bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the control of water-dropwort (Oenanthe pimpinelloides) in South Australia
Authors: Mitchell GJ , Carter RJ , Chinner SR
Published: March 2005

Water-dropwort (Oenanthe pimpinelloides L.), a tuberous perennial herb, is currently known in South Australia from only a single locality in the Mount Lofty Ranges. There is little information on water-dropwort control, and 2 experiments were conducted to assess the effects of sowing pasture, with or without presowing herbicides, on the control of this weed. Phalaris (Phalaris aquatica L.) and perennial clovers were successfully introduced into infested pastures by direct drilling in autumn. Water-dropwort regenerated from seed more densely in unsown plots than plots of established perennial pasture, suggesting that upgrading pastures may be a strategy to reduce the rate of spread by seed of this weed. A range of herbicide treatments applied to waterdropwort at the stem elongation stage in spring before autumn sowing of pastures provided effective shortterm control. The best short-term control was provided by glyphosate at 1440 g a.i./ha; metsulfuron methyl at 6, 12, and 36 g a.i./ha; and metsulfuron methyl at 12 g a.i./ha tank-mixed with glyphosate or 2,4-D amine at 720 or 1000 g a.i./ha, respectively. These treatments, and chlorsulfuron at 21 g a.i./ha, also significantly (P<0.05) reduced water-dropwort abundance (relative to untreated areas) for up to 18 months after sowing and initially improved the density of sown pasture species, but these improvements were not evident 14 months after resowing. Although prior season herbicide treatments controlled water-dropwort in newly sown pastures, 2 separate applications of herbicides, in May and October, gave no better control of water-dropwort than a single herbicide application in spring. Water-dropwort infestations do not appear to prevent successful direct drilling of phalaris and perennial clovers. Although pasture renovation did not provide long-term suppression of water-dropwort, the maintenance of vigorous pastures may reduce the rate of population growth from seedlings of this weed. Recropping restrictions may limit the role of chlorsulfuron for water-dropwort control in pasture renovation situations.
Three metalaxyl sensitivity levels in Australian isolates of Pseudoperonospora cubensis (Berk. et Curt.) Rost
Authors: O'Brien RG , Weinert MP
Published: March 2005

Isolates of Pseudoperonospora cubensis from the Murrumbidgee Irrigation Area (MIA), New South Wales, and the Burdekin district, Queensland, were compared for metalaxyl sensitivity with a known sensitive isolate. Several different fungicide application techniques were used (foliar sprays, soil drenches, floating leaf discs), but the relativity of metalaxyl sensitivity between isolates was maintained. Isolates from the Burdekin district were highly resistant and came from fields where control of downy mildew was poor. Isolates from the MIA showed intermediate sensitivity but there was no apparent loss of field control. In a floating disc experiment the EC50 values of sensitive, intermediate, and resistant isolates were in the ranges >0.01-<0.1, >1-<10, and >100 �g metalaxyl/mL, respectively.
Use of intramuscular oxytocin injections to measure milk output in nondairy sheep, and its effect on milk composition
Authors: Bencini R
Published: March 2005

This paper describes a double Latin square design experiment to determine the effect of various doses of oxytocin injected intramuscularly in nondairy ewes on the induction of milk ejection and milk composition. Eight New Zealand Romney ewes without experience as dairy sheep were injected intravenously with 1 IU synthetic oxytocin and machine-milked to empty their udders. After 4 h, the procedure was repeated using 0, 1, 5, or 10 IU oxytocin in I mL sterile saline solution, this time injected intramuscularly. All doses of oxytocin significantly (P<0.01) increased the amount of milk at the second milking, and there was no difference between 1, 5, and 10 IU. Only the 10 IU treatment affected the composition of the milk: fat concentration was increased from an average of 5.2 to 6.4% (P<0.05). It was concluded that 1 IU of oxytocin injected intramuscularly is adequate to obtain milk withdrawal and that the composition of the milk is not affected provided the dose injected is <5 IU.
Nature and magnitude of soil erosion in sugarcane land on the wet tropical coast of north-eastern Queensland
Authors: Prove BG , Doogan VJ , Truong PNV
Published: March 2005

This paper reports measures of soil erosion in sloping sugarcane land under conventional cultivation and various no-tillage surface management techniques and explores the reasons for the differences measured. Soil erosion from conventionally cultivated ratoon cane lands was measured in the range 47-505 t/ha.year, with an average annual loss of 148 t/ha.year. No-tillage practices reduced this erosion to <15 t/ha.year. Groundcover did not affect soil erosion significantly. In the absence of hydrological data, it is anticipated that consolidation of the soil surface at harvest, rather than ground surface cover, is the dominant factor reducing soil erosion. The effect of groundcover on soil erosion is less than the accuracy of the measurement techniques employed (� 20 t/ha.year). Physical and chemical analyses of in situ and eroded soil indicate that sediment from the no-tillage practice may be transported further from the erosion site and carry a more mobile fraction of nutrients.
Carcass and meat quality of second-cross cryptorchid lambs grazed on chicory (Cichorium intybus) or lucerne (Medicago sativa)
Authors: Hopkins DL , Holst PJ , Hall DG , Atkinson WR
Published: March 2005

