bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in the maternal body and feto-placental growth following various lengths of feed restriction during mid-pregnancy in sheep
Authors: McCrabb GJ , Hosking BJ , Egan AR
Published: November 2004

The impact of maternal feed restriction during pregnancy on components of the maternal body and feto-placental growth was investigated to assess its influence on lamb birth weight. Single-bearing ewes were well-fed for the duration of pregnancy or feed restricted between the 30th and 96th, 50th and 96th or 75th and 96th day of pregnancy. Well-fed ewes increased in liveweight between the 30th and 96th day of pregnancy (48 g/day), while ewes feed restricted between the 30th and 96th, 50th and 96th and 75th and 96th day of pregnancy lost 55, 87 and 203 g/day respectively. Maternal fat deposits and muscle tissue of feed restricted ewes at the 96th day of pregnancy were less than for well-fed ewes. Placental weight was lower (P < 0.05) in ewes feed restricted between the 30th and 96th day of pregnancy, but not in ewes feed restricted between the 50th and 96th or the 75th and 96th day of pregnancy. Re-feeding ewes at the 96th day of pregnancy following feed restriction between the 30th and 96th day of pregnancy was associated with muscle tissue deposition during late pregnancy, while well-fed ewes depleted both fat deposits and muscle tissue during lat pregnancy. Lamb birthweight was not significantly affected by feed restriction during mid-pregnancy, despite various rates of depletion and repletion of maternal body reserves, and different patterns of placental growth.
'WHEATMAN' a decision support system for wheat management in subtropical Australia
Authors: Woodruff DR
Published: November 2004

This paper presents the basic relationships used in compiling a decision support system for wheat growers in the subtropical, prime-hard regions of Australia. The major factors addressed by this decision aid are climate variability, soil type and water status; N and P soil status and fertilizer addition; variety phenology, planting time and frost risk; weed infestation. The major decisions involved include fertilizer choice and quantity, choice of the variety development pattern to use for a given planting opportunity, and wild oat control measures. It demonstrates how the output from relatively complex, dynamic wheat models can be used at the farm level by introducing a number of factors (nitrogen status, frost risk, soil water status at planting, grain yield and protein records) measurable and specific to a given farm and/or paddock. The importance of such local measurements, and the consequent tailoring of the output to the user's conditions, on the user's confidence in, and ownership of, the final decision is demonstrated.
A simulation model of kenaf for assisting fibre industry planning in northern Australia. III. Model description and validation
Authors: Carberry PS , Muchow RC
Published: November 2004

NTKENAF (Version 1.1) is a computer model which simulates the growth of kenaf (Hibiscus cannabinus L.) under rainfed conditions in tropical Australia. In daily time-steps, the model simulates the phenology, leaf area development, biomass accumulation and partitioning, soil water balance and dry matter yields of kenaf plants based on climatic and management inputs. The model assumes adequate nutrition and no effect of pests and diseases. The model uses daily maximum and minimum temperature, solar radiation and rainfall. The duration from sowing to flowering is predicted using temperature and photoperiod. Leaf growth is described as a function of node production (as determined by temperature), leaf area per node and leaf area senescence. Potential daily biomass is predicted from leaf area index, the light extinction coefficient and radiation use efficiency, and partitioned to the economic stem yield. Soil evaporation is predicted using a two-stage evaporation model, and plant transpiration is predicted from the daily biomass accumulation, a transpiration efficiency coefficient and predicted daily vapour pressure deficit. Plant extractable soil water is dependent on the available soil water range for each depth increment, the extraction front velocity, and the extent of water extraction at each depth. Daily transpiration and leaf growth are decreased below potential values once the fraction of available soil water declines below a threshold value. NTKENAF V1.1 has been validated against observed data from kenaf experiments conducted at two sites (lat. 13�48'S. and 14�28'S.) in northern Australia. The predictive accuracy of the model was good over a range in above-ground biomass up to 25 000 kg ha-1 (n = 40, r2 = 0.94, root mean square deviation = 1716 kg ha-1). Validations were also undertaken for predictions of the core and bark stem components, leaf area index and plant extractable soil water contents. The development of NTKENAF has provided a tool which can greatly aid assessment of the feasibility of a fibre industry based on kenaf in northern Australia.
Using the n-alkanes of plant cuticular wax to estimate the species composition of herbage mixtures
Authors: Dove H
Published: November 2004

This study examined whether or not between-species differences in the concentrations of saturated hydrocarbons (n-alkanes) in the cuticular wax of pasture species could be exploited to estimate the species composition of herbage mixtures. Six sets of mixtures were prepared, containing either two, three or four species. The levels of cuticular wax alkanes were estimated in samples of the pure species and the mixtures, and used in simultaneous equations to compute species composition. The levels of Lolium perenne and Trifolium subterraneum in mixtures of these two species were accurately estimated from alkane analyses, as were the levels of these two species and Holcus lanatus when all three were mixed. In mixtures of T. subterraneum, L. rigidum and Phalaris aquatica, the first two species were well estimated, but phalaris was under-estimated, perhaps because of its relatively low alkane levels. In mixtures of these three species and Medicago sativa, the amounts of the grass species were estimated accurately, but the two legume species were not well distinguished from each other. However, total legume content was estimated very accurately. The species composition of mixtures of T. subterraneum and the above three grasses was also accurately estimated. It is concluded that the use of cuticular wax alkanes should allow a greater differentiation of herbage mixtures into their component species than was possible in previous studies using other markers. Results are also presented to indicate that ratios of alkane concentrations, especially the ratio of C29:C33 alkanes, can also be used to quantify, or at least rank, the clover content of herbage mixtures.
Cadmium in wheat-grain and milling products from some Australian flour mills
Authors: Oliver DF , Gore PJ , Moss HJ , Tiller KG
Published: November 2004

