bluuebunny/crossref_metadata_2025 huggingface dataset:
Rhizobial inoculation and fertilizer rates as factors in the establishment of subterranean clover in South Australia
Authors: Harris JR
Published: November 2004

The rate of application of phosphatic fertilizer was found to be the most important single factor influencing first year establishment of sown pastures of subterranean clover. In soils of low fertility in South Australia, increases in the rate of application of superphosphate were accompanied by decreases in the number of unthrifty plants and increases in herbage yield. A minimum rate of superphosphate was found to be necessary to ensure a satisfactory establishment. The use of lime in the form of basic superphosphate was accompanied by increase in yield and decrease in the number of poor plants, but current theories are inadequate to explain its mode of action. Use of a trace element mixture containing copper, zinc, manganese, and molybdenum produced significant increases in yield, but did not decrease the number of poor plants.Heavy dressings of artificial nitrogenous fertilizers or inoculation by effective strains of Rhizobium trifolii Dang. produced increases in yield, but did not produce significant reduction in the number of poor plants. Untreated, control plants showed regular nodulation, and it was found that an indigenous population of strains of Rh. Trifolii apparently efficient in nitrogen fixation already existed in these soils. Increases in herbage yield of as much as 50% were obtained in the first year; this justifies recommending rhizobial inoculation as a commercial practice, but the effect was not sustained in subsequent years. There was no evidence to indicate that lack of artificial inoculation would jeopardize establishment of sown pastures in these soils.
Loss of zirconium from 12 soils derived from granite
Authors: Wild A
Published: November 2004

Analyses are given for zirconium in 12 soil profiles formed from granite in Sew South Wales and Queensland. On the basis that on rock weathering there is no change of volume, it is shown that a loss of zirconium is general in the lower horizons of the profiles and amounts to 20–50% of the rock zirconium. The high losses imply loss of zirconium from grains of zircon. In view of the use of zircon ns an index mineral in soil studies, it is important that the size of zircon grains which are affected should be further investigated.
Flower initiation in relation to maturity in crop plants. II. Internode lengthening in relation to grazing in oat varieties
Authors: Aitken Y
Published: November 2004

Experience has shown that certain oat varieties recover better than others after grazing. Sowings at, Melbourne in autumn 1958 and 1959 confirm that the varieties with superior recovery usually commence internode lengthening later than those with poor recox7ery. Poor recovery is due to damage of the main shoot caused by grazing after internode lengthening has begun. Factors which affect the time of internode lengthening include flower initiation and the time of sowing. In sowings between May and November (late autumn to late spring) elongation begins at or soon after initiation. It therefore occurs earlier in the early-maturing varieties (which initiate earlier) than in later ones. In sowings between December and April, some varieties, especially within the late maturity group, begin internode elongation before initiation. This reaction can be produced experimentally by high temperatures, especially when combined with photoperiods below 15 hr. In the selection of varieties for grazing, the factors to be considered are: (a) the length of growing season; (b) the time at which, and period over which, grazing is required; (c) the extent to which recovery after grazing is important. If a high total yield from a number of grazings is required, a variety with delayed internode lengthening should be chosen, the particular one selected being from a maturity group suited to the local growing season. However, if early grazing is required, a variety with rapid internode lengthening d l probably prove to be a better choice even though grazing may be at the expense of subsequent recovery.
Flowering of Australian wheats and its relation to frost injury
Authors: Gott MB
Published: November 2004

It is known that the onset of the reproductive stage in wheat is an important factor in determining severity of damage by frost. Nineteen Australian and five overseas varieties have been tested for their sesponse to cold treatment of the seed (vernalization) and length of day (photoperiod), two factors known to influence ear formation. Many of the Australian wheats, although of the spring type, show small but, definite acceleration of ear initiation after vernalization treatment, although the period of ear development after initiation is unaffected. The Australian winter type of Minflor behaves similarly, but with a greater acceleration, characteristic of its winter habit. Minflor Winter wheat may be vernalized by cold temperature not only as a seed, but at any time during vegetative growth. Neither guanosine nor gibberellin replaced vernalization in a winter wheat. Short (9 hr) photoperiod delays ear initiation in all varieties, vernalized or non-vernalized, compared with continuous light, but varieties differ greatly in their sensitivity to day length. After initiation, some varieties are relatively unaffected by short day in the development of the ear, while others continue to be delayed. Minflor Winter is one of the varieties least delayed by short day. No 'short day induction' of unvernalized plants could be demonstrated, although there was an early period of indifference to day length in both a spring and a winter variety. Field behaviour in the light of the vernalization and photoperiodic responses, and their influence on frost escape, are discussed. In view of the genetic bases of these responses, the wider employment of controlled conditions is likely to prove useful to Australian wheat breeders in the future.
Total body water in Merino and Romney Marsh Sheep estimated by alcohol (ethanol) dilution.
Authors: Budtz-Olsen OE , Cleeve JD , Oelrichs BA
Published: November 2004