The meat quality of cross-bred cryptorchid lambs (6 months old) that had been grazed on chicory (Cichorium intybus; n = 20) or lucerne (Medicago sativa; n = 20) for 8 weeks preslaughter was studied. Unfasted preslaughter liveweight (range 42.5-51.5 kg) was not affected (P>0.05) by treatment. There was no difference (P>0.05) between groups for age at slaughter, hot carcass weight, or measures of fatness GR and Fat C (fat depth over longissimus thoracis et lumborum) when adjusted to a common carcass weight of 21.9 kg. Lucerne-fed lambs were, however, significantly (P<0.05) fatter at the 5th rib. There was no significant (P>0.05) difference between groups for pH, colour values (where L* indicates relative lightness, a* relative redness, b* relative yellowness), Warner-Bratzler shear values, or cooking loss. There was no significant (P>0.05) difference between groups for mean fat colour score or for the distribution of the scores. The b* values for subcutaneous fat tended (P = 0.06) to be greater for lucerne-fed lambs. A comparison of the mean values for aroma and flavour of the longissimus thoracis et lumborum showed no significant (P>0.05) difference between groups and no difference in overall acceptability. Finishing lambs on the chicory cultivar used in this experiment did not adversely affect meat quality and did not result in fatter carcasses than lucerne-fed lambs.
Variation in pathogenicity and virulence of Phytophthora clandestina on four cultivars of subterranean clover
Authors: Purwantara A , Flett SP , Keane PJ
Published: March 2005

The pathogenicity of 6 isolates of Phytophthora clandestina on seedlings of 4 cultivars of subterranean clover was studied. There was a highly significant isolate x cultivar interaction in pathogenicity tests on axenic seedlings and seedlings grown in pasteurised potting mix or untreated sandy loam soil, indicating the existence of race-cultivar specificity. The isolates showed differences in virulence against the cultivars. Three isolates (race 0) caused severe disease only on Woogenellup; 2 isolates (race 1) caused severe disease on Larisa, Trikkala, and Woogenellup, but not on Meteora; one isolate (race 2) caused severe disease on Meteora and Woogenellup, but not on Larisa and Trikkala. As well as differing in virulence (the ability of a race to attack a range of cultivars), the races also differed in their aggressiveness on Woogenellup, with race 2 being the most, and race 0 the least, pathogenic. The isolates varied in their growth rate on agar medium, but this was not related to virulence or aggressiveness.
Use of a kernel milkline score to determine stage of maturity in maize crops harvested for silage
Authors: Havilah EJ , Kaiser AG , Nicol H
Published: March 2005

A scoring system based on the position of the boundary (milkline) between the solid starch phase and the liquid phase on the surface of the maize kernel was evaluated as an indicator of crop stage of maturity. Milkline score (MLS) varies from 0 when the kernel contents are all liquid and no milkline is visible to 5 when the kernel contents are all solid and grain filling is complete. The scoring sytem is continuous in intervals of 0.5 units. The MLS was linearly related to the dry matter (DM) content of the cro in experiments at Nowra (R2 = 0.72), Wagga Wagga (R2= 0.82), and Grafton (R2 = 0.65). The predicted dry matter content at MLS 2.5 was 34.2% at Nowra, 36.0% at Wagga Wagga, and 33.7% at Grafton. Under normal seasonal conditions, milkline scoring can be used by farmers to help decide when their crops are ready for harvest. Crop DM is optimal for silage productions when MLS is in the range 2-3. However, the technique may not be reliable with severely stressed crops. Sampling 10 cobs from an area of 0.25 ha gave a 95% confidence of detecting the MLS with a precision � 0.37 unit. At Nowra the milkline moved down the kernel at a rate of 1 MLS unit/9 days. This rate may be different in other environments. At the same site there was a significant (P<0.05) quadratic relationship between milkline score and DM yield, with maximum yield obtained at MLS 3.4. However, this relationship accounted for only 16.76% of the variation, and clearly, other factors influenced DM yield.
Climatic risk to peanut production: a simulation study for Northern Australia
Authors: Meinke H , Hammer GL
Published: March 2005

A dynamic peanut simulation model was used to quantify climatic risk to peanut production in Northern Australia. We demonstrate how district yield information can be usefully combined with simulation results to assess objectively impact and causes of climatic variability on production. Our analysis shows that the rapid expansion of the peanut industry in the region corresponded with relatively stable, above average yields caused by that period in the historical record having above-average and less variable summer rainfall. During this period the timing and amount of rainfall was such that yields higher than average could often be achieved, and harvests were only rarely interrupted by prolonged wet periods. These conditions created unrealistically high expectations of yields by producers, and when the climate was more variable during the 1980s, it was perceived as a greater deviation from the norm than justified by the long-term record.
A comparison of three fallow management strategies for the long-term productivity of wheat in northern New South Wales
Authors: Felton WL , Marcellos H , Martin RJ
Published: March 2005

Four experiments were commenced after a 1980 wheat crop, and a fifth after the 1981 crop, at different sites representing the major soil types of northern New South Wales in the 550-700 mm rainfall zone, to examine the influence of 3 fallow management practices [no tillage (NT); stubble retention after harvest, cultivation (SM); stubble burning after harvest, cultivation (SB)] on wheat production. Data considered in this paper cover the continuous wheat subtreatments of the 5 experiments (1981-90). Nitrogen applied at 50 kg Nlha in addition to the basal treatment was included as a treatment from 1986 to 1988. Across all sites and seasons, grain yields were in the order SB>SM = NT, stubble retention having a greater effect than tillage. In some years at some sites, differences in grain yield and grain N yield were not significant. In others, when significant yield differences occurred, variations in grain yield and grain N yield were highly correlated with differences in soil N available for the crop. The data show that the influence of fallow management interacted with season and crop nutrition, and required long-term study for proper assessment.
Some advantages of long-term grazing trials, with particular reference to changes in botanical composition
Authors: Jones RM , Jones RJ , McDonald CK
Published: March 2005

