. Total oligosaccharide content ranged from just under lo%, to almost 23% dry matter. In all cases the quantity of oligosaccharides (raffinose, stachyose and verbascose) was higher than that of disacharides (sucrose and melibiose). Verbascose ranged from 0.0 to 33.4% of total oligosaccharide content, and raffinose from 4.7 to 47.4%. Stachyose was the predominant and most constant sugar in majority of the seeds examined, the highest level (75%) being recorded in one line of L. hispanicus. The amounts of stachyose and verbascose, which are considered to be of major importance as 'flatus factors', were higher than those recorded for most established legume crops, although considerable variation was found between lupin species and some within a lupin species. Sufficient variability appears to be present within L. angustifolius in total oligosaccharides, and to a smaller extent in component saccharides [other than that apparently associated with existing domestication gene(s)] to warrant selection for improved saccharide composition as part of the breeding process.
Some relationships between plant population, yield components and grain yield of wheat in a Mediterranean environment
Authors: Anderson WK
Published: November 2004

Eight spring bread wheat cultivars (Triticum aestivum L.), differing widely in their nominal yield component characteristics, were tested under rain-fed conditions for three years at sowing densities ranging from 50 to 800 seeds m-2. The objectives of the experiments were to estimate the relationship between grain yield and particular yield components, the expression of plant type (yield components) in relation to plant density, and the plant population x cultivar interaction for grain yield over a range of seasons in a given environment. The 'optimum' plant population (at maximum grain yield) varied over 30-220 plants m-2, depending on season and cultivar. In general, variation in the 'optimum' population was greater between seasons for a given cultivar than between cultivars within seasons. The relationship between grain yield and yield components was examined at the 'optimum' population rather than at an arbitrary population at which grain yield may have been suboptimal for some cultivars or seasons. Grain yields at the optimum populations for the various cultivar x season combinations were positively related to culms m-2, spikes m-2 and seeds m-2. They were not clearly related to culm mortality (%). When averaged across seasons, cultivar grain yields were positively related to harvest index, but the general relationship was not so clear when seasons and cultivars were examined individually. Spike size (seeds spike-I or spike weight) and seed size were also not clearly related to grain yield at the 'optimum' population, and it was thus postulated that the production and survival of large numbers of culms, which in turn led to large numbers of seeds per unit area, were the source of large grain yields. Some interactions were found between yield components and plant population for some cultivars that could have implications for plant breeders selecting at low plant densities. The implications for crop ideotypes of the individual plant characters at the 'optimum' population are also discussed. Interactions between cultivars and plant populations implied that some cultivars required different populations to achieve maximum yields in some seasons. There was a tendency for larger yields to be achieved from cultivar x season combinations where the optimum population was larger, which suggested that commercial seed rates should be re-examined when changes to plant types or yield levels are made.
Phytophthora crown rot of almond trees
Authors: Wicks T , Lee TC
Published: November 2004

Phytophthora cambivora, P. citrophthora, P. cryptogea, and P. megasperma were isolated from either crown cankers or the soil around the crown of declining almond trees in South Australia. Severe root rot and crown cankers developed on Chellaston almond seedlings grown in soil artificially infested with the A1 but not the A2 mating type of P. cambivora. Cankers on inoculated plants were similar to those on naturally infected plants. Cankers did not develop on almond seedlings grown in soil infested with either P. citrophthora, P. cryptogea or P. megasperma. Neither extensive root rotting nor crown cankers developed in apricot and peach seedlings grown in soil artificially infested with the A1 mating type of P. cambivora. Phytophthora spp. were detected in 44% of the soil samples collected near the crown of dead and declining trees from 26 commercial almond orchards. In a severely affected orchard up to 17% of mature trees were either dead, missing or in a serious state of decline. Naturally infected trees were frequently found in poorly drained soils and were often associated with dripper irrigation outlets placed close to the trunk.
Variation in tolerance in Phalaris aquatica L. and a related species to aluminium in nutrient solution and soil
Authors: Culvenor RA , Oram RN , Fazekas de St Groth C
Published: November 2004

