bluuebunny/crossref_metadata_2025 huggingface dataset:
Phosphorus status of subterranean clover: a rapid and simple leaf test
Authors: Bouma D , Dowling EJ
Published: March 2005

A simple and rapid method is presented for the assessment of the phosphorus status of subterranean clover. The method rests on extracting fresh leaf tissue (400 mg) with five drops 10 N H2SO4 and measuring phosphorus in the filtered extract by a molybdenum blue colour method, visually or calorimetrically. No special skills or equipment are required and the method is therefore potentially suitable for use by advisers and farmers. Two standard blue colours would be sufficient for a visual separation between non-deficient, moderately deficient or severely deficient plants. The method was tested in early spring with leaf samples obtained from two field experiments (five phosphorus levels), a sand culture experiment, and a pot experiment with phosphorus deficient soil (five phosphorus levels in each). Close relations were obtained between relative yields (yields as a percentage of the maximum in each experiment) and extractable phosphorus (R2 = 0.93). The curve fitted to the relation had a clearly defined inflexion point, indicating a critical value of 150 ppm extractable phosphorus at 90% of the fitted asymptote for relative yield. The relation for total phosphorus and yields was not as close (R2=0.77) and the critical value not clearly defined. Extractable phosphorus was closely related to total phosphorus below the critical value for extractable phosphorus, but not above this value. Likely physiological are discussed.
Post-harvest control of anthracnose and stem-end rots of Fuerte avocados with prochloraz and other fungicides
Authors: Muirhead IF , Fitzell RD , Davis RD , Peterson RA
Published: March 2005

Mature unripe Fuerte avocados from Alstonville (northern New South Wales) and Walkamin (northern Queensland) were dipped in fungicides immediately after harvest. In screening tests in which the fungicides were applied for 5 min, prochloraz [1 g active constituent (a.c.)/l] controlled anthracnose (Glomerella cingulata var. minor), a severe form of stem-end rot caused by Dothiorella aromatica and Botryodiplodia theobromae, and a mild form of stem-end rot caused by G. cingulata var. minor and Stilbella cinnabarina. Prochloraz increased the percentages of disease-free fruit from 1 to 90% at Alstonville and from 6 to 77% at Walkamin. Percentages of fruit with acceptable disease levels were similarly increased. Other fungicides were less effective in the screening experiments. CGA 6425 1 (0.2 g a.c./l) and carbendazim (1 g a.c./l) controlled both forms of stem-end rot, but not anthracnose. Guazatine (1 g a.c./l) controlled only the mild form of stem-end rot. In a second experiment with avocados from Alstonville, prochloraz was applied at 0.125, 0.25, 0.5, and 1.0 g a.c./l for 0.5, 1,2 and 4 min. Every treatment except 0.125 g a.c./l for 1 min controlled anthracnose and improved overall disease control. Prochloraz neither caused nor exacerbated several physiological disorders that developed during ripening in these investigations.
Boron supplying power, boron adsorption capacity and productivity of some acidic soils from the Central Tablelands of New South Wales
Authors: Haddad KS , Kaldor CJ
Published: March 2005

The reliability of the hot-water soluble boron (HWSB) content of a soil as a measure of total boron available to plants during intensive cropping, and its relationship with the boron-supplying power (BSP) of the soil, as affected by the soil's parent material, was studied in a glasshouse trial. Fifteen surface soils (0- 15 cm) from six parent materials from the Central Tablelands of New South Wales were used. In each pot of soil, three crops were planted in succession: sunflower (Helianthus annuus cv. Hysun 3 I), subterranean clover (Trifolium subterraneum cv. Woogenellup), and maize (Zea mays cv. XL45). Lime and borax were applied in a 2x2 factorial combination. Crop responses to these applications, their relationship with soil BSP and HWSB content, and soil boron adsorption capacity (BAC) when borax was added were also investigated. In soils not treated with borax or lime, the following were significantly correlated (r > 0.51): crop yield, crop uptake of boron, HWSB content before cropping, and BSP. However, BSP was not correlated with the amount of HWSB lost from the soil during cropping. In sandstone, granitic and quartz-rich fine sedimentary soils, the amount of boron taken up by the crops was not significantly different from the amount of HWSB removed from the soil. Therefore, their BSP (0, 74 and 145 g B/ha respectively) was not significantly greater than zero and thus their HWSB content simply and reliably measures their boron status. From crop responses in granitic and quartz-rich fine sedimentary soils (HWSB content 0.26 and 0.30 �g B/g of air dried soil, respectively) it was shown that these soils require boron supplementation whenever their HWSB content is less than about 0.34 �g B/g air dried soil, particularly if they are cropped intensively or heavily limed. The BSP of tuff, basaltic and alluvial soils (388, 407 and 620 g B/ha) was significantly greater than zero. Therefore, these soils have boron reserves not measured by the HWSB method and their HWSB content does not reliably measure boron available for crops. All soils adsorbed boron when borax was applied. The BAC did not differ significantly between the six soil types. The overall effect of lime was to significantly increase dry matter yield. Boron uptake by the crops, and soil BSP and BAC were not significantly affected by liming.
Irrigated pasture productivity and its variability in the Shepparton region of northern Victoria
Authors: Stockdale CR
Published: March 2005

