bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimates of selection parameters associated with protein and oil content of soybean seeds (Glycine max (L.) Merr.)
Authors: Shorter R , Byth DE , Mungomery VE
Published: November 2004

Three crosses of soybean involving United States and other germplasm were examined in the F3 and F4 generations at two locations, one near the coast, the other on the Darling Downs. Line and line x location interaction variances within crosses for most traits were almost all significant, except for protein, oil, and protein plus oil yield where line variances were non-significant when data were combined over locations. Line variances were considerably smaller for all traits when estimated across, rather than within, locations. For protein, oil, and protein plus oil percentage, the line x location interaction variance component generally was smaller than the line variance component in two crosses, but larger in a third even though the latter cross had the largest line variance for these traits. The line x location interactions may have been related in some cases to lower protein and oil percentages of late-maturing lines in that location where cold conditions prevailed late in the season. Heritability percentages computed from F4 variance components ranged from 49 to 89% and were largest for the chemical pexentage traits within locations. Standard unit heritability percentages estimated from F3–F4 generations were lower than those computed via the variance component method, and approached zero for oil percentage, protein plus oil percentage, and the chemical yield traits in some crosses if the generations were grown in different locations. Genotypic correlations between protein percentage and seed yield ranged from –0.50 to 0.16 across crosses and were opposite in sign to those between oil percentage and seed yield. Genotypic and phenotypic correlations between protein and oil percentage were highly negative in two crosses (–0.62 to –0.96) but much less negative in the third cross (–0.24 to –0.35). Predicted genetic advance (percentage of population mean) ranged from 5.9 to 26.1% for the chemical yield traits and from 1.5 to 6.3% for protein or oil percentage. Indirect selection for chemical yield through seed yield was 90–109% as efficient as direct selection, and a selection index that combined seed yield and either protein, oil, or protein plus oil percentage generally was no more efficient than direct selection for the corresponding chemical yield trait. Indirect selection for chemical yield through chemical percentage was much less efficient than direct selection for chemical yield.
Quantitative inheritance studies in sugar-cane. III.* The effect of competition and violation of genetic assumptions on estimation of genetic variance components
Authors: Hogarth DM
Published: November 2004

Several assumptions underlying the theory of quantitative genetics may not be valid for sugar-cane. The assumption of no epistasis was studied by comparing independent estimates of genetic variance components based on different genetic assumptions.Sugar content was measured with excellent statistical precision, and independent estimates of genetic variance components for this character agreed very well, which indicated that violation of genetic assumptions had little effect on estimation. For other characters, agreement was not as good, and there was evidence to show that epistatic variance was important for weight per stalk. For all characters, maternal effects were negligible. Additive genetic variance was more important than dominance genetic variance for all characters except yield of cane, for which the two variances were equally important. Inter-plot competition was unimportant, but several characters, notably yield of cane, exhibited substantial within-plot competition. This type of competition did not affect estimation of genetic variances, but has important implications for selection. Estimates of heritability and degree of genetic determination were determined for each character studied.

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*Part II, Aust. J. Agric. Res., 22: 103-9 (1971).
Determination of spikelet number in wheat. I. Effect of varying photoperiod on ear development
Authors: Rahman MS , Wilson JH
Published: November 2004

The effects of constant photoperiods (8, 9, 10, normal and 24 hr) and of transfer to another photoperiod at floral initiation (from 24 hr to 10 and vice versa) on rate of development and spikelet number per ear were studied in eight wheat cultivars grown at 20°C. The objective was to know what factors related to photoperiod control spikelet number. The lengths of the vegetative, spikelet and ear elongation phases, the numbers of spikelets and leaves, the numbers of phytomers and lengths of the shoot apices at floral initiation increased, but the rate of spikelet initiation decreased, as the photoperiod decreased from 24 to 8 hr. Responses to varying photoperiod for all these parameters were similar in the different cultivars but the sizes of the responses differed. Within a given cultivar, an increase in spikelet number was always associated with longer durations of the vegetative and spikelet phases and longer apices at floral initiation. The results of the transfer treatments suggest that spikelet number is not fully determined by the time of floral initiation, but can be altered significantly by manipulating the environment during the spikelet phase. It was concluded that the main factors determining spikelet number are rate and duration of spikelet initiation.
Identification of trisomics in diploid lucerne (Medicago sativa)
Authors: Gillies CB
Published: November 2004

Nine trisomics (including one double trisomic) derived from diploid and tetraploidMedicago sativa L. and M. falcata L. were examined at the pachytene stage of meiosis, and the extra chromosomes were tentatively identified on the basis of pachytene chromosome idiogram descriptions. Although identification of chromosomes involved in trivalent formation was not always possible, the trisomic chromosome could often be identified on the basis of its failure to form bivalents. Trisomics for five of the eight chromosomes were identified. Positive establishment of trisomic lines now requires the use of linkage data to confirm chromosome identities.
Effects of food intake and composition on the concentration of glucose in the blood of lactating cattle
Authors: McClure TJ
Published: November 2004