The range of aluminium tolerance in P. aquatica and P. arundinacea L. was examined and compared with the range in some crop and pasture species of known tolerance. In nutrient solution and aluminium-toxic soil, a distinct class of P. aquatica plants extremely sensitive to aluminium was resolved. The tolerance of each P. aquatica line was correlated with the frequency of sensitive plants, which ranged from 0 to 100%. Significant variation in tolerance remained after exclusion of the sensitive class. The aluminium concentration in nutrient solution required for 50% growth reduction varied from approximately 2 to 6 ppm Al among P. aquatica lines. The more tolerant lines, which included Sirosa and Sirolan, were markedly less tolerant than cocksfoot, tall fescue, subterranean clover and known tolerant cereal cultivars. Root extension was the most sensitive character. However, ranking of P. aquatica lines according to yield in solution gave better agreement (r = 0.81, P < 0.01) with ranking according to relative yield in unlimed versus limed aluminium-toxic soil than did root extension in solution (r = 0.69, P < 0.01). Reference to yield is thus considered necessary for selection among more tolerant plants in a breeding program. The aluminium tolerance of P. arundinacea was superior to that of P. aquatica, and P. arundinacea CPI 69103 was as tolerant as tall fescue in aluminium solutions. Significant improvement of P. aquatica appears possible in the longer term by hybridisation with P. arundinacea, whereas limited improvement should be achieved in the short term by intraspecific recombination and selection.
Growth and the distribution of phosphorus in wheat developed under various phosphorus and temperature regimes
Authors: Batten GD , Wardlaw IF , Aston MJ
Published: November 2004

Experiments were designed to examine the effect of the level and duration of application of phosphorus (P) on yield in wheat and the effect of growth conditions prior to anthesis on the utilisation of P taken up during the early stages of development. In the first experiment, wheat (Triticum aestivum cv. Kite) was grown in sand and supplied with a complete nutrient solution containing either 1 mM phosphate or 0.25 mM phosphate. The supply of P was maintained until grain maturity, or stopped at different stages of development (floral initiation, flag leaf emergence, anthesis). The increase in total plant dry matter over this period ranged from 8.8 to 17.6 g/plant, with the 1.0 mM P supply and from 4.1 to 9.5 g/plant with the 0.25 mM P supply. Supply of P beyond anthesis resulted in more tiller dry matter and increased the P content of the grain, but did not increase grain yield at either level. With 1 mM P to maturity, up to 21% P of the grain P could be attributed to retranslocation of P within the plant after anthesis. With 0.25 mM P to floral initiation, 58% of the grain P could be attributed to such retranslocation. In a second experiment plants (cv. Kite) were grown initially at 18/13�C with 0.25 mM P until floral initiation and thereafter with a P-free solution until maturity. Between floral initiation and anthesis plants were placed in six dayhight temperatures, extending (in 3�C steps) from 15/10�C to 30/25OC, and then returned to the standard condition of 18/13�C. Higher pre-anthesis temperatures reduced the pre-anthesis growth period and the plant height, but increased the leaf phosphorus concentration and uptake of phosphorus per plant in both the pre- and post-anthesis periods. Net CO2 exchange indicated that leaf senescence in P-deficient plants was closely associated with the export of nitrogen as well as the export of P. Grain P increased from 0.15% to 0.3% when the preanthesis temperature was increased from 15/10 to 30/25�C, although grain yield per main culm did not vary greatly. These findings highlight the importance of environmental conditions in determining the level of P deficiency in wheat, and show that grain yield is not limited by the amount of P in the grain.
Effect of changes in moisture profiles of a transitional red-brown earth with surface and slotted gypsum applications on the development and yield of a wheat crop
Authors: Jayawardane NS , Blackwell J , Stapper M
Published: November 2004

The low productivity of transitional red-brown earths for flood irrigated upland cropping is associated with their low infiltration rates and inadequate aeration of the root zone. The effect of the measured changes in the moisture and aeration profiles with surface and slotted gypsum applications on growth and development of a wheat crop was evaluated in a preliminary field study, on non-replicated plots.The patterns of changes in moisture profiles in the gypsum slotted plots were similar to those observed in the previous season, namely, deeper preferential wetting and faster internal drainage through the slots. This resulted in lower volumetric moisture contents in the slots and in the surface and subsurface layers between slots, compared to the non-slotted plots.The critical moisture contents were defined for each soil depth at which an air-filled porosity of 0.08 mm3 mm-3 was reached. For the transitional red-brown earth used in this study, air-filled porosity needs to be larger than 0.08 mm3 mm-3 to provide a soil pathway for oxygen flow to roots. The moisture profiles in the no-gypsum, surface gypsum and slotted gypsum plots measured throughout the cropping season indicated the period of time when oxygen flow through different soil layers was likely to be restricted. The moisture contents were higher than the critical value in the surface and subsurface layers of the non-slotted plots, particularly in the plot with no gypsum applications, during a period in winter with prolonged rainfall and low evapotranspiration rates. This resulted in reductions in the rates of phasic development, tillering, canopy closure and dry matter production and finally lower yields in the non-slotted plots, especially in the plot without gypsum. Differences in grain yields were mainly due to differences in the number of spikes m-2.During the second half of the growing season higher potential evapotranspiration, lower rainfall and accurate irrigation scheduling resulted in the moisture contents being maintained below the critical limits at all depths in all plots. Consequently, the two yield components which were determined during this period, namely, the number of kernels per spike and kernel weight, showed only slight variations between plots.
Classification of a collection of the legume Alysicarpus using morphological and preliminary agronomic attributes
Authors: Gramshaw D , Pengelly BC , Muller FW , Harding WAT , Williams RJ
Published: November 2004

