bluuebunny/crossref_metadata_2025 huggingface dataset:
Peanut resistance to Sclerotinia minor and S. sclerotiorum
Authors: Cruickshank A. W. , Cooper M. , Ryley M. J.
Published: March 2003

The fungi Sclerotinia minor and S. sclerotiorum are the causal agents of two similar diseases of peanut (Arachis hypogaea L.). Both diseases cause significant losses in the Australian peanut industry. Development of cultivars with resistance to Sclerotinia will be an important component of integrated control. The aims of this project are to generate information that will assist in breeding for Sclerotinia resistance in peanut: to identify Sclerotinia-resistant peanut germplasm, to understand the inheritance and estimate heritability of resistance, and to test the effectiveness of identified sources of resistance against both S. minor and S. sclerotiorum. This study has clearly established that material that shows resistance to S. minor in the USA is resistant to S.�minor and likely to be resistant to S. sclerotiorum in Australia. The high level of resistance to both S. minor and S.�sclerotiorum in germplasm from Texas, particularly TxAG-4, was confirmed. VA 93B showed good resistance in the field, which is primarily due to the open bush type rather than physiological resistance. Physiological resistance to S. minor was also identified in a cultivar and a landrace from Indonesia and a rust-resistant line from Queensland. All germplasm found to have high physiological resistance to S. minor belonged to the Spanish type. Inheritance of physiological resistance to S. minor was studied using a Generation Means Analysis (GMA) of the cross TxAG-4/VA 93B and its reciprocal. The broad-sense heritability of physiological resistance on a single plant basis was estimated at 47%, much higher than earlier estimates obtained in field studies. The average gene action of Sclerotinia resistance genes from TxAG-4 was found to be additive. No dominance effects were detected in the GMA. A small but significant reciprocal effect between TxAG-4 and VA 93B indicated that VA 93B passed on some physiological resistance maternally. An experiment was conducted to confirm the value of resistance against both S. minor and S. sclerotiorum. TxAG-4 was found to have physiological resistance to both S. minor and S. sclerotiorum. This resistance was expressed against both Sclerotinia species by progeny that were selected for resistance to S. minor. On the basis of the information obtained, the comparative advantages of 3 strategies for Sclerotinia-resistant cultivar development are discussed: (1) introduction of germplasm; (2) recurrent backcrossing with screening and crossing in the BCnF1 generation; and (3) pedigree selection. At present, introduction and backcrossing are recommended as the preferred strategies.
Effects of deficit irrigation on growth, yield and fruit quality of eggplant under semi-arid conditions
Authors: Kirnak Halil , Tas Ismail , Kaya Cengiz , Higgs David
Published: March 2003

Eggplant (Solanum melongena L.) cv. Pala was grown in the field from March to August 2001 in order to investigate the effects of deficit irrigation on fruit yield and quality (i.e. soluble dry matter, fruit size), leaf relative water content, leaf area index (LAI), leaf chlorophyll concentration, electrolyte leakage, and leaf nutrient composition (N, P, K) in eggplant. Treatments were: (1) well-watered treatment receiving 100% replenishment of A pan evaporation on a daily basis (C); (2) water-stressed treatment receiving 90% replenishment of A pan evaporation at 4-day intervals (WS1); (3) water-stressed treatment receiving 80% replenishment of A pan evaporation at 8-day intervals (WS2); and (4) water-stressed treatment receiving 70% replenishment of A pan evaporation at 12-day intervals (WS3). A total of 1276 mm of water was applied to C treatment, and the seasonal water use of eggplant ranged from 905 to 1373 mm. The C treatment had the highest yield as well as the largest and the heaviest fruit. WS1 did not significantly affect fruit yield or fruit size but fruits were slightly lighter; plant height, stem diameter, and shoot and root dry weights, LAI, leaf relative water content, nutrient concentrations, and chlorophyll concentrations in leaves were the same as in C; SDM was higher than C. The WS2 and WS3 treatments caused reductions in most parameters, except water-soluble dry matter (SDM) concentrations in fruits, compared with the unstressed (C) treatment. WS2 and WS3 treatments enhanced fruit quality (in terms of SDM) and increased electrolyte leakage compared with C. WS2 and WS3 reduced marketable yield by 12% and 28.6%, respectively, compared with C. The highest total water use efficiency and irrigation water use efficiency were in WS2, resulting in a 20.4% water saving compared with C. The results revealed that the optimal irrigation strategy for eggplant could depend on balancing the situational requirements in terms of irrigation water, yields, and fruit size and quality.
Detection and occurrence of a new pathotype of Puccinia triticina with virulence for Lr24 in Australia
Authors: Park R. F. , Bariana H. S. , Wellings C. R. , Wallwork H.
Published: March 2003