The seasonal distribution and variability of growth of three types of irrigated pastures were measured at Kyabram over a period of up to seven years. The pasture types studied were (1) paspalum (Paspalum dilatatum)-dominant perennial pasture, (2) ryegrass (Lolium perenne)/clover (Trifolium repens) perennial pasture, and (3) annual pasture based on subterranean clover (Trifolium subterraneum) and Wimmera ryegrass (Lolium rigidum). The influence of environmental factors on the year-to-year variability in monthly growth rates was also examined. Annual growth curves were constructed for each pasture type, and examination of the variability about each monthly mean indicated that the spring months, and October in particular, were the most variable months for pasture growth. Environmental factors were found to account for part of the year-to-year variation in pasture growth of paspalum pastures in August, September, October, November and April. Higher mean maximum temperatures significantly increased growth in September, October and April, with the greatest response occurring in October; hours of sunshine was the significant factor influencing growth in August and November. Annual pasture growth also responded to changes in mean maximum temperature or hours of sunshine in September and October. The comparative mean annual production of paspalum pasture, ryegrass/clover pasture and annual pasture was 18.3, 18.3 and 11.0 t DM/ha, respectively. These levels of production represented 1.1, 1.2 and 1.6% conversion of photosynthetically active radiation during the growing period of the three pasture types, respectively. These levels of productivity and the animal production that should result, suggest that the pasture productivity on many irrigated dairy farms is either very low or the pasture that is grown is inefficiently utilized. Because animal productivity depends on pasture productivity more than any other single factor, farmers should make improvement of pasture growth their major aim while having regard for the variability in growth that can result from variations in environmental factors.
Change in soil pH, manganese and aluminium under subterranean clover pasture
Authors: Bromfield SM , Cumming RW , David DJ , Williams CH
Published: March 2005

Changes in soil pH, manganese and aluminium as a result of long periods under subterranean clover pasture were examined in soils formed on granite, basalt and sedimentary rocks near Goulburn, New South Wales. Decreases in the pH of yellow duplex soils formed on granite, sedimentary rocks and basalt had occurred to depths of 60, 40 and 30 cm, respectively. The smaller depth of acidification in the latter two soils is considered to be due to their shallower A horizons over well buffered, clay B horizons. Under the oldest pastures (55 years) the decreases exceeded one pH unit throughout the entire sampled depth (60 cm). In some soils, under old improved pastures, calcium chloride-extractable manganese had increased to more than 20 ppm throughout the 60 cm profile and to greater than 50 ppm in the surface 10 cm. These levels are considered toxic to sensitive plant species and the highest levels may be toxic to subterranean clover. The amounts of extractable manganese in soils appear to be determined by both pH and the amounts of reactive manganese. In general, the amounts of total and reactive manganese were appreciably higher in the soils of basaltic origin. Substantial increases in extractable and exchangeable aluminium had also accompanied the decrease in pH and, in the surface 10 cm, were greatest in the soils formed on sedimentary parent materials. In many of the soils under old improved pastures, exchangeable aluminium, as a percentage of the effective cation exchange capacity, now exceeds 12%, especially in the 5-10 cm layer, and is probably harmful to sensitive species. Increases in exchangeable aluminium also occurred below the surface 10 cm and, in the granitic soils under the oldest pastures, exchangeable aluminium accounted for 30-50% of the effective cation exchange capacity throughout the 5-50 cm soil depth. The adverse changes in pH, manganese and aluminium observed in this study can be expected to continue under many improved pastures and to generate soil conditions unsuitable for many agricultural plants. The use of lime to arrest or reverse these changes seems inevitable.
Ease of calving, growth and carcass characteristics of crossbred calves in the lower South East of South Australia
Authors: Deland MPB , Ponzoni RW , McNeil RW
Published: March 2005

Hereford, Charolais and Brahman sires were mated to Hereford, Shorthorn, Jersey and Friesian xshorthorn cows for four successive years from June 1969 at Struan Research Centre in South Australia. Assistance was given during 15 .9% of calvings resulting from Charolais sires, 6.8% resulting from Brahman sires and 2.1% from Hereford sires (differences statistically significant, P < 0 05). A greater percentage of Friesian x Shorthorn (13.8) than of Shorthorn (5.0) or Jersey (4 3) cows were assisted at birth (P< 0.05). There were no significant differences between the percentage of Hereford cows assisted (10.9) and that of any of the other dam breeds. There were no significant differences in calf mortality among sire breeds or among dam breeds. Charolais-sired calves were heavier at birth, 270,340 and 430 d old and had heavier (1 95 kg) carcasses with a smaller proportion of fat than Brahman- and Hereford-sired carcasses (180 and 167 kg respectively) at 430d old. Brahman-sired calves were heavier than Hereford-sired calves at birth, 370, 430 d old. However, they were significantly lighter at 270 d old. Hereford cows gave birth to significantly heavier calves than Shorthorn and Jersey cows but there were no clear differences due to dam breed in growth rates of calves, carcass weights or composition. It was concluded that the use of Charolais sires in the lower South East of South Australia can result in significant increases in the growth rate of slaughter cattle and in the production of leaner carcasses. Brahman sires did not exhibit clear advantages over Hereford sires. No definite conclusions could be drawn about the dam breeds examined in the study.
Supplementing Merino ewes at mating for reproductive gain in central western New South Wales
Authors: Denney GD
Published: March 2005

