bluuebunny/crossref_metadata_2025 huggingface dataset:
The effectiveness of several fertilizers in supplying sulfur to temperate pastures
Authors: Dear BS
Published: March 2005

Pastures on two contrasting soils, one a heavy-textured soil derived from basalt and the other, a light-textured soil from dacite, were treated with several sulfur fertilizers at a single rate of sulfur application (20 kg/ha). The fertilizers ranged from ammonium and calcium sulfates to forms of elemental sulfur, with a composite form (sulfur-fortified superphosphate) included. The dry-matter yield and sulfur concentration of the pasture were measured over three or four years, and the net recovery of sulfur from the various fertilizers was calculated. The most soluble source, sulfate of ammonia, was the most effective source of sulfur to the pasture on the heavy-textured soil, followed by the less soluble gypsum but this order was reversed on the light-textured soil, which may have lost sulfate by leaching. The two forms of elemental sulfur (prilled Agri-Sul and granular Foam S) were much less effective at both sites and sulfur-fortified superphosphate was of intermediate effectiveness. However, the effectiveness of the elemental forms was better sustained into the third year, indicating that less frequent application of such forms would be feasible, provided that much heavier initial rates were used.
Pasture, sheep and timber production from agro-forestry systems with subterranean clover sown under 15-year-old Pinus radiata by a method simulating aerial seeding
Authors: Anderson GW , Batini FE
Published: March 2005

A fifteen-year-old plantation of P. radiata at Mundaring, Western Australia, was thinned to densities ranging from 0 to 200 trees/ha, and pruned to 6 m. Subterranean clover cv. Seaton Park was sown with fertilizer by a method simulating aerial seeding. Pasture, sheep and tree growth and changes in soil and foliar nutrient levels were measured over a four year period. Clover establishment was most satisfactory. In the second year the pastures under tree densities of 150 or more trees/ha carried 60% of the numbers of sheep carried on the pastures with no trees. Two years later, following increased canopy growth and shading, this relative carrying capacity was down to 40%. After four years, soil and foliar nutrient levels were not affected by tree density. At the lowest density of trees (< 100 stems/ha), individual tree diameter growth and volume production per hectare were stimulated and there was least loss of agricultural productivity. This density was therefore preferable for agroforestry.
Lablab bean (Lablab purpureus) for grain and forage production in the Ord irrigation area
Authors: Wood IM
Published: March 2005

Grain and forage production of six accessions (Rongai, Highworth, T58/ 13, CPI 3 1 1 13, CPI 41 222 and CPI 60 216) of lablab bean (Lablab purpureus) were measured over two seasons in the Ord Irrigation Area. All accessions were quantitative short day plants, flowering during the early dry season (May-July). Forage yields at flowering were generally unaffected by sowing date for sowings made between December and February, but declined with later sowings. There were marked differences between accessions in the forage yield at flowering, and the peak yield of 8.6 t/ha was obtained with a December sowing of accessions T58/ 13; this comprised 3.6 t/ha of leaf containing 3.7% nitrogen and 5.0 t/ha of stem containing 1.1 % nitrogen. The uptake of nitrogen by the tops between sowing and flowering ranged up to 1.8 kg/ha.d (1 94 kg N in 108 days) indicating the potential value of lablab as a green manure crop. Grain yields ranged from 0.27 to 3.05 t/ha over all sowing dates and accessions with the peak yield being obtained in a February sowing of cv. Highworth. All accessions became smaller and bushier as sowing was delayed. This facilitated harvesting for grain. Cutting and removal of foliage at the onset of flowering led to rapid regrowth and renewed flowering, and gave grain yields up to 90% of those obtained from undefoliated treatments. The cultivar Highworth was best for grain production and for dual purpose forage and grain production.
Response of rapeseed (Brassica napus) to phosphorus, boron and lime on an acid soil near Canberra
Authors: Myers LF , Lipsett J , Kirchner R
Published: March 2005

The failure of a rape crop on a light-textured acid soil was investigated by a factorial field experiment with four rates of lime (0, 500, 1000 and 2000 kg/ha), four rates of phosphorus (0, 13, 28, 42 kg/ha) and, at stem extension, two levels of a boron spray (0, 0.6 kg/ha). The second crop failed in the same way as the first unless phosphorus was applied at sowing; the lowest rate was adequate, and higher rates did not increase the response. On the phosphate-treated plots the boron spray increased seed yield (measured on hand-harvested quadrats) substantially (75%) as the result of a small increase in flower number (32%) and a large increase in pod number (1 16%). Machine-harvested yields on the 'plus boron' plots were reduced by shattering and were 40% higher than controls (P<0.01). There was no response to lime applied one month before sowing and no interaction of lime with boron or phosphorus. The boron response was not lime-induced. The mechanism of the response to phosphorus and the questions raised by the lack of response in yield to lime in relation to aluminium and manganese toxicity were not resolved. The results indicate that phosphorus should receive at least as much attention as lime in the investigation of rape-growing on acid soils. Boron should also be investigated because of its important role in seed set of rape.
Seasonal changes in plasma testosterone concentration and mating activity in Border Leicester, Poll Dorset, Romney and Suffolk rams
Authors: D'Occhio MJ , Brooks DE
Published: March 2005