A group of 16 cows, each suckling one calf, were fed on rations composed of maize meal, cottonseed meal, urea and rice straw in one of four different ratios and at two levels, (a) ad libitum and (b) in restricted amounts. The composition of the feed affected intake. Both the gross intake and the estimated intake of metabolizable energy were closely correlated with liveweight change. The intake of metabolizable energy was correlated with blood glucose in the cows fed ad libitum, but not in the cows fed on restricted amounts of the rations. It was concluded that feed quality significantly affected the blood glucose concentration of the lactating cows, but that within the ranges used in this experiment, feed intake and the intake of metabolizable energy had little effect.
Transpiration and leaf water potentials of wheat in relation to changing soil water potential
Authors: Seaton KA , Landsberg JJ , Sedgley RH
Published: November 2004

Changes in the transpiration rate of wheat in drying soils were followed in experiments in which plants were grown in two small weighable lysimeters in a glasshouse. Hourly measurements of soil water potential (Ψs) were made at three depths in each lysimeter. The water potential of flag leaves was measured with a pressure chamber, and stomatal resistance with a pressure drop porometer. Data on root densities and distribution were also obtained. Transpiration rates fell below estimated potential levels when the average value of Ψs in the root zone was reduced to –1 to –5 bars, depending on soil storage, root distribution and potential transpiration rate. From this point Ψs fell rapidly in the surface layers, more slowly at depth. It was found that accurate calculations of daily water uptake could be made from changes in soil water content. The minimum value of leaf water potential (�1 )attained each day declined progressively through the drying cycle, but there was evidence that stomatal resistance (rs) is not uniquely related to Ψ1; initial stomatal closure occurred at Ψ1, values which decreased from –11 to –25 bars as drying progressed. This adaptive mechanism is related to changes in osmotic potential of the leaves. Whole plant resistances (Rp), derived from leaf water potentials and fluxes through individual stems, increased as stem populations increased. In the high population lysimeter Rp decreased from 300 to 100 bar sec mm-3 as canopy transpiration rates increased from 1.5 to 4.5 x 10-4 mm sec-1. In the low population lysimeter Rp decreased from 70 to 30 bar sec mm-3 as transpiration increased from about 2.2 to 4.5 x 10-4 mm sec-1. The higher resistances appear to confer significant advantages in terms of water conservation and adaptation to drought.
Uptake of soil nitrogen by legumes in mixed swards
Authors: Vallis I , Henzell EF , Evans TR
Published: November 2004

The partitioning of uptake of soil nitrogen between legumes and grasses in mown, mixed swards was studied at two sites in south-eastern Queensland. The swards contained either Lotononis bainesii, Desmodium intortum or Trifolium repens with Digitaria decumbens at one site, and either L. bainesii, T. repens, Macroptilium atropurpureum, Vigna luteola or Stylosanthes guyanensis with Chloris gayana at the other site. (15NH4)2SO4 equivalent to c. 0.3 kg nitrogen ha-1 was added every 4 weeks in an attempt to label the soil mineral nitrogen, and the partitioning of 15N uptake between species used as an estimate of the partitioning of uptake of soil nitrogen. Although two of the legumes (L. bainesii and T. repens) obtained 70–100% of the total 15N uptake at some of the spring harvests, when growth of the associated tropical grasses was limited by low temperatures, none of the legumes obtained more than c. 25% of the annual 15N uptake over a 2-year period. Proportional 15N uptake by the legumes was curvilinearly related to the proportion of legume dry matter yield in the mixtures. Annual 15N uptake by the grass-legume mixtures was up to 360% as high as by the grass control. This had only a small effect on estimates of the proportion of legume nitrogen derived from symbiotic fixation, but caused a large discrepancy in isotopic estimates of nitrogen transfer. The proportion of fixed nitrogen in the legumes averaged 94% at one site and 92% at the other, nearly always exceeded 80%, and was independent of legume yield.
The effects of severe feed restriction on bulls and steers. I. Liveweight loss, behaviour and non-carcass body composition
Authors: Price MA
Published: November 2004