Wheat grain and associated milling products from individual commercial mills and mills at the Eread Research Institute Sydney) were analysed for cadmium. Highest cadmium concentrations were found in the bran and pollard fractions and lowest concentrations in the wheat grain and flour. The mean concentrations in bran and pollard ranged from 0.005 to 0.105 mg kg-1 and 0.005 to 0.078 mg kg-1, respectively. In contrast, the mean concentrations in grain ranged from 0.003 to 0.035 mg kg-1 and in flour from 0.003 to 0.023 mg kg-1. Cadmium analysis of wheat grain was found to be an effective method of monitoring the cadmium concentration in flour and flour products. Marked regional variations of cadmium concentration in grain and milling products were found. However, further investigation would be required to determine the reasons for these regional differences. All the grain and bran samples analysed in this study were within the maximum permissible concentrations set by the National Health and Medical Research Council (Australia) for cadmium.
Radiometry accurately measures chlorsulfuron injury to barley
Authors: Lemerle D , Fisher JA , Hinkley RB
Published: November 2004

Chlorsulfuron was applied post-emergence to four barley (Hordeum vulgare L.) cultivars sown at the end of May (sowing date 1, SD1) and mid June (SD2) in weed-free field trials at Wagga Wagga in 1990. Crop growth and development was measured from the time of application to maturity by destructive harvests and using a multispectral radiometer. Chlorsulfuron significantly (P < 0.05) reduced dry matter (DM), leaf area index (LAI) and tillering as measured by destructive harvests between the three-leaf stage and anthesis, from both SD1 and SD2, and there was no significant (P > 0.05) interaction between cultivar and herbicide treatment. The interaction between cultivar and chlorsulfuron was marginally significant (P < 0.1) for LA1 as measured by the radiometer (LAI-R) from SD2. Tolerant cultivars (Grimrnett and Lara) had greater LAI-R than the sensitive cultivars (Schooner and Clipper) in all treatments at all stages of development. LAI-R of the untreated controls reached a plateau at the end of tillering, whereas LAI-R of chlorsulfuron-treated barley increased until mid-jointing. LAI-R of sensitive cultivars showed a greater proportional reduction from chlorsulfuron treatment between the end of tillering and mid-jointing than did the tolerant cultivars. The radiometer showed potential as a rapid, non-destructive and inexpensive method for measuring crop damage caused by herbicides. The effect of chlorsulfuron on grain yield depended significantly on the cultivar (herbicidexcultivar interaction, P < 0.05). At SD1, chlorsulfuron reduced grain yield of Schooner to 54% of untreated controls and Clipper to 66%, compared with the more tolerant Grimmett (83%) and Lara (76%). Similar but smaller responses were measured from SD2. Kernel number per m2 was the most important determinant of yield reflecting the early effect of the herbicide on crop growth.
Isoquinoline alkaloids and keto-fatty acids of Argemone ochroleuca and A. mexicana (mexican poppy) seed. I. An assay method and factors affecting their concentration
Authors: Fletcher MT , Takken G , Blaney BJ , Alberts V
Published: November 2004

An assay for the isoquinoline alkaloids of Argemone ochroleuca and A. mexicana seeds is described. The method consists of extraction into weakly acidified methanol and ion-pair high performance liquid chromatography with sodium lauryl sulfate and tartaric acid in acetonitri1e:water as eluent. Analysis of A. ochroleuca seed showed it to contain dihydrosanguinarine and dihydrochelerythrine (c. 3 : 2) as major alkaloid components with minor amounts of protopine, sanguinarine, berberine and chelerythrine. A single sample of authenticated A. mexicana seed contained dihydrosanguinarine as the major alkaloid with minor amounts of sanguinarine and berberine, in agreement with earlier studies. Dihydrosanguinarine and dihydrochelerythrine were measured as their oxidized products, sanguinarine and chelerythrine, after U.V. irradiation. A crystalline solid which separates from A. ochroleuca seed oil was shown to contain 11-oxo-octacosanoic acid and 11-oxo-triacontanoic acid, which are also the major components of a similar solid from A. mexicana seed oil. Mexican poppy seed (probably A. ochroleuca) collected from various regions of Queensland during 1987-89 showed that place of origin and length of storage of intact seed had little effect on alkaloid levels. Exposure of crushed seed to light, however, caused a rapid decrease in the concentration of dihydro-alkaloids. Total alkaloid content correlated with seed maturity, with immature seed containing much less than mature seed.
Making the sums add up — the importance of quantification in nutrition
Authors: Lindsay DB
Published: November 2004

The importance of quantitative estimates of the flow through individual biochemical pathways in assessing nutrition of ruminants is reviewed.
Forecasting wheat yields in Australia with the Southern Oscillation Index
Authors: Rimmington GM , Nicholls N
Published: November 2004