The leaf rust resistance gene Lr24 remained effective in Australia from at least 1983, when the first wheat cultivar with this gene was released, until 2000, when a virulent isolate of Puccinia triticina was detected. Results of comparative greenhouse studies were consistent with the hypothesis that the new virulent isolate developed from pathotype 104-1,2,3,(6),(7),11 by mutation to virulence for Lr24. The new pathotype was first detected in South Australia (October 2000), and was subsequently detected in southern New South Wales (November 2000), Victoria (March 2001), and Queensland (March 2001), suggesting that it originated in South Australia and then spread to other parts of the eastern Australian wheatbelt. Greenhouse tests of 28 Australian wheat cultivars possessing Lr24 revealed that all except Dennis, Giles, Petrie, and Sunsoft 98 were seedling susceptible to the new pathotype. Cultivars Giles, Petrie, and Sunsoft 98 were postulated to carry Lr13, whereas cv. Dennis carries either Lr17b or Lr13. Adult plant field tests of 20 cultivars with Lr24 conducted during 2001 confirmed the resistance of Giles, Petrie, and Sunsoft 98, whereas all other cultivars tested were either moderately resistant to moderately susceptible or susceptible to the new pathotype. Given that some of these cultivars appear to possess Lr34, and that the expression of this gene is influenced by temperature and other environmental factors, further field testing under different seasonal conditions will provide a more accurate indication of their response. Cultivars with Lr37 or Lr13 in combination with Lr1 or Lr2a remain effective to all known pathotypes of P. triticina in Australia. Several new sources of resistance to P. triticina that are effective to Australian pathotypes are currently being evaluated, along with additive adult plant resistances. These sources should provide a greater diversity of resistance to this pathogen in future Australian wheat cultivars.
The long-term impact of nitrogen fertiliser on perennial ryegrass tiller and white clover growing point densities in grazed dairy pastures in south-western Victoria
Authors: McKenzie F. R. , Jacobs J. L. , Kearney G.
Published: March 2003

A 3-year grazing experiment determined the impact of multiple applications of different rates of nitrogen (N) fertiliser, applied over autumn and winter in 1997, 1998, and 1999, on perennial ryegrass (Lolium perenne)/white clover (Trifolium repens) tiller and growing point densities (stolon apices with at least 2 nodes). Annual pasture dry matter (DM) yields were also monitored. Four treatments were replicated 3 times in a randomised block design and included: 0 N (A); 3 applications of 25 kg N/ha (B); 3 applications of 50 kg N/ha (C); and 3 applications of 75 kg N/ha (D). Urea (46% N) was the N source. Grazing of treatment plots occurred at a pre-grazing herbage mass of 2200–2500 kg DM/ha.Over 3 years, N applications consistently increased annual pasture DM yields by 0.9–3.3 t/ha when a total of 75–225 kg N/ha was applied annually.Generally, treatments B, C, and D resulted in higher perennial ryegrass tiller densities than treatment A. An exception occurred from July 1998 in Year 2 to July 1999 in Year 3, when all perennial ryegrass densities were similar. Nitrogen fertiliser generally produced no consistent effect on white clover growing point density, with the exception of July–December in Year 2 when treatments B, C, and D resulted in lower growing point densities than treatment A. Clover growing point density decreased over the trial period irrespective of treatment. There were no N fertiliser effects on 'other' grasses and broadleaved weeds. 'Other' grasses (mainly winter grass, Poa annua) did, however, peak in density (up to 2500 tillers/m2) from July to September each year.Seasonally, the peak perennial ryegrass tiller density was similar each year and occurred during late winter–early spring (5450 tillers/m2 in July 1997; 6200 tillers/m2 in August 1998; 5400 tillers/m2 in July 1999). This was followed by a trough over midsummer (800 tillers/m2 in January 1998; 725 tillers/m2 in January 1999). White clover growing point density declined over 3 years. During this decline there were peaks in June 1997 (2650 growing points/m2), November 1997 (1600 growing points/m2), June 1998 (1250 growing points/m2), April 1999 (1050 growing points/m2), and November 1999 (850 growing points/m2). Troughs occurred in January 1998 (530 growing points/m2) and February 1999 (380 growing points/m2).It is concluded that although increasing applications of N increased annual pasture DM yields and generally increased perennial ryegrass tiller densities, with little effect on clover growing point densities, there is little to suggest that N fertiliser alone would enhance the persistence of these pasture species. Persistence is likely to be influenced by a combination of factors including grazing management and climatic effects, rather than N fertiliser alone.
Crop productivity in relation to species of previous crops and management of previous pasture
Authors: Harris R. H. , Scammell G. J. , Müller W. J. , Angus J. F.
Published: March 2003