The effects of substantial liveweight loss on the behaviour and body composition of half-sib Hereford bulls and steers were studied by using a serial slaughter technique and starting with nine animals—three bulls and six steers—of similar liveweights (mean 472 kg) but different fatness (the steers having appreciably more fat). Following the establishment of initial body composition by slaughter of a bull and two steers (group I), two bulls and four steers were given 0.91 kg of poor quality hay per day for 142 days. The six cattle all had similar liveweight losses (mean 170 kg) during this period, but the bulls were extremely emaciated and lethargic by day 142 while the steers were not. Slaughter and comparison of the pair of bulls with one pair of steers (group 2) at this time indicated a considerably greater loss of carcass weight and lesser loss of offal weight by the bulls than by the steers. The remaining pair of steers (group 3) continued to lose weight for a further 57 days, by which time they appeared as emaciated as the group 2 bulls had been, though not so lethargic. The proportions of feet, head and hide relative to carcass weight were significantly (P < 0.05) greater in bulls than steers, but there were no significant sex differences in the proportions of liver, spleen, heart or kidney. Except for the head, the interaction between weight loss and sexual status had no significant effect on offal proportions; the head percentage increased significantly more in bulls than steers during weight loss. The effect of progressive weight loss in the three groups of steers was a significant (P < 0.05) increase in the feet, head, hide, spleen and heart weights relative to carcass weight. It is concluded that from a management point of view, behaviour is a better guide to waning fat reserves than appearance, and that steers, because of their greater fat content, would survive a period of feed restriction longer than bulls of the same liveweight.
Determination of spikelet number in wheat. II.* Effect of varying light level on ear development
Authors: Rahman MS , Wilson JH , Aitken Y
Published: November 2004

The effects of two light levels (0.98 and 4.90 cal cm-2 hr-1) on rate of development and spikelet number per ear were studied in eight wheat cultivars grown under a 16 hr photoperiod at 20°C. The objective was to ascertain how light affects spikelet number. At the lower light level the durations of the vegetative, spikelet and ear elongation phases were greater, but the number of spikelets per ear, number of phytomers present at floral initiation, final leaf number, number of phytomers that were converted into spikelets, apex length at floral initiation and rate of spikelet initiation were smaller than at the higher light level. Responses to varying light level for a11 these parameters were similar for different cultivars, but the sizes of the responses differed. Within a given cultivar, an increase in spikelet number was associated with longer apices at floral initiation and a higher rate of spikelet initiation. It was concluded that these two factors are important determinants of spikelet number.

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*Part I, Aust. J. Agric, Res., 28: 565 (1977).
Ultrastructural studies on the bacterium associated with the ratoon stunting disease of sugarcane
Authors: Weaver L , Teakle DS , Hayward AC
Published: November 2004

The bacterium associated with ratoon stunting disease of sugar-cane was studied in thin sections of agar-embedded pellets of fibrovascular extracts, and in situ in the xylem of sugar-cane. The bacterium often possessed a single large lamellar mesosome, and the cell wall was smooth in outline and of the Gram-positive type. It lacked the acidic mucopolysaccharide capsule which was observed in several species of plant pathogenic coryneform bacteria. The bacterium was seen in the lumen and the pits of the xylem vessels and sometimes appeared to be in the xylem cell wall.
Nitrogen and phosphorus requirements of wheat following subterranean clover pasture
Authors: Osborne GJ , Batten GD , Kohn GD
Published: November 2004

The effects of superphosphate and nitrogen fertilizer on wheat yield, grain nitrogen and phosphorus levels, total soil nitrogen and available soil phosphorus were studied over a 6-year period on plots which had received 718–3343 kg superphosphate ha-1, during a preceding ley pasture-crop period. Wheat yields generally declined with time on all treatments, fertilizer nitrogen reducing the rate of decline. From 125 to 2.50 kg superphosphate ha-1 year-1 was required to maintain maximum wheat yields when nitrogen fertilizer was also applied, but only 125 kg was required in its absence. Grain nitrogen content varied from 1.47 to 2.11% and was not a good indicator of nitrogen fertilizer requirement. Nitrogen removal per crop varied from 27 to 41 kg ha-1 in the presence of added nitrogen and from 21 to 31 kg ha-1 without added nitrogen. Soil nitrogen levels declined at rates varying from 8 to 40 kg ha-1 year-1. Grain phosphorus levels varied from 0.21 to 0.44%. Phosphorus removal in the grain varied from 4 to 8 kg ha-1 per crop. Changes in available soil phosphorus on plots which had previously received 718, 1593, 2468 or 3343 kg superphosphate ha-1 were closely correlated with the rate of superphosphate applied with the crop (r = 0.97, 0.97, 0.93 and 0.80). The amount of superphosphate required to maintain soil phosphorus levels was calculated, and the following conclusions regarding superphosphate use in the pasture-crop rotation in southern New South Wales have been made. Where pastures are not topdressed, the amount of superphosphate needed with each crop varies with the number of years of cropping, the level of soil nitrogen, the number of years of untopdressed pasture relative to the years of crop, and the initial soil phosphorus level.
The relation between herbage copper, EDTA-extractable soil copper and species composition in pastures growing on a range of soil types
Authors: Beavington F , Wright WA
Published: November 2004

A survey of the copper status of herbage and its supporting soil over various soil parent materials (all with acid soils) on part of the coast of New South Wales showed levels of herbage copper ranging from < 1 to 14 ppm, EDTA-extractable soil copper from 0.2 to 32 ppm and a correlation between these two variables of r = 0.51 (P < 0,001). Very low levels of herbage copper were associated with high proportions of inferior grasses and both were associated with low 'available' soil copper. High levels of herbage copper were associated with high proportions of clover though not necessarily with the highest levels of 'available' soil copper. The content of molybdenum in herbage varied widely giving many very low copper/molybdenum ratios.
Influence of temperature and humidity on tripping of lucerne flowers
Authors: Hely FW , Zorin M
Published: November 2004