Wheat yields in Australia have been correlated with values of the Southern Oscillation Index (SOI), an index of a major climatic phenomenon known to affect Australian rainfall. The SOI provides the basis for the seasonal prediction of rainfall. Values of the SOI, routinely available before and near the sowing date, can provide skilful yield forecasts. These forecasts would be available several months before harvest starts, require little data, and are quick and easy to prepare. The best predictors appear to be trends in the SOI, i.e. the SOI values near planting minus the values in the previous year, rather than absolute values. Wheat yield is negatively correlated with the SOI of the year prior to planting and positively correlated with the SOI during the crop season. The skill levels of SOI vary from r2 = 36% for Queensland to r2 = 6% for South Australia.
Soil management for irrigated vegetable production. I. The growth of processing tomatoes following soil preparation by cultivation, zero-tillage and an in situ-grown mulch
Authors: Stirzaker RJ , Sutton BG , Collis-George N
Published: November 2004

A sequence of lettuce and tomato crops was grown in a field experiment on a sandy loam soil in order to study the relationship between soil tillage and plant growth under the near optimal water and nutrient conditions which are characteristic of vegetable production. This paper describes the performance of processing tomato crops, grown over two seasons under a range of soil management systems. The soil management systems included a cultivated and a zero-tillage treatment, as well as a zero-tillage treatment which followed a crop of subterranean clover (Trifoliurn subterraneum L.). The subterranean clover was sown in autumn and senesced in early summer to form an in-situ mulch. The bulk density of the soil in the zero-tillage treatment was high, and this was associated with a large reduction in vegetative growth, compared with the cultivated treatment. The bulk density of the soil was also high in the treatment where the subterranean clover was grown, but the vegetative growth of tomatoes was equal to that in the cultivated treatment. Despite the large differences in vegetative growth among treatments, there was no significant difference in the fruit yield. These results show that processing tomatoes can be successfully grown under zero-tillage when irrigation and fertilizer are well managed, and that vegetative growth and fruit yield are poorly correlated. The in-situ mulch of subterranean clover improved the physical conditions of the soil compared to the zero-tillage treatment, successfully controlled weeds and reduced soil erosion, but at the cost of having land out of production during the winter.
Changes in plasma amino acid patterns and wool growth in response to abomasal injections of amino acids during late pregnancy and early lactation
Authors: Stewart CA , Masters DG , Williams IH , Connell PJ
Published: November 2004

Provision of sulfur-containing amino acids into the abomasum has increased wool production in non-reproducing sheep and, on the basis of such studies, they have generally been considered as the primary limiting nutrients for wool growth. The specific amino acid needs of reproducing ewes were investigated in the current study. Three groups of pregnant ewes were fitted with temporary abomasal fistulae. For the last 3-4 weeks of pregnancy and the first 3 weeks of lactation, solutions containing sodium hydroxide (as a carrier) or methionine or a mixture of valine, arginine, lysine and threonine (VALT) were injected into the abomasum twice per day. The injection of methionine did not increase protein deposition during pregnancy; this was indicated by the failure of the treatment to lower the concentration of other amino acids in plasma, or increase liveweight, lamb birth weight or wool growth. Responses in early lactation were different with the methionine injected sheep having a lower concentration of free lysine, valine, alanine and serine in plasma, indicating an increased rate of protein deposition, and a faster growth rate in the ewes. Injections of VALT caused a decrease in the concentration of cystine and methionine in plasma and depressed wool growth and tensile strength. Theresults indicate that a lack of methionine was not limiting protein deposition during late pregnancy, but may have been during early lactation. Valine, arginine, lysine and threonine were not the primary limiting amino acids in late pregnancy or early lactation.
Fleece growth in Australian cashmere goats. 1. The effects of nutrition and age on fleece growth, prolactin and thyroxine concentration
Authors: Kloren WRL , Norton BW , Waters MJ
Published: November 2004

Australian cashmere goats were studied from January to July to assess the effects of increasing feeding level (maintenance, M: 42 g D M / W0.75/day, 1.4 M, 1.8 M and 2.3 M (ad libitum)) and age (Young, 6 months; Old 18 months) on fleece growth, and plasma concentrations of prolactin (Prl) and thyroxine (T4). Comparisons of fleece composition (weight, cashmere fibre diameter, proportion of cashmere) were made from fleece shorn monthly (left side) and at the end of the experiment (right side). There was no significant (P > 0.05) effect of feeding level or age on cashmere weight (39.8 g), cashmere diameter (15.3 8m) or hair weight (224.7 g) at shearing in July. Similar results were observed with monthly fleece composition studies, although cumulative cashmere weight for Young goats (27.1 g) was significantly (P <0.05) less than that of Old goats (48.5 g), and average fibre diameter of cashmere of Young goats (13.6 8m) was less than that of Old goats (15.6 8m). Serum Prl concentration in groups on higher feeding levels (1.8 M, 2.3 M) increased significantly (P < 0.05) over the duration of the study (45 to 70 ng/mL and 15 to 70 ng/mL for 1.8 M and 2.3 M respectively), whilst that of the groups on lower feeding levels (M, 1.4 M) remained low (15 ng/mL). The results are discussed in relation to the seasonal change in fleece composition and hormone secretion for the different feeding levels and age groups, and a possible antagonism between Prl secretion and fleece growth.
Fleece growth in Australian cashmere goats. III. The seasonal patterns of cashmere and hair growth, and association with growth hormone, prolactin and thyroxine in blood
Authors: Kloren WRL , Norton BW , Waters MJ
Published: November 2004