A collection of 121 accessions of the legume genus Alysicnrpus was grown out and classified using morphological and agronomic attributes. Nineteen morphological-agronomic groups were identified and matched, where possible, to previous taxonomic classifications. Substantial diversity was found for perenniality, plant habit, flowering and pod maturity dates, seed size, pod shape and pod surface sculpture and for attributes involving dimensions of plant parts. Confusion in previous species naming was also apparent. The value of a broad classification of a large collection of plants as a prelude and aid to subsequent research is highlighted, and the possible agronomic potential of the morphological-agronomic groups also considered.
Further studies on epidemiological factors influencing control of banana bunchy top disease and evaluation of control measures by computer simulation
Authors: Allen RN
Published: November 2004

The basic infection rate of bunchy top disease in established bananas averaged 0.0342 new infections per infectious plant per day, but varied seasonally with a maximum in summer. The mean distance of spread for the aphid vector was 15.2 m. The latent period was 59.8 days and correlated with the time required for the growth of 3.7 new banana leaves. A microcomputer program was written to simulate spread of banana bunchy top disease in space and time. In the absence of disease control, disease spread from an initial primary infection in July or January to 124 or 153 infected plants, respectively, in one year. When disease control was maintained by removing diseased plants whenever the number of infected plants exceeded a given threshold, the numbers of diseased plants detected each inspection were positively correlated with the infection threshold, but the numbers of inspections required to maintain control increased markedly as the infection threshold was decreased. A practice of removing apparently healthy plants within 5 m of plants detected with bunchy top disease symptoms in five or more leaves was found to locate about 30% of the remaining undetected infected plants when disease was first detected in a plantation. However, its use as a routine control measure was ineffective in reducing the number of inspections required to maintain control or in reducing the risk of disease spreading to adjoining plantations. Removal of apparently healthy plants within 5 m had some bearing on disease control when applied around plants with disease symptoms in two leaves or less, but also caused a significant loss of healthy plants.
The prevalence of epitheliogenesis imperfecta in Sahiwal cattle and their crosses in a north Queensland beef herd
Authors: Fordyce G , Holroyd RG , Beaman NJ , James TA , Hoffmann D , Shepherd RK
Published: November 2004

Epitheliogenesis imperfecta (EI) has been diagnosed in calves on a north Queensland beef cattle research station. There are five Bos indicus cross, inter se mated breed groups on the station: 1/2 Brahman, 3/4 Brahman, 1/2 Sahiwal, 3/4 Sahiwal and High Grade Sahiwal. The disease was confined to the three Sahiwal breed groups and caused calf losses over seven years from 1978 of 0.2%, 3.4% and 1.0% in the 1/2, 3/4 and High Grade groups respectively. The Sahiwal breed was identified as the origin of the gene responsible for the disease. The source of the gene within the Sahiwal breed was investigated, and several ancestors were identified as almost certainly being heterozygotes. Analyses of relationships of affected and non-affected calves to the 10 Sahiwals that were originally imported into Australia identified the one that was most likely the source of the El gene.
Inoculation methods for assessing resistance in wheat to crown rot caused by Fusarium graminearum group 1
Authors: Dodman RL , Wildermuth GB
Published: November 2004

A range of inocululatron methods for assessing resistance in wheat to crown rot caused by Fusarium graminearum Group 1 was evaluated in the glasshouse and in the field. When grain was colonized with the pathogen, ground and applied with the seed at planting or spread around young plants as an aqueous suspension, high levels of crown rot were produced, but resistance (usually measured as per cent diseased plants or tillers) was still expressed. Similar results were achieved with induced field inoculum obtained by inoculating an area of wheat to obtain a high incidence of disease and incorporating the stubble into the soil. Natural field inoculum and inoculation of seed with spores produced lower levels of disease, although differentiation of resistant and susceptible cultivars was still possible. Other methods, suitable only for plants in pots and often for more specific purposes (for example, for inoculation at different stages of plant growth) were also studied. Resistance was best expressed where inoculum was applied onto or into soil, rather than directly onto or into plants. Currently, the resistance of all potential cultivars for release in Queensland is assessed in the field by sowing seed dusted with benomyl into furrows along which ground, colonized grain is distributed. Crown rot severity is then determined at maturity.
Evaluation of fungicides for curative activity against Tranzschelia discolor, cause of the rust disease of French prune (Prunus domestica L.)
Authors: Kable PF , Keen BJ , Bambach RW
Published: November 2004