In four experiments at Condobolin on the Central Western slopes of New South Wales between 1976 and 1979, mature Merino ewes were given supplements for four to five weeks over mating and the effects on their reproductive performance were recorded. The ewes were run on barrel medic or native pasture with mating commencing in late February or early March each year. The supplements were: experiment 1 -1upins (0.25 kg/d), oats (0.25 kg/d); experiment 2-lupins (0.25 kg/d), oats (0.25 kg/d); experiment 3-lupins (0 25 kg/d), lupins (ad libitum), lupins (0.25 kg/d) with ad libitum oats and lucerne hay; experiment 4-lupins (0.25 kg/d). In experiment 4, ewe liveweight was manipulated in the pre-feeding period to obtain two liveweight classes at the start of supplementation. In the three to four weeks before mating, ewes either maintained or lost weight in experiments 1,2 and 4. However, in experiment 3, ewe liveweight increased after heavy summer rains caused an abundance of pasture. The only significant effect of any supplement on flock reproduction was to increase the ovulation rate. This resulted from lupin supplementation but only in two of four years (experiments 1 and 4). However, on these occasions, lambing rates did not significantly increase due to three factors: more barren ewes, higher ova loss or greater peri-natal lamb loss. Oats supplementation in experiments 1 and 2 did not significantly increase reproductive performance, nor was there an effect of any supplement in experiment 3. The results indicate that repeatable reproductive responses to lupin supplementation are unlikely to occur in the area of the study.
Antagonists of the cereal cyst nematode Heterodera avenae Woll. in Australian soils
Authors: Stirling GR , Kerry BR
Published: March 2005

Cereal growing soils of South Australia and western Victoria were surveyed for antagonists of second-stage juveniles and females of H. venae. Of eight species of fungi and two species of predacious mites isolated from soil, the only antagonists observed actually attacking H. avenae veniles were the nematophagous fungi Hirsutella rhossiliensis and Nematoctonus haptocladus. More than 23 000 females of H. avenae from 375 sites were examined over three years; about 1 % were diseased. The most widely distributed parasites were Verticillium chlamydosporium, Catenaria auxiliaris and an unidentified sterile fungus. Nematophthora gynophila, a fungus associated with the decline of H. avenae in England, was not found. However, when soil from England containing resting spores of N. gynophila was mixed with H. avenae infested soil from South Australia, females infected by the fungus were recovered. Both C. auxiliaris and the unidentified sterile fungus were found only in fine textured soils in wetter districts, and were more active during the 1979-80 wet season than the following two dry seasons. V. chlamydosporium was found throughout the sampling area and was not confined to soils which were frequently moist, or to soils of a particular texture. Its population densities were generally low (less than 50 chlamydospores/g). The possible use of fungi parasitic on H. avenae for biological control of the nematode in Australia is discussed.
Evaluation of fresh market tomatoes of the determinate type irrigated by trickle and grown on raised beds covered with polyethylene mulch
Authors: Sumeghy JB , Huett DO , McGlasson WB , Kavanagh EE , Nguyen VQ
Published: March 2005

Experiments were conducted in November and December, 1981, at three commercial growing sites in New South Wales (Duranbah, Medowie and Richmond) to evaluate the yield and quality of eight determinate cultivars of fresh market tomatoes. Flora-Dade, which is the most widely grown commercial cultivar in Australia, was included as a control. Over all sites, Sunny, Duke and Royal Flush were the highest yielding cultivars, with increases of 25, 22 and 20% respectively, over Flora-Dade. Sunny was the highest yielding cultivar at Medowie and Richmond. Fruit for quality assessment was harvested at an early colour stage and ripened at 20�C. Fruit of Flora-Dade was firmer than all other cultivars. Sunny and GS393 had similar shelf life to Flora- Dade. Chemical composition and sensory tests showed little differences between cultivars.
Reducing post-harvest disease in Fuerte avocados by temperature management
Authors: Fitzell RD , Muirhead IF
Published: March 2005

The effects of temperature on the development of post-harvest disease caused by Glomerella cingulata var. minor and Dothiorella aromatica were studied in three experiments. In the first, avocados were ripened with ethylene at six constant temperatures from 15 to 30�C. The rate of disease development increased as the temperature increased and final disease levels in ripe fruit were higher at 27�C and 30�C than at 24�C and below. Alternative handling regimes were compared in experiment 2. Disease levels were high (rating 2.0 on a 0-5 scale) in fruit held at constant 27�C, and low (rating 0.3) after ripening with ethylene at constant 17�C. Low levels (ratings 0.4-0.7) were maintained when fruit were held at 7 or 27�C for up to 3 d before ripening with ethylene at 17�C. However, higher ratings (1.1-2.3) were recorded when partially-ripened fruit were transferred to 27�C after various periods of ripening at 17�C. In the third experiment, temperature management was assessed during April (ambient temperatures 18-28�C) and May (14-20�C). In April, the percentage of diseased fruit was reduced from 69% at ambient temperatures to 30% by holding at 17�C after the third day. In May, disease levels in both treatments were comparable (29 and 35% respectively). However the level increased to 71 % when May fruit were held at simulated April temperatures. The results demonstrated that high ripening temperatures increased the incidence of post-harvest disease. The high levels of wastage observed in Fuerte during late summer and autumn, when temperatures often exceed 24�C, should be reduced by ripening with or without ethylene at wholesale markets at 17�C, and by retailing at the same temperature after ripening.
Evaluation of an intraruminal device to provide an iodine supplement for sheep
Authors: Ellis KJ , George JM , Laby RH
Published: March 2005