Seasonal changes in the plasma testosterone profile and mating activity were compared for Border Leicester, Poll Dorset, Romney and Suffolk rams (three of each breed) maintained under field conditions at latitude 35�S. Border Leicester, Romney and Suffolk showed maximum testosterone levels from February to May. Peak mating activity occurred from March to August, but the precise time and duration of the peak differed between the three breeds. A correlation (r = 0.65, P<0 .05) existed between seasonal changes in plasma testosterone and mating activity in Border Leicester but not in Romney or Suffolk. However, in all three breeds, peak testosterone levels preceded peak mating activity by 1-2 months. Poll Dorset rams showed an extended period of high testosterone levels from August to March but no seasonal peak in mating activity. There was no real relationship, in any breed, between plasma testosterone concentration and mating activity for individual rams within any month.
Seasonal changes in the plasma testosterone profile in Merino rams
Authors: D'Occhio MJ , Brooks DE
Published: March 2005

The pattern of testosterone secretion (i.e. profile of plasma testosterone sampled every hour for 24 h) was characterized for Merino rams at various times during the year at latitude 35�S to assess seasonal trends. The profiles of plasma testosterone were always characterized by random peaks regardless of season. However, at any particular time of the year, there were large differences between individual rams in the number of peaks124 h (range 1-7). Mean plasma testosterone levels were higher and a greater number of peaks were recorded per 24 h in summer (December-January) than in winter (July) and spring (September-October). Seasonal changes observed in the plasma testosterone profile of Merino rams were consistent with the concept that activity of the hypothalamic-pituitary-gonadal axis in sheep is entrained to changes in the photoperiod. Merino rams at latitude 35�S are therefore markedly seasonal from an endocrine point of view, although they are not generally regarded as seasonal breeders based on mating behaviour.
Correction - Resistance of lucerne lines at different stages of plant growth to spotted alfalfa aphid and blue-green aphid
Authors: Lloyd DL , Franzmann BA , Hilder TB
Published: March 2005

The relative resistances of lucerne (Medicago sativa) lines to the spotted alfalfa aphid (SAA) ( Therioaphis trifolii (Monell) f. maculata) and the blue-green aphid (BGA) (Acyrthosiphon kondoi Shinji) are generally assessed as seedlings and not as mature plants. To determine if the orders of resistances dre maintained, two separate glasshouse experiments assessed the relative resistances of 11 and 12 lucerne lines after infestation by SAA and BGA respectively at these stages: seedling, regrowth after cutting, and mature growth. Relative resistance between growth stages was compared by measuring aphid populations, percentage plant mortality and percentage yield reduction of surviving plants, and correlating the ranking for those indices. There was no change in the order of resistance to SAA between growth stages. Plants of both mature-age growth stages were, however, more tolerant of SAA than were seedlings. The technique employed in the experiment did not discriminate for resistance to BGA, though the yield of all lines was reduced by BGA. The implications of these findings are briefly discussed.
Extension of crop sowing time during dry weather by means of stubble mulching and water injection
Authors: Radford BJ , Nielsen RGH
Published: March 2005

The practices of stubble mulching and water injection were tested to determine what extension of crop sowing time they provided during dry weather at four sites on the Darling Downs, Queensland (Acland, Toowoomba, Moola and Dalby). Crops tested were wheat, sunflower, sorghum and maize. Crop residues (wheat, barley and sorghum) retained on the soil surface as mulches reduced soil water loss from the seedbed after prolonged soil drying. This resulted in a lower rainfall requirement to refill a mulched seedbed, despite some absorption of rainfall by the mulch itself. A lower rainfall requirement could make sowing possible on a mulched but not an unmulched seedbed, given a suitably marginal sowing rain. Higher soil water contents under mulch increased seedling emergence of wheat, sunflower, sorghum and maize after prolonged soil drying. This effectively extended sowing time. On the assumption that sowing time was the period that resulted in crop emergence > 50%, extensions of sowing time were determined from graphs of emergence vs time. For example, about 2000 kg/ha of wheat stubble at Acland extended the sowing time of sunflower (6 cm deep) by 4.0 d. Water injection at 60 ml/m extended sorghum, sunflower and maize sowing time by up to 2.5 d in dry soil but reduced sowing time of these three crops at high soil water levels (under mulch). It was concluded that the additional periods of sowing time obtained during dry weather from stubble mulching or water injection could help distribute the peak demand for labour during sowing operations more evenly.
Effect of seed hydration-dehydration pre-treatment on germination of soybean lines at sub-optimal temperatures
Authors: Bharati MP , Lawn RJ , Byth DE
Published: March 2005

The effect of temperature on germination and the effect of hydration-dehydration pre-treatments on germination at suboptimal temperatures were evaluated for several soybean (Glycine max) lines. Optimal temperatures for germination and hypocotyl-radicle elongation were ca. 31�C and 27-31�C respectively. Prior hydration at 31�C hastened rate of germination and/or synchronized germination within seedlots at 10�C, and in less vigorous seedlots, increased germinability. These effects were progressively dissipated by subsequent dehydration-storage treatments, a response more pronounced with dehydration at higher temperature, dehydration to original water content, and longer storage after dehydration. With less vigorous seedlots, germinability and/or rate of germination at 10�C after dehydration and storage were actually reduced relative to untreated seed. The effect of pre-treatment appeared due to both an increase in the rate of initial water uptake at suboptimal temperature, and to the more rapid activation of metabolic activity during germination. Although the effect of pre-sowing hydration per se on germination at suboptimal temperature was encouraging, the magnitude and unpredictability of the effect following dehydration suggest that the approach may have limited practical application in mechanized soybean production.
Tick infestations and their effects on growth of Bos indicus × Bos taurus cattle in the wet tropics
Authors: Mellor W , O'Rourke PK , Waters KS
Published: March 2005