The ergosterol biosynthesis inhibitors, propiconazole, RH-2161 and RH-3866, exhibited strong curative activity against Tranzschelia discolor infections in French prune leaves. Foliar sprays (25-50 ppm) applied during the latent period, up to 7 days after inoculation, completely suppressed the disease. When these fungicides were applied after the appearance of symptoms, they inhibited further lesion growth and sporulation. Other fungicides having some curative activity were triforine and oxycarboxin. Fungicides with little or no curative activity against T. discolor were bitertanol, PP969, triadimefon and tridemorph.
Inheritance of resistance to Fusarium oxysporum f. sp. lycopersici races 2 and 3 in Lycopersicon pennellii
Authors: McGrath DJ , Gillespie D , Vawdrey L
Published: November 2004

An accession of Lycopersicon pennellii, PI414773, was resistant to race 2 isolate 18947 and race 3 isolate 14844 of Fusarium oxysporum f. sp. lycopersici. Tomato cultivar Contender, which is homozygous for gene 1-2, was resistant to race 2 but susceptible to race 3 of the pathogen. Cultivar Rouge de Marmande was susceptible to both race 2 and race 3. The inheritance of resistances to race 2 and race 3 in PI414773 was investigated in test crosses involving parents Contender, Rouge de Marmande and PI414773. Segregation of the F2 of the crosses Rouge de Marmande x PI414773 and Contender x PI414773 revealed that resistance to race 2 in PI414773 was controlled by two independent dominant genes, one of which is allelic with gene I-2. Segregations in F2, backcrosses and inbred backcrosses derived from Contender x PI414773 indicated that a single dominant gene conferred resistance to race 3. The symbol I-3 was proposed for this gene.
An ultrasound technique to measure placental growth in ewes
Authors: Kelly RW , Newnham JP , Johnson T , Speijers EJ
Published: November 2004

Changes in mean diameter of cotyledons were measured from day 45 to 141 of pregnancy using real time ultrasound on 40 3-6-year-old Merino ewes, averaging 46 kg liveweight at day 45, and carrying one foetus. Observations were made at about 2-weekly intervals. Half of the ewes were sacrificed at day 94 and the remainder at day 141 to correlate the observations taken during pregnancy with actual data. There was a significant quadratic relationship (P < 0.001) between mean cotyledon diameter and a square root transformation of day of pregnancy. Maximum diameter of the cotyledons, as estimated by real time ultrasound, occurred at the observation on day 80 of pregnancy. The between-ewe comparison of mean diameter of the cotyledons measured by ultrasound just prior to slaughter with actual mean diameter recorded at slaughter showed a significant correlation (P < 0.001) for both the day 94 (r = 0.69) and day 141 (r = 0.71) results. Within ewes, the correlation between diameter and weight of the cotyledon was high (0.92, 0.86 for days 94 and 141 respectively), and the slope of the linear regression was less (P < 0.001) on day 141 than day 94 (0.45 v 0.32). Eighty-three per cent of the variation between ewes in total weight of cotyledons on day 94 of pregnancy was accounted for by a regression using sex of foetus, number of cotyledons and mean diameter of cotyledons measured by ultrasound on day 80 of pregnancy. In comparison, for day 141 of pregnancy 49% of the variation between ewes in total weight of cotyledons was accounted for by a regression using mean diameter on day 66 of pregnancy and number of cotyledons. The technique has potential value in studying patterns of development of the cotyledons during pregnancy in the ewe, but further validation is necessary.
Effect of rotation and conservation tillage of earthworms in a red-brown earth under wheat
Authors: Rovira AD , Smettem KRJ , Lee KE
Published: November 2004

The effects of two rotation and two tillage systems on earthworm populations have been studied in a red-brown earth under wheat. At the time of sampling, the earthworm population under direct drill was nearly double that under conventional cultivation. The total number of worms was not affected by crop rotation with pasture or lupins, but following pasture there were significantly more large worms. It is suggested that at this site the earthworm population may be responding rapidly to alterations in food supply and water stress under the different agricultural systems.
Estimation of genetic variance and allied parameters through biparental mating in opium poppy (Papaver somniferum L.)
Authors: Srivastava RK , Sharma JR
Published: November 2004