The seasonal patterns of cashmere and hair growth, and prolactin, thyroxine and growth hormone concentration in blood were investigated in male, female and castrated male 6- month-old Australian cashmere goats for 27 months. Seasonal patterns of cashmere growth were distinct with length increasing from a minimum in December to maximum (50-60 mm) in July. Initiation of cashmere growth in female goats was consistently earlier than that of males, with that of castrates being similar, later and earlier than males in 1987, 1988 and 1989 respectively. The initiation of cashmere growth progressed in a wave from the hip to the shoulder (6 weeks). There were no significant effects of sex on maximum length of cashmere grown. Prolactin secretion was also seasonal, increasing from minimum values in July-August (20 ng/mL) to peak levels around December (50-350 ng/mL). Thyroxine concentrations were higher in summer than winter, but seasonal changes were not as distinct as those of prolactin. Growth hormone secretion was aseasonal, and declined with age. It has been proposed that peak levels of prolactin in December were associated with the initiation of cashmere growth, with active growth occurring as levels declined. Neither thyroxine nor growth hormone appear to have a regulatory influence on the cashmere growth cycle.
Reducing post-partum anoestrous interval in first-calf Bos indicus crossbred beef heifers. 1. Effects of pre- and post-partum supplementation strategies
Authors: McSweeney CS , Fitzpatrick LA , D'Occhio MJ , Reid D , Entwistle KW
Published: November 2004

The effects of pre-and post-partum (ppp) v. post-partum (pp ) supplementation on reproductive function were compared in Bos indicus x Bos taurus (5/8 x 3/8) first-calf heifers. Twenty-four pregnant heifers were allocated to three treatment groups all fed roughage hay ad libitum. The dietary treatments were: (1) nil supplement controls, (2) cracked maize (1 kg) plus formaldehyde treated sunflower seed meal (0.5 kg) daily for 60 days post-partum, (3) supplement 2 from 1-2 months pre-partum to 60 days post-partum. Supplementation did not affect hay intake prior to calving (6.5 kg/day), but significantly increased (P < 0.05) intake by approximately 50% after calving compared with a 20% increase in the controls. Maternal liveweight, adjusted for the weight of the foetus and gravid uterus, was 345 kg in all groups at 5 weeks before calving. This weight declined by 6 kg in unsupplemented animals and increased by 16 kg with supplementation before calving. During the 2 months after calving, ppp supplemented animals maintained weight, pp supplemented heifers gained 26 kg, and controls lost 39 kg. Birth weight of calves from heifers supplemented before parturition was 34.2 � 1.9 kg, 5.6 kg heavier than the other calves (28.64�0.7 kg). Milk yield and N secretion tended to be highest in ppp supplemented heifers in the peri-partum period. Two months after calving, milk yield and secretion of N, fat and lactose were not different in both supplemented groups, but were significantly higher (P < 0.05) than in the controls. Endogenous pulsatile release of LH and FSH was not detected in heifers from any group 50 days after calving. Following GnRH injection (100 8g, i/m), the LH response was not significantly different between groups, but the unsupplemented animals had greater ( P < 0.05) FSH responses than the supplemented heifers. Supplemented heifers had lower ( P = 0.07) plasma GH concentrations prior to calving; after calving, GH levels were in the order: ppp supplemented < pp supplemented < controls. There was no indication that supplementation affected ovarian folliculogenesis in animals treated with exogenous gonadotrophin, and all animals were in an anoestrous state at 60 days post-partum. In conclusion, the type of supplementation practiced here did not appear to improve reproductive performance in first-calf heifers weighing 340-360 kg in early lactation. However, ppp supplementation was the most effective treatment in reducing GH levels and maintaining liveweight in the peri-natal period, both of which have been associated previously with reducing post-partum anoestrous interval.
Occurrence of barley yellow dwarf virus serotypes MAV and RMV in over-summering grasses
Authors: McKirdy SJ , Jones RAC
Published: November 2004

Over-summering grasses were collected in the south-west of Western Australia in 1991 and 1992 and tested by ELISA using serotype specific polyclonal antibodies for presence of barley yellow dwarf virus (BYDV) serotypes MAV, PAV and RPV (1991) or MAV, PAV, RPV and RMV (1992). In 1991, 33 samples from 33 sites were tested and MAV was detected in four of 12 samples of Pennisetum clandestinum found infected with BYDV. Presence of MAV was confirmed by retesting these samples using MAV specific monoclonal antibodies. In 1992, 802 samples from 16 grass species were collected from 579 sites in six regions. BYDV was detected in 214 (27%) samples at 178 (31%) sites. MAV was found in 50% and RMV in 38% of infected samples. Both were found either alone or in mixed infections with each other or with PAV and/or RPV; all four serotypes were found in 18 (8%) infected samples. The most important hosts were four perennials: Cynodon dactylon, Eragrostis curvula, Paspalum dilatatum and P. clandestinum. Eight other perennial and five annual grass species were also infected. MAV was most commonly found in C. dactylon and P. clandestinum and RMV in P. dilatatum. All four serotypes were present in the six regions sampled, but the relative proportions of the serotypes found varied from region to region. This paper represents the first extensive survey of MAV and RMV serotypes of BYDV in over-summering grasses in Australia. Aphid species found during this survey infesting over-summering grasses were Rhopalosiphum padi,R. maidis and Hysteroneura setariae. In the Mediterranean type climate of the south-west of Western Australia, BYDV and aphids on over-summering perennial grasses constitute the main reservoir of infection and means of spread to cereal crops. Factors favouring grass survival over summer result in increased cereal crop infection.
The effect of inoculation of cashew with NutriLink on vesicular arbuscular mycorrhizal infection and plant growth
Authors: Haugen LM , Smith SE
Published: November 2004