The effects of bi-monthly dipping with Promacyl and no dipping on tick numbers and liveweight gain of young Bos indicus x Bos taurus cattle grazing tick infested improved pastures were compared in three experiments over three years at Utchee Creek, northern Queensland. Reduction in weight gains, due to ticks, of 24 and 30 kg (P<0.01) were measured over 11 and 17 months. Tick counts on undipped cattle were low (0-40/side) but rankings of tick counts on individual animals were repeatable (0.4-0.60). Liveweight gains of undipped cattle were unrelated (P> 0.05) to mean tick counts. When cattle were changed from an undipped to dipped treatment, they gained 18 kg more (P < 0.01) over six months than those changed from dipped to undipped. The latter groups carried more ticks than corresponding undipped cattle in the first two experiments.
The composition, fat distribution and yield of carcass beef from steers and heifers when entire, spayed, pregnant or fitted with an intravaginal device
Authors: Saul GR
Published: March 2005

An experiment at the Pastoral Research Institute, Hamilton, compared the carcass composition and yield of one group of 14 Hereford steers, and four groups of 14 heifers, either spayed, fitted with an intravaginal device, pregnant or entire. The animals were slaughtered at 18 or 22 months when average fat depths and carcass weights were 5.8 mm and 188.0 kg, or 7.5 mm and 219 kg, respectively. When compared at a constant carcass weight, the steers generally had heavier boneless primary cuts, with less fat than the heifers (P<0. 05). Steers also had less channel and kidney fat, subcutaneous fat, intra-muscular and inter-muscular fat and consequently less total fat than heifers (P<.05) . Differences between heifer groups were generally small and non-significant. When compared at the same age, differences between heifers and steers in carcass fatness were generally not significant (P>0. 05) but trends similar to those described above were apparent. Estimated yield of carcass beef (muscle plus saleable fat) was affected by sex, fat depth and level of fat specified in the carcass beef. When lean carcass beef (1 5% fat) was specified, steers yielded about 3.8% more than heifers at the same weight and fat depth, but when fatter carcass beef (20% fat) was specified, this difference was reduced to about 3.2%. Removal of channel and kidney fat from the carcass brought the yield of steer and heifer carcasses to within about 3.0% of each other.
Field tests for evaluating spotted alfalfa aphid resistance in lucerne cultivars: a comparison with glasshouse studies
Authors: Lodge GM , Greenup LR
Published: March 2005

Aphid development, dry matter production and seedling and plant survival data were collected for 22 lucerne cultivars growing at Tamworth, New South Wales. These data were used to investigate whether or not the field performance of these cultivars reflected the range of spotted alfalfa aphid (SAA) resistances determined in published reports of percentage seedling survival in glasshouse screening tests. Numbers of SAA were assessed on seedlings and established plants of each cultivar during heavy, natural field infestations (10.6-23.0 SAA/seedling and 4.2-325.3 SAA/stem). Mean total numbers of SAA/seedling did not differ significantly between cultivars, but compared with the two SAA-susceptible cultivars, Hunter River and 77-6-1 545, lower numbers ( P < 0.01) of large nymphs were found on all SAA resistant cultivars except Matador, Resistador II, DeKalb Brand 167, AS 13R, Amador, Mesilla and Falkiner. However, dry matter yields of all cultivars at first flower were not significantly different, although percentage seedling survivals of the two SAA susceptible cultivars were lower (P< 0.01) than those of the SAA resistant cultivars. For established plants, the SAA susceptible cultivars 77-6-1545 and Hunter River had higher total numbers of SAA and SAA large nymphs (P<0.01) than the SAA resistant cultivars. Within the resistant cultivars, Condura 73 Brand, AS 13R, Amador and Falkiner had higher total numbers of SAA (P<0.01) and Condura 73 Brand, AS 13R, Amador, Lahontan, Lahontan Cycle 4 and Falkiner produced more large nymphs ( P< 0.01) than the other cultivars. Despite these differences in aphid numbers, differences in dry matter yields of established plants of SAA resistant cultivars were generally not significant. However, mean yield of SAA susceptible cultivars was 53% lower than that of resistant cultivars, and mean plant survival of SAA susceptible cultivars was 12% compared with 57.6% for resistant cultivars. With the levels of SAA infestations and the temperatures experienced during our field experiments (17�C and 28�C), neither total aphid numbers per seedling nor dry matter yield indicated the range of SAA resistance determined for these cultivars in glasshouse seedling tests. However, rankings of the total number of SAA and SAA large nymphs per stem generally reflected the ranking of SAA resistances found in glasshouse tests and so these may be used to identify SAA resistant and susceptible plants in the field. Overall, glasshouse screening tests were a poor indicator of the yield and survival of seedlings and established plants of the resistant cultivars tested.
Effect of soil properties on the yield and persistence of Mediterranean perennial grasses in southern Western Australia
Authors: Biddiscombe EF , Rogers AL , Anderson GW , DeBoer ES
Published: March 2005