Commercially manufactured intraruminal devices providing iodine supplementation for grazing sheep were tested for three years in a flock of 200 ewes, and iodine release rates and accumulation in tissues were measured in a small flock of first cross ewes and wethers. Retention of the device exceeded 99.5%. The rate of iodine release increased from about 500 �g/d during the first few months to about 1100 �g/d resulting in an effective life of almost three years. The ewes were not iodine deficient, and supplementation by this device did not improve reproductive performance. Thyroxine levels in plasma, and iodine concentrations in tissue, were not elevated to levels which might be considered toxic, confirming the safety of the device.
Productivity of grazed Makarikari grass-lucerne, Rhodes grass-lucerne and lucerne pastures in the northern wheat belt of Australia
Authors: Lloyd DL , Nation JG , Hilder TB , O'Rourke PK
Published: March 2005

Three Makarikari grasses (Panicum coloratum var. makarikariense) viz. 0.4634, cv. Pollock and cv. Bambatsi and Rhodes grass (Chloris gayana) cv. Pioneer, each grown with lucerne (Medicago sativa) cv. Hunter River, and sward lucerne were compared for productivity and stability in a rotational grazing system at three stocking rates (22.2, 14.8 and 7 . 4 Merino wethers/ha for grasslucerne pastures; 14.8, 11.1 and 7.4/ha for lucerne swards) on a cracking clay soil on the Darling Downs, Queensland over four years. There were no differences between the Makarikari grass cvv. Pollock and Bambatsi pastures. However, each produced more dry matter and animal liveweight, and persisted better, than Rhodes grass pasture during dry conditions that occurred during the first two years. Rhodes grass nevertheless recovered during two subsequent wet summers. During those two dry years, wool production from sward lucerne was equal to that of the grass-lucerne pastures at both 14.8 and 7.4 animals/ha. Animal liveweight from lucerne was greater than from grass-lucerne pastures at 7.4 animals/ha only. Wide variation, both between and within seasons, was measured in the quantity of feed produced by pastures in this study. This is discussed in relation to the concept of stocking rate of pasture grown on limited areas of grain farms in the northern wheat belt, and to the provision of a continuing feed supply in integrated crop-pasture systems.
The use of desiccant, defoliant and growth regulating sprays to advance the harvest of edible dry beans (Phaseolus vulgaris) in Tasmania
Authors: Forbes JJ , Pratley JE
Published: March 2005

An experiment tested whether growth regulating chemicals could advance harvesting of edible dry beans (Phaseolus vulgaris) by reducing the moisture content of the pods. Of five chemicals tested at four application times, Endothal, potassium iodide, and potassium iodide plus Ethrel advanced the date of harvest, based on moisture content of the beans, by at least 10 d. Seed yields were greatest at the later application dates of these chemicals. Alar also increased seed yield but did not reduce moisture content.
Biological control of Eutypa armeniacae 5. Guidelines for establishing routine wound protection in commercial apricot orchards
Authors: Carter MV
Published: March 2005

A pilot system is described for production and storage of macroconidia of Fusarium lateritium in quantities sufficient for use in wound protection against Eutypa dieback disease in commercial orchards. Data from field and laboratory experiments confirm the efficacy of F. lateritium at 106 spores/ml and benomyl at 200 �g/ml as wound protectants and reveal the importance of delivering the biocide(s) in sufficient volume of carrier liquid to ensure penetration to the full depth of the infection courts in the host sapwood. It is concluded that protection of commercial apricot orchards from Eutypa dieback by benomyl in water suspension, delivered via pneumatic applicators, is feasible provided that manufacturers of equipment intended for this are willing to observe design criteria which ensure an adequate output of spray fluid. While the population of the pathogen remains sensitive to benzimidazoles, there appears to be no immediate need to develop commercial production of F. lateritium for this purpose.
Effects of pasture availability and liveweight on the feeding of grass hay to grazing sheep
Authors: Birrell HA
Published: March 2005