Comments are made about some advantages of long-term grazing trials, with special reference to the fact that important botanical changes may occur only after many years, sometimes with subsequent changes in animal production. Rainfall variability is a major reason for these delayed changes, but other factors such as changing soil fertility, longevity of individual plants, and the cumulative effect of stocking rates are involved. The need for trials to document the long-term effect of treatments on botanical change is in conflict with the current (1995) trends for research funding to be directed towards shorter term projects; and yet, botanical change is an important component of sustainability, which is currently accorded high priority. Various ways of addressing the problem of predicting long-term botanical change are discussed, including the use of modelling. Suggestions are made about ways in which long-term grazing trials can be made more effective. Extensive 'on-farm' surveys, provided the pastures concerned are in widespread commercial use, may be a partial alternative to grazing trials.
Runoff and soil loss from long-term tillage treatments under natural rainfall
Authors: Barker PJ
Published: March 2005

No abstract available.
Performance of crossbred progeny of Trangie Fertility Merino and Booroola Merino rams and Poll Dorset ewes. 1. Lamb birth weight, survival and growth
Authors: Hall DG , Fogarty NM , Gilmour AR
Published: March 2005

Merino rams of the Trangie Fertility and Booroola strains were joined to Poll Dorset ewes in single sire mating groups over 3 years. Forty sires produced a total of 1250 lambs in 885 litters from 451 ewes. Lamb birth weight averaged 4.1 kg, 80.8% of lambs survived to 3 days of age and growth rates to weaning (mean 93 days) averaged 289 g/day. Lambs with Trangie Fertility sires grew 15 g/day faster and were 1.3 kg heavier at weaning than those lambs with Booroola sires (P<0.001). There were no effects of sire strain on birth weight or lamb survival. Birth weight increased with dam liveweight in mid-pregnancy (P<0.001), and weaning weight and growth rate increased with dam liveweight at joining (P<0.001). Survival of lambs was predominantly a function of birth weight. Lambs weighing 4 kg at birth from primiparous dams had survival rates of 76% compared with 88% for lambs from multiparous dams (P<0.01). No lamb under 2.0 or over 6.3 kg survived, and 48% of deaths occurred within 1 day of birth. Dystocia, particularly of heavy, single-born lambs, caused 53% of observed lamb deaths. For the traits birth weight, lamb survival, weaning weight and growth rate, the direct heritabilities were 0.24 � 0.10, 0.05 � 0.05, 0.19 � 0.10 and 0.12 � 0.08 respectively; the corresponding maternal heritabilities were 0.08 � 0.05, 0.05 � 0.04, 0.05 � 0.05 and 0.07 � 0.05 respectively; and the common environmental effects among litter mates (c2) were 0.57 � 0.08, 0.47 � 0.08, 0.15 � 0.08 and 0.13 � 0.08 respectively.
Performance of crossbred progeny of Trangie Fertility Merino and Booroola Merino rams and Poll Dorset ewes. 2. Reproductive activity, liveweight and wool production of ewe lambs
Authors: Fogarty NM , Hall DG , Gilmour AR
Published: March 2005

Liveweight, wool production, oestrous expression and ovulation rates of 260 Trangie Fertility Merino x Dorset (TD) and 278 Booroola Merino x Dorset (BD) ewes born in late winter-spring over 4 different years were analysed from post-weaning to first joining at about 19 months of age. The percentage of ewes expressing oestrus reached a peak of 68% in May-June, declined to 7% in September and rose to 93% in January prior to first joining. The proportion of ewes ovulating followed a similar pattern. The proportion of ewes expressing oestrus in March, May and June increased (P<0.001) substantially with increasing age and liveweight, which accounted to some extent for the large differences in oestrous activity between years. There was little difference between the strains in proportion of ewes expressing oestrus or ovulating throughout the year. TD ewes were heavier (P<0.001) than BD ewes, the difference increasing from 2 to 4 kg at 7 and 19 months. They also produced 0.3 kg more clean wool which had 1.2 pm higher fibre diameter (P<0.001). Ovulation rate, measured in each of 2 years at 2-monthly intervals, increased from 7 to 19 months of age. BD ewes had a higher ovulation rate than TD ewes on all occasions, and the difference averaged +0.4 ovulations. The mean ovulation rate in February (19 months) for ewes born over 3 years was 2.1 ova for BD and 1.4 ova for TD ewes (P<0.001). Based on subsequent ovulation rate and litter size records, 42% of the BD ewes were identified as carriers of the FecB gene. Ages at first oestrus and ovulation varied considerably between years (P<0.001). There was no difference between the strains in age at first oestrus, although BD ewes first ovulated at a younger age (P<0.05) than TD ewes. The stud of origin of the dam, dam age, dam parity and birth type were not significant for any reproduction trait. There was significant (P<0.001) variation in liveweight due to the origin of the dam. Half-sib estimates of heritability for ewe liveweight, ovulation rate at various seasons and wool production traits were generally high with relatively high standard errors as they were based on 23-40 degrees of freedom for sire.
Variation among low rainfall white clover (Trifolium repens L.) accessions for morphological attributes and herbage yield
Authors: Jahufer MZZ , Cooper M , Lane LA
Published: March 2005