The effect of ten soil types on yield and survival of three perennial grasses, each mixed with volunteer annual species, was studied for three years under periodic grazing. Yields of cocksfoot (Dactylis glomerata cv. Currie), phalaris (Phalaris aquatica cv. Australian) and tall fescue (Festuca arundinacea cv. Melik) were higher on a gravelly yellow podzolic soil than on other types; phalaris also yielded well on a red podzolic soil. Analysis by multiple linear regression showed that the yield of all sown grasses was high when perched water of the A and upper B horizons was recorded early in winter and sustained until late spring. High gravel content in the A horizon improved cocksfoot and fescue yield and depressed that of phalaris. The high gravel content was associated with increased gravel and decreased water retention of the top of the B horizon at 15 bars. Higher texture classes in the A horizon tended to depress yields of cocksfoot and fescue with no apparent effect on phalaris. The higher texture classes of the clay and clay loam soils tended to decrease general root penetrations. Cocksfoot and phalaris were more productive on shallow than on deep A horizon soils, but fescue yield was not affected by this soil property. Yields of the species can be estimated accurately from regression equations based on three or four soil properties. The results suggest options for selecting perennial grasses suitable for specific soil types among the red earth and red and yellow podzolic groups in the South Western Region of Western Australia. The central problem is that cocksfoot, phalaris and fescue can yield well but do not do so on all soil types.
Reclamation of salt-affected soils in the Goulburn Valley of Victoria
Authors: Mehanni AH , Bleasdale GE
Published: March 2005

A heavy soil (Goulburn loam) in the Goulburn Valley that was badly salinized was quickly reclaimed after control of the watertable to between 60 and 90 cm with subsurface drains. Within 16 months of installing slotted PVC drains 1 .5 m deep and 8.6 m apart, the electrical conductivity of a saturation extract decreased from 16.9 to 1 -9 mS/cm and crop yields increased substantially (oats from 1833 to 321 0 kg/ha, millet from 638 to 31 89 kg/ha). In addition, a white clover-based perennial pasture was established, which in the first season yielded 6985 kg/ha clover compared with 613 kg/ha in the absence of drains. The effects on the reclamation process and crop productivity of ripping the soil to 40 cm, applying gypsum at 10 t/ha, or a combination of both treatments were investigated. No soil treatment was effective without drainage due to the persistence of the shallow saline watertable. With drainage, gypsum applications decreased exchangeable sodium from 8.3 to 3.7% and increased hydraulic conductivity from 1 12 to 24.4 cm/d in the surface 15 cm. Gypsum also increased infiltration by 40%, leaching of chloride by 33% and yield of oats and clover by 44 and 29% respectively. Ripping either alone or combined with gypsum was of no added benefit
Liveweight response to supplementation of pen-fed and grazing cattle eating barley stubble
Authors: May PJ , Barker DJ
Published: March 2005

Liveweight responses to two levels of supplementary feeding were compared in young cattle grazing barley stubble or fed baled material in pens. Over the 58 d of the experiment, unsupplemented animals in pens lost 0.5 kg/d, those receiving the low energy-mineral supplement maintained their initial weight, and those receiving a moderate energy-mineral supplement gained 0.3 kg/d. In contrast, cattle grazing stubble did not show any liveweight response to supplementation, all three treatments gaining at 0.6-0.7 kg/d. Grazing cattle were apparently capable of selecting a diet of much higher quality than the leaf and stem material on offer. The results emphasize the need for caution in extrapolating, to the grazing animal, results obtained in pen-feeding evaluation of heterogenous materials such as crop residues.
Hay conservation for cattle on winter-grazed green panic (Panicum maximum var. trichoglume) pasture in south-eastern Queensland
Authors: Scattini WJ
Published: March 2005

The effects of stocking rate and hay conservation on liveweight gains of weanling Hereford cattle grazing a green panic (Panicum maximum var. trichoglume cv. Petrie) pasture in winter and spring only were measured over seven years. A 2 x2 factorial experiment included stocking rates of 1 .5 and 2 . 5 animals/ha, with and without hay conservation. Protein supplementation using a mixture of cottonseed meal and urea was an additional treatment in two winters. Stocking rate had little effect on pasture yields at the start of grazing or on hay yields. The mean liveweight gains per animal at stocking rates of 1 . 5 and 2.5 animals/ha were 69 and 50 kg, respectively, on non-conserved pasture, and 86 and 54 kg on conserved pasture. Liveweight gain response to conservation was greater at the lighter stocking rate and appeared due to greater accessibility of higher quality pasture in situ rather than to feeding of hay per se. At the light stocking rate, little or no hay was required. Feeding protein produced 6 kg more liveweight gain per animal during the supplementation period in the two winters but this advantage disappeared by the end of grazing. Liveweight gain per hectare decreased with increased stocking rate in both hay and no-hay groups in the first and third year, decreased in the hay group only in the second year and increased in both groups in the last four years of the experiment. The benefit from making and feeding hay was small and the economics of the practice would depend on alternative uses for excess hay.
Variation in non-wool components of the greasy fleece over the body of Merino sheep
Authors: Thornberry KJ , Atkins KD
Published: March 2005