Genetic variances and allied genetic parameters were estimated for eight economic traits through biparental mating designs in two populations: (i) a local land race, and (ii) a segregating F2 population of Indian opium poppy. Estimates of additive variance were larger than the dominance variances (o2A > o2D) or environmental variance (+-R > n�2) for the majority of the eight traits examined. Narrow sense heritability (h2NS) estimates were high (60-89%) for five traits, moderate (28.3%) for peduncle length and low (< 13%) for capsule index and morphine content in the local land race, and high (57-93%) for all the eight characters in the F2 population. Average degree of dominance in the local population leaned heavily towards overdominance (G > 1 .O) for six charcters (four in negative and two in positive directions) and towards partial dominance (G < 1.0) for the remaining two traits: latex yield and flowering time (both in negative direction). Accordingly, combination breeding for latex yield and flowering duration, (F1) hybrid breeding for seed yield, morphine content and capsule number and/or population breeding for other traits, were suggested for rapid genetic improvement of opium poppy.
Induced systemic resistance in Stylosanthes spp. to Colletotrichum gloeosporioides
Authors: Davis RD , Irwin JAG , Shepherd RK
Published: November 2004

Systemic resistance to anthracnose caused by Colletotrichum gloeosporioides was induced in Stylosanthes humilis cv. Paterson and S.guianensis cv. Endeavour plants by protection inoculation (PI) with sub-lethal amounts of C. gloeosporioides inoculum. The protection was demonstrated on leaves produced after the plants had first become infected. When challenged with inoculum, these leaves produced significantly less severe lesions than on corresponding leaves on non-protected plants. The induced resistance effect diminished with time on the youngest leaves of plants which were challenged up to 39 days from the PI. The experiments also showed that young Stylosanthes spp. leaves (up to seven days after first appearance) were more susceptible to anthracnose infections than older leaves. When leaves of S. humilis and S. guianensis were inoculated at 24 and 30 days after first appearance respectively, very few infections occurred. These two factors may help explain observed anthracnose occurrence patterns in Stylosanthes spp. pastures.
Water loss by floral structures of avocado (Persea americana cv. Fuerte) during flowering
Authors: Whiley AW , Chapman KR , Saranah JB
Published: November 2004

Transpiration rate (E) and epidermal conductance (gc,) were determined for avocado leaves and floral parts under controlled environmental conditions (28�C; PAR 60 8mole quanta m-2 s-1; VPD 1.14 kPa). E of hydrated flowers was shown to be approximately 60% that of similarly treated leaves. Around 13% of total transpirational water loss from tree canopies could be attributed to floral organs. The mean gc of leaves and flower panicles was similar at 0.028 and 0.023 mm s-1 respectively. The available canopy surface area for water loss increased by c. 90% during flowering. Xylem water potentials in panicle segments with open flowers were lower than those of mature leaves measured on trees in the field. Maximum transpiration rate of leaves measured in the field was 6.7 8g cm-2 s -1 at 0700 hours, declining to 3.0 8g cm-2 s-1 at 1100 hours, while stomatal conductance (gs) on the same leaves fell from 10.2 mm s-1 at 0700 hours to 2.52 mm s-1 at 1100 hours. Scanning Electron Microscope studies of leaves and floral structures highlighted morphological and anatomical features for water conservation. Mature leaves have an epicuticular wax-like layer on the adaxial surface. Stomates were located only on the abaxial surface, which was also covered wlth wax-like deposits. Stomate density was estimated at 73 000 cm-2 on sun leaves. Stomates were also located on abaaial surfaces of flower sepals and petals. All floral structures were densely pubescent, thereby increasing the effective boundary layer depth.
Responses of meat chickens offered 4-deoxynivalenol- and zearalenone-containing wheat, naturally infected with Fusarium graminearum
Authors: Mannion PF , Blaney BJ
Published: November 2004