An experiment at Rutherglen in north-eastern Victoria compared 5 grass-removal methods in subterranean clover-based pastures that were grown before cropping sequences of canola–wheat–lupin–wheat or wheat–wheat–lupin–wheat. The cropping sequences were started in 3 successive years to provide replication in time. Grass removal from the pasture was more effective in winter than in spring and led to yield increases by the first and second crops. The largest increase (80%) was by the first canola crop after winter-cleaned pasture. The yield increase by the equivalent wheat crop was 42%. Since annual grasses and canola do not host the same root pathogens, we conclude that the yield responses were not due to root-disease control but probably to increased N supply. Assays of wheat roots confirmed that root disease was negligible throughout the experiment. Wheat growing in the year after canola yielded 11% more than wheat growing after wheat. The most surprising result was a 17% increase in the yield of wheat growing 3 years after canola compared with wheat growing 3 years after wheat, with wheat–lupin sequences in the intervening years for both systems. We suggest that canola and lupin, both of which are non-hosts of arbuscular mycorrhizal fungi, reduced mycorrhizal root colonisation in the fourth-year wheat crop, leading to less drain on assimilates.
Di-ammonium phosphate and mono-ammonium phosphate improve canola growth when banded in a P-fixing soil compared with triple superphosphate
Authors: Thomas B. M. , Rengel Z.
Published: March 2003

Banding of fertiliser may restrict fixation of P by soils and thus improve P fertiliser use efficiency. Using pots that allow soil to be sectioned, we examined the effect of banding triple superphosphate (TSP), mono-ammonium phosphate (MAP), and di-ammonium phosphate (DAP) on canola (Brassica napus L. cv. 'Karoo') growth and nutrition in P-fixing soils and the pattern of nutrient distribution from these bands. After 28 days, growth of canola fertilised with MAP or DAP was greater than that of canola fertilised with TSP. Nutrient analysis of the shoots indicated that these differences in growth were most likely the result of differences in nitrogen nutrition. Movement of P was greatest from the DAP band. This was attributed to less fixation of P as a result of an increase in the pH surrounding the DAP band that reduced the fixation of P as Al or Fe phosphate. This study showed that canola grew better when fertilised with DAP or MAP; given the greater movement and availability of P and N from the DAP compared with MAP band, the DAP fertiliser would result in the best canola production in this P-fixing soil.
The geographical diversity of the frequency of the Glu-D1f allele in Asian common wheat, and the transmission route through which the wheat may have reached Japan
Authors: Nakamura H.
Published: March 2003

The frequency of the high-molecular-weight (HMW) glutenin Glu-D1 alleles in Japanese, Chinese, and other Asian common wheat varieties was analysed in order to investigate a possible transmission route for common wheat to Japan. Although the frequency varied among the areas, the allele Glu-D1f was present in wheat from northern and southern Japan, in Xinjiang, Nanjing, Zhejiang, and Beijing in China, and in Afghanistan. However, a high frequency of the Glu-D1f allele was found predominantly in southern Japan. It was not detected in wheat from any other Asian region. This distribution of an adaptively neutral character suggests a specific route of transmission for common wheat to eastern China and Japan. It was introduced from Afghanistan, carried to Xinjiang (in north-west China), Nanjing, and Zhejiang (in south-east China), and then to southern Japan along the so-called Silk Road. It is believed that cultivated common wheat originated in the Middle and Near East and was carried along the Silk Road through China to the Far East, Japan. The latter country is the most geographically remote region from the origin of common wheat. During the course of its long journey and its adaptation to diverse local environments, Japanese common wheat has developed a unique composition of glutenin Glu-D1 alleles.
Factors influencing the germination of macroconidia and secondary conidia of Claviceps africana
Authors: Bhuiyan Shamsul A. , Galea Victor J. , Ryley Malcolm J. , Tay David , Lisle Allan T.
Published: March 2003

The influences of temperature, time, and moisture on the germination of macroconidia and secondary conidia of Australian isolates of Claviceps africana were studied in vitro. The optimum temperature for germination of both macroconidia and secondary conidia of C. africana was 20°C. Although germination of macroconidia ceased near 31°C, approximately 30% of secondary conidia germinated at 37°C after 48 and 72 h of incubation. Sorghum flower extract agar stimulated macroconidium and secondary conidium germination, irrespective of temperature. Germination of macroconidia and secondary conidia on water agar started after 4 h of incubation at 20°C, reaching a maximum after 16–24 h and 14 h, respectively. Maximum germination of both macroconidia and secondary conidia was at ≥ –5 bars at 20°C. Germination of secondary conidia ceased at –35 bars, whereas macroconidia germinated at water potentials as low as –55 bars at 20°C.
Seedbanks and seedling emergence of saffron thistle (Carthamus lanatus) in eastern Australian pastures
Authors: Grace B. S. , Sheppard A. W. , Whalley R. D. B. , Sindel B. M.
Published: March 2003