Twelve one-year-old ewes were randomly selected from each of four flocks running together at pasture at the Agricultural Research Centre, Trangie, New South Wales. The flocks represented fine wool, medium wool non-Peppin and medium wool Peppin strains of Merino. Wool samples were collected from nine sites over the body of each ewe. Gradients over the fleece in percentage suint, percentage wax, wax:suint ratio, percentage dust, percentage vegetable matter and estimated clean scoured yield were demonstrated. Although flocks differed in the average level of these components, gradients were similar for the different flocks. The mid-side appeared to be a satisfactory sampling position for estimating the suint, wax, wax:suint ratio, dust and yield characteristics of the whole fleece. The mid-side values for these characteristics were similar to the average values for all nine sites and the correlation coefficients between mid-side values and the total of all sites for percentage suint, percentage wax, wax:suint ratio, percentage dust and estimated yield were 0.94, 0. 8.9, 0.90 and 0.87 respectively. These were higher than for any other single sampling position. The correlation between mid-side and the overall value for vegetable fault was only 0.56 and neither the mid-side nor any other single site appeared to be sufficiently reliable to predict total vegetable matter content.
Evaluation of a subjective fat scoring system for lamb carcasses
Authors: Lee GJ , Thompson JM , Fitzgerald JR
Published: March 2005

Two surveys were conducted, the first to examine the ability of subjective fat scores to sort carcasses independently of variation in carcass weight, and the second to objectively describe fat scores in terms of an easily recorded carcass measurement. Survey 1 examined the distribution of subjective fat scores (1-very lean to 5-very fat) within carcass weight ranges for 60 262 carcasses. There was little variation in fat scores within carcass weight ranges and therefore fat scores provided little additional information for sorting carcasses over that of carcass weight alone. This was particularly so in the two most common carcass weight ranges (14.0- 16.5, and 17.0- 19.5 kg) in which over 95% of carcasses were given fat score 3. This highlighted the need to establish an objective basis for fat scores. The second survey related fat scores to tissue depth, measured 1 10 mm from the midline of the 12th- 13th rib junction (GR) for a range of carcass weights. GR measurements for fat scores 3,4 and 5 were positively related to carcass weight. Nevertheless, individual fat scores reflected carcasses of similar percentage subcutaneous fat over a range of carcass weights, although the range of GR within fat score-carcass weight category was large, with considerable overlap between scores. Objective boundaries for fat scores in terms of GR measurements are proposed for a range of carcass weights.
Effects of lice infestation on the growth of beef heifers in Victoria
Authors: Bailey PJ , Carroll WAD , Knee B
Published: March 2005

Ten experiments were carried out to examine some of the effects of lice infestation on heifers grazing on six commercial properties in the high rainfall areas of Victoria. In all experiments, famphur, a pour-on lousicide, effectively controlled lice populations (main species Linognathus vituli). Lice infestation was associated with lower growth rates in only two experiments. Significant correlations between lice infestation and liveweight gain of untreated heifers were found in three of ten experiments, but infestation accounted for only 23-30% of the variation in liveweight gain. The results support other studies conducted in Western Victoria, and the need for routine whole herd treatment against lice is questioned.
The growth of weaner sheep on clover or grass pastures during summer in Western Victoria
Authors: Kenny PT
Published: March 2005

Three pasture types were grazed by weaner sheep during two summers in the Western District of Victoria: (1) dried off grass-subterranean clover pasture (DP); (2) dried off pasture with a higher subterranean clover content (SUB); and (3) pasture with a high proportion of green strawberry clover. Additional treatments during the first summer included sheep grazing DP and fed a supplement of subterranean clover hay (80% clover) or grass hay (77% grass). Further information was obtained by feeding both hays to penned sheep. The digestibility of the SUB pasture declined between early and mid-summer, crude protein content remained constant and neutral detergent fibre content increased markedly. During both summers, the average growth rates of sheep grazing strawberry clover, SUB or DP were 106, 12 and -2 g/d, respectively. In the first summer, supplements of clover hay and grass hay significantly increased the growth rates of weaners on DP by 39 and 44 g/d, respectively. Sheep supplemented with clover hay or grass hay during the first summer grew 0.44 and 0.28 kg more wool, respectively, than unsupplemented sheep grazing DP. In the winter and spring following both summers, poorly grown sheep showed compensatory growth sufficient to make up for lack of growth during summer. Conservation of subterranean clover dominant pasture as hay, and feeding it as a supplement in summer, appears a more effective means of improving the growth and wool production of weaner sheep than simply grazing the mature plant in situ. However, there would be a much greater potential for improvement if a legume that remained green throughout the summer could be found to substitute for subterranean clover.
Phosphorus compounds measured in a rapid and simple leaf test for the assessment of the phosphorus status of subterranean clover
Authors: Irving GCJ , Bouma D
Published: March 2005

Experiments were done to determine what proportion of the phosphate extracted from fresh leaf tissue by five drops of 10 N H2SO4 represents inorganic tissue phosphate, and to what extent hydrolysis of organic phosphates during and after the extraction, and during the development of the blue phosphomolybdate complex, could contribute to the values obtained. The extraction is the basis of a simple and rapid test for the assessment of the phosphorus status of subterranean clover (Bouma and Dowling 1982). Extraction of leaf tissue of subterranean clover and sunflower with 0.2 M HClO4 at O�C, which was shown to extract inorganic leaf phosphorus without causing significant hydrolysis of organic phosphates, gave values not significantly different from those in H2SO4 extracts. The rate of hydrolysis of endogenous organic phosphates in tissue, extracted and left at room temperature for periods of up to 40 min. after adding H2SO4, did not differ significantly from zero. Errors due to hydrolysis during the 30 min. previously recommended for colour development are reduced to negligible proportions by reducing the time for colour development to 10 min. and by adding citric acid at this point. Anion-exchange chromatography of 10 N H2SO4 and 0.2 M HClO4 extracts confirmed the similarity of their composition and provided estimates of the various phosphate compounds present. The extraction of fresh leaf tissue with 10 N H2SO4 provides a satisfactory estimate of the endogenous inorganic phosphorus content.
Response of Inga rice to application of nitrogen fertilizer at varying growth stages
Authors: Bacon PE , Heenan DP
Published: March 2005