The responses of meat chickens offered wheat naturally infected with F. rarninearum Schwabe (DONZEA wheat), a control wheat, a protein and trace nutrient concentrate (PTNC), and diets comprising a mixture of PTNC with either DON-ZEA or control wheat were examined over the period from 7 to 28 days of age. The six treatments were: (1) a choice of PTNC, DON-ZEA wheat and control wheat, (2) a choice of PTNC and DON-ZEA wheat, (3) a choice of PTNC and control wheat, (4) a choice of a PTNC and DON-ZEA wheat diet and a PTNC and control wheat diet, (5) a PTNC and DON-ZEA wheat diet, (6) a PTNC and control wheat diet. The DON-ZEA wheat and the DON-ZEA diet contained 19 and 12 mg 4-deoxynivalenol kg-', respectively, and 3 and 2.6 mg zearalenone kg-1, respectively. Each treatment was assigned to three groups of 10 chickens in a randomized block design. The primary response in chickens offered DON-ZEA wheat, either separately or in mixed diets, was a reluctance to eat the affected feed. This was most evident in treatment 1 when given a choice between DON-ZEA wheat (103 g wheat consumed bird -1) and control wheat (505 g wheat bird-1), and in treatment 4 when offered the DON-ZEA diet (326 g bird-1) and the control diet (821 g bird-1). The chickens showed less reluctance to eat the DON-ZEA wheat (396 g wheat bird-1) and the DON-ZEA diet (1073 g bird-1) when these were offered as the sole grain (treatment 2 ) or diet (treatment 5), respectively, although intakes were less than that of the control wheat (570 g wheat bird-') and of the control diet (1184 g bird-1) when these were offered as the sole grain or diet (treatments 3 and 6, respectively). It is concluded that diets based on wheat naturally infected with F. graminearurn may depress growth rate in meat chickens by reducing their feed consumption.
Relationships between stripe rust severity and grain yield loss at Dooen, Victoria
Authors: Brown JS
Published: November 2004

The relationship between stripe rust severity and grain yield loss in wheat was studied in two field experiments. Wheat cultivars varying in response to the disease were used to produce epidemics of differing severity. Regression models were used to examine the relationship between disease severity and yield loss. The best estimator of yield loss was an estimate of disease severity at the end of anthesis-early berry growth stage. The relationship between per cent yield loss (YL) and per cent disease severity (DS) at that growth stage was established to be YL = 0.479DS + 0.84.
Factors limiting the intake of feed by sheep. 12. Digesta load and chewing activities in relation to lactation and its attendant increase in voluntary roughage consumption
Authors: Weston RH
Published: November 2004

Lactating and non-pregnant, non-lactating ewes were compared with respect to voluntary consumption of a medium quality roughage and various aspects of digestion of the roughage as fed at intakes near ad libitum. The lactating ewes, relative to their control counterparts (i) consumed more roughage, (ii) ate more rapidly, (iii) maintained higher levels of digesta in the rumen, omasum, abomasum, and caecum + proximal colon, (iv) showed no difference in particle size distribution in rumen digesta, (v) exhibited enhanced rumination activities and (vi) on average, cleared a particulate marker more rapidly from the rumen. It was estimated that the lactating ewes had a higher energy deficit than the controls. It was concluded that (i) the greater rate of removal of feed dry matter from the reticula-rumen (mass/time) during lactation was largely attributable to the enhancing effect of the prevailing higher reticulo-rumen digesta load on rumination, digestion and propulsion, (ii) neither capacity to use energy nor physiological capability of the reticula-rumen played a primary limiting role in the regulation of roughage intake, with the control of animals, (iii) the comparative data are consistent with a concept that energy metabolism and digesta load interact in the regulation of roughage intake, and (iv) scope exists for increasing consumption of the roughage by appropriate physiological manipulation of the animal.
Phosphorus efficiency in pasture species. I. Measures based on total dry weight and P content
Authors: Chisholm RH , Blair GJ
Published: November 2004

Two solution culture experiments were conducted to compare the efficiency of phosphorus use and indicies for measuring it in a tropical and a temperate pasture legume. The species chosen were Stylosanthes hamata cv. 'Verano' (Caribbean stylo) and Trifolium repens cv. 'Ladino' (white clover).The first experiment used two solution P concentrations (2, 16 8M) to investigate differences between species in the rate and extent of P uptake. The second experiment used five solution P concentrations (1, 2, 4, 8, 16 8M ) to evaluate differences between species in internal efficiency of P utilization.There was no difference between white clover and stylo in the capacity to remove P from the same solution P concentrations. However, in both species the extent of depletion of solutions by plants grown at high P was not as great as that plants grown at low P. The ranking of species in terms of their internal efficiency or relative growth rate changed with time and P concentrations.Growth of white clover was better than stylo where there was a moderate deficiency of phosphorus. Alternatively, growth of stylo was better than white clover where phosphorus deficiency was more severe. The relative growth rate of stylo at low (2 8M ) P was maintained above 8% per day after prolonged P stress, whilst in white clover at the same P concentration RGR fell to less than 2% per day.Internal P efficiency or the amount of dry matter accumulated per unit P accumulated per unit time showed that white clover was more P efficient than stylo in the early stages of growth.
Some characteristics of Australian isolates of Zucchini Yellow Mosaic Virus
Authors: Greber RS , Persley DM , Herrington ME
Published: November 2004