The importance of passport data on rainfall at collection sites of accessions as a guide to identifying germplasm to be used in the genetic improvement was assessed by using 40 white clover accessions from the germplasm collection at Glen Innes, New South Wales. This set together with 2 standard cultivars, Haifa and Huia, were evaluated in the field. The objectives were to: (i) estimate the magnitude of genotypic variation among accessions for morphological attributes and herbage yield in a dryland summer rainfall environment; and (ii) compare estimates of genotypic variation for, and correlations among, the attributes and herbage yield for the 40 accessions with results from a study based on a random sample of accessions from the same collection. Herbage yield was measured in 4 seasons (autumn 1992-summer 1993) together with stolon and other plant attributes which were measured in 1 season (summer 1993). There was significant (P<0.05) variation for herbage yield among accessions. Hierarchical agglomerative classification was used to group the accessions based on herbage yield. This identified a single member group with greater herbage yield than the 2 groups which contained the cultivars Haifa and Huia. There was no association between the composition of the accession groups identified by classification and the passport data on average annual rainfall at the collection sites of accessions. There was some consistency between the estimates of repeatability, genotypic variation and genotypic correlations obtained from the low rainfall set of accessions used in this study and the random sample previously examined. It was concluded that selection of accessions from the collection for use in genetic improvement of herbage yield and the morphological attributes for dryland summer rainfall environments of the Northern Tablelands of New South Wales. should not be confined to specific groups originating from low rainfall regions.
Seed softening patterns from single seed crops of subterranean clover (Trifolium subterraneum L.) in a cool temperate environment
Authors: Evans PM , Hall EJ
Published: March 2005

An experiment was set up in northern Tasmania with 7 cultivars of subterranean clover widely ranging in maturity and levels of hardseededness. They were planted as pure swards and in a mixture with perennial ryegrass. After seed set in the first year, all seedling regenerations were counted and then killed, and seed populations were measured each summer for 6 years. No significant differences in seed losses existed between the pure swards and the mixtures or between cultivars. Negative exponential functions of the relationship between seed banks and time fitted the data well with r2 ranging from 0.87 (Nungarin) to 0.998 (Trikkala). By mid-summer of the sixth year the percentages of the original seed left in the ground were: Enfield 12%, Woogenellup 19%, Trikkala 20%, Nungarin 21%, Larisa 24%, and Karridale and Mt Barker 31%. Seeds at higher latitudes were lost at about half the rates experienced at lower latitudes with drier, hotter summers. The higher percentages of seed remaining in plots with later maturing cultivars suggest that environmental conditions favoured the production of hard seeds while the reverse was the case with very early, hardseeded cultivars like Nungarin.
Annual ryegrass and volunteer cereal control in lupins using selective post-emergent herbicides
Authors: Chambers A , Code G , Scammell G
Published: March 2005

The relative effectiveness of herbicides from the aryloxyphenoxypropionate (fop) and cyclohexanedione (dim) chemical families for the control of volunteer wheat (Triticum aestivum L.), oats (Avena sativa), triticale (Triticum x Secale) and annual ryegrass (Lolium rigidum Gaud.) in narrow-leafed lupins (Lupinus angustifolius) were evaluated over a 3-year period near Rutherglen in north-eastern Victoria. Herbicides tested included diclofop-methyl, fluazifop-pethyl, haloxyfop, propaquizafop, quizalofop-p-ethyl, clethodim, cycloxydim, sethoxydim, and mixes of fluazifop-p-ethyl + diclofop-methyl, and fluazifop-pethyl + sethoxydim. Effective grass control needed to prevent disease carryover is defined as greater than 98%. Haloxyfop at 78 g a.i./ha and clethodim at 120 g a.i./ha consistently gave greater than 98% control of all target species. Quizalofop-p-ethyl at 12 g a.i./ha gave greater than 98% control of volunteer cereals but annual ryegrass control ranged from 83.7 to 44.1%. Cycloxydim at 100 g a.i./ha produced similar oat and ryegrass control to that of 563 g a.i./ha diclofop-methyl. Sethoxydim at 93 g a.i./ha, gave significantly (P < 0.05) better control of annual ryegrass than the recommended rates of diclofop-methyl, fluazifop-p-ethyl and propaquizafop. The addition of 47 g a.i./ha sethoxydim to 32 g a.i./ha fluazifop-p-ethyl significantly improved ryegrass control than low rates of fluazifop-p-ethyl alone.
Site preparation for Pinus establishment in south-eastern Queensland. 2. Effect of cultivation and cultivation width on growth
Authors: Costantini A , Podberscek M , Nester MR
Published: March 2005

The standard site preparation practice used for Pinus plantation establishment on well-drained soils in south-eastern Queensland is blade (subsurface, wing rip) cultivation to a width of 2.0 m and a depth of 0.2 m. This operation requires high drawbar power and is difficult to achieve in high strength soils, or in soils where roots and stumps hinder progress of the blade through the soil. The aim of the study reported in this paper was to better define cultivation growth relationships for Pinus caribaea var. hondurensis plantations in order to determine if site preparation objectives could be achieved with a reduced cultivation effort. A highly significant 'soil type x cultivation' interaction was observed. In contrast to the growth responses observed on hardsetting soils, cultivation did not improve growth on non-hardsetting soils. There is an opportunity therefore to reduce reforestation site preparation costs by only cultivating soils that show a growth response. The cultivation response on hardsetting soils has increased throughout the study period, and is attributed to a reduction in soil penetration resistance. The response however shows diminishing gains with increasing cultivation widths. Blade cultivation widths of 1.2 m were found to capture 97% of the gains that could be expected from widths of 2.0 m. A significant 'family x soil penetration resistance' interaction was observed. An opportunity to increase plantation productivity by targeting better performing families to hardsetting soils is suggested.
Growth and forage intake of Hereford steers fed giant Parramatta grass hay (Sporobolus indicus) and the effects of dietary nitrogen supplements
Authors: Mears PT , Hennessy DW , Williamson DW , McLennan DJ
Published: March 2005