This investigation was initiated to assess whether inoculation of cashew (Anacardium occidentale) seedlings under commercial nursery conditions would result in mycorrhizal development in the root systems and increased growth of the plants. Three experiments were carried out to investigate the effects of different nursery factors on infection and plant growth. These were: use of triple superphosphate, pH of the potting mix (varied by lime additions) and removal of the cotyledons. Inoculation with the commercially available mycorrhizal inoculum Nutrilink� (containing spores of Glomus intraradices) resulted in mycorrhiza formation, but the levels of infection were low even in the absence of triple superphosphate addition. The highest infection (55%) was observed in seedlings from which the cotyledons had been removed. Inoculated plants in general grew less well than non-inoculated plants under all conditions. This depression may be the result of changes in pH following inoculation or the result of development of mycorrhizal infection. There were no positive effects of inoculation on nutrient concentrations in the tissues, except that inoculated plants had higher concentrations of K in both leaves and roots. Addition of lime to the potting mix did not significantly affect the extent of infection or the responses of the plants. Cotyledon removal was associated with higher infection and a reduction in the negative effect of inoculation on growth, although plant growth was reduced in inoculated and non-inoculated treatments. It does not appear that inoculation with NutriLink is appropriate in the potting mixes used, particularly as the formulation causes changes in pH of the potting mixes. Other strategies will need to be adopted to optimize potential benefits of mycorrhizas in cashew production.
Seasonal changes in abundance of earthworms (Annelida:Lumbricidae and Acanthodrilidae) in soils used for cereal and lucerne production in South Australia
Authors: Baker GH , Barrett VJ , Carter PJ , Williams PML , Buckerfield JC
Published: November 2004

The abundances of the introduced earthworms, Aporrectodea rosea, A. trapezoides, Microscolex dubius and M. phosphoreus were monitored monthly in the top 30 cm of soil at three farms used for cereal and lucerne production in South Australia. The farms had approximately 500 mm annual rainfall. Total earthworm densities of up to 303 m-2 were recorded, with the Aporrectodea spp. far more abundant than the Microscolex spp. Highest numbers were found in winter and early spring, when the soils were wettest (water suction potential < approx. 150 kPa) and the majority of worms were present in the top 10 cm of soil. During the drier months of the year, most worms were found below 10 cm depth. Adults with mature clitella were restricted to winter and spring. Juveniles and adults (with regressed clitella) of Aporrectodea spp. survived summer.
Effects of depth and time of sowing on emergence of Danthonia richardsonii Cashmore and Danthonia linkii Kunth
Authors: Lodge GM , Schipp AJ
Published: November 2004

Two experiments examined the effects of sowing time and depth (surface and 10, 25, 50 mm) on emergence of Danthonia richardsonii Cashmore and Danthonia linkii Kunth. Experiment 1 was conducted from January to December 1990 on a loam/sand mixture in boxes. Emergence was highest in both species for seeds sown onto the soil surface in summer and autumn (P < 0.05). Sowing at any depth at any time of the year, or surface sowing in winter and spring, markedly reduced emergence. Experiment 2 was conducted in the field at Tamworth, northern New South Wales from September 1991 to August 1992, on a red brown earth and a black earth. This study confirmed that emergence in both species was highest from surface sown seed. Field emergence was lowest in winter, but in contrast to experiment 1, it was higher in spring, particularly on the black earth. Seedling emergence appeared to be related to mean maximum temperature, decreasing in winter as it declined below 20�C, and increasing in spring when it was greater than 23�C. Differences in seed weight were reflected in emergence of D. richardsonii and D. linkii in experiment 1. Similar emergence was recorded for the loamlsand mixture and sand, indicating that there was little effect of texture. Phalaris aquatica L. cv. Sirosa surface sown in December had lower emergence ( P < 0.05) than both Danthonia spp., but emergence of this larger seeded cultivar was higher at depths of 10 and 25 mm. Laboratory studies to determine reasons for the low emergence of D. richardsonii and D. linkii from depth, indicated that neither had an obligate light requirement for germination. Depth, however, reduced germination (P < 0.05) compared with surface sowing of seed. Seedlings at depth also were observed to have slower rates of shoot and root elongation. In the field, the most successful establishments of D. richardsonii and D. linkii seedlings are likely to occur from surface sowings in April and May. Sowing in spring may also be possible if mean maximum soil temperatures exceed 23�C, and seedlings can establish before the onset of hot, dry conditions in summer.
Variability in grain protein concentration of peas and lentils grown in Australia
Authors: Stoddard FL , Marshall DR , Ali SM
Published: November 2004

Protein and yield data were obtained from South Australian and Interstate pea and lentil variety trials conducted between 1986 and 1989, covering 94 pea and 58 lentil genotypes. Crude protein concentration varied significantly across sites and averaged 25.0% in peas and 24.4% in lentils. Protein concentration was not significantly correlated with yield at most individual sites. Minimum protein concentration in peas was 1.6% below the mean of three check cultivars in line RA155, while the maximum was 2.3% above that mean in lines P255-2 and P262-1. In lentils the range was 1.2% above the check mean in ILL5562 and 1.0% below in ILL6017. A further lentil genotype, 'Chilean', was 6.0% above controls, but was inadequately replicated in these trials. Genotypic variation in pea and lentil protein concentration was lower than in many other species, but the lack of correlation between protein and yield suggests that independent selection of both characters during breeding is possible and should be successful without the rate of gain in one trait being reduced by that in the other.
Non-starch polysaccharides and broiler performance on diets containing soyabean meal as the sole protein concentrate
Authors: Irish GG , Balnave D
Published: November 2004