Lucernes representing diverse indigenous habitats were studied over a range of temperatures and atmospheric humidities during flowering to investigate physical resistance of flowers to tripping. The amount of automatic flower tripping measured at 25°C varied from 1 to 14% of available flowers between lucernes. Studies of automatic tripping over a 20–40°C temperature range showed that most lucernes responded strongly to higher temperatures; but high latitude lucernes did not increase in automatic tripping. A small reduction in relative humidity with constant temperature over the 20–40°C temperature range caused greatly increased automatic tripping in two Australian lucernes, but produced smaller increases in lucernes introduced from a similar latitude. It had no effect on high latitude lucerne. At 25°C induced tripping, simulating the actions of pollen-collecting bees, showed differences in resistance to tripping between lucernes similar to those in automatic tripping. This pattern of differences may be related to that of seed production by these lucernes under field conditions, in south-eastern Australia.
Formaldehyde treatment of concentrate diets for sheep. I. Partition of the digestion of organic matter and nitrogen between the stomach and intestines
Authors: Faichney GJ , White GA
Published: November 2004

The effect of formaldehyde treatment of barley/soybean meal diets was studied in fistulated crossbred sheep at four protein levels. The overall digestion of organic matter was similar for all diets; the small differences in the partition of organic matter digestion in response to treatment were not significant. Dietary starch was completely digested. The partition of starch digestion was variable but was not affected by protein level or treatment. The relationship between nitrogen intake and the amount of non-ammonia nitrogen (NAN) digested in the intestines was curvilinear; NAN digested was calculated to reach a maximum when 17.4% of the dietary organic matter was crude protein. Formaldehyde treatment substantially increased the amount of NAN digested in the intestines; a treated diet in which 12.6% of the organic matter was crude protein would provide the same amount of NAN digested as the 17.4% untreated diet. The apparent digestibility of NAN in the intestines was not affected by protein level or treatment; treatment at the highest protein level appeared to cause a reduction in true digestibility to 0.75 from the mean of 0.80 obtained for the other diets. Treatment appeared to have no consistent effect on the efficiency of bacterial protein synthesis. The flows of water and of digesta from the rumen and abomasum were not affected by protein level or treatment; differences between sheep were responsible for much of the variance in these parameters. The treatment reduced rumen ammonia and volatile fatty acid levels and plasma urea levels. Neither the amount and composition of the long-chain fatty acids reaching the intestine nor their digestion there were affected by the treatment.
Utilization of amino acids by pre-ruminant lambs. III.* The influence of age and the dietary proportions of essential and non-essential amino acids on the levels of urea, ammonia and free amino acids in the blood plasma of milk-fed lambs
Authors: Dove H
Published: November 2004

Jugular blood samples were obtained from 10.5 kg and 28 kg lambs receiving a diet of reconstituted cows' whole milk. The lambs were then given diets in which the proportion of essential amino acids (BAA) in the dietary crude protein was altered over a wide range. A second blood sample was taken after lambs had received such diets for 12 days. Plasma obtained from these samples was analysed for free amino acids, urea and ammonia. The pattern of plasma free amino acids (PFAA) in lambs given reconstituted cows' whole milk is described. In both the pre-treatment and post-treatment samples, the heavier lambs appeared to have lower plasma levels of all EAA, and high plasma levels of glycine, serine, urea and ammonia. In the lighter lambs, there were pronounced responses of PFAA levels to changes in the dietary proportion of EAA. At low proportions, the levels of most EAA in plasma were low. Lysine and phenylalanine were exceptions. In addition, levels of many non-essential amino acids (non-EAA), particularly serine and glycine, were high. At high proportions of EAA, plasma levels of all EAA, especially methionine, rose markedly. Within the non-EAA, serine, proline and glycine were reduced, while taurine and cystathionine increased. In the plasma of the heavier lambs, the response of some amino acids to a given dietary change differed from the response in the lighter lambs. This was especially true of methionine, tyrosine, phenylalanine and arginine. There was also marked between-animal variation in plasma levels. When expressed as molar proportions of total PFAA, results were similar to those of the lighter lambs. There was a pronounced similarity between the response of the PFAA to diets with a low proportion of EAA, and the PFAA pattern characteristic of developing kwashiorkor.