In the first of two experiments the amount of hay (69% organic matter digestibility) eaten by 1.5 -year-old Corriedale wethers when fed every 2 d was measured in a series of grazing trials to study the effects of pasture availability and liveweight. The greatest amount of hay (1 .8 kg/head. 2 d) was eaten on dry summer pasture, but consumption fell when green growth appeared. During winter, on slow growing pastures, hay consumption (1.3 kg/head .2 d) was highest at about 0.7 t herbage (DM)/ha, but less hay was consumed on plots with lower amounts of pasture. On pasture more abundant than 0.7 t DM/ha hay intake decreased, but small amounts were still eaten at very high yields (about 5 . 0 t DM/ha). Pooled data of all winter observations yielded the following expression for predicting the organic matter intake of hay voluntarily eaten when fed every 2 d (y, g/2 d) from the quantity of pasture available (x, t DM/ha): Y = 330 + 738exp (- 0.0322x4) : r2 = 0.87 ; P < 0.01 Various weather conditions experienced in different periods of one trial changed the responses slightly. Wet or frosty weather reduced hay consumption on sparse pasture relative to that on fine days. Heavy animals (49-57 kg) ate more hay (450 vs 170 g/d) at high availabilities than light animals (44 kg) and spent less time grazing than light animals (5 vs 7 h) indicating a preference by lighter animals for a high quality diet from pasture. In the second experiment, daily consumption of hay (61 % organic matter digestibility) and pasture were estimated at a range of pasture availabilities (0.5- 1.5 t DM/ha). When hay was fed, each 100 kg increment in pasture dry matter availability decreased the voluntary organic matter intake of hay by 57 g/d, while apparent consumption of pasture organic matter increased by 92 g/d. Grazing time was not reduced as much as expected from the substitution of hay for pasture, from 10 h with no hay to 9 h when fed, and suggests a slow rate of pasture intake with selection of higher quality material to complement the hay diet. A practical implication of these results is that heavy animals in good condition will eat hay in preference to grazing pasture, while lighter animals which are assumed to have a greater need for supplement prefer to consume the higher quality pasture.
Effects of different stocking intensities in early life on the productivity of Merino ewes grazed as adults at two stocking rates. 3. Survival of ewes and their lambs, and the implications for flock productivity
Authors: Langlands JP , Donald GE , Paull DR
Published: March 2005

A stocking rate of 20 sheep/ha in adult life was associated with greater mortality of ewes and their lambs than a stocking rate of 10 sheep/ha, but mortality was not affected by the nutrition of the ewes in early life. Survival of lambs born as twins to weaning was 42% at the high stocking rate and 72% at the low. Corresponding values for singletons were 73 and 87%. Differences in survival of singleton but not twin lambs were established during the first 5 d of life. Mortality of ewes was greater at a high stocking rate and by nine years of age approximately twice the number of ewes had died at the high as at the low stocking rate. Incisor wear and losses were greater in sheep stocked as adults at the high stocking rate, and within this flock was more marked in ewes reared at a low than in those reared at a high stocking rate. Severe wear and loss of incisor teeth were not correlated with cumulative mortality at 108 months. Data reported in this and in the two previous papers in this series were synthesized into a computer model which was used to predict wool production and the numbers of lambs and surplus ewes available for sale when culling age was varied from four to eight years. Wool production and the numbers of surplus sheep available for sale were predicted to be greater at the higher stocking rate with the exception of the number of surplus female lambs available from flocks in which their mothers were culled at six years or earlier.
Comparison of the fat status of lambs during continuous growth and following nutritional restriction and subsequent re-alimentation
Authors: Hodge RW , Star M
Published: March 2005

Crossbred lambs were allocated to one of four treatments: continuously grown at pasture; weaned and fed hay to maintain liveweight at 32 kg for 120 d and re-alimentated by grazing at pasture; fed peas and hay ad libitum or at restricted levels in a feedlot. The lambs were slaughtered at 32, 37,42 and 47 kg unfasted liveweight. Results of multiple regression analyses showed that carcasses of the continuously grown lambs contained significantly more subcutaneous fat in the 9th- 12th rib cut and significantly more kidney and channel fat than the carcasses of the re-alimentated lambs. Similar results were obtained from measurements of the depth of subcutaneous fat at 13 sites on the carcass and from subjective appraisal of fat status. The equations showed that these effects were greatest at carcass weights of 14- 17 kg and that the difference in fat status lessened as carcass weight of the re-alimentated lambs increased. During re-alimentation, neither the rate of carcass gain nor type of diet significantly affected the various measurements of fat status.
Feeding value of subterranean clover, lucerne, phalaris and Wimmera ryegrass for lambs
Authors: Freer M , Jones DB
Published: March 2005

The feeding values of subterranean clover, lucerne, phalaris and Wimmera ryegrass were measured in three experiments using weaned lambs. With dried herbage, the voluntary intake of each species increased linearly with organic matter digestibility over the range tested (57-83%). Regressions for the two grasses did not differ from each other, nor did those for the two legumes; a common regression for the legumes had the same slope as that for the grasses but dry matter intake was about 190 g/d greater on legume diets. Digestibility accounted for 50 and 68% of variation in intake of legumes and grasses, respectively, but when cellulose concentration in the diet was used as the predictor, a single regression satisfied all the data and accounted for 76% of variation in intake. Energy retention by weaned lambs offered diets of dried subterranean clover or lucerne was 53% greater than that by lambs receiving the same intake of metabolizable energy from phalaris. When the intake of the two legume diets was unrestricted, this difference increased to 128%. Despite the 30% higher voluntary intake of the legume diets, the weight of digesta in the reticula-rumen at the end of a meal was the same as it was for the phalaris diet. When all four species were compared in the field, with herbage amply available, lambs grazing the two legumes retained 57% more energy than those on the grasses during the main spring period when the species were of comparable digestibility. As there was little or no difference, under the conditions of this experiment, in the intake of food from the four swards, it is concluded that the difference in feeding value resulted from more efficient use of metabolizable energy. Overall, subterranean clover had as high a feeding value for lambs as lucerne, and phalaris was not inferior to Wimmera ryegrass.
Intake, digestion, and nitrogen and sulfur retention in Angora goats and Merino sheep fed herbage diets
Authors: Doyle PT , Egan JK , Thalen AJ
Published: March 2005