A simple method for the estimation of total body water in sheep by alcohol dilution is described. It was found that Romney Marsh ewes have a significantly higher water content than Merinos. Increased total body water is therefore not the factor which allows the Merino to survive in a hot dry environment in which the Romney Marsh does not thrive. It is pointed out that total body water cannot be used in the usual way for the determination of the fat content in live sheep.
The development of cuttings of the Washington navel orange to the stage of fruit set. I. The development of the rooted cutting
Authors: Gates CT , Bouma D , Groenewegen H
Published: November 2004

The development of rooted cuttings of the Washington Navel orange through two cycles of growth is described, and the effects of phosphorus nutrition and the relative value of nitrate and ammonium as sources of nitrogen are assessed. Alternation of shoot and root development over the period of the experiment was observed. There appeared to be no build up of dry matter reserves in the plant tops before new shoot initiation, but rather a rhythmic distribution between root and shoot of the dry matter assimilated. The initiation of new shoots was followed by a rapid increase in leaf area, by an increase in dry matter per unit leaf area, by a rapid increase in whole plant dry weight, and by higher growth rates. In this latter respect, the behaviour of this woody perennial contrasts with the normal growth pattern of annuals, where the growth indices tend to fall with time. Phosphorus shortage delayed plant development, so leading to lower dry weight values in all plant parts. No differences in growth due to nitrate or ammonium as sources of nitrogen could be detected.
The development of cuttings of the Washington navel orange to the stage of fruit set. III. The fruiting cutting
Authors: Gates CT , Bouma D , Groenewegen H
Published: November 2004

Studies of the effect of NPK fertilization on fruiting cuttings of the Washington Navel orange are described and are considered in relation to previous developmental studies. Fruiting occurred on the second cycle growth flush. The growth of the plant as a whole was affected by nutrient supply. Where fruit was developed, its development was at the expense of the rest of the plant, and especially of the parts nearest to it. In this regard, the dominant role of the fruit with respect to the vegetative parts, differed from the somewhat uniform pattern of response between the vegetative parts that was previously observed for a differential in phosphorus supply. The importance of adequate nutrition in early stages of fruit development is apparent, and the value of the technique in field studies is noted.
The relationship between acquired resistance to Peronospora tabacina in Nicotiana tabacum and soil nitrogen levels
Authors: Mandryk M
Published: November 2004

When plants (Nicotiana tabacum L. cv. Virginia Gold) were supplied with suboptimal levels of nitrogen, the acquired resistance to blue mould (Peronospora tabacina Adam) evoked by injection of spore suspensions of the same pathogen into stems was associated with dwarfing, reduction in leaf areas, nitrogen deficiency-like symptoms, and premature senescence. However, when plants were supplied with adequate nitrogen, no morphological changes were associated with acquired resistance. The protective effect of stem injection against subsequent leaf infection was shown to be persistent and not affected by plant vigour, age, or soil nitrogen level. The protective effect of stem injection against subsequent leaf infection was shown to be persistent and not affected by plant vigour, age, or soil nitrogen
level.
A study of the incisor teeth of beef cattle
Authors: Tulloh NM
Published: November 2004

The width of the dental bridge across the four pairs of incisors was measured in Hereford, Angus, and Shorthorn cattle. Width across the incisors increased rapidly from birth until the age of 7 months. It then remained practically unchanged until the age of 20 months after which width increased rapidly during the eruption of the first pair of permanent incisors. Further rapid increases occurred during the eruption of other permanent incisors. At the age of 13 months when all animals in one group of cattle had reached mature width across their deciduous incisors, this measurement was significantly greater in steers than in heifers. At this same age width across the incisors was significantly greater in Hereford and Angus cattle than in Shorthorns, and significantly greater in Hereford than in Angus cattle. No significant relation was found between width across the incisors and body weight or body weight gain in cattle with normal deciduous incisors. Similarly, the reduction in width following the extraction of the outside lateral deciduous incisors had no significant effect on body weight gain. The heritability of width across the incisors was calculated as twice the standard correlation coefficient between measurements of cows and their qffspring, and was found to be high (2r = 0.656). It is concluded that width across the incisors is a character which was of no economic importance under the grazing conditions used. The mean age (days) at which one or both of the first pair of permanent incisors were fist observed in steers was significantly less in Shorthorns (681.2 ± S.E. 11.5) than in Hereford (724.9 ± S.E. 14.9), with Angus cattle (708.3 ± S.E. 10.7) not significantly different from either of the other breeds. The eruption process for the first permanent incisors has been described in six stages, and the periods to pass through three of these stages have been estimated. The medial time for the whole process was 99 days. No check in body weight gain was associated with the eruptioa process.
Interspecific hybridization in Phalaris: Hybrids between Phalaris tuberosa and the hexaploid race of Phalaris arundinacea
Authors: McWilliam JR
Published: November 2004