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*Part II, Aust. J. Agric. Res., 28, 933 (1977).
The utilization by grass of sulphur and phosphorus from clover litter
Authors: Till AR , Blair GJ
Published: November 2004

35S and 32P were used to produce double-labelled clover (Trifoliurn repens) which was subsequently used as litter on carpet grass (Axonopus affinis) swards. The re-utilization of 35S and 32P was studied under two temperatures (15/10 and 28/22°C) and three watering regimes (daily, every 3 days and every 6 days), in controlled environment chambers. No significant watering effects were observed, but temperature had a marked efftct on sulphur and phosphorus uptake by plants. After 56 days the total incorporations of sulphur and phosphorus, as percentages of that applied in litter, were: tops, S 3.9, P 3.6; roots, S 4.6, P 18.6 at 15/10°C; and tops, S 9.3, P 11.0; roots, S 5.6, P 17.3 at 28/22°C. The estimated half-times for disappearance of sulphur and phosphorus from litter ranged from 27 to 44 days.
The adaptation of winged bean (Psophocarpus tetragonolobus (L.) DC.) in Papua New Guinea
Authors: Khan TN , Erskine W
Published: November 2004

Thirty genotypes of winged bean were grown in five diverse environments in Papua New Guinea in order to estimate the genotypic, environmental and genotype-environmental variance of grain yield and pod number per plant, seed number per pod, 20-seed weight, pod length and shelling percentage. A maximum grain yield of 2200 kg ha-1 was realized. Environmental and genotypic variance contributed 69.9 and 0.3% respectively to the overall variance of grain yield. A significant genotype x environment interaction for grain yield was adequately explained by joint regression analysis. Correlation studies emphasized the importance of testing genotypes in both the highlands and lowlands. Variation in grain yield was largely due to fluctuations in pod number. Grain yield and pod number showed strong negative genetic correlations with seed number per pod, 20-seed weight and pod length.
Genetic and phenotypic parameters for pre-weaning growth and weaning conformation of Angus cattle
Authors: Barlow R , Dettmann EB
Published: November 2004

Weaning weight (WW) and conformation score (CS) records on Angus calves from four New South Wales herds were analysed by least-squares procedures. Paternal half-sib components of variance and covariance were used to obtain estimates of heritabilities of various measures of growth and cs, as well as genetic, phenotypic and environmental correlations. Estimates of the heritabilities of measures of growth ranged from 0.20 (all data) to 0.24 when derived from heifer data only. The heritability of cs was 0.24 when the data were adjusted for ww, and 0.19 when no covariate was included in the analysis. All correlations among different measures of growth were positive and close to unity. There were small positive phenotypic and environmental correlations (0.19 to 0.36) and small negative genetic correlations between ww and cs (–0.02 to –0.41).
The effect of duration of performance test on genetic gain in pigs
Authors: McPhee CP
Published: November 2004

The problem of making the best use of a limited number of performance-testing places in the genetic improvement of pigs is examined. A model is given which balances the duration of testing and its effect on the accuracy of breeding value determination, against throughput and its effect on selection intensity. The model is a phenotypic one with easily estimated parameters in lieu of the more exact genetic one whose parameters are difficult to estimate. It is illustrated with data taken from the Queensland performance-testing station which evaluates boars on an index combining feed conversion ratio, growth rate and back fat. Full performance records from 26 to 90 kg liveweight are subdivided into four consecutive parts of equal weight interval. A range of feasible one and two stage selection schemes based on performance in one or more of these parts are compared. Relative to the present full testing scheme, the best single stage selection, that based on performance in the last two parts (3 + 4), is 14% more efficient. The best two stage selection scheme, also a 3 + 4 part test with a 50% culling at the end of part 3, is 19 0%, more efficient. Highest efficiencies are achieved by imposing a preliminary culling on growth rate before entry to the testing facility; e.g. selection of the best 25% on part 3 growth rate followed by part 4 index selection within the test facility is 36% more efficient than the present full test. The limitations of the model and some practical problems of part testing schemes are discussed.
Corrigendum - The effect of duration of performance test on genetic gain in pigs
Authors: McPhee CP
Published: November 2004

The problem of making the best use of a limited number of performance-testing places in the genetic improvement of pigs is examined. A model is given which balances the duration of testing and its effect on the accuracy of breeding value determination, against throughput and its effect on selection intensity. The model is a phenotypic one with easily estimated parameters in lieu of the more exact genetic one whose parameters are difficult to estimate. It is illustrated with data taken from the Queensland performance-testing station which evaluates boars on an index combining feed conversion ratio, growth rate and back fat. Full performance records from 26 to 90 kg liveweight are subdivided into four consecutive parts of equal weight interval. A range of feasible one and two stage selection schemes based on performance in one or more of these parts are compared.Relative to the present full testing scheme, the best single stage selection, that based on performance in the last two parts (3 + 4), is 14% more efficient. The best two stage selection scheme, also a 3 + 4 part test with a 50% culling at the end of part 3, is 19%, more efficient. Highest efficiencies are achieved by imposing a preliminary culling on growth rate before entry to the testing facility; e.g. selection of the best 25% on part 3 growth rate followed by part 4 index selection within the test facility is 36% more efficient than the present full test. The limitations of the model and some practical problems of part testing schemes are discussed.
Growth and flowering in salt-stressed avocado trees
Authors: Downton WJS
Published: November 2004