The total water-soluble and water-insoluble non-starch polysaccharides (NSP) were determined in seven soyabean meals processed in Australia, three soyabean meals processed in the U.S.A., and one sunflower meal processed in Australia. Sunflower meal had a higher content of total NSP than any of the soyabean meals, due mainly to increased concentrations of cellulose and xylose in the insoluble NSP and uronic acids in the soluble NSP. Galactose and fucose concentrations were much greater in the insoluble NSP of soyabean meals. Soyabean meals processed in the U.S.A. had lower concentrations of total NSP, cellulose and xylose than equivalent meals processed in Australia. Broiler chickens fed diets containing soyabean meal as the sole dietary protein concentrate grew significantly more poorly than broilers fed isoenergetic and isonitrogenous diets in which approximately 25% of the soyabean meal was replaced with sunflower meal. There was a significant (P < 0.05) negative correlation (r2 = 0.57) between the water-soluble xylose content of the soyabean meals and the improvement in growth observed with sunflower meal supplementation. Multi-enzyme preparations designed to act on soyabean meal NSP substrates failed to induce any improvement in the growth of broilers fed soyabean meal diets. The poor performance of broilers fed the soyabean meal diets did not appear to be related to inadequate processing or to the NSP content or composition of the soyabean meals. Measurement of free sugars in the supernatant of the digesta in the ileum indicated that the stachyose derived from the oligosaccharides of soyabean meals appeared to exert an antinutritive effect when soyabean meal was present at high concentrations as the sole protein concentrate in broiler diets.
Response in female fertility and calf growth to selection for pregnancy rate in tropical beef cattle
Authors: Davis GP , Corbet NJ , Mackinnon MJ , Hetzel DJS , Entwistle KW , Dixon R
Published: November 2004

Direct response to divergent selection based on estimated breeding value for female pregnancy rate in a herd of Bos indicus cross cattle was evaluated along with correlated responses in calf survival, weaning rate, cow liveweight and calf growth. Pregnancy rates were significantly higher ( P < 0.05) in heifers of the High line compared with the Low line (High-Low=15� 5%) and in lactating 4-year-old cows (25�9.5%) and in 3 of the 5 years of the study (average difference 24%). The Low line had significantly ( P < 0.05) higher pregnancy rates in 1 year (-16�5.4%). These differences in pregnancy rates were reflected in weaning rates, but calf survival was only different between the lines in 2 of the 4 years analysed (-6� 3.0% in 1990 and 18�6.5% in 1991). The High line had a significantly ( P < 0.05) shorter days to calving than the Low line in heifers (High=309�2.2 days v. Low= 315�2.5 days), lactating 3-year-old cows (3l5� 3.6 days v. 331�4.1 days), non-lactating 3-year-old cows (301�5.4 days v. 320�4.6 days) and lactating 4-year-old cows (311�3.9 days v. 336�4.9 days). Differences between the lines in pre-weaning growth varied according to generation with significantly lower (P < 0.05) weaning weights (182�3.1 kg v. 189�3.3 kg) and pre-weaning growth (790�17 g/day v. 826� 17 g/day) in first generation High line calves from foundation dams and no difference between the lines in second generation calves from first generation dams. Post-weaning growth was significantly higher ( P < 0.05) in High line calves (350� 5 g/day v. 327�5 g/day). The results indicate that selection of sires on EBV for pregnancy rate leads to improved fertility in heifers and 4-year-old lactating cows without adverse effects on progeny growth.
Soil moisture and temperature affect condensed tannin concentrations and growth in Lotus corniculatus and Lotus pedunculatus
Authors: Anuraga M , Duarsa P , Hill MJ , Lovett JV
Published: November 2004

Maku big trefoil and Dewey birdsfoot trefoil were grown at 14/10, 20/16, 26/22 and 32/28�C (14/10 h) in growth cabinets. Growth rates and condensed tannin (CT) concentrations were measured as soil moisture was changed from field capacity (FC) to 20% FC to FC again in three regrowth cycles. Seasonal dry matter accumulation and CT concentrations were also measured on these cultivars together with Sharnee big trefoil, Monarch cicer milkvetch, Chemung crownvetch and WL605 lucerne at two sites in the field. Condensed tannin concentrations were not greatly affected by temperature alone. However, moisture stress induced proportionately larger reductions in growth rates of big trefoil as temperature increased, and correspondingly larger rises in CT concentrations. Condensed tannin concentrations in birdsfoot trefoil were largely unaffected by these factors. In big trefoil, the responses in CT levels and growth rates continued even when soil moisture was returned to FC. Low temperature did not appear to affect CT concentrations in big trefoil, but caused some slight elevation in concentrations in birdsfoot trefoil. In the field, CT levels in the big trefoil cultivars, and in birdsfoot trefoil, were elevated in summer and autumn, when temperatures were high and periods of soil moisture stress occurred. The potential for elevated CT levels in big trefoil appears to be enhanced when growth rates are reduced by moisture stress and temperaturs are high. Big trefoil should be carefully screened for CT concentrations in the process of cultivar development. High CT levels are not a problem in birdsfoot trefoils such as Dewey.
The recovery of fertilizer phosphorus by wheat, its agronomic efficiency, and their relationship to soil phosphorus
Authors: Holford ICR , Doyle AD
Published: November 2004