Interspecific hybrids from the cross Phalaris tuberosa (2n = 28) x Phalaris arundinacea (2n = 42) are described. The close relationship between P. tuberosa and the hexaploid race of P. arundinacea is indicated by the ease of hybridization. The F1 hybrid is functionally male-sterile, but sets occasional seed when backcrossed to P. tuberosa. Meiosis in the 35-chromosome F1 hybrids was irregular. Pairing at diakinesis averaged 11.3 bivalents, with a range of 7–14. Univalents were present in all hybrids, averaging 10.3 per cell, and were observed as laggards at anaphase I and II. Sterility appears to be largely chromosomal, associated with numerical and structural differences between partially homologous genomes. The cytological behaviour of the 70-chromosome allopolyploids, produced by doubling the F1 hybrids, was fairly regular. The predominant diakinesis association was in the form of bivalents, with a mean value of 32.1. Univalents and quadivalents were present, but at a low frequency. There was a continued expression of allosyndetic pairing as indicated by the formation of bridges and fragments at anaphase. The average fertility of allopolyploids, despite irregularities at meiosis, was high, and only 30% below the P. tuberosa controls. The growth of the F1 hybrids was superigr to that of the parents, both in the seedling stage and in swards. This superiority was most pronounced in the autumn and summer. In this respect the hybrid combines the seasonal growth characteristics of both parents. The unusual vigour, long growing season, and adaptability of the hybrid justify efforts to develop it as a commercial variety. Three possible plant-breeding approaches to achieve this objective are presented.
Effects of previous superphosphate applications on the pasture environment and the response by pasture to a current dressing
Authors: McLachlan KD , Norman BW
Published: November 2004

A study was made of the effect of previous superphosphate applications on the response by pasture to the calcium, phosphorus, and sulphur in a current dressing. The trial was located on the Southern Tableland of New South Wales on soils of granitic, sedimentary, and basaltic origin. In each case the legume component of the pasture was subterranean clover (Trifolium subterraneurn L.). The evidence shows that there is scope for altering the phosphorus and sulphur content of superphosphate to produce more efficient fertilizers for particular stages in pasture development and for particular soils. The residual value of the phosphorus was greater than the residual value of the sulphur in superphosphate. Even on the basaltic soils, phosphate "fixation" was of no practical significance. Nevertheless, any change in the relative phosphorus sulphur requirement of pastures with increasing amounts of superphosphate previously applied, resulted from a decline in the requirement for phosphorus, not from a change in the sulphur requirement. The number of years since the last application of superphosphate was shown to be the best predictor of responses to both phosphorus and sulphur, which indicated that the residual value of both these elements is limited in time. Implications of the lapse rate – the decline in effectiveness of the fertilizer with time – are discussed. The results show that pasture production was limited by phosphorus deficiency on soils where previous evidence suggested that the build-up of organic matter may be limited by sulphur deficiency.
Studies on the carbohydrate metabolism of sheep. XVII. Feed requirements and voluntary feed intake in late pregnancy, with particular reference to prevention of hypoglycaemia and hyperketonaemia.
Authors: Reid RL , Hinks NT
Published: November 2004

The increase in nutrient requirements of ewes with advancing pregnancy has been measured in terms of the additional feed necessary to prevent hyperketonaemia, with particular reference to the difference between ewes carrying single and those carrying twin lambs. The additional feed required during late pregnancy to prevent the ewe drawing appreciably on body reserves depended on the total foetal weight. In twin-bearing ewes the increase in the last 2 weeks of pregnancy was as high as 80% of the ewe's own maintenance requirements; the total requirement usually exceeded the voluntary feed intake during this period. It is concluded that the efficiency of utilization of the metabolizable energy of the additional feed is low, and that the additional feed requirement depends on the bodily condition of the ewe. In contrast to ewes in medium body condition, the voluntary feed intake of fat, twin-bearing ewes declined markedly in late pregnancy. This decline was not simply a consequence of reduction in abdominal space due to the large volume occupied by twin foetuses or by abdominal fat. The fat pregnant ewe, when undernourished as a result of a marked decline in voluntary feed intake, was better able to maintain blood glucose, and hence blood ketone levels, in the normal range than the ewe in medium body condition, but there was evidence that birth weights and viability of twins were low. In consequence, the usefulness of ketone level as a general criterion of undernutrition during pregnancy is restricted, but it is suggested that the technique used has special applications in nutritional studies on pregnant ewes.
Corrigendum - Effect of local advection on evaporation rate and plant water status.
Authors: Millar BD
Published: November 2004

The effects of local advection on the evaporation rate (E) and the relative turgidity (RT) of Ladino clover grown in lysimeters were measured at four distances down wind from the leading edge of a small irrigated field adjoining a drier area. Both E and RT decreased with increasing distance down wind from the leading edge, and were directly proportional to powers of the down-wind dimension (x). Presumably plant growth rate may also depend on the distance down wind.Plants near the leading edge showed early afternoon wilt during a mild day in autumn, although soil moisture content was very high. This is in keeping with the concept of a "ceiling absorption rate". Some agronomic implications of these advective effects are discussed.
Nutritional evaluation of meat meals for poultry. I. Variation in quality and its association with chemical composition and ash and lipid factors
Authors: Sathe BS , Cumming RB , McClymont GL
Published: November 2004