The effect of salinity (0, 5, 10 and 2 0 mM sodium chloride) on the growth, ion composition and flowering response of Fuerte scion grafted to rootstocks of Mexican, Guatemalan and Mexican × Guatemalan (Zutano) race is described. Scions on the Mexican and Zutano stocks were less tolerant of salinity than scions on the Guatemalan stock based on measurements of stem diameter and biomass. The less tolerant trees also contained higher concentrations of sodium and chloride in leaves. The entry of sodium into scions on the Mexican and Zutano stocks was associated with increased succulence of stems and leaves. This response altered the mineral composition of the leaves. Leaf potassium and nitrogen per unit of dry weight increased on the Mexican stock given 20 mM sodium chloride. By taking account of the changes in succulence, however, it could be demonstrated that potassium and nitrogen concentrations on a leaf water basis remained close to control values. Calcium ion failed to make the adjustment, and the already low calcium levels were further reduced by succulence. Succulence was responsible for a 25–37% dilution of sodium and chloride in the leaves of scions on Zutano and Mexican stocks, given 2 0 mM sodium chloride. Salt stress promoted the flowering of Fuerte scion. Low salinity (5mM sodium chloride) failed to stimulate flowering in trees on the Guatemalan stock. High salinity (20mM sodium chloride) was detrimental to flowering in scions on the Mexican stock and resulted in reduced numbers of floral buds, flowers per bud, inflorescences per bud and flowers per inflorescence. The experimental results are discussed in relation to the salinity situation in the irrigated horticultural areas along the River Murray.
Studies on the control of wet bubble disease of mushrooms with benzimidazoles
Authors: Nair NG , Baker HJ
Published: November 2004

Wet bubble disease of the cultivated mushroom was controlled by incorporating benzimidazoles in the casing. Benomyl at the rate of 0.95 g/m2, and carbendazim and thiabendazole at the rate of 0.62 g/m2, were effective in controlling the disease. The benzimidazoles applied to casing were sufficient to give good control whether the inoculum was introduced before or after casing. A number of cases were observed in commercial mushroom farms where the disease was causing significant crop losses in spite of the use of benzimidazoles. This lack of control was found to be due to the unavailability of the applied fungicides following their absorption onto the casing. Exhaustive extraction methods yielded the greater part of the benzimidazoles applied to peat moss and spent compost casing materials. No bacterial degradation of the benzimidazoles applied to casing was observed.
Selection of pea lines for resistance to pathotypes of Ascochyta pinodes, A. pisi and Phoma medicaginis var. pinodella
Authors: Ali SM , Nitschke LF , Dube AJ , Krause MR , Cameron B
Published: November 2004

The pathogenicity of 45 isolates of Ascochyta pinodes, Ascochyta pisi and Phoma medicaginis var. pinodella collected in South Australia has been examined on selected pea lines. Twenty-six isolates of A. pinodes were differentiated into 15 pathotypes, 15 isolates of A. pisi were differentiated into 13 pathotypes, and four isolates of P. medicaginis var. pinodella into one pathotype. Adequate sources of resistance were identified against all the pathotypes excepting pathotypes 1 of A. pinodes and A. pisi. The necessity to breed for broadly based resistance to Ascochyta species is discussed.
The nutrition of ruminants grazing native and improved pastures. I. Seasonal variation in the diet selected by grazing sheep and cattle
Authors: Langlands JP , Holmes CR
Published: November 2004

The chemical composition of the forage on offer on a native pasture dominated by Poa sieberana and Themeda australis, on a similar native pasture dressed with superphosphate and oversown with white clover, and on two Phalaris aquatica (formerly tuberosa)–Trifolium repens pastures dressed with superphosphate and grazed at different stocking rates during summer, was determined at monthly intervals during 1974 and 1975. Samples were also plucked to simulate grazing in 1975, and extrusa were collected from oesophageally fistulated cattle in both years and from fistulated sheep in 1975. Digestibility and nitrogen content of the diet were determined, and in 1974 the extrusa were manually separated into green and senescent fractions. Samples of rumen liquor were also collected through rumen fistulae, and analysed for ammonia, and total and individual volatile fatty acids. The application of superphosphate and white clover, and the replacement of native grasses with Phalaris aquatica, both induced large increases in nutritive value measured in terms of digestibility, protein, macro- and micro-elements in the forage on offer and in the diet selected. Changes in the composition of the forage on offer were attributable to an increase in green material, and to the greater nutritive value of both green and senescent fractions as the extent of pasture improvement increased. Digestibility, nitrogen and mineral content of the diet selected by cattle and sheep increased with pasture improvement, the nutritive value of the diet selected by sheep being greater on all pastures although the difference was greatest on native pasture. The increase in nutritive value of the diet selected by cattle on improved pasture was associated with an increase in the green component of the diet and in the nutritive value of the green material selected.
Drought resistance in spring wheat cultivars. I. Grain yield responses
Authors: Fischer RA , Maurer R
Published: November 2004