Giant Parramatta grass (GPG) (Sporobolus indicus var. Major), a serious weed of pastures of subtropical Australia, is poorly grazed by cattle leading to reports of low production on badly infested pastures. To provide information for cattle producers we recorded feed intake and liveweight change of steers in a 56-day study, and nitrogen (N) excretion over 5 days when GPG was fed as hay. Data were compared with those for GPG hay supplemented with urea (7 g urea/kg hay), or with urea and cottonseed meal (CSM; 750 g/steer.day), and with those for steers fed a native pasture (NP) hay, which included a legume (Aeschynornene falcata). Each steer was also fed daily a mixed mineral supplement of 35 g sprinkled on the hay. Urea increased (P<0.01) daily GPG hay intake from 4.2 to 5.0 kg/steer, but there was no significant increase in intake (4.5kg/steer) when CMS was included. Steers on NP hay had a mean daily intake of 5.1 kg/steer which was similar to that of steers offered GPG hay + urea. Urea increased daily liveweight gain from 323 to 555 g/steer (P<0.05); the addition of CSM further increased (P<0.05) the gain to 676 g/steer. Steers on NP hay had a mean daily liveweight gain of 480 g/steer. The gain for steers offered CSM with GPG hay + urea was higher than that predicted by GrazFeed (1993) for a low digestible, low NP hay, supplemented with urea and CSM. Improved production of steers through using nitrogen supplements, may provide an opportunity for cattle to use this weed as a hay or silage in pastures as part of a program to control weed ingress in subtropical pastures.
The performance of Brahman-Shorthorn and Sahiwal-Shorthorn beef cattle in the dry tropics of northern Queensland. 5. Scrotal circumference, temperament, ectoparasite resistance, and the genetics of growth and other traits in bulls
Authors: Fordyce G , Howitt CJ , Holroyd RG , O'Rourke PK , Entwistle KW
Published: March 2005

The genetics of growth to 24 months, scrotal circumference (SC) at 24 months and temperaments at 6, 12 and 18 months in 7 year groups of F2 et seq., 1/2 Brahman, 1/2 Sahiwal, 3/4 Brahman and 3/4 Sahiwal bulls were investigated in the dry tropics of northern Queensland. Cattle tick (Boophilus microplus) and buffalo fly (Haematobia irritans exigua) resistance were also assessed at 24 months. Scrotal circumference at 24 months was highest in 1/2 Sahiwal crosses (28 cm v. 26-27 cm; P<0.05) with pronounced variation between years (24-31 cm; P<0.05). Temperaments (TEM score; flight distance) were generally poorest in 3/4 Sahiwal crosses (P<0.05). Bulls of 1/2 Bos indicus content were twice as susceptible as 3/4 crosses to tick infestations (P<0.05). There were no genotype differences in natural buffalo fly infestations. Temperaments, tick resistance and buffalo fly resistance all had no consistent significant relationships with either each other or with weights or growth rates to 24 months. Paternal half-sib estimates of heritabilities across all genotypes were generally moderate for weight (0.20-0.36), growth rates (0.08-0.46), and SC (0.32), low for TEM score (0.08-0.14), and high for flight distance (0.32-0.70). The genetic correlations (rG) between growth rates in both dry and wet seasons after weaning were high (>0.9); however, the rG of weaning weight with postweaning seasonal growth rates to 24 months were consistently negative (-0.09 to -0.71; P>0.05). The rG of SC with post-weaning growth rates were negative (-0.4 to -0.8). The rG of SC with weights up to 18 months were not significantly different to zero, but tended to be negative with weight at 24 months.
Breeding Australian crossbred ewes with Arabian fat-tailed rams for intensive lamb production
Authors: Malik RC , Razzaque MA , Abbas S , Al-Mutawa T , Al-Khozam N
Published: March 2005

The reproductive performance under intensive management of Border Leicester x Merino (BLM), Dorset x Merino (DM), and Suffolk x Merino (SM) ewes imported from Australia, and local fat-tailed Naeemi (N) ewes mated to N rams was studied. Progeny performance for birth and weaning weights, average daily gain (ADG) and preweaning survival was also evaluated. BLM ewes showed the highest reproductive performance. They produced and weaned (at 8 weeks) significantly more lambs (P<0.05) than any of the other ewe genotypes. The reproductive performance of the BLM, N, DM and SM ewes, mated twice, 8 months apart, was 127, 85, 91 and 85 respectively for percentage of lambs born to ewes joined, 109, 72, 77 and 70 respectively for percentage of lambs weaned to ewes joined, and 17.8, 13.5, 12.1 and 11.6 kg respectively of lamb weaned per ewe joined over the period of 13 months from the first joining until last lambs weaned. The effect of season on ewe reproduction was significant. Birth weight was not influenced by genotype or season but did change significantly with litter size. Genetic group, litter size, season of birth and birth weight were significant sources of variation in the ADG and weaning weight of the lamb. N x BLM lambs were weaned at significantly heavier weights than lambs of the remaining 3 groups. Season of birth and birth weight also significantly affected preweaning lamb survival. About 86% of the lambs born alive were weaned with little difference between genetic groups in survival rates.
Recovery of field-grown canola from sulfur deficiency
Authors: Hocking PJ , Pinkerton A , Good A
Published: March 2005