Weed management has often proved difficult because of persistent seedbanks that allow recruitment to occur for many years after the weed has otherwise been controlled. The number of seeds in seedbanks of Carthamus lanatus, a widespread and troublesome weed, has not been investigated. Little is known about longevity of its seedbanks in pastures of eastern Australia.The numbers of seeds in the soil and the rate of seed loss were investigated at 3 sites in eastern Australia. Seedbanks were found to be patchy, and they had mean densities between 815 and 2290 seeds/m2 after the main germination flush. These seedbanks decreased over time and between 11 and 15% of seeds remained in the soil after 2 years without further input. More seeds were lost in the first year than in the second year, and pasture cover did not affect the rate of seed loss.Seeds buried in mesh bags and exhumed regularly showed that dormancy was lost, induced, then lost again within the 2-year experiment. Maximum seed germinability coincided with peak germination times. The likelihood of a seed producing a seedling was reduced when seeds were sown at high density. C. lanatus seeds appear to be well adapted for persistence in eastern Australian pastures by maintaining a bank of seeds that generally germinate when conditions favour seedling survival.
Simulating phenology and yield response of canola to sowing date in Western Australia using the APSIM model
Authors: Farré I. , Robertson M. J. , Walton G. H. , Asseng S.
Published: March 2003

Canola is a relatively new crop in the Mediterranean environment of Western Australia and growers need information on crop management to maximise profitability. However, local information from field experiments is limited to a few seasons and its interpretation is hampered by seasonal rainfall variability. Under these circumstances, a simulation model can be a useful tool. The APSIM-Canola model was tested using data from Western Australian field experiments. These experiments included different locations, cultivars, and sowing dates. Flowering date was predicted by the model with a root mean squared deviation (RMSD) of 4.7 days. The reduction in the period from sowing to flowering with delay in sowing date was accurately reproduced by the model. Observed yields ranged from 0.1 to 3.2 t/ha and simulated yields from 0.4 to 3.0 t/ha. Yields were predicted with a RMSD of 0.3–0.4 t/ha. The yield reduction with delayed sowing date in the high, medium, and low rainfall region (3.2, 6.1, and 8.6% per week, respectively) was accurately simulated by the model (1.1, 6.7, and 10.3% per week, respectively). It is concluded that the APSIM-Canola model, together with long-term weather data, can be reliably used to quantify yield expectation for different cultivars, sowing dates, and locations in the grainbelt of Western Australia.
Growth of Lotus creticus creticus and Cynodon dactylon under two levels of irrigation
Authors: Vignolio O. R. , Biel C. , Herralde F. de , Araújo-Alves J. P. L. , Savé R.
Published: March 2003

Soils with scarce plant covering are very susceptible to water and wind erosion. Two species recommended for permanent cover of soil are Lotus creticus creticus and Cynodon dactylon. The performance of both species cultivated in pure stands and in mixture and with 2 watering regimes, high (12.64 L/bag) and low (8.36�L/bag), was analysed in polyethylene bags between March and July in greenhouse conditions. With low watering the growth of both species was lower but mortality of plants was not observed. Growth of stems in L.�creticus and stolons in C. dactylon did not stop with low watering. The growth of C. dactylon was higher than that of L. creticus at both watering regimes. Total root and green shoot biomass of each species was affected by watering. Green leaf area, root weight ratio, root hydraulic resistance, and watering efficiency (g biomass/L watering) differed with the combination of species. Green leaf area, root hydraulic resistance, and watering efficiency were higher in C. dactylon than in L. creticus. Root weight ratio was higher in L. creticus than in C. dactylon, but the specific length and area of roots were higher in C. dactylon than in L. creticus. Net photosynthesis rate of each species was only affected by watering regime. Performance of both species was not affected by the mixture and it has the potential to be a successful ground cover.
Locating genes associated with Ascochyta fabae resistance in Vicia faba
Authors: Román* B. , Satovic* Z. , Avila C. M. , Rubiales D. , Moreno M. T. , Torres A. M.
Published: March 2003

Ascochyta blight, caused by Ascochyta fabae Speg.,is a disease of faba bean (Vicia faba L.) of world-wide distribution. Although sources of resistance have been identified, little is known about its genetic basis and gene location. Molecular analyses were carried out using plant tissue from 196 individual F2 plants derived from a cross between susceptible and resistant lines. F2-derived F3 lines were inoculated under controlled growth-chamber conditions and evaluated for disease severity and infection type index. The linkage map was constructed by MAPMAKER V2.0 and the quantitative trait loci (QTL) analysis was carried out using QTL Cartographer. One hundred and twenty-one out of 130 marker loci could be mapped into 16 linkage groups. Nine linkage groups were assigned to specific chromosomes analysing common markers with previous studies that used primary trisomics to establish the chromosomal location of markers/genes. By simple interval mapping (SIM), 2 zones of putative QTL action were detected. Using forward-backward stepwise regression, 4 markers were selected to be used as cofactors in composite interval mapping (CIM). Putative QTLs (Af1 and Af2) were identified on linkage groups VIII (chromosome 3) and IVa (chromosome 2), respectively, and jointly contributed about 46% of the total phenotypic variance. Af1 displayed pure additive gene action and Af2 showed considerable dominant effect.
Sugarcane clones vary in their resistance to sugarcane whitegrubs
Authors: Allsopp Peter G. , Cox Michael C.
Published: March 2003