Phosphorus (P) uptake by wheat from both soil and fertilizer, the recovery of fertilizer P and its agronomic efficiency, and the fertilizer P required for maximum profit were measured in 55 wheat fertilizer experiments during 1986-89 in the northern and central wheat belts of New South Wales. Moisture conditions during crop growth had a dominant effect on all these parameters, whose values were generally highest in the wettest year (1988) and much lower in the driest year (1989). Lactate-extractable soil P was well correlated with each of these parameters, there being a different relationship for the 3 years of adequate rainfall (1986-88) from that for the very dry year: in general, the values of each parameter in the dry year were about half the values in the wetter years. Recovery of fertilizer P in the grain was very low and declined at increasing levels of soil P from about 13% at 1 mg/kg to 2% at 50 mg/kg in 1986-88. This indicates high potential levels of fertilizer P residues in this soil/climatic environment. Fertilizer P required for maximum profit was much better correlated (r2 = 0.50) with soil P than was the requirement for 90% of maximum yield (r2 = 0.30), and the latter did not differentiate between the moist and dry years.
Management of Lolium perenne/Trifolium repens pastures in the subtropics. I. Effect of defoliation interval, seeding rate and application of N and lime
Authors: Fulkerson WJ , Slack K , Moore K , Rolfe C
Published: November 2004

This plot cut study, conducted on the subtropical north coast of New South Wales, evaluated the effect of defoliation interval, seeding rate and application of nitrogen and lime on production and survival over summer of a Lolium perenne/Trifolium repens pasture. There was a 117% or 12 781 kg DM/ha difference in DM yield between the worst and best treatment combinations over the 17 month period of the study. The best treatment combination for yield also gave the highest rate of ryegrass survival and lowest levels of 'summer grass' ingression over the first summer. Defoliation at 4 weeks or 'when ready' (before onset of senescence, 'lodging' or rust), compared to at 2 weeks, increased DM yield by 18 and 32% in year 1 and 41 and 59% in year 2 respectively. The larger difference in year 2 was primarily due to a greater ingression of 'summer grass' (winter dormant) and a lower survival of ryegrass plants over the first summer in the most frequently cut plots. The lower root DM in summer at the more frequent cutting interval may have been one factor responsible for the defoliation effect. DM yields of a 'clover dominant' sward (nil N except at sowing and 8 kg ryegrass/ha; clover = 53%) was 85% in year 1 and 50% in year 2 (up to August) of that of a 'ryegrass dominant' sward (100 kg urea ha-1 mo-1 and 35 kg ryegrass/ha; clover = 8%). The lower yield of the 'clover dominant' pasture in year 2 was partly due to a greater level of 'summer grass' infestation. Application of N increased plant survival over summer, but under grazing, many plants may have been lost through sod pulling by stock, as roots were more restricted to the surface. Application of lime increased DM yield in both years.
Radiation interception and biomass accumulation in a sugarcane crop grown under irrigated tropical conditions
Authors: Muchow RC , Spillman MF , Wood AW , Thomas MR
Published: November 2004

Little quantitative information relating yield accumulation in sugarcane to climatic factors is available to allow the maximum yield in different seasons and locations to be determined. By comparison of actual yield with the climatically determined maximum yield for a given crop, the extent of yield limitation due to management and soil and pest factors can be assessed. This paper analyses the relationship between radiation interception and biomass accumulation for an autumn-planted sugarcane crop grown under irrigated conditions at Ayr, Qld (lat. 19.5� S.). Crop samplings were conducted from 167 to 445 days after planting (DAP). Less than 60% of the seasonal incident solar radiation was intercepted by the crop. A radiation extinction coefficient of 0.38 was estimated from the relationship between green leaf area index and the fraction of the radiation intercepted (fi). A maximum crop radiation (SW, 0.35-2-5 8m) use efficiency (RUE) of 1.75 g MJ-1 was determined. The maximum crop growth rate over a 140 day period was 41.1 g m-2d-1. However, this value is dependent on fi and the incident radiation ( S ) , and accordingly would be expected to vary across locations. In contrast, the RUE value of 1.75 g MJ-1is independent of fi and S, and can be used as a baseline value to assess the extent of yield limitation and the scope for yield improvement at different locations. The maximum biomass production was 72 t ha-1and the maximum fresh cane yield was 201 t ha-1. However, these maximum yields were attained up to 4 months before the final sampling. Future research should examine the wider applicability of this early yield plateau, and focus on the factors responsible for the early cessation in yield accumulation.
Diagnosis and prognosis of molybdenum deficiency in black gram (Vigna mungo L. Hepper) by plant analysis
Authors: Jongruaysup S , Bell RW , Dell B
Published: November 2004