Sulfate-sulfur was applied to sulfur (S)-deficient canola at several growth stages in a field experiment at Cargo near Orange, New South Wales. Applications of 0, 10 or 40 kg S/ha (S0, S10 and S40) as mixtures of potassium sulfate and potassium chloride were made at sowing, the 5-6 leaf rosette stage, flower buds visible, stem elongation and first flowering. The plots received either 80 or 160 kg nitrogen (N)/ha at sowing. Plants from the S0 plots showed symptoms of severe S deficiency during rapid stem elongation, and had a 52% reduction in seed yield and a 21% reduction in seed oil concentration compared with the S40 plants. Application of S10 at sowing, or topdressing S-deficient plants with this rate of S, was inadequate because, although seed oil concentrations were normal (39-42%), seed yields were 25% lower than those from plots that received S40. Topdressing S-deficient plants with S40 at either the 5-6 leaf rosette stage, flower buds visible or stem elongation resulted in the same seed yields and seed oil concentrations as obtained when S40 was applied at sowing. However, there was a 15% reduction in seed yield but no reduction in seed oil concentration when the S40 topdressing was delayed until flowering. Although S10 was inadequate to correct the S deficiency, there was no reduction in either seed yield or seed oil concentration when S10 was topdressed as late as flowering, when compared with this rate of S applied at sowing. Seed meal protein levels were increased by the S40 topdressings. Concentrations of S in seed from the S0 and S10 plants were below the critical value of 0.36% for canola. Seed N:S concentration ratios of S-deficient plants were greater than 10, but 7.5 for plants which received adequate S. Total glucosinolates in seed were increased by the application of S, but the levels were still well below the limit set for the canola standard.
Supplementation of high fecundity Border Leicester x Merino ewes with a high protein feed: its effect on lamb survival
Authors: Hinch GN , Lynch JJ , Nolan JV , Leng RA , Bindon BM , Piper LR
Published: March 2005

Two hundred and fifty Border Leicester x Merino ewes (40% heterozygous for the Booroola Fec B gene) were used in an experiment, replicated over 2 years, to examine the effects of cottonseed meal-based supplementation on lamb survival, birth, marking and weaning weight, as well as, liveweight and fleece characteristics of ewes. From 50 to 100 days of pregnancy, half of the ewes were supplemented with 80 g/head.day. The supplemented group was then split according to litter size and, until 30 days after lambing, were offered pellets at 80, 160 and 220 g/head .day, respectively, for ewes bearing single, twin and triplet (or more) lambs. Over the 2 years, ewes averaged 2.11 lambs per parturition and supplementation significantly increased lamb survival to weaning (73 v. 58%) with no interaction with litter size. Although supplementation had a positive effect on birth weight of all but twins, the effects of supplementation on survival were independent of birth weight effects. Significant effects of year, sire breed and litter size on lamb survival and birth weight were also noted. No effects of supplementation were apparent on lamb growth while ewe age, sire breed, sex and rearing rank all significantly influenced growth rates. Ewe weights, fleece weights and staple strength were significantly influenced by year, ewe age and litter size but not by supplementation. These findings indicate the benefits to lamb survival of providing a 'bypass' protein supplement to high fecundity flocks even when ewes are grazing good quality pastures.
Perennial legumes for the high rainfall zone of eastern Australia. 2. Persistence and potential adaptation zones
Authors: Hill MJ , Mulcahy C , Rapp GG
Published: March 2005

Cultivars and accessions of a range of perennial legumes were evaluated in small plot field trials at 4 on-farm locations on the Northern Tablelands of New South Wales. Variable establishment from seed resulted in good stands at 2 sites, and moderate to poor stands at the other 2 sites. In spite of this, trends in behaviour of individual species were apparent even where stands were very poor. This was exemplified by the gradual improvement in frequency of Trifolium medium at the most montane site. Trifolium ambiguum and Coronilla varia were most persistent across all sites. Good stands of Lotus corniculatus, L. pedunculatus, T. pratense and Medicago sativa thinned out within several years with M. sativa most persistent. Astragalus cicer thinned out rapidly on the relatively acidic soils but maintained a good stand at 1 site on a deep, free-draining granite. From these results and known climatic responses, simple logical rules were constructed to predict potential legume adaptation zones for eastern Australia. The zones of adaptation for the range of species are compared with a nominal zone for T. repens to identify areas where legume persistence might be improved with additional species.
Growth, yield and neurotoxin (ODAP) concentration of three Lathyrus species in mediterranean-type environments of Western Australia
Authors: Siddique KHM , Loss SP , Herwig SP , Wilson JM
Published: March 2005

The growth, phenology, grain yield and neurotoxin (ODAP) content of Lathyrus sativus, L. cicera and L. ochrus were compared with a locally adapted field pea (Pisum sativum L.) to examine their potential as grain legumes in Western Australian farming systems. About 17 lines of each species were obtained from ICARDA, Syria, and grown at 3 agro-climatically different sites. In general, the 3 species were later flowering than field pea, especially L. cicera and L. ochrus; however, L. sativus was the last species to mature. The best Lathyrus lines produced biomass near flowering similar to field pea. At the most favourable site, grain yields were up to 1.6, 2.6 and 1.7 t/ha for L. sativus, L. cicera and L. ochrus respectively, compared with a field pea grain yield of 3.1 t/ha. There was considerable genotype and environmental variation in ODAP concentration in the seed. On average, the ODAP concentration of L. ochrus (6.58 mg/g) was about twice that of L. sativus, and L. cicera had the lowest ODAP concentration (1.31 mg/g). Given that Lathyrus spp. have not had the same breeding effort as field pea and other grain legumes in Australia, these results encourage further selection or breeding. In the shor-tseasoned, mediterranean-type environment of Western Australia, harvest indices and grain yields could be improved with early flowering. Low ODAP concentration should also be sought.
Effects of bunch trimming and double bunch covering on yield of bananas during winter in New South Wales
Authors: Johns GG
Published: March 2005