To determine the extent and type of resistance to sugarcane whitegrubs in clones of sugarcane and some of their wild relatives, pot trials and field trials were carried out. The pot trials tested 405 clones and estimated tolerance effects by differences in the yields of tops, roots, and stubble of infested and uninfested plants and estimated antibiosis effects by differences in the survival and final weights of larvae placed into the pots. Two field trials used a split-plot design, insecticide treated or untreated, to determine tolerance effects on yields of commercial cane and antibiosis/antixenosis effects through differences in the number of larvae in untreated plots. Comparison of pot trials and field trials allowed an estimate of the usefulness of pot trials in estimating resistance to whitegrubs under commercial farming conditions.
Both pot and field trials showed that a range of tolerance and antibiosis resistance mechanisms to whitegrub feeding exists within the current sugarcane germplasm and close relatives. Tolerance effects were apparent in the growth of tops, roots, and stubble. Antibiosis effects were apparent on grub survival and grub growth. Some of these tolerance effects are partially correlated with the general vigour of clones, but there are a number of clones that depart from the general relationships for tolerance and antibiosis. These clones would be especially important in any future program to increase the levels of resistance within the breeding gene pool. There was reasonable repeatability of pot-based tolerance levels between pot trials and with results derived from field trials. These results would be best incorporated into the current sugarcane-breeding program through a specific subprogram targetting grub resistance and using recurrent selection with rapid generation turnover. This would require the development of an appropriate screening system and may require 2 stages. The first would need to handle large numbers of clones to discard the least resistant. This could be followed by a more intensive screening (e.g. our pot technique) to identify the most resistant clones. Those identified after the first cycle of selection would then be recombined to produce more progeny and the process repeated. It is likely that several cycles would be necessary to increase resistance to a level that provides an economic protection.
A GnRF vaccine (Improvac®) and porcine somatotropin (Reporcin®) have synergistic effects upon growth performance in both boars and gilts
Authors: McCauley I. , Watt M. , Suster D. , Kerton D. J. , Oliver W. T. , Harrell R. J. , Dunshea F. R.
Published: March 2003

The use of a vaccine (Improvac) directed against gonadotrophin-releasing factor (GnRF), to prevent boar taint in male pigs, is also associated with an increase in feed consumption, growth, and higher deposition of subcutaneous fat. Daily administration of porcine somatotropin (pST) consistently increases average daily gain, and feed conversion efficiency, and reduces subcutaneous fat, particularly in gilts. The objective of this study was to examine the effect of combining these treatments in boars and gilts. Forty-eight pigs (Large White × Landrace), housed individually, were used in a 2 × 2 × 2 factorial experiment with the respective factors being vaccination with GnRF vaccine (at 14 and 18 weeks of age), daily injection with pST (from 18 weeks to slaughter at 22 weeks), and sex (boars and gilts). Performance was measured over the period of pST administration. Over the entire 28 days of the study, daily gain was lower for gilts than for boars (1216 v. 1410 g/day, P < 0.001), was increased by pST (1219 v. 1407 g/day, P < 0.001), but not significantly altered by vaccination against GnRF (1284 v. 1342 g/day, P = 0.15). However, GnRF vaccination increased daily gain in the second 2 weeks of the study, and overall, there were interactions such that the vaccine increased gain in all groups except boars not receiving pST. Feed intake over the study period was less for gilts than for boars (3139 v. 3407 g/day, P < 0.001), was decreased by pST (3537 v. 3009 g/day, P < 0.001), and increased by vaccination against GnRF (3139 v. 3407 g/day, P < 0.001). When averaged over the entire study, feed conversion ratio (FCR) was higher for gilts than for boars (2.76 v. 2.51, P = 0.013), was decreased by pST (3.05 v. 2.22, P < 0.001), but unchanged by vaccination against GnRF (2.62 v. 2.65, P = 0.70). Fat deposition was lower in gilts than in boars (335 v. 378 g/day, P = 0.037), was decreased by pST treatment ((442 v. 271 g/day, P < 0.001), and increased by vaccination against GnRF (333 v. 379 g/day, P = 0.026). In boars, fat androstenone was reduced by vaccination against GnRF (0.10 v. 2.47 μg/g, P < 0.001) and tended to be reduced by pST (1.71 v. 2.44, P = 0.10), but only vaccination against GnRF reduced skatole (0.174 v. 0.050 μg/g, P < 0.001). The combination of the treatments in all cases was at least additive, and in some cases synergistic. The concomitant vaccination against GnRF and treatment with pST affords an opportunity to increase growth rate and feed intake above control levels and above those of pigs treated with either treatment alone.
A comparative study for yield performance and adaptation of some Australian and CIMMYT/ICARDA wheat genotypes grown at selected locations in Australia and the WANA region
Authors: Sivapalan S. , O'Brien L. , Ortiz-Ferrara G. , Hollamby G. J. , Barclay I. , Martin P. J.
Published: March 2003