The growth, nitrogen use and yield of rice cv. lnga were examined in three experiments in 1978, 1979 and 1980. In each experiment, one rate of nitrogen was applied at six different times between permanent flood and three weeks after panicle initiation. Application of 50 kg N/ha in 1978 and 70 kg N/ha in 1980 at permanent flood increased yield. A higher rate (100 kg N/ha) at permanent flood in 1979 greatly increased vegetative growth but had little effect on grain yield. The grain yield response to 100 kg N/ha in 1979 significantly increased when application was delayed until panicle initiation. Nitrogen topdressing up to 14 d after panicle initiation resulted in an increased percentage of filled florets per panicle and heavier grains compared with application 14-21 d before panicle initiation. Delaying nitrogen application till 2 1 d after panicle initiation resulted in lower numbers of florets per panicle and consequently reduced yield.
Resistance of cultivars of Avena sativa to, and host range of, an oat-attacking race of Ditylenchus dipsaci in South Australia
Authors: Stanton JM , Fisher JM , Britton R
Published: March 2005

The host range of a population of Ditylenchus dipsaci in South Australia showed that the oat race was present. The commercial oat cultivars, Algerian, Elan, Avon and Cassia, possessed useful resistance to this race in field and laboratory trials. Popular commercial oat cultivars, West and Swan, were susceptible. Rotational crops such as Vicia faba (field beans) and Pisum sativum (peas) were susceptible but clovers (Trifolium spp.), lucerne (Medicago sativa) and grasses (Lolium rigidum) had some resistance in a laboratory trial. Data on tolerance were sparse. Tolerance was related to numbers of nematodes (resistance) in the host. The difference between assessment of tolerance to nematodes which undergo a single generation in a season (e.g. Heterodera spp., Globodera sp.) and those undergoing several generations (e.g. Ditylenchus spp.) is discussed.
Effects of shearing time and time of lambing on wool growth and processing characteristics
Authors: Arnold GW , Charlick AJ , Eley JR
Published: March 2005

Wool growth rate, seasonal pattern of fibre diameter, clean fleece weight, quality and the processing characteristics of wool were measured on medium-wool Merino sheep shorn in March (autumn) or October (spring) coupled with March or June lambing. These four management systems were compared under two nutritional regimes in the medium rainfall area of Western Australia. The sheep grazed annual pastures only, or had lupin grain and stubble during summer in addition to the pasture. The study ran for two shearing periods. Time of shearing was the dominant factor. Sheep shorn in March produced 14% more clean wool and fewer tender fleeces than sheep shorn in October. The autumn wool had a lower yield, higher fibre diameter and when processed had a higher card loss, lower percentage noil and lower top and noil yield. However, mean fibre length in the top was substantially higher and the variation in fibre length lower. Vegetable matter was higher in autumn shorn wools. There were some interacting effects of lambing time and type of feed regime. Sheep fed lupins had lower yielding wool but this effect was more pronounced in June lambings and was reflected in differences in top and noil yield. From measurements of wool growth rate, it was found that the extra wool was produced in autumn after shearing, due possibly to stimulated appetite that cannot occur after spring shearing because the sheep are too fat.
Establishment of four pasture grasses and Siratro from seed oversown into dense and open speargrass pastures
Authors: Cook SJ
Published: March 2005

In two experiments, seed of Gayndah and Biloela buffel grass (Cenchrus ciliaris), green panic (Panicum maximum var. trichoglume), signal grass (Brachiaria decumbens) and Siratro (Macroptilium atropurpureum) was broadcast into a range of seedbeds imposed on native speargrass (Heteropogon contortus) pastures that had either been cleared of trees 4-5 years before sowing (C) or had the trees killed at sowing (K). The seedbeds were: untreated control (NP); mown to 3 cm before and at sowing (M); M followed by regular clipping (MD); burnt (B); B followed by regular clipping (BD); and herbicide (H). Seed was also sown into a cultivated seedbed (P) in C. The number of plants established 15-16 months after sowing was highest in the cultivated seedbed and lowest in seedbeds where competition from the native grasses was greatest. Competition was greater in C than in K, the native pastures in C having about three times more dry matter than those in K. Burning reduced competition but also reduced seedling emergence. It increased establishment slightly in K but not in C. The M and MD treatments failed to increase establishment over that of the NP control. Herbicides reduced competition and increased establishment in C and K, but only for signal grass and Siratro in C when drier conditions occurred in the second experiment. Siratro established better than the grasses in the presence of competition when weather conditions were favourable, but there was little Siratro or grass establishment when water deficits occurred soon after emergence, especially in C
Phosphorus requirements and responses of tropical pasture species: native and introduced grasses, and introduced legumes
Authors: McIvor JG
Published: March 2005