Bunch trimming (removal of male bud and several distal hands from bunches soon after flowering), and double covering (use of 2 bunch covers simultaneously) of banana bunches that emerge during winter in northern New South Wales could have the potential to increase the size, and hence grade and price of harvested fruit. Consequently bunches were either trimmed to 6, 8 or 10 hands or left untrimmed (male bud retained), and either single or double bunch covers were applied on a commercial plantation on 3 occasions during winter, and the effects on fruit size and quality were recorded. Bunch emergence to bunch harvest interval was reduced by an average of 5 days by bunch trimming. Finger length increased with increasing severity of bunch trimming, with the average length for the top 6 hands increased by 2.3% (P<0.01) for the 10-hand treatment to 6.1% (P<0.001) for the 6-hand treatment. Finger weight increased with increasing severity of bunch trimming, with weights for the top 6 hands increased by up to 14% (P < 0.001) on the 6-hand treatment. Double covering increased finger weight of the top 6 hands by 4% (P < 0.01). Trimming to 10, 8 and 6 hands increased the yield per bunch of extra large grade fruit by 18, 23 and 39% respectively. Double covering did not affect the yield of extra large fruit significantly. After excluding hands suffering from the mixed ripe condition, the 6-hand treatment yielded 51% more marketable extra large fruit than untrimmed bunches. Potential profitability of the treatments depended on price scenario. When prices were low the 6-hand treatment appeared most profitable, but at higher prices the 10-hand treatment would be preferable. Double covering appeared not to be worthwhile for all price scenarios used.
The role of limited oxygen supply and soil microorganisms on germination and survival of lupin seeds (Lupinus angustifolius L. cv. Gungurru) in waterlogged soil
Authors: Sarlistyaningsih L , Sivasithamparam K , Setter TL
Published: March 2005

The role of limited oxygen supply and soil microorganisms in the germination and survival of lupin seeds was studied in waterlogged soil and in solution culture at low oxygen pressures. Oxygen pressures in soil solutions decreased with time in all waterlogged soil treatments and in stagnant solution culture containing seeds. No seeds germinated in unsterilised waterlogged soil, but up to 95% of seeds germinated after 6 days in sterilised waterlogged soil. Germination and survival of seeds decreased significantly with time in solution cultures at 0 or 2 kPa O2, but remained high at 21 kPa O2. These solution culture studies confirmed that low oxygen supply in soil during waterlogging, which resulted mainly from activity of micro-oganisms, was the major factor causing the reduction in survival of lupin seed in waterlogged soil.
Influence of soil fumigation and seed tuber treatment on the control of Rhizoctonia solani on potatoes
Authors: Wicks TJ , Morgan B , Hall B
Published: March 2005

Five field experiments were conducted in South Australia to determine the effect of soil fumigation (metham sodium) and chemical and biological seed tuber dressing on the severity of Rhizoctonia solani on potato stems and tubers. These experiments indicated that both soil- and tuber-borne inoculum must be considered in any program aimed at controlling R. solani. Tuber treatments of either a 20 min dip in 2% formaldehyde, sprays with pencycuron (0.15 mL a.i./10 kg seed), iprodione (2 mL a.i.110 kg seed) or a spore suspension of lo6 spores/ml of Verticillium biguttatum or a dust with tolclofos methyl (4 g a.i.110 kg seed) were most effective if planted in soil fumigated with 500 L/ha metham sodium or soil with low levels of R. solani. A commercial formulation of Trichoderma harziannum and T. koningii applied as a dust at 1.3 g110 kg seed was in most cases ineffective when treated seed was planted into either fumigated or unfumigated soil. The incidence of progeny tubers with sclerotia varied between sites and ranged from 85% in an unfumigated soil planted with infected tubers to 2% in a fumigated soil planted with pencycuron-treated tubers. Except for 1 experiment where tubers were harvested early, neither seed treatments nor fumigation improved total nor marketable yield.
Effect of postharvest dipping in insecticides on the vase life of Geraldton waxflower
Authors: Seaton KA , Joyce DC
Published: March 2005

In postharvest dipping treatment of Geraldton waxflower (Chamelaucium uncinatum), 13 insecticides tested at recommended application rates caused no visual injury, but some reduced vase life. Flowers of cv. Purple Pride were more sensitive to insecticides than leaves. There was no loss of vase life of flowers following dipping in chlorpyrifos, dimethoate or permethrin. Following dipping in deltamethrin, carbaryl, dichlorvos, cypermethrin, endosulfan or fenvalerate there was 31-49% loss of vase life. No loss of vase life was observed for cv. Alba, after dipping in carbaryl, fenvalerate or dimethoate. Insecticide dips containing wetting agent and a fungicide (e.g. a combination of deltamenthrin, Aqua and benomyl) was a suitable dip for Geraldton waxflower. Wetting agents varied in their effect on vase life. Aqua shortened vase life less than Agral, and D-CTrate less than D-C-Tron. Stems rapidly lost weight when held out of water following dipping, and vase life was reduced when ambient temperatures were above 30�C or drying times exceeded 60 min. It was concluded that flowers should be kept cool and well hydrated following dipping treatment.
Edge row effects on yields in an oat trial
Authors: Barchia I , Cooper JL
Published: March 2005