On the basis of chick growth and efficiency of feed conversion, wide variation in the nutritional value of Australian meat meals has been observed, with all samples inferior in value to imported fish meal. No necessary relationship was observed between the crude protein and fat contents of the meals and the chick growth-promoting ability or efficiency of feed conversion. Small variations in growth response were significantly associated with the amount of ash contributed by meat meals to diets. However, ash was not the major cause of the differences between high and low quality meals. The addition of ash or ether extract from low quality meat meal to high quality meal did not indicate the presence of growth-depressing or toxic factors in these fractions. The results are interpreted as indicating that neither total protein content, ash content, or lipid content, nor ash or lipid toxic factors was the main cause of variation in the nutritional value of the meat meals studied.
Thermal insulation of short lengths of Merino fleece
Authors: Bennett JW , Hutchinson JCD
Published: November 2004

The thermal insulation of the air and of short lengths of fleece, such as might be left after shearing, has been determined with a hot plate apparatus in various sites on the trunk of a model sheep. The model was placed in a wind tunnel and could be set at any angle to the wind. The insulation of the fleece in still air was about 1.5 clo units per cm, being similar to that found by others for the pelage of many mammals and for the best clothing materials. The superiority in still air of the insulation of fleece plus air for a 1.27 cm (½ in.) length over that of 0.48 cm (3/16 in.) length was maintained in wind. The effect of wind on insulation of the fleece alone at an individual site depended on the angle of the sheep to the wind. The angle of incidence of the wind was as important as the rate of air movement at the site. For the trunk of the sheep as a whole, angle to wind was not important. The longer lengths of fleece were more affected than the shorter lengths. Thus, at a wind speed of 10-11 m.p.h. the insulation of a 0.48 cm length averaged 1.34 clo/cm, but it was only 1.10 clo (high midside site only) for a 2.54 cm (1 in.) length. The insulation of the air was not greatly different from that found by previous workers for man. The reasons for the difference are discussed, and the application of the present data to fleeced animals and field conditions is explained. For this, the convection term has been calculated so that the data can be used in conjunction with other values of radiative exchange appropriate for field conditions. The relation between fleece length and net cooling by evaporation from the tips of the fleece is discussed in the light of the experimental results, and also the relation of these results to Priestley's (1957) calculation of solar heat load on a sheep.
The inheritance of black pigmentation in a family of inbred Peppin Merinos
Authors: Hayman RH , Cooper DW
Published: November 2004

Recurrence of pigmented sheep has been recorded in a family of inbred Peppin Merinos. A recessive gene w has been postulated to account for the presence of pigment. Pigmented types are classified into three categories: head pattern, piebald, and black spotted. It is suggested that the pattern of pigmentation is affected by other genes. A description of two types included in the classification head pattern is given.
The application of body weight data to performance testing of beef cattle
Authors: Seebeck RM , Campion DW
Published: November 2004

A least squares method particularly suited to automatic computation, for calculating adjustments to remove extraneous variation in performance test data, is described. Multiplicative adjustments can be calculated for discontinuous variables, e.g. sex, or for continuous variables, e.g. age at weaning. By calculation of all desired adjustments simultaneously each adjustment factor is as free as possible from the effects of the other variables. Results are given of the application of the technique to weaning weights of stud Hereford and Aberdeen Angus cattle reared on one property. With the use of several different models of analysis, the effects of age of dam, sex, year of birth, age at weaning, sire, and birth weight were investigated and comparisons drawn between the two breeds used, and between this study and other published work. The effect of some of these variables on birth weight is discussed, and the relative effects of some of the variables on weaning weight and birth weight compared. The use of a combination of traits to form a selection index is also discussed.
Two unrelated viruses which cause woodiness of passion fruit (Passiflora edulis Sims)
Authors: Taylor RH , Kimble KA
Published: November 2004

In Victoria cucumber mosaic virus (CMV) has been shown to be the cause of the woodiness disease of Passifloua edulis. This virus causes a slow decline of infected P. edulis seedlings, and a more rapid decline of vines grafted onto P. caerulea rootstocks. In Queensland a similar disease of passion fruit also occurs. The Queensland disease was shown to be caused by a virus which differed markedly from CMV, This virus, which is designated herein as passion fruit woodiness virus (PWV), has flexuous rod-shaped particles about 670 mµ in length. PWV was shown to be stylet-borne by the aphid Myzus persicae and to be transmitted to Phaseolus vulgaris and Sesbania exaltata by sap inoculation. The physical properties of PWV were determined, and two isolates of the virus were purified and antisera prepared against them.
Status of introduced parasites of Queensland fruit fly (Strumeta tryoni), 1960–1962
Authors: Snowball GJ , Lukins RG
Published: November 2004