Plants of five native or naturalized grasses (Bothriochloa pertusa, Chloris barbata, Chrysopogon fallax, Digitaria ciliaris, Heteropogon contortus), eight introduced grasses (Andropogon gayanus CPI 57497, Cenchrus ciliaris cv. Biloela, Chloris gayana cv. Callide, Chrysopogon sp. CPI 52213, Dichanthium annulatum CPI 50819, Paspalum plicatulum cv. Rodd's Bay, Urochloa oligotricha CPI 47122, U. mosambicensis CPI 46876) and three introduced legumes (Macroptilium atropurpureum cv. Siratro, Stylosanthes hamata cv. Verano, S. scabra cv. Seca) were grown in pots of phosphorus deficient soil with varying rates of added phosphorus. Their phosphorus requirements and responses were compared. The two Stylosanthes species were the least responsive of all. Among the grasses, C. fallax, A. gayanus and B. pertusa were the least responsive and D. ciliaris, C. gayana and D. annulatum the most responsive. The increases in yield when phosphorus was applied were mainly due to increases in tiller numbers, with smaller increases in rate of leaf appearance and leaf size. Digitaria ciliaris, U. oligotricha and C. barbata required smaller additions of phosphorus to achieve near maximum yields than did other species. Bothriochloa pertusa and D. annulatum required the most. Critical phosphorus concentrations in whole tops at 35 d (immediate pre-flowering stage) ranged from 0.20% in C. ciliaris to 0.39% in S. hamata. Overall, critical phosphorus concentrations in whole tops were similar to those in the youngest expanded leaves. When the species were grouped on the basis of their phosphorus requirements in the field, the groups were more closely related to responsiveness to applied phosphorus than to the amount of applied phosphorus required for near maximum yield. Species tolerant of low phosphorus conditions (e.g. Stylosanthes) gave smaller responses than less tolerant species (e.g. D. ciliaris and U. mosambicensis).
Evaluating hybrids between Leucaena leucocephala and L. pulverulenta as potential forage plants
Authors: Bray RA
Published: March 2005

The growth of two lines of Leucaena leucocephala, four lines of L. pulverulenta, and 19 hybrids between the two species was studied in the glasshouse and in the field. Although the hybrids initially grew more slowly than the control L. leucocephala lines, most outgrew them in the field, yielding up to 50% more edible material (with about 80% of the mimosine level), and up to 100% more non-edible material. It is concluded that these hybrids have considerable potential, especially as dual purpose (forage/fuel) plants. A strategy for producing hybrid seed under field conditions is proposed
Responses of nine tropical grasses to nitrogen fertilizer under rain-grown conditions in south-eastern Queensland. 2. Concentrations and uptakes of nitrogen, phosphorus and potassium in plant tops
Authors: Cook BG , Mulder JC
Published: March 2005

Nitrogen, phosphorus and potassium concentrations were determined in plant tops harvested every four weeks from nine tropical grasses fertilized with nitrogen on ten occasions at eight week intervals. Nitrogen was applied at three rates-25, 50 and 100 kg/ha (N25, N50, N100)-on each occasion. Grasses were rain-grown without grazing at a site near Gympie with an average annual rainfall of 1160 mm. Overall, nitrogen concentration in the tops increased and potassium concentration decreased with increasing nitrogen application. Phosphorus concentrations were constant at N25 and N50, but were lower at N 100. Mean nitrogen concentration was highest at 2.4% in Pennisetum clandestinum cv. Whittet, and lowest at 1 .9% in Chloris gayana cvv. Callide and Katambora, with intermediate concentrations occurring in Digitaria decumbens, Setaria sphacelata var. sericea cv. Narok, Panicum maximum cvv. Gatton and Makueni, Brachiaria decumbens cv. Basilisk and Paspalurn plicatulum cv. Bryan. Phosphorus concentration was highest in Whittet at 0.38% and lowest in Bryan at 0.25%. Potassium concentration was highest in Whittet at 2.53% and Narok at 2.29% and lowest in Katambora at 1 .48%. The implications of these concentrations and calculated nutrient uptakes are discussed in relation to animal and plant nutrition.
Control of Drosphila spp., Carpophilus spp. and Ephestia figulilella (Gregson) in sultana grapes grown for dried fruit
Authors: Buchanan GA , McDonald G , Evans PWC
Published: March 2005

Sultana grapes grown in Australia for dried fruit are attacked by insects before and during harvest, and during drying and storage. Insect damage, including crop loss and contamination of the dried grapes with insect matter, varies between and within seasons according mainly to the incidence of rain damage. The effectiveness of chlorpyrifos for control of vinegar flies (Drosophila simulans Meigen, D. melanogaster Sturtevant), dried fruit beetles (Carpophilus hemipterus L., C. dimidiatus Fabricius, and C. humeralis Fabricius), raisin moth (Ephestia figulilella Gregson), Indian meal moth (Plodia interpunctella (Hiibner)), and saw-toothed grain beetle (Oryzaephilus surinamensis (Linnaeus)) was investigated at Irymple, Victoria, in field experiments during 1979 and 1980. In 1979, pre- and post-harvest treatments of chlorpyrifos, applied at a rate designed to give an initial residue of 25 mg/kg in the grapes, reduced insect infestation in drying and dried grapes. In 1980, chlorpyrifos was applied pre-harvest at three rates designed to give initial residues of 50, 5, and 2 mg/kg, respectively. Treatments of 50 and 5 mg/kg were effective in controlling insects in the fresh, drying and dried grapes for each of four successive harvest occasions, and during storage in a commercial packing shed. Chlorpyrifos 2 mg/kg was less effective than the higher rates in controlling raisin moth, Indian meal moth and saw-toothed grain beetle in the latter phases of the experiment. An application of dip mixture (1 % drying oil plus 17 g/litre K2CO3) suppressed vinegar flies and dried fruit beetles for a short period but had no effect on the other insect pests.
Dimethoate dipping of tomatoes against Queensland fruit fly, Dacus tryoni (Froggatt)
Authors: Swaine G , Hargreaves PA , Jackson DE , Corcoran RJ
Published: March 2005