Diagnosis and prognosis of molybdenum (Mo) deficiencies in black gram crops by plant analysis is difficult because Mo standards have not been set and tested in the field. Therefore, critical Mo concentrations, for the diagnosis of Mo deficiency at early flowering and for diagnosis and prognosis at pod filling in black gram, were determined in two glasshouse experiments by examining the relationship of Mo concentrations in young leaves and nodules to shoot nitrogen content or seed dry matter in plants treated with seven levels of Mo supply on a Mo-deficient sandy loam. In severely Mo-deficient plants, shoot dry matter (DM) and shoot nitrogen (N) content were depressed. Molybdenum concentrations in plant parts increased with increasing Mo supply and were closely related to shoot N content. shoot DM, and seed DM. Critical Mo concentrations for diagnosis of hi0 deficiency were obtained from the relationship between N content and &lo concentrations in leaves and nodules. and for prognosis of Mo deficiency were obtained from the relationship between seed yield and Mo concentrations in plant parts. Critical Mo concentrations were much higher in nodules than in leaves, and among young leaf blades, they increased with decreasing leaf age. For diagnosis of Mo deficiency, blades of the leaf immediately older than the youngest fully expanded leaf (YFEL+lb) and nodules are recommended plant parts. Their respective critical concentrations were 22 and 9600 ng Mo/g DM at flowering, and 22 and 3378 ng Mo/g DM at initial pod set. Molybdenum concentrations in the YFEL+lb and nodules at podding were also related to seed production at maturity. Recommended critical h10 concentrations in the YFELflb and nodules at initial pod set for the prognosis of IbIo deficiency for seed DM were 18 and 3000 ng Mo/g DM respectively.
Growth, nutrient uptake and tipburn severity of hydroponic lettuce in response to electrical conductivity and K:Ca ratio in solution
Authors: Huett DO
Published: November 2004

A commercial hydroponic nutrient solution formulation was developed to reflect the high K:N uptake of a range of vegetable crops (Huett and Dettmann, Aust. J. Agric. Res. 1992, 43, 1653-65). This standard formulation had a K:N ratio of 1.7: 1.0 and a K:Ca ratio of 1.25 : 1 00 (equivalent weight basis). Head lettuce cv. Coolguard and cv. Fame and non-heading cv. Red Mignonette were grown in recirculating culture to maturity with the standard formulation to examine the effect of electrical conductivity (EC) (0.4-3.6 dS m-l) and, for the latter two cultivars, nutrient formulation K: Ca ratio (from 1.00:3.50 to 3.50: 1-00) on growth, nutrient uptake and tipburn severity. Plants grown at an EC of 0.4 dS m-l were N and K deficient, while recently matured leaves and youngest leaves contained the highest Ca concentrations which decreased with increasing EC. When cv. Coolguard was grown at an EC of 1.0 dS m-l, N and K deficiency was eliminated and leaves contained the highest Ca concentration. Maximum fresh weight of leaf and head was recorded at 1-6 dS m-' and the decline in nutrient solution N and K concentrations over the growth period was 13 and 42% respectively. An increase in the K: Ca ratio of the formulation increased (P < 0-05) leaf by 13% and leaf+head fresh weight at maturity by 10% for cv. Fame whereas, for cv. Red Mignonette, a reduction in the K : Ca ratio increased ( P < 0.05) leaf fresh weight by 29% compared with the standard formulation. A reduction in the K : Ca ratio increased ( P < 0.05) the Ca concentration in the youngest leaves of cv. Fame and of cv. Red Mignonette at 1.6 and 3.6 dS m-l. Leaf K concentrations were generally reduced ( P < 0.05) by low EC and low K:Ca ratio. Hot conditions led to tipburn developing in cv. Red Mignonette at the 2 week harvest. The number of leaves plant-1 with tipburn at maturity (week 3) was reduced ( P < 0.01) from 23.1 to 4.4 as EC was reduced from 3.6 to 0 - 4 dS m-1 and was reduced ( P < 0 05) from 15.2 to 12.3 as the nutrient formulation K : Ca ratio was reduced from 3.5 : 1.0 to 1.25 : 1.00. Over the last week of the growth period, the number of leaves with tipburn remained stable at an EC of 0-4 dS m-l whereas, at 3.6 dS m-l, the number of leaves with tipburn increased by 253%. Tipburn developed in young leaves of cv. Red Mignonette which had a Ca concentration range from 1.7 to 3.2 g kg-1 and was generally absent from recently matured leaves which had a Ca concentration of 11.0 g kg-1. Young leaves of the tolerant cv. Fame had a Ca concentration of 5-9 g kg-1.
Genetic parameters for Australian maternal and dual-purpose meatsheep breeds. III. Liveweight, fat depth and wool production in Coopworth sheep
Authors: Brash LD , Fogarty NM , Gilmour AR
Published: November 2004

Heritability was estimated for weaning liveweight of 7030 Coopworth sheep from 10 flocks representing 92 sires by derivative-free restricted maximum likelihood procedures using an animal model. Similar analyses were used for yearling liveweight and greasy fleece weight with over 4000 animals, fat depth on 2184 animals and fibre diameter on 966 animals. The fixed effects of flock-year-management group, sex, birth type, rearing type and age were significant for most traits. Estimates of heritability were 0.45 � 0 - 07 for weaning liveweight, 0.38 � 0.07 for yearling liveweight, 0 28 � 0.05 for greasy fleece weight, 0.18 � 0 08 for fibre diameter and 0.13 � 0.04 for ultrasonic fat depth at the C site. The genetic correlations of liveweights with greasy fleece weight were positive, but close to zero with fibre diameter. The genetic correlation between greasy fleece weight and fibre diameter was 0.422 � 0.25. Fat depth was highly genetically correlated with liveweights at weaning (0.53 � 0.22) and yearling (0.64 � 0- 20) ages, was highly negatively correlated with fibre diameter (-0.55 � 0.28) and had a small positive genetic correlation with greasy fleece weight (0.15 � 0.34).