The paper describes fruit sampling carried out in eastern Australia during January 1960–March 1962 to assess the status of parasites of the oriental fruit fly (Dacus dorsalis) liberated in Australia during 1956–1959 against the Queensland fruit fly (Strumeta tryoni). Opius oophilus was the only introduced parasite extant on the mainland in 1962, parasitizing up to 78% of the host fly stages in Averrhoa carambola in north Queensland and 0–35% in other fruit types. O. oophilus was well established in north Queensland at five localities near Cairns and two near Innisfail, and less well established at three localities near the Queensland–New South Wales border. It had died out during 1960 from two localities further south in New South Wales in which it had been well established since late 1958. O. oophilus was present on Lord Howe Island from October 1959 to March 1961 but died out subsequently. O. longicaudatus was extant in low numbers on the island in 1962. Under Australian conditions Opius oophilus mated satisfactorily. The parasite was able to utilize as hosts fruit flies of the following species: Strumeta barringtoniae, S. cacuminata, S. humeralis, S. tryoni, and possibly Afrodacus jarvisi and S. kraussi, but preferences could not be measured with available techniques. Although it was reared from a total of 14 types of fruits, O. oophilus displayed marked discrimination between fruits, but the preferences varied with season and locality. The most consistent preference was for Averrhoa carambola in north Queensland. O. oophilus showed no preference for operating in the more highly infested fruits of any of the six fruit types tested. The maximum dispersal recorded of a population of O. oophilus from a liberation site was 5 miles, 46 months after establishment. A review of climatic factors indicated that winter temperatures of 60°F or less were unfavourable to the persistence of O. oophilus. The presence of O. oophilus was not associated with a reduction in the degree of infestation of fruits. It is suggested that this is contributed to in the north, where climatic conditions for the parasites are favourable, ,by the presence of abundant fruits which are infested by Dacinae but not favoured by the parasite.
The cobalt status of Tasmanian soils. II The recovery of applied cobalt in pot experiments
Authors: Nicolls KD , Honeysett JL
Published: November 2004

In glass-house experiments, cobalt was added at rates corresponding to 18, 32, or 36 oz CoSO4.7H2O per acre to 27 soils, mostly krasnozems. This treatment raised the cobalt content of subterranean clover tops significantly on only 13 soils, and on only five of the 13 by more than 0.05 p.p.m. Cobalt in control plants ranged from 0.05 to 0.32 p.p.m. The largest recovery of applied cobalt, by two successive crops of subterranean clover, was 4% of that applied. Mechanical contamination of plant material was avoided by adding the cobalt before sowing the first crop. Perennial ryegrass and white clover gave similar results, over four or five harvests. The implications for the practice of top-dressing pastures with cobalt salts are discussed. Cobalt application at the 36 oz rate increased cobalt in subterranean clover more than the 18 oz on three of the four soils tested at the two rates. There was some evidence for a greater recovery of applied cobalt from the more acid soils, over a pH range of 4.9 to 6.2.
Microbial metabolism in the forestomachs and the large intertine of sheep
Authors: Williams VJ
Published: November 2004

Sheep were fed on either lucerne chaff, high wheat grain, or high maize grain rations. Analyses were made on digesta from the rumen and large intestines of cannulated and slaughtered animals. The results for the large intestine showed that, when equal quantities of dry matter are given, the composition of the ration can affect the pH, the water content, and the total dry matter of the digesta; diet can also affect the total quantities of volatile fatty acid and ammonia in the organ.The proportions of the individual volatile fatty acids in the caecal fluid were not affected by the different diets fed in this experiment. The data did not suggest any consistent pattern in the pH or in the concentrations of ammonia and volatile fatty acid in the caecal fluid during the 24 hr between feeds.
Sclerotinia laxa Aderh. & Ruhl: A cause of brown rot of stone fruits not previously recorded in Australia
Authors: Jenkins PT
Published: November 2004

A fungus with the cultural characteristics of Sclerotinia laxa Aderh. & Ruhl. has been determined as a cause of blossom and twig blight and fruit rot of stone fruits in southern Victoria. This is the first report of a brown rot species other than S. fructicola (Wint.) Rehm. occurring in Australia. European plum (Prunus domestica) is the host most severely affected, and there is evidence that the disease has spread from this host to adjacent cherry, peach, and apricot varieties. The distribution of S. laxa appears to be restricted to the Wandin, Tyabb, and Red Hill districts of southern Victoria. S. fructicola also is a cause of blossom blight and fruit rot in these districts, and is the only brown rot fungus which causes losses of stone fruits in the major canning fruit districts of northern Victoria.
The seasonal growth characteristics of irrigated cotton in a dry monsoonal environment
Authors: Stern WR
Published: November 2004