A regional adaptation analysis was conducted to provide a basis for effective and efficient wheat germplasm exchange between Australia and the WANA region. A set of 38 Australian and CIMMYT/ICARDA genotypes was tested for grain yield in 29 environments in Australia and the WANA region for 3 years commencing in 1994–95 season. Classification analysis of grain yield data identified 9 genotypic groups and 5 environmental groups with similar patterns in yield performance within each group. Genotypes with similar origin and pedigree were similar in yield performance across environments in Australia and the WANA region. Environmental conditions across both regions showed similarity in discriminating genotypes for their yield performance. Genotypes Attila, Spear, Excalibur, and 82Y:1186 were highest yielding in Australia and the WANA region. However, genotypes Nesser, Pfau/Seri//Bow, Hartog, Vulcan, and Sunland showed wide adaptation across both regions. Genotypes Cranbrook, Genaro 81, Seri 82, Kauz, SUN 190A, and Pgo/Seri 82 showed specific adaptation to favourable environments. Genotypes in each group, based on yield performance, showed differing degrees of yield stability. Pfau/Seri//Bow has the potential for release for commercial production in Australia and the WANA region. The genotypes Pfau/Seri//Bow, Hartog, Sunland, and Vulcan could be used in trials in both regions as indicator varieties to evaluate new breeding lines for mutual exchange between the 2 sets of breeding programs.
Response of wheat genotypes efficient in P utilisation and genotypes responsive to P fertilisation to different P banding depths and watering regimes
Authors: Valizadeh G. R. , Rengel Z. , Rate A. W.
Published: March 2003

The capacity of wheat roots to lift water from subsoil with high moisture content into dry topsoil (hydraulic lift) and the subsequent impact on P uptake from dry topsoil are poorly understood. Two experiments were set up to test the capacity of 4 wheat genotypes differing in P efficiency to take up P from the fertiliser banded in dry topsoil (with wet subsoil). The interactions among genotypes, banding depths, and watering regimes (whole-profile or subsoil-only watering) were also characterised. The root system increased soil water content from 64 to 90 g/kg soil around the P fertiliser band by taking up water in the subsoil and releasing it into the dry topsoil during the night. Phosphorus applied as a band at 20 mg P/kg soil in dry topsoil (5 cm deep) significantly increased P uptake and shoot weight compared with a nil P control. Westonia and Gutha genotypes (efficient in P utilisation, based on dry matter produced per unit of P taken up) had higher shoot weights than Aroona and Wawht 2074 (genotypes responsive to P fertilisation, based on dry matter produced per unit of P fertiliser applied). Greater growth of wheat genotypes occurred in the treatment with P fertiliser banded at a depth of 5 cm compared with 15 cm in the whole-profile watering treatment, but no difference between banding depths was noted in the subsoil-only watering treatment. Wheat genotypes responsive to P fertilisation increased P uptake and shoot weight at the 5-cm P banding depth and the whole-profile watering treatment compared with genotypes efficient in P utilisation. Phosphorus-utilisation-efficient genotypes increased shoot growth more than other genotypes in the subsoil-only watering treatment. It can be concluded that roots of various wheat genotypes lift water from wet subsoil into the dry topsoil (hydraulic lift). Phosphorus fertiliser banded at 5-cm depth in dry topsoil increased P uptake and wheat growth due to the presence of hydraulically lifted water. Genotypes that are efficient in utilising P increased shoot weight more than genotypes responsive to P fertilisers in the subsoil-only watering treatment. In contrast, P-responsive genotypes increased shoot growth more than P-utilisation-efficient genotypes when P fertiliser was banded at 5-cm depth, and a whole-profile watering regime was imposed.
Production of zearalenone, deoxynivalenol, nivalenol, and acetylated derivatives by Australian isolates of Fusarium graminearum and F.pseudograminearum in relation to source and culturing conditions
Authors: Blaney B. J. , Dodman R. L.
Published: March 2003