The voluntary intake and digestion of three pasture hays of varying quality by Angora goats was compared with that by Merino sheep. The excretion and retention of nitrogen and sulfur were also measured. When a high quality hay was given, there were no differences between goats and sheep in the intake of organic matter (68 vs 61 g/kg0.75.d) or in organic matter digestibility (digestible organic matter intake) (72 vs 7 1 %). However, the goats appeared to utilize nitrogen less efficiently than the sheep as evidenced by nitrogen retention (673 vs 794 mg/100 g digestible organic matter intake.d), and there was a tendency for sheep to use absorbed energy more efficiently for body tissue synthesis. The apparent digestion of organic matter (65 vs 57%), plant cell wall constituents (67 vs 59%), nitrogen (29 vs 19%) and sulfur (40 vs 33%) in a medium quality hay low in nitrogen was greater in goats than in sheep. There were no differences in intake, but the goats were more efficient at conserving nitrogen (nitrogen retention -87 vs -200 mg/ 100 g digestible organic matter intake.d). Similar trends occurred when a poor quality hay with a higher nitrogen content was given. Goats have apparent advantages over sheep in their ability to digest fibrous feeds and conserve limiting nutrients from such feeds. Consequently, they may require less supplementary feeding than sheep in temperate areas during late summer and autumn when animals graze mature pastures.
Poppy seed meal (Papaver somniferum) as a protein source for growing pigs
Authors: Statham M
Published: March 2005

Oil-extracted poppy seed meal was examined for its value as a pig-feed protein source. The material had a crude protein content of 37.8% and digestible energy content of 13. 1 MJ/kg dry matter. A trial using growing pigs indicated the absence of any growth-depressing factors and, apart from a lower lysine content, a protein quality similar to that of soybean meal.
A comparison of methods of estimating lucerne population for monitoring persistence
Authors: Lodge GM , Gleeson AC
Published: March 2005

Two sowing rates, 4 and 12 kg/ha, and two sowing methods, broadcast and drilled into 18 cm rows, were used to give different population densities and spatial distributions of a semi-winter dormant lucerne, Condura 73 Brand, in mown dryland plots. Lucerne population in these plots was monitored for the first 12 months after sowing by either estimating the frequency of cells occupied by plants, using a 1 m2 steel mesh with a 10 cm x 10 cm or a 5 cm x 5 cm grid, or estimating plant population by taking crown counts at the soil surface. To estimate the true plant population for each sowing rate and method, plots were excavated regularly and plant tap roots counted. Crown counts consistently underestimated the true plant population over the range of 35-450 plants/m2. The underestimation was greater at the higher sowing rate. At populations greater than 150 plants/m2, frequency estimates were not sensitive to changes in plant numbers, but within the range of 20-80 plants/m2 they reliably reflected changes in plant populations. In a second experiment, six lucerne cultivars with a range of dormancy characteristics and crown structures were used to investigate the effect of crown size and type. Although crown counts underestimated (P<0.05) the actual plant population of a highly winter active, narrow-crown cultivar, there were no significant differences between cultivars in the number of plants or their frequency estimates.
Breeding disease resistant, aphid resistant lucerne for subtropical Queensland
Authors: Clements RJ , Turner JW , Irwin JAG , Langdon PW , Bray RA
Published: March 2005

The breeding and preliminary evaluation of two new lucerne cultivars are described. Each is shown to possess a satisfactory level of resistance to Phytophthora megasperma f.sp. medicaginis (Phytophthora root rot), Colletotrichum trifolii (Colletotrichum crown rot), Therioaphis trifolii f, maculata (spotted alfalfa aphid) and Acyrthosiphon pisum (pea aphid) and a lower but adequate level of resistance to A. kondoi (blue-green aphid). The first cultivar, code-named APC Cycle 3 and subsequently released as cv. Trifecta, is a broadly based cultivar with a genetic background substantially based on cv. Hunter River. In a field trial at Gatton Research Station, it outyielded cv. CUF 101 by 19%, cv. Siriver by 24% and cv. Hunter River threefold over a 16-month period, and persisted significantly better than those cultivars. It showed some winter activity and was classified as winter active in Queensland. Polycross progeny testing showed that APC Cycle 3 contains significant genetic diversity for yield and persistence, and further response to selection for these characters could be obtained. Heritabilities ranged from 0.79 to 0.86 for yield and persistence. A positive genetic correlation (rg= 0.87) between winter yield and main season yield was measured, and yield was positively correlated genetically with persistence. The second cultivar, code-named SP Cycle 3 and subsequently released as cv. Sequel, was derived from cvv. Siro Peruvian and CUF 101. It is highly winter active.
Long term patterns of seed softening and seedling establishment from single seed crops of subterranean clover
Authors: Taylor GB , Rossiter RC , Palmer MJ
Published: March 2005