Cotton plantings were made at the Kimberley Research Station (128° 36´ E., 15° 42´ S.) from September to July to give overlapping growth curves extending from September 1961 to December 1962. Crop growth was examined in relation to radiation and temperature. Beginning at the third week from sowing, each planting was sampled 12 times at intervals of 15 days. At each sampling, dry matter, leaf area index, number and dry weight of bolls, and seed cotton yield were determined. The development of total dry matter and leaf area index showed a strong seasonal trend. The number of bolls produced was less in the late plantings, and the seed cotton yield was correspondingly lower. The highest seed cotton yields and the highest ratios of seed cotton to total dry matter (30%) were obtained with January–February plantings. The growth rates between 50 and 100 days were used to analyse seasonality; the highest seasonal growth rate was 164 mg dm-2 day-1 in December–January and the lowest value was zero in early September. By using fitted harmonics, a multiple correlation was established between maximum and minimum temperatures and growth rates 30 days later. Potential rates of net photosynthesis of tops were calculated from observed radiation data with the use of the de Wit model and with allowance for light wastage, root growth, and respiration. There was good agreement between observed and potential growth rates from December to April. Midday stomatal apertures declined from November to May, and this appeared to be a seasonal effect. An annual pattern for the diffusive resistance of carbon dioxide through the leaf surface into the substomatal cavities is calculated. Radiation did not appear to be the primary limiting factor, and the seasonal growth pattern was interpreted in terms of the composite effect of maximum and minimum temperatures on extension growth, stomatal opening, and the presence or absence of suitable sinks for carbohydrates. Growth rates are evaluated against rates observed elsewhere, and means of exploiting the Kimberley environment are discussed.
Calibration of soil and leaf analyses for the control of sugar-cane fertilization rates in Southern Queensland
Authors: Yates RA
Published: November 2004

Data from a large series of trials over a number of different soil types have been studied to determine the value of leaf and soil analyses for controlling the fertilization of sugar-cane. Statistical data on the correlations obtained are presented. The response to nitrogen fertilizer could not be assessed from leaf analysis data, but the level of mineral nitrogen in incubated topsoil was well correlated with the amount of fertilizer required. The response to phosphate fertilizer could be assessed through soil, leaf, or juice phosphate analyses, the leaf analysis being the most accurate, with a critical value of 0.18% phosphorus in the dry lamina of the top visible dewlap leaf. The reliability of this assessment depended on the soil calcium/magnesium ratio being normal, and there being no trace element interaction. The response to potassium fertilizer was only poorly correlated with soil potassium. The correlation with leaf potassium was good, and was modified by the response of leaf potassium to potassium fertilizer and by the level of phosphate in the leaf. At 0.174% phosphorus, the critical level for leaf potassium was 1.69%; this fell to 1.44% at 0.22% phosphorus. Assessment of critical values in leaf tissue was complicated by difficulties in selecting sampling times due to very variable growth rates, and by associated variations in leaf analyses. The levels of calcium and magnesium have not been found to affect the critical levels of potassium.
The role of temperature in the development of blue mould (Peronospora tabacina Adam.) disease in tobacco seedlings. II. Effect on plant growth
Authors: Hill AV
Published: November 2004

Healthy tobacco plants and tobacco plants inoculated with conidia of Peronospora tabacina were subjected to a wide range of temperature conditions. Two strains of the pathogen were used. Both affected plant growth, the greatest and most obvious effects being at night temperatures of 16–24°C. Growth, as measured by stem length, leaf number, and leaf size in plants inoculated with strain APT2, was limited by stem necrosis rather than by leaf necrosis. There was less stem necrosis at the higher day temperatures and fewer dead leaves at all temperature regimes, with strain APT2 than with APT1. At high day temperatures, stem necrosis tended to be restricted to the region of the external phloem, with consequently less severe effects on growth.
Corrigendum - The effect of photoperiod on flowering, growth habit, and dry matter production in four species of the genus Stylosanthes SW
Authors: t Mannetje L
Published: November 2004

S. humilis H.B.K., S. guyanensis (Aubl.) Sw. subsp, guyanensis, S. mucronata Willd., and S. montevidensis Vog. were subjected to photoperiods of 8,10,12, and 14 hr in the CSIRO Phytotron in Canberra. S. guyanensis and S. humilis appeared to be short-day plants and S,.montevidensis a long-day plant for flowering. S. mucronata showed a rather indefinite response, but appeared to flower more rapidly under short days than under long days. Under photoperiods of 8 and 10 hr, S. humilis had a prostrate habit and S. montevidensis plants were stunted, while under photoperiods of 12 and 14 hr both species grew erect. S. guyanensis and S. mucronata showed no differences in growth habit with photoperiod. Dry matter yields for the 12 and 14 hr photoperiods were significantly larger than those for the 8 and 10 hr photoperiods for all species except S. mucronata, which gave a significantly higher yield only under the 14 hr photoperiod.
The relative supply of carbohydrate and nitrogen to wheat grains, and an assessment of the shading and defoliation techniques used for these determinations
Authors: Wardlaw IF , Carr DJ , Anderson MJ
Published: November 2004

Leaf contribution to grain dry weight and grain nitrogen was estimated in four varieties of wheat from their responses to shading and defoliation treatments. The relation between movement of nitrogen and dry material from leaves to grains appeared as an important factor in the differences between varieties in respect to the percentage nitrogen content of grains. Experiments with labelled carbon, however, showed that there was a significant redistribution of assimilates from other parts when the ear was shaded or the flag leaf removed.
Diurnal and daily changes in the excretion of urinary silica by Merino sheep
Authors: Nottle MC
Published: November 2004