Australian isolates of Fusarium pseudograminearum (Fp = F. graminearum Group 1) and F.�graminearum (Fg = F. graminearum Group 2) can produce mycotoxins including zearalenone (ZEA), 4-deoxynivalenol (DON), and nivalenol (NIV). Fp isolates from wheat and barley tillers in southern Queensland all produced ZEA and DON in culture, and one typical isolate also produced 3-acetyldeoxynivalenol. Most Fg isolates from wheat and sorghum grains in southern Queensland produced ZEA and DON and one typical isolate also produced 15-acetyldeoxynivalenol. Fg isolates from maize plants in northern Queensland were all ZEA and NIV producers, which was consistent with previous reports, and they also produced high concentrations of acetyl-nivalenols. ZEA and either DON or NIV production by cultures derived from different conidia (and ascospores in Fg isolates) varied by 4–18-fold for ZEA and 2–4-fold for DON/NIV production, and there were significant negative correlations between ZEA and either DON or NIV, indicating a common controlling process. The pattern of ZEA production was quite different between Fp and Fg, with ZEA production being relatively delayed in Fg. After 7 days incubation at 28�C on maize meal, one Fp isolate produced 49 mg ZEA/kg, but in both DON-producing and NIV-producing isolates of Fg, ZEA concentrations after 7 days were <1 mg/kg. ZEA and DON were produced on sorghum and combined wheat–barley grains as well as maize meal, although there were trends for maize meal to be more productive, probably due to greater surface area or different gaseous exchange. Low temperature incubation of a Fg DON-type isolate increased ZEA production, but did not affect either a Fg NIV-type isolate or a Fp isolate. Relationships between these patterns of mycotoxin production, pathogenicity, and implications for crop contamination are discussed.
The development of a Lolium multiflorum cultivar with a low moisture content and an increased readily digestible energy to protein ratio
Authors: Marais J. P. , Goodenough D. C. W. , Figueiredo M. de , Hopkins C.
Published: March 2003

A breeding program was conducted to improve the forage quality of Lolium multiflorum. Fifteen cultivars grown in spaced-plant trials were subjected to selection for a low moisture and a high non-structural carbohydrate content. Results showed consistent positive correlations between non-structural carbohydrate content, dry matter content, and digestibility in vitro of the grass. In a small plot trial comparing F6 plants (Selection 121) with 11 commercial L. multiflorum cultivars, Selection 121 gave the second-highest dry matter yield (difference not significant, P > 0.05) of the cultivars tested. The dry matter content of Selection 121 was significantly higher and the acid detergent fibre content significantly lower than that of the commercial cultivars. Furthermore, the total non-structural carbohydrate content was significantly higher and the nitrogen content significantly lower than that of the other L. multiflorum cultivars, giving Selection 121 nutritionally a much more favourable readily digestible energy to protein ratio than the commercial cultivars. Selection 121 was subsequently named 'NCD Enhancer' and is inscribed on the South African Variety List.
Lodging reduces sucrose accumulation of sugarcane in the wet and dry tropics
Authors: Singh G. , Chapman S. C. , Jackson P. A. , Lawn R. J.
Published: March 2003

Previous experiments in the Australian tropics have observed a 'slowdown' in biomass accumulation in mature sugarcane crops. By installing scaffolding to prevent lodging, we eliminated the growth 'slowdown' in 3 experiments to confirm that lodging and stalk death are part of the explanation. In both the wet and dry (irrigated) tropics, lodging of sugarcane significantly decreased both fresh cane yield and commercial cane sugar content (CCS). Prevention of lodging increased cane yield by 11–15%, CCS by 3–12%, and sugar yield by 15–35% at the final harvest in August–September. The rate of increase in CCS in lodged cane was reduced following lodging, although CCS had partially recovered by harvest.A possible component of the lodging effect is a slowdown in the growth due to the ageing of the crop. However, a younger crop (late crop treatment) grew no faster than the scaffolded treatment and so discounted this. In the dry tropics, where cane is irrigated and grows under high radiation, sugar yield was 40 t/ha with scaffolding installed. The increased yield (compared with 35 t/ha in lodged cane) was due to both the survival of an extra 0.8 stalks/m2 and increased accumulation of sugar in live stalks. In 2 years in the wet tropics where sugar yield with scaffolding was 16 t/ha, the same factors, with the addition of increased biomass accumulation in live stalks, were responsible for the increase.
Levels of total phosphorus, phytate-phosphorus, and phytase activity in three varieties of Western Australian wheats in response to growing region, growing season, and storage
Authors: Kim J. C. , Mullan B. P. , Selle P. H. , Pluske J. R.
Published: March 2003

Two experiments were conducted to examine varietal, environmental, and storage influences on total phosphorus (P), phytate-P content, and phytase activity in a cohort of wheats grown in Western Australia. In Expt�1, a 3 × 3 × 2 factorial experiment examined the influence of wheat variety (Arrino, Stiletto, Westonia), growing region (high, medium, low rainfall zone), and harvest year (1999, 2000). In Expt 2, the effect of storage for 6 months on the P composition of the wheats was examined. The total P and phytate-P concentrations ranged from 1.66 to 4.48 g/kg (DM) and from 1.05 to 3.32 g/kg (DM), with mean values of 2.64 (s.e. ±0.142) and 1.79 g/kg (s.e. ±0.127), respectively. Phytase activity ranged from 327 to 811 phytase activity units (FTU)/kg, with a mean value of 563 FTU/kg (s.e. ±29.6). Phytate-P content was significantly correlated with total P concentration (r = 0.97, P < 0.001). Harvest year tended to influence the total P and phytate-P content (P = 0.079 and P = 0.082, respectively) of the wheats, whereas wheat variety had a significant effect on the phytase activity (P < 0.05). Precipitation level (mm) was positively correlated to total P and phytate-P contents (P < 0.05). Storage for 6 months after harvest did not change the P content of wheat.
Amino acid digestibility of meat and bone meals for broiler chickens
Authors: Ravindran V. , Hendriks W. H. , Camden B. J. , Thomas D. V. , Morel P. C. H. , Butts C. A.
Published: March 2003