Isolates of zucchini yellow mosaic virus (ZYMV) were obtained from six cucurbit species from four states of Australia and identified by host range, electron microscopy and serology. A survey of coastal Queensland in 1986-87 showed no ZYMV north of Townsville nor around Rockhampton, but major centres of ZYMV incidence with specific pathotypes, around Ayr, Bowen and in south-east Queensland. Pathotypes were distinguished using Cucumis melo differentials, Trichosanthes anguina and Phaseolus vulgaris. Three ZYMV isolates were compared with watermelon mosaic virus 2 and papaya ringspot virus, cucurbit strain, on 20 hosts from 5 families. The effect of ZYMV on 19 cvv. of pumpkin, squash, zucchini, cucumber, rockmelon and watermelon was examined in the field where marketable fruit production was most affected in Cucurbita maxima and C. pepo, moderately in C. melo and Citrullus lanatus and least in C. moschata and C. sativus. One instance of ZYMV seed transmission in C. pepo and transmission by Aphisgossypii was demonstrated. Resistance breeding progress with C. maxima using a C. ecuadorensis source and in C. lanatus using Citrullus sp. cv. Egusi is reported. Virus purification was achieved using carbon tetrachloride and Triton X-100 clarification with sucrose pad and gradient centrifugations. An antiserum was produced and reacted well in agarose gel-diffusion tests without prior virus particle disruption.
N2 fixation and its value to soil N increase in lupin, field pea and other legumes in south-eastern Australia
Authors: Evans J , O'Connor GE , Turner GL , Coventry DR , Fettell N , Mahoney J , Armstrong EL , Walsgott DN
Published: November 2004

N2 fixation and its potential contribution to increasing soil total N were estimated in field-grown crops of lupin and pea in 21 trials at 10 locations in New South Wales and Victoria, during 1984 to 1987. Chickpea, faba bean and annual medic were included at some sites. Across experiments there were differences in annual rainfall (267 to 646 mm), soil N (0.02 to 0.20%), soil pH (CaCl2,4.3 to 8.0) and sowing date (24 April to 16 June). Most experiments were conducted on acidic (pH < 4.8) red-earth, the others on grey-cracking clay or sandy soil, both of higher pH The differing sites, seasons, and sowing time contributed to variation in legume biomass (2.02 to 14.33 t/ha) and total N (45 to 297 kg N/ha), and the amount of N harvested with grain (8 to 153 kg N/ha), which were related.Lupin fixed an average of 65% of total crop N, and pea 61%, but there was considerable variation about these averages (20 to 97%). Significant differences in % N2 fixation between legumes within sites were few. The amount of N2 fixed averaged 98.5 kg N/ha by lupin and 80.5 kg N/ha by pea, varying 26 to 288 kg N/ha and 16 to 177 kg N/ha, respectively. Variation in proportional and total N2 fixation was associated with biomass, soil mineral N, and sowing date. N2 fixation increased with more biomass and declined with higher soil mineral N, and later sowing (lupin). Each additional tonne of dry matter increased fixed N by c. 20 kg N/ha. Differences in amounts of fixed N between legumes within sites were due primarily to biomass differences.N2fixed by lupin contributed an average of 38.2 kg N/ha to soil N, and by pea, 17.9 kg N/ha. The contribution was variable, -41 to 135 kg N/ha (lupin) and -32 to 96 kg N/ha (pea), and correlated with proportional and total N2 fixation. Positive increase to soil total N occurred when lupin fixed at least 50% of its crop N, and pea 65%. This occurred in most crops. Legumes frequently used less of the available soil N than cereals.
Variation in turf-type morphological characters within Lolium perenne L. cv. Victorian
Authors: Rogers ME
Published: November 2004

Aspects of plant morphology and flowering were measured in a spaced-plant collection of perennial ryegrass (Lolium perenne L.) cv. Victorian in order to assess the possibility of improving this cultivar for turf. The Victorian perennial ryegrass collection was also compared with a smaller collection of fine-leafed turf ryegrasses. Within cv. Victorian, positive phenotypic correlations were found betwecn the character�s leaf length and width, leaf length and sheath length, leafwidth and sheath length, leafwidth and leaf tensile strength, and leafiness (leaf number per unit ground area) and angle of growth. The correlated responses to selection were significant (P<0.001) for all characters, with the exception of heading date. Heritability values, calculated by using three methods, were also very high (>0.70). These heritabilities, combined with the fact that the variation found within Victorian ryegrass often encompassed the entire range in the turf ryegrass cultivars, indicate that an improved turf-type could be developed within cv. Victorian. However, some compromise must be made in selection strategies due to unfavourable correlations between the character's turf wear, assessed by using leaf tensile strength and appearance, and between vegetative growth and seed production.
Integrated control of pink root (Pyrenochaeta terrestris) of onions by dazomet and soil solarization
Authors: Porter IJ , Merriman PR , Keane PJ
Published: November 2004