Urine collected at 2-hr intervals over a 24-hr period from a group of five sheep fed on the same diet in five different ways showed considerable fluctuations in volume, pH, and silica concentration. pH values ranged from 7.8 to 4.8, and silica concentration from 830 to 110 µg/ml. The latter appeared to be inversely related to urine volume, which reached a maximum c. 12 hr after feeding. Urine collected at 24-hr intervals for 10 consecutive days from eight sheep showed marked variations in silica concentration and specific gravity. These variations appeared to be inversely related to urine volume, and silica concentration seemed to be influenced also by daily variations in total silica excretion. Considerable differences were found in the mean values for different sheep. The significance of these results are discussed in relation to siliceous urinary calculus formation.
Mats of unincorporated organic matter under irrigated pastures
Authors: Kleinig CR
Published: November 2004

A mat of partially decomposed organic matter which forms on the surface of solls carrying irrigated pastures is described. It was found under both annual and perennial irrigated pastures on soil types ranging from sandy loams and loams (red-brown earths) to heavy clays (grey and brown soils of heavy texture). Mat weights ranged from 8 000 to 92 000 lb/acre, and the amounts of nitrogen held in them from 85 to 1 240 lb/acre, for 8- to 15-year-old pastures. Age of pasture was not significantly correlated with either mat weight or mat nitrogen content, but it was significantly correlated with the total nitrogen content of the mat and surface soil. The distribution of accumulated nitrogen between the mat and surface soil varied considerably under annual pastures on heavy-textured soils. Carbon/nitrogen ratios indicate considerable decomposition of the organic matter In the mat, and up to 0.60 in, of water available to the pasture was retained in this layer after irrigation. The significance of the mat under irrigated pastures is discussed in terms of water and nitrogen relationships.
The tolerance of sheep to sodium chloride in food or drinking water
Authors: Wilson AD
Published: November 2004

Sodium chloride was added in different amounts to the diet or drinking water of Merino sheep. The food intake declined at the higher concentrations (10–20% in food, 1.5–2.0% in water) but the decline was not related solely to the amount of sodium chloride ingested. The water intake increased in relation to the amount of sodium chloride ingested, irrespective of diet or means of ingestion (food or water). It is suggested that the acceptability or taste of food or water containing high levels of salt is a factor in determining the salt tolerance of sheep. The salt intake–water intake relationship is used to estimate the possible saving of fresh water to be derived from diluting it with saline bore water.
A kinetic study of phosphate absorption by excised roots of Stylosanthes humilis, Phaseolus lathyroides, Desmodium uncinatum, Medicago sativa and Hordeum vulgare
Authors: Andrew CS
Published: November 2004

A kinetic analysis was made of phosphorus absorption by excised roots of Stylosanthes humilis, Phaseolus lathyroides, Desmodium uncinatum, Medicago sativa (lucerne), and Hordeum vulgare (barley). The mechanism of phosphorus uptake by the first four species was similar to that already described for barley by Hagen and Hopkins, in that two first order simultaneous reactions (designated a and b) would account for total phosphorus uptake. The phosphorus absorption rate of S. humilis was much greater than that of the other four species at all phosphorus substrate concentrations used. At low phosphate substrate concentrations (1 x 10-6M KH2PO4), absorption rates were in the order: barley > P. lathyroides > D. uncinatum > lucerne; at high concentrations (2 x 10-4M KH2PO4) they were nearly equal. Furthermore, the relative proportion of the total uptake contributed by the b reaction, i.e. associated with HPO42-, was greater for S. humilis at all substrate concentrations used than for the other species. These differences can be explained in part by certain biological constants. The outstanding difference was that S. humilis had a much higher rate constant for both reactions concerned with phosphate uptake, i.e. k3a and k3b, than the other species. In addition the b carrier concentration, i.e. Σ Rb, was higher than for the other species, with the exception of barley, and furthermore the ratio of Σ Ra to Σ Rb was very narrow for S. humilis, being 1.61 for S. humilis and 3.97, 7.31, 8.04, and 6.04 for the other species respectively. Similarly the apparent dissociation constant for the b reaction in S. humilis, Kmb, was high, and the ratio of Kma to Kmb was narrow, relative to the values for the other species. Physical data on the roots, such as damp to dry weight ratios, average length, and number per unit weight, were determined and used in conjunction with the biological constants in an attempt to interpret the phosphate uptake results.
Wool follicle arrangement and vascular pattern in the Australian Merino
Authors: Nay T
Published: November 2004