With a view to understanding the basis of cultivar differences in yield under drought, a wide range of cereal cultivars representing durum wheats (Triticum turgidum L.), triticales (X Tritosecale Wittmack), barleys (Hordeum vulgare), and especially tall and dwarf bread wheats (T. aestivum L.) were studied in field experiments in north-western Mexico over three seasons. Drought was created in this rain-free environment by permanently terminating irrigation at various stages before anthesis. Control treatments were well watered throughout the growing period. Detailed measurements of plant water status, leaf area and dry matter production, anthesis date, yield components and grain yield were made. This paper presents primarily the grain yield data. Drought levels were such that the mean yield of all cultivars under drought ranged from 37 to 86% of control yield, corresponding to irrigation cut-offs varying from 69 days before mean anthesis date to only 10 days before. In each experiment the grain yield under drought showed highly significant cultivar differences, which appeared consistent between years. Yields were adjusted for drought escape by using a correction factor which ranged from 2.9 to 8.5 g/m2 per day advance in flowering, being greater in experiments with less severe drought. The demonstration of linear relationships between cultivar yield and drought intensity, as indicated by the mean yield of some or all cultivars, prompted the consideration of cultivar yield under drought as the function of yield potential (Yp, yield without drought), drought susceptibility index (S), and intensity of drought. The cultivar groups showing lowest S values (most droughtresistant) were tall bread wheats and barleys; dwarf bread wheats were intermediate, and durum wheats and triticales were the most susceptible. However, because dwarf wheats have a higher yield potential (Yp) than tall bread wheats, it is suggested that, as a group, tall bread wheats would outyield dwarf wheats only under very severe drought. Also there was considerable within-group variability of S and Yp. Cultivar S values were consistent across experiments. Yield responses of tall and dwarf bread wheat groups obtained in these experiments agreed with those seen in extensive international trials under dryland conditions.
In vitro digestibility and chemical composition of three tropical pasture legumes, Desmodium intortum cv. Greenleaf, D. tortuosum and Macroptilium atropurpureum cv. Siratro
Authors: Ford CW
Published: November 2004

Leaflets and petioles of Desmodium intortum cv. Greenleaf and Desmodium tortuosum (Florida beggarweed) and leaflets of Macroptilium atropurpureum (Siratro) were analysed for nitrogen: sodium, potassium, phosphorus, carbohydrates (monosaccharides, cyclitols and polysaccharides), organic acids, lignin and polyphenols. The major cyclitol, D(+)-pinitol, was isolated and characterized, along with D-glucose, D-galactose and myo-inositol. The major organid acid was malonic acid, and small amounts of oxalic and succinic acids were also present. The major chemical difference between the legumes appeared in the polyphenols. D. intortum leaflets containqi large amounts of proanthocyanidins (20% catechin equivalent), such polyphenols being undetected in the other legumes. The proanthocyanidins gave three anthocyanidins, two of which were identified (delphinidin and cyanidin). The polyphenols of D. intortum, because of their ability to complex with protein, appeared to be the major cause of the resistance of this legume to bacterial decomposition. However, they did not fully explain the low in vitro digestibility of this legume, since there w'as no significant inhibition of bacterial or pepsin activities, up to 70% of the total crude protein in D. intortum leaflet being liberated with pepsin treatment. The major resistance to in vitro digestion occurred, in the cell wall, where it is possible that some proanthocyanidins were complexed with either cellulose or protein, protecting linkages from cleavage.
Flower initiation in relation to maturity in crop plants. IV.* Sowing time and maturity type in pea (Pisum sativum L.) in Australia
Authors: Aitken Y
Published: November 2004

Seven varieties of pea (Pisum sativum L.) sown monthly through the year in the temperate climate at Melbourne (38° S.), varied in their pattern of reproductive development according to their maturity type. The pattern was simple in the five early to mid-season varieties (Alaska, Collegian, Canner's Perfection, Dun, Partridge) in which rate was controlled directly by temperature, whereby the growing period after spring sowing was half that after winter sowing. The pattern was complex in the late varieties (Mackay, Austrian Winter) in which the slowest development followed sowing in late summer and early autumn. At each sowing, the range in time of flowering of early to late varieties resulted from a decreasing tendency to reach flower initiation from fast (Alaska) to very slow (Dun, Partridge, Mackay and Austrian Winter), together with an increasing positive sensitivity to photoperiod and a negative sensitivity to temperature. Both responses ranged from absent in Alaska to weak in Canners, Collegian and Dun, slightly more in Partridge and to strong in the two latest varieties. In Partridge, the sensitivity to photoperiod continued after flower initiation, causing abscission of flower buds in winter-sown plants. Three relationships can be used to forecast the ability of a variety to fit its seed maturity to a given growing season: the correlation between (1) early and later stages of development; (2) leaf stage at flower initiation and at first flower; (3) rate of development and temperature. Thus a sound basis for planning yield improvement is provided.