Single seed crops of eight varieties of subterranean clover (Trifolium subterraneum) were grown in swards in four successive years in a medium rainfall environment at Bakers Hill, Western Australia. Measurements were made of seed production, the progress of seed softening within the first two summers, and residual hard seed and seedling numbers after the break of season for up to six successive regeneration years. Patterns of seed softening were also measured in a laboratory oven with a diurnal temperature fluctuation of 60/15�C. Approximately half the seeds of all varieties softened over the first summer and generally well over half the residual seeds softened during the second summer. Up to 18% of seeds of the hardest seeded variety, Northam, and 11% of Geraldton seeds persisted to the end of the third summer as hard seeds. Seed softening patterns showed a significant variety x regeneration year interaction due mainly to a slower rate of softening of Northam seeds relative to the other varieties after the first summer. In six of the varieties, seeds generally softened more slowly in the laboratory than in the field but in the case of the other two varieties this trend was reversed. Nevertheless, ranking of varieties for rate of seed softening was similar in field and laboratory. Seedling establishment ranged from 28 to 100% of soft seeds, depending on the incidence of late summer and autumn rains. It appeared that all varieties in the study would regenerate satisfactorily at densities of more than 15 plants/dm2 after at least one year in which little or no seed is set. Slower rates of softening would probably be desirable in drier regions or in rotation systems involving cropping.
Correction - Effects of crop residue incorporation on soil porperties and growth of subsequent crops
Authors: White PJ
Published: March 2005

A field study was carried out on four black earths to identify major factors influencing soil and plant growth traits when crop stubble was removed from or incorporated in the seedbed. The aim of the experiment was to identify important variables for further research. Wheat (Triticum aestivum), barley (Hordeum vulgare), sorghum (Sorghum bicolor) and sunflowers (Helianthus annuus) were used as both stubble species and test crops. A range of stubble quantities (596-11080 kg/ha) and qualities (C:N, C:P and C:S ratios of 24-148, 125-1600, and 182-1000 respectively) and periods of incorporation (up to 67 d) were involved. Data were analysed by paired t-tests and regression with combinations of factors. The technique used is discussed and its limitations examined. Due to logistical constraints, randomization was restricted, stubble removal technique was varied and a rotary hoe was used instead of conventional tillage machinery. Nitrate nitrogen (0- 10, 10-20 cm) was depressed when stubble was incorporated and this was related to the stubble C:N ratio. The effects on ammonium nitrogen (0-10 cm) and phosphorus (0-10 cm) were unclear. Stubble quantity was not well correlated. The importance of environmental factors during incorporation was unclear. During the inter-crop period, soil water content at 0-6 cm was significantly increased for up to 4 d after rainfall or irrigation when stubble was incorporated, and this was related to stubble quantity. It is suggested that stubble incorporation increased the volume of large soil pores which were filled by rain but subsequently dried rapidly. Likely short and long term effects of stubble incorporation on soil water are discussed. Incorporation of stubble did not consistently affect plant emergence or seedling vigour. Patchy stands in commercial crops may be due to isolated pockets of stubble formed by inadequate spreading of trash after harvesting or cultivation. Significant depressions of plant growth occurred later at sites 1 and 2 (wheat and barley) but not at sites 3 and 4 (sorghum and sunflowers). These depressions were primarily related to soil nitrate nitrogen (0-10, 10-20 cm) which was depressed by the wide C: N ratio of added stubble. Plant growth was positively correlated with stubble quantity at sites 2 and 3, and this was related to the sulfur and phosphorus contents of the stubble, respectively.
Migration of stored-grain insect pests from a small wheat bulk
Authors: Sinclair ER , Alder J
Published: March 2005

One hundred unsexed adults of each of the following coleopterous species were added to 27 .3 kg of clean wheat: Sitophilus oryzae (L.) (rice weevil), Rhyzopertha dominica (F.) (lesser grain borer), Tribolium castaneum (Herbst) (rust-red flour beetle), and the flat grain beetles Cryptolestes pusillus (Schonherr), C. ferrugineus (Stephens), and C. pusilloides (Steele and Howe). For 15 months, measurements were made of population size and emigration from this wheat bulk. The highest populations recorded for each species were: 138 850, 65 680, 9 060, 47 000, 15 530, 11 940, respectively, and total emigrant numbers during the period were: 774 682, 278 094, 123 784, 335 588, 39 070, 9 352, respectively. Such high numbers of emigrants in relation to relatively low source populations emphasize the significance of small amounts of infested grain as sources of infestation of large grain bulks, and hence the importance of grain hygiene. The proportion of females in the populations of four species changed significantly from 0.50 as populations developed. Emigration behaviour was influenced most commonly by temperature, insect numbers, and wheat age, but these factors did not act uniformly on all species. Negligible numbers of emigrants returned to the food source. Low numbers caught in food traps away from the source were consistent with these not being attractive but traps near the shed walls caught greater numbers than expected.
Evaluation of techniques for estimating the yield of irrigated pastures intensively grazed by dairy cows. 1. Visual assessment
Authors: Stockdale CR
Published: March 2005

A visual assessment technique was evaluated for estimating pre- and post-grazing pasture yields in experiments in which dairy cows rotationally graze irrigated pastures. Visual assessment, when associated with the harvesting of standard quadrats, accounted for 62.3 and 68.4% of the variability in pre- and post-grazing yield, respectively. The mean residual standard deviations associated with the pre- and post-grazing regressions were 490 and 395 kg dry matter/ha and, when the variable yields were taken into account, these represented coefficients of variation of 15.6 and 19.0%, respectively. By using the coefficient of variation as the criterion for precision, pre-grazing regressions were significantly more precise than post-grazing regressions. In practice, visual assessment by a double sampling procedure can be used to estimate pre- and post-grazing yields in dairy cow grazing experiments where herbage intakes and growth rates are required, provided sufficient readings are taken to allow an acceptable level of precision. It is suggested that about ten standards are required to formulate a calibration regression regardless of whether or not the pasture to be assessed has been grazed. Although the double sampling technique may be suitable for research purposes, it has been demonstrated that the completely subjective eye appraisal, often used by farmers and their advisers for feed budgeting, can result in many incorrect assessments. A more objective technique needs to be developed for this purpose.
Effects of pasture type and grazing management in autumn on the performance of dairy cows in late lactation and on subsequent pasture productivity
Authors: King KR , Stockdale CR
Published: March 2005