Yield responses of oat (Avena sativa L.) genotypes to the presence of pathways between plots were examined in an irrigated field trial. Four replicates of 15 genotypes were sown in plots 18 m long, with 11 rows of plants. Yields were measured from the centre and both edge rows of each plot. Most genotypes yielded better in the edge rows than the centre row, but the extra yield gained from edge rows varied. Therefore, including edge rows into whole plot harvest when measuring the yield of cereal may bias genotype comparisons. The reliability of trial results could be improved by sowing wider plots and only harvesting the central section of each plot. Because differences in exposure to light seem to be a major factor in producing edge effects, orientating plots north-south would also be an advantage.
Response of narrow-leafed lupin (Lupinus angustifolius L.) to foliar application of growth regulators in Western Australia
Authors: Seymour M
Published: March 2005

Four experiments were conducted during 1991-93 in the south coastal and lakes regions of Western Australia, to test the hypothesis that foliar application of a range of growth regulators will improve the pod set and seed yield of narrow-leafed lupins (Lupinus angustifolius L.). The chemicals tested (not all in any 1 year) were: Cultar (250 g paclobutrazol/L), Pursuit (240 g imazethapyr/L), Cytokinin (21 g 6-benzyladenine/L), Legumex (400 g 2,4-DB/L), Cytolin (20 g gibberellins A4 and A7/L and 20 g 6-benzyladenine/L), Bladex (500 g cyanizine/L), Diuron 500F (500 g diuron/L), Lexone (750 g Metribuzin/kg), NAA (40 g 1-napthalene acetic acid/L), Pix (38 g mepiquat chloride/L), Gesatop 500 (500 g simazine/L), High Yield (unknown active ingredient), Lontrel (300 g clopyralid/L), a Cultar-Lontrel mix, and a Lexone-Brodal(500 g diflufenicad) mix. Chemicals were applied from as early as 6 weeks before flowering on the main stem to as late as flowering on the 1st-order branches. Any gross physical effects were visually assessed. Canopy height and components of yield were measured at some of the experimental sites. In 2 experiments, no chemical had any significant effect on seed yield (P>0.05). At the 2 remaining sites, Cultar, Lontrel, and the Lexone-Brodal mix increased seed yield of lupins by 230-250 kg/ha. Seed yield increases were related to improvements in pod set. No chemical had any significant effect (P>0.05) on dry weight production. Timing of application was critical, with application 6 weeks before flowering giving the most consistent positive responses.
Efficacy of the insect growth regulators tebufenozide and fenoxycarb for lepidopteran pest control in apples, and their compatibility with biological control for integrated pest management
Authors: Valentine BJ , Gurr GM , Thwaite WG
Published: March 2005

The insect growth regulators tebufenozide and fenoxycarb were compared with the industry standard organophosphate, azinphos-methyl, in a replicated field trial. In both the 1992-93 and 1993-94 seasons, the 2 insect growth regulators maintained damage levels to harvested and windfall apples below 1% for both codling moth (Cydia pornonella L.) and lightbrown apple moth (Epiphyas postvittana Walker). This was despite considerable pest pressure as indicated by pheromone trap catches of both species. In the first season of the trial, E. postvittana was controlled more effectively (P<0.05) by tebufenozide than by fenoxycarb. In both seasons, populations of two-spotted mite, Tetranychus urticae Koch, and European red mite, Panonychus ulmi Koch, were higher in plots under azinphos-methyl treatment than in either insect growth regulator treatment. Neither insect growth regulator appeared to suppress populations of the phytoseiids Typhlodromus pyri Scheuten and Typhlodromus occidentalis Nesbitt. Limb jarring in the second season showed statistically significant (P<0.05) differences in populations of other predators which may have contributed to the biological control of phytophagous mites in the insect growth regulator treatments. Numbers of spiders, Stethorus spp., and apple dimpling bug (Carnpylomma liebknechti Girault) nymphs were all lower in the azinphos-methyl treatment. Results are discussed in relation to reducing dependence on conventional pesticides by use of more target-specific compounds which may be more compatible with biological control.
Sowing time and tillage practice affect chickpea yield and nitrogen fixation. 2. Nitrogen accumulation, nitrogen fixation and soil nitrogen balance
Authors: Horn CP , Dalal RC , Birch CJ , Doughton JA
Published: March 2005

Following long-term studies at Warra, on the western Darling Downs, chckpea (Cicer anetinum) was selected as a useful grain legume cash crop with potential for improvement of its nitrogen (N) fixing ability through management. This 2-year study examined the effect of sowing time and tillage practice on dry matter yield, grain yield (Horn et al. 1996), N accumulation, N2 fixation, and the subsequent soil N balance. Generally, greater N accumulation resulted from sowing in late autumn-early winter (89-117 kg N/ha) than sowing in late winter (76-90 kg N/ha). The amount of N2 fixed was low in both years (15-32 kg N/ha), and was not significantly affected by sowing time or tillage. The potential for N2 fixation was reduced in both years due to high initial soil nitrate levels and low total biomass of chickpea because of low rainfall. Nitrogen accumulation by grain was higher under zero tillage (ZT) than conventional tillage (CT) for all sowing times, and this affected the level of grain N export. The consequence of low N2 fixation and high N export in chickpea grain was a net loss of total soil N, (2-48 kg N/ha under CT and 22-59 kg N/ha under ZT). Management practices to ensure larger biomass production and lower soil nitrate-N levels may result in increased N2 fixation by chickpea and thus a positive soil N balance.