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*Part III, Aust. J. Agric. Res., 17: 1 (1966).
The effect of manganese on seed yield and the split seed disorder of sweet and bitter phenotypes of Lupinus angustifolius and L. cosentinii
Authors: Walton GH
Published: November 2004

In two experiments at Lancelin, on soil highly prone to the split seed disorder of lupins, the responses of 10 Lupinus angustifolius and 21 L. cosentinii phenotypes to manganese fertilizer rates were examined. In the absence of manganese, the concentration of the element in the seed was less than 10 ppm in all phenotypes of angustifolius, and they carried an average of 41 seeds per plant. In the sweet lupins only, the incidence of split seeds increased rapidly as the manganese concentration fell below 10 ppm. No phenotypes of cosentinii showed any split seed symptoms. Manganese sulphate at 15 kg/ha reduced split seed from an average of 48% of the seed numbers to 6%, and increased seed numbers to an average of 55 per plant. The difference between lupin species is probably due to differences in their ability to take up manganese and transport it from vegetative to reproductive plant parts, which in augustifolius would appear to be associated with the biochemical process of alkaloid synthesis by the iucundus gene. This aspect warrants further investigation. In sweet angustifolius lupins there is a negative relationship between split seed and seed yield, superimposed over a manganese deficiency effect of reduced seed numbers found in both sweet and bitter phenotypes. Application of manganese increased seed yield by an average of 45% in the sweet angustfolius lines, through higher seed numbers and heavier seed weight (less split seed). The genes for non-shattering of pods in angustifolius (tardus and lentus) and the very early-maturing genotype (Bo + xe) in L. cosentinii doubled the percentage of abnormal seeds (aborted ovules), a problem not related to manganese availability or the split seed disorder. The non-susceptibility of cosentinii should provide a useful low alkaloid lupin for the soils prone to the split seed disorder.
The effect of level of nitrogen nutrition on earliness in upland cotton (Gossypium hirsutum L.)
Authors: Malik MNA , Evenson JP , Edwards DG
Published: November 2004

The responses of both morphological and product quantity measures of earliness in two cotton cultivars to nitrogen stress applied either continuously or over specific developmental stages are reported. Continuous nitrogen stress increased the number of days to appearance of the first flower bud and first flower in both cultivars, had little or no effect on the main-stem node at which the first-fruiting branch appeared, and increased flower bud shedding only in the less determinate early cultivar Rex. The total number of fruiting points produced up to first flower appearance was reduced by nitrogen stress in both cultivars. Nitrogen stress from planting to appearance of the first flower bud greatly increased the time taken for flowering to occur at the first 30 fruiting points through delaying first flower appearance in both cultivars and increasing the horizontal flowering interval in Rex. Nitrogen stress applied later generally had little effect on this earliness index. Nitrogen stress from planting to first flower bud appearance strongly reduced the production rate index in Rex. However, nitrogen stress from first flower bud to first flower appearance resulted in a rapid rate of seed cotton production in both cultivars. Stimulation over the control was particularly marked in cultivar Bar 7/8. The relationship between earliness index and production rate index was explored, and the nitrogen effects on these indices evaluated. The combined use of these indices in field trials to identify factors limiting earliness is advocated.
Amino acid imbalance in ruminant lambs
Authors: Egan AR , Rogers QR
Published: November 2004

In a series of 14 experiments young Merino x Dorset Horn or Merino x Suffolk wethers were fed on wheaten straw or wheaten hay supplemented with a mineral mixture and, in some cases, urea and/or molasses. The diets were contrived to provide between 8 and 12% of digestible energy as protein digested in the intestines. A mixture of amino acids estimated to provide suitable proportions of essential amino acids and adequate non-essential amino acids was developed. With each diet, either the complete amino acid mixture, or a mixture from which one essential amino acid was excluded (imbalanced mixture), was infused per abomasum. In several experiments feed intake was depressed by imbalanced mixtures in which methionine, threonine, isoleucine and lysine were the respective deletions from the mixture, but was elevated by the infusion of the complete amino acid mixture. In each experiment an imbalanced infusion resulted in a decrease in plasma concentration of that amino acid excluded from the mixture to levels only 15–50% of control (pre-infusion) levels. All other essential amino acids were increased in concentration in plasma, reaching 1.5 to 6 times the concentrations in pre-infusion conditions. Infusions of greater amounts of amino acids resulted in greater changes in the plasma amino acid concentration. These results indicated that, although ruminant lambs ingesting herbage diets are unlikely to be subjected to an effective amino acid imbalance, they have the physiological capacity to respond to amino acid imbalances. This needs to be considered when rumen bypass of amino acids or proteins is being considered in practical or experimental circumstances.