An experiment at Kyabram, Victoria, studied the effects of pasture allowance on the production of grazing dairy cows in late lactation (autumn). Cows strip-grazed paspalum dominant or ryegrass-white clover perennial pastures for 60 d from March to May. Mean pasture allowances were 23.2, 13.3 or 6.9 kg digestible dry matter/cow.d. Reduced pasture allowance during late lactation reduced milk yield and body condition. This occurred because pasture intake was positively related to pasture allowance. Each additional kilogram of dry matter (DM) eaten produced 0.93 kg milk and 0.045 kg milk fat. Cows grazing ryegrass-white . clover pastures produced more milk and milk products at equivalent DM intakes than did cows grazing paspalum dominant pastures, and they were in better condition. This was due to herbage quality: cows grazing ryegrass-white clover pastures were able to select higher quality diets than could those grazing paspalum dominant pastures. When the results were compared with those from two previous stall-feeding experiments, the marginal efficiencies for milk production in all experiments were not significantly different; an extra 1.19 kg fat corrected milk was produced for each additional kilogram of digestible dry matter of pasture eaten. . The pastures were not grazed from May to September but their growth and quality were measured during this period. The amount of pasture left at drying off influenced the growth and quality of the pastures throughout winter: daily growth declined by 3.31 kg DM/ha between May and July, and by 6 56 kg DM/ha between July and September, as herbage yield at drying off (May) increased by each additional tonne of DM per hectare. Also, the ryegrass-white clover pastures grew more herbage at equivalent DM yields than did the paspalum dominant pastures. The implications of these results for grazing management are discussed.
Effects of pasture type on the growth and wool production of weaner sheep during summer and autumn
Authors: Kenny PT , Reed KFM
Published: March 2005

The productivity of weaner sheep grazing lucerne, white clover, red clover or Persian clover and pastures sown with subterranean clover and perennial ryegrass, cocksfoot or tall fescue, was measured in summer-autumn trials incorporating four soil types in each of three years. During summer and autumn, the mean growth rate of sheep grazing lucerne, white clover or Persian clover pastures was 50 g/d compared with 1 g/d for sheep grazing perennial grass-subterranean clover pastures. Sheep grazing strawberry clover on reclaimed swampland, and sheep in a feedlot (fed hay and lupin grain) averaged 100 and 75 g/d, respectively. Sheep grazing red clover averaged 45 g/d over years 1 and 2. In year 2, a subterranean clover-dominant pasture was included in the study. Its feeding value was similar to that of the perennial grass-subterranean clover pastures. Sheep grazing legume pastures, and sheep in the feedlot, consistently produced more wool (up to 700 g/head) than sheep grazing the perennial grass-subterranean clover pastures. The concentration of neutral detergent fibre in herbage from legume pastures was frequently lower (P< 0.05) and the concentration of crude protein was frequently higher (P< 0.05) than in herbage from grass pastures. The dry matter digestibility of legume herbage was higher (P<0. 05) than that of grass herbage on only one occasion. Measurements of crude protein and neutral detergent fibre of pasture in December accounted for 67% of the variation in liveweight gain (P<0.01). Ewe weaners grazing red clover pasture exhibited an increase (P< 0.05) in teat length of 3.9 mm in 21d of grazing. Oestrous activity of ewe weaners was related to liveweight gain (r = 0.77). The implications of the results for agricultural systems are discussed.
Prediction of bone-in retail cuts and edible meat of crossbred lamb carcasses
Authors: Hodge RW , Oddie N
Published: March 2005

Multiple regression equations describing the percentage yield of bone-in retail cuts and edible meat were developed for lamb carcasses ranging in breed (lambs from Border Leicesterx Merino ewes sired by Suffolk, Southdown, Poll Dorset and Corriedale rams), sex (entire males, wethers and ewes) and carcass weight (12-25 kg). The regression equations first developed contained carcass weight as the sole predictor and these were compared with equations containing carcass weight and two additional predictors: fat depth over the 12th rib and percentage kidney and channel fat. Breed and sex, conformation score, carcass length and leg length were tested with carcass weight in separate analyses. The equations containing carcass weight and measures of fat status accounted for more of the variation in yield of retail cuts and edible meat and had lower residual standard deviations (RSD) than did equations containing the other variables. Fat depth, and percentage kidney and channel fat provided a similar degree of accuracy in predicting the percentage of retail cuts (RSD of 2.96 and 2.87 respectively) or edible meat (3.33 and 3.17 respectively). Inclusion of the quadratic terms had no significant effect on the values for RSD. The variation in fat status of 17 kg carcasses was such that the predicted yields of retail cuts or edible meat ranged from 65 to 71 % and from 49 to 55%, respectively. It was concluded that a lamb classification system need only provide objective information on carcass weight and kidney and channel fat to enable the industry to identify carcasses differing in economic value.