The relationships between blood supply and follicle arrangement patterns were studied in the Australian Merino with the intention of finding means of identifying individual primary follicle groups in new-born lambs and adult animals. It was found that individual primary follicle groups could be identified by using as a guide the blood supply pattern at sebaceous gland level, and that the individual groups were members of a higher unit composed of several groups called "fields". The observed differences in the "field" configuration in individual animals led to the identification of two extreme types of follicle arrangement in the vertical plane, called 'straight' and "tangled". It was also observed that the blood supply pattern in the straight type showed three distinctly recognizable vascular levels: the subepidermal, the mid-dermal net, and the dermal net. The connecting vessels between these three levels and the drainage and supply vessels between the dermal and mid-dermal net had a generally straight course. In the tangled type the pattern was distorted and the mid-dermal level indistinct. The supply and drainage vessels had an oblique and often tortuous course.
Inheritance of growth habit and quanititative characters in intervarietal crosses in Leucaena leucocephala (Lam.) de wit
Authors: Gray SG
Published: November 2004

Five varieties of Leucaena leucocephala covering the range of variation in growth habit in this species were crossed in all combinations. Measurements were made on leaf size, stem length, and flowering date on F1 populations of seven crosses raised in a spaced-plant trial. Genotypic effects were significant for each character. Most of the F1 means approximated to those of the higher parent. The asymmetrical distribution of the F1 means about the mid-parent point indicated that there was some heterosis, in addition to additive effects. Segregation ratios in F2 and F3 populations indicate that branching habit is controlled by two pairs of disomically inherited genes. One of these controls erect growth with lax branching v. bushy growth with denser branching. The other controls absence v. presence of strong basal branching. Measurements of stem length and stem number were made on F2 populations of several crosses. These characters appeared to be controlled by multiple genes affecting vegetative vigour. These genes are transmitted independently of the genes controlling branching habit.
Epidemiology of blue mould (Peronospora tabacina Adam)
Authors: Hill AV , Paddick RG , Green S
Published: November 2004

The occurrence of blue mould disease of tobacco in the Ovens Valley district of Victoria was recorded at intervals of 2 weeks in observation rows during six successive seasons. First appearance of the disease was not associated with any particular plant growth stage or time of the year. There was an association with infected transplants and with wet days in the two preceding weeks. Subsequent increase in the number of diseased plants was related to rain on two of three consecutive days. The highest percentages of plants with disease occurred in plots where symptoms appeared before December 24. The percentage of plants with blue mould increased up to the commencement of flowering, usually late in January. There was a time interval of 2–5 weeks from first appearance to maximum percentage of plants diseased, the shorter period occurring when more than 25% of plants were diseased at the first record. The rate of spread of disease between fields was proportional to the number of fields already infected. The disease spread more slowly when the plants were sprayed with fungicides.
The digestion of chopped and ground roughages by sheep. II. Digestion of nitrogen and some carbohydrate fractions in the stomach and intestines
Authors: Hogan JP , Weston RH
Published: November 2004

A study of the intake and digestion of lucerne and wheaten hays was made with Merino wethers offered chopped hay near ad libitum, ground hay at the same level as the chopped hay, and ground hay near ad libitum. These treatments were imposed to separate the effects of grinding per se from those associated with the increased intakes of roughages permitted by grinding. The following conclusions were reached: (1) Grinding permitted a substantial increase in food consumption on both diets. (2) Grinding per se of both hays produced little change in the relative importance of stomach and intestines as sites of digestion of any of the feed components studied. Grinding had no effect on the digestibility of lucerne hay but reduced that of wheaten hay, mainly by reducing the digestion of the cell wall constituents. (3) When both ground hays were offered near ad libitum, digestibility was reduced, mainly because of a fall in digestibility of the cell wall constituents. With lucerne hay, grinding increased the organic matter intake by 37% above chopped hay but the organic matter digested was increased by only 27%. By contrast, on wheaten hay an increase of 42% in organic matter intake on ground hay resulted in the digestion of only 18% more organic matter than on chopped hay. On both diets the relative extent of digestion occurring in stomach and intestines was similar to that observed with chopped hay. (4) On all three lucerne diets there was a net loss of 22–25% of dietary nitrogen from the stomach. By contrast, on the wheaten hay diets a substantial gain of nitrogen occurred during the passage of digesta through the stomach; the amount of nitrogen gained was independent of feed processing and feed intake. The crude protein apparently digested in the intestines was approximately 17% of the total organic matter digested on the lucerne diets and 10–12% of that digested on the wheaten hay diets. (5) Within diets the relative proportions of individual rumen VFA were the same on chopped and ground hay offered near ad libitum. (6) Grinding probably did not cause any change in the composition of the end products of digestion. (7) On the lucerne hay diets, 16–20% of the organic matter digested in the rumen was soluble carbohydrate, on wheaten hay approximately 40–50%.
The inheritance of marker genes in Medicago truncatula Gaertn. II. Their suitability for the use in a plant breeding programme
Authors: Simon JP , Millington AJ
Published: November 2004

In the F2 generation of crosses between selected strains of Medicago truncatula Gaertn. there was independent segregation of the genes for the marker characters "red leaf", "smooth pod", and "clockwise-anticlockwise coiling pattern of the pod". A new marker, "erect type" of vegetative development, is a recessive character which is not linked to the "red leaf" gene. The absence of linkage greatly enhances the value of these characters as strain markers.