Dipping of tomatoes for 3 min. in a solution of dimethoate of 425 mg/litre strength was shown to be effective against infestations of Queensland fruit fly. An efficacy standard of no survivors in 30 000 individuals treated was achieved; dimethoate residues were below the relevant maximum residue limit of 1 mg/kg, and no taint was produced in green or ripe fruit.
Bacterial blights of peas in Victoria
Authors: Wimalajeewa DLS , Nancarrow RJ
Published: March 2005

The incidence of two bacterial blights of peas, caused by Pseudomonas syringae pv. pisi and Pseudomonas syringae pv. syringae, was surveyed in Victoria from 1979 to 1982. One hundred and seven crops including cultivars of green and field pea were inspected. The incidence of both blights was higher on field pea. Of the field pea plants inspected, 5.3% were affected by the more severe blight caused by pv. pisi and 2. 5% by pv. syringae. There was a higher incidence of both blights in crops in the northern area of the State. Green pea crops were relatively free from both diseases. The significance of the findings in the survey, especially to the field pea industry in Victoria, is discussed.
Thinning Golden Delicious apples with pre-bloom naphthalene acetic acid and later carbaryl sprays
Authors: Jones KM , Koen TB , Meredith RJ
Published: March 2005

A trial in southern Tasmania examined the thinning effects of naphthalene acetic acid (NAA) on Golden Delicious apples. The NAA was applied at pink bud or balloon blossom at 12, 18 and 24 ppm, with or without carbaryl at 1800 ppm applied 10 d after full bloom. Carbaryl was also applied alone 10 and 20 d after full bloom, and a hand thinned treatment was included. The higher concentrations of NAA did the most thinning but only the hand-thinned and 24 ppm NAA at balloon blossom with carbaryl treatment thinned enough to produce the required fruit size. The NAA sprays at balloon blossom thinned considerably more than those at pink bud. Neither NAA nor carbaryl alone was as effective as the combination. Reduction of fruit numbers increased mean fruit weight from 101 g in the control to 149 g in the 24 ppm NAA at balloon blossom with carbaryl. There was no evidence that increasing the concentration of NAA reduced mean fruit weight. This trial demonstrates that the effect of balloon stage sprays of NAA combined with later carbaryl sprays on Golden Delicious is similar to that achieved by the normal practice of spraying with NAA 7-14 d after full blossom, followed by carbaryl at 20 d. Reduction from 128 fruit/ 100 blossom clusters in the control to 76 after spraying at balloon blossom is still outside present aims of 30-50 fruit and is not considered to be severe enough thinning to assure adequate fruit size.
Effects of frequency of zeranol implantation on liveweight gain of steers grazing improved pastures in central Queensland
Authors: Mason GW , Blight GW , Rudder TH
Published: March 2005

Various combinations of single and repeat zeranol treatment were examined during two consecutive growing seasons, using Brahman x Murray Grey crossbred steers grazing improved pastures at Moura in central Queensland. Compared with untreated controls, the response (P<0. 05) to the initial implant of 36 mg zeranol varied from 0 . 166 to 0.208 kg Iiveweight/d during the 92-98 d period after implantation. Repeat implantations gave responses of 0.06 1 (P> 0.05) and 0.101 (P< 0.05) kg/d during the following 97 and 94 d. Steers that had only one implant gained more quickly than those on their repeat implant at the same time: 1.161 vs 1.014 (P<0. 05) and 0.658 vs 0.593 (P> 0.05) kg/d in the two seasons, respectively. Final liveweight was similar for steers given four implants over both growing seasons (594 kg), two implants to give response during the second growing season (592 kg), and one implant to cover the second half of the first growing season, and one implant to cover the latter half of the second growing season (589 kg). When managerial factors and cost of the drug are considered, the preferred strategy appears to be either two implants during the final growing season, or one implant during each of the two growing seasons.
Comparison of production from an agroforestry system in a mid-rotation stand of Pinus pinaster with that from open pasture
Authors: Anderson GW , Batini FE
Published: March 2005

The growth, persistence and sheep carrying capacity of clover pastures grown in the open and under thinned stands of Pinus pinaster, and the responses of the trees to annual applications of superphosphate, with and without clover, were measured from the 15th to the 18th years of the rotation. Good clover establishment was achieved both under 90 trees/ha and in the open. In the second year, pastures under the stands of P. pinaster carried 93% of the numbers of sheep on pastures with no trees. By the fourth year, growth of the tree crowns had doubled their shading capacity and the relative carrying capacity of the pastures was 76%. Although significant increases in the soil levels of phosphorus, nitrogen and organic matter were recorded in the pastured and fertilized treatments, foliar analysis of pine needles showed no difference between fertilizer treatments. Except for potassium, foliar levels were at or below the levels regarded as adequate for growth. Annual increments in diameter and volume ranged from 1.4 to 2.1 cm, and 4 5 to 5.3 m3/ha, respectively. Whereas superphosphate increased diameter growth, superphosphate and clover together depressed diameter increment. Pinus pinaster and P. radiata are compared as agroforestry species.