At Frankston in southern Victoria in 1984-85, dazomet applied at 750 kg/ha either alone or in combination with solarization, reduced disease incidence and severity of pink root, increased yields by at least 100% and improved storage quality of onions. Solarization for 6 weeks delayed the development of pink root, but had no effect on either the disease incidence or severity at harvest. Solarization, however, did increase yields by 23% at harvest compared to untreated soils.A bioassay of 0-10 and 10-20 cm layer of soil after treatment showed that dazomet applied alone or in combination with solarization reduced the number of plants infected by P. terrestris to less than 5% in both layers. Untreated and solarized plots had more than 86% of the plants affected. A similar bioassay taken 3 months later just before sowing showed that the number of plants infected with pink root had increased in the 0-10 cm layer of plots treated with dazomet, indicating that some reinfestation had occurred. There was no reinfestation in the combined treatment.Fusurium spp. were isolated from almost 100% of roots sampled, and although more than 70% were pathogenic under controlled conditions in the glasshouse, they did not appear to cause disease in the field or significantly affect yields.Cultivation of soils after harvest in 1985 and remoulding seedbeds prior to sowing the next crop apparently caused reinfestation of soils, and there was no residual benefit from treatments applied in 1984.
Wool growth and sulfur amino acid entry rate in sheep fed roughage based diets supplemented with bentonite and sulfur amino acids
Authors: Fenn PD , Leng RA
Published: November 2004

In two experiments, sheep were offered a roughage-based diet supplemented with either cysteine or bentonite as a solid, or bentonite, cysteine or methionine added to their drinking water. Supplementation with cysteine as a solid had no effect on wool growth, while supplementation via drinking water had no effect on wool growth or cysteine entry rate into the blood. Supplementation with methionine via drinking water increased the entry rate of methionine into blood by 69% (P< 0.05) as measured by a continuous infusion of [35S]-methionine. This coincided with subsequent increases in wool growth of 16% (P< 0.05) compared to sheep fed a basal diet alone. Compared with the basal diet alone, supplementation with 30 g/day bentonite as a dry powder or 60 g/day as a suspension in drinking water increased wool growth by 19 and 20% respectively. Bentonite given as sole supplement did not increase the entry rate of either cysteine or methionine into the blood of sheep. When bentonite and sulfur amino acids were complexed or mixed, wool growth was not increased above that for bentonite or the amino acid alone.
Nodulation and early growth of faba bean (Vicia faba L.) and pea (Pisum sativum L.) as affected by strain of Rhizobium, NO3- supply, and growth temperature
Authors: Herdin a , Silsbury JH
Published: November 2004

The effectiveness of each of two strains of Rhizobium, TA 101 and SU 39 1, on 'Fiord' faba bean and on two cultivars of pea 'A102' and 'Early Dun', was estimated in pot experiments. Plants were grown either without NO3- or with up to 7.5 mM NO3- and at 10, 15, and 20�C to assess the effects of mineral nitrogen and of temperature on plant growth, nodulation, and nitrogen fixation (acetylene reduction).The strains TA 101 and SU 391 were slow to nodulate 'Fiord' faba bean (up to 50 days from sowing) but were rapid (20 days) on pea. TA 101 nodulated the pea cultivar 'A 102' significantly better than it did 'Early Dun', and was generally more effective in supplying N to its host than was SU 391 in the absence of NO3-.Nodule development in 'Fiord' inoculated with SU391 was slightly stimulated in the presence of 2.5 mM NO3-, which compensated for the poor early seedling growth which occurred when plants were grown without mineral nitrogen. Both 5.0 and 7.5 mM NO3- delayed nodulation, decreased nodule number and decreased nodule activity of 'Fiord'. NO3- also had a strongly depressive effect on nodulation and nodule activity of pea but strongly promoted plant growth.Seedling growth and nodulation were poorer at 10�C than at either 15 or 20�C in both faba bean and pea. Nodulation of 'Fiord' was markedly reduced by the low temperature, and it appears likely to be slow in the field when the soil temperature is low (10�C) as may occur after late sowing. The known yield advantage of early planting of this cultivar may in part be due to better nodulation under warm (15�C) soil conditions. It is concluded that strains TA 101 and SU 391 are not very effective on 'Fiord' faba bean, although poor seedling growth due to poor nodulation with these inoculants may be compensated for by soil mineral nitrogen. Concentrations of soil NO3- equivalent to 2.5 to 5.0 mM, however, may depress the capacity of both faba bean and pea to fix nitrogen in the field.