Variation in the apparent ileal digestibility of amino acids in 19 meat and bone meal samples, obtained from commercial rendering plants in New Zealand, was determined using 5-week-old broilers. Assay diets contained meat and bone meal as the only source of protein, and chromic oxide as an indigestible marker for the calculation of amino acid digestibility values. Correlations of chemical composition (crude protein, ash, crude fat, and gross energy) and in vitro assays (protein solubility in 0.2% potassium hydroxide and nitrogen digestibility by 0.2% pepsin hydrolysis) with ileal amino acid digestibility were also examined. Considerable variation was observed in the contents of crude protein (38.5–67.2 g/100 g), ash (13.0– 56.5 g/100 g), crude fat (4.3–15.3 g/ 100�g), and gross energy (9.4–22.3 MJ/kg) of meat and bone meal samples. The amino acid concentrations and ileal digestibility of amino acids also varied substantially. Cystine, the first limiting amino acid in meat and bone meal, had the lowest digestibility estimates. Correlation analyses showed that the ash content was the only chemical parameter that was consistently correlated with amino acid digestibility. Digestibility of amino acids, with the exception of aspartic acid, threonine, serine, tyrosine, histidine, and cystine, was negatively correlated with ash content, with samples with high ash levels having lower digestibility. Both in vitro assay measurements were found to be insensitive indicators of variations in amino acid digestibility.
A review of the biology linking fibre diameter with fleece weight, liveweight, and reproduction in Merino sheep
Authors: Adams N. R. , Cronjé P. B.
Published: March 2003

There is increasing economic pressure on the Merino industry to grow finer wool and at the same time to turn off more sheep meat. Fleece weight generally decreases with finer fibre diameters, so theoretically, finer wool sheep should be able to partition more nutrients to reproduction and muscle growth. However, complex and often indirect mechanisms appear to prevent this in practice. This review summarises the available data on genetic and phenotypic relationships between wool fibre diameter and fleece weight, liveweight, fatness, and reproductive performance, and develops mechanistic hypotheses for these relationships that could be tested experimentally.Selection for reduced fibre diameter may decrease liveweight, fatness, and reproductive performance. These characteristics are also affected by the availability of nutrients, and finer fibre diameter may affect nutrient metabolism through 2 adaptations that tend to maintain fleece weight: an increase in follicle density and/or an increase in relative fibre length. These act in different ways. Follicle density may affect final body size through linkages established during fetal development. Increased fibre growth rate requires an increase in protein synthesis rate in the skin, which in turn may affect whole-body protein turnover rate and the sensitivity of tissues to insulin. Other pathways potentially affected by fibre diameter include the control of feed intake, prenatal programming of insulin sensitivity, and a reduced responsiveness of tissues to nutrient supply. However, none of these mechanisms accounts for the reports of an increased proportion of dry ewes in fine wool sheep, particularly if run in environments that experience periods of low quality pasture.Although associations between fibre diameter and growth rate, fatness, and reproduction rate are repeatable, there are not yet enough data for such associations to be realistically accounted for in breeding goals. More experimentation and a better knowledge of the causative relationships will facilitate development of finer wool sheep for environments where sheep turnoff normally provides a significant proportion of income from the sheep enterprise. Such mechanistic understanding will facilitate the development of molecular techniques for targetted selection, and the identification of more useful attributes for a quantitative genetics approach to improving simultaneously the profitability from both wool and meat.
Soil solution composition in association with the toxicity of banded di-ammonium phosphate to wheat and amelioration by CaCO3
Authors: Zhang X. K. , Rengel Z.
Published: March 2003

Our previous publications showed that gradients of pH, electrical conductivity, ammonium, phosphorus, and calcium were formed between di-ammonium or mono-ammonium phosphate bands and roots. These gradients shifted and diminished with time. Roots suffered from ammonia toxicity near the band, but soil liming before banding ameliorated the toxicity. In the present study, DAP was banded 1 cm away from wheat (Triticum aestivum) seeds sown in slightly acidic sandy Lancelin soil that was either limed (CaCO3) or not. After 35 days, the pH and concentration of 9 ions were measured in soil solution extracted from soil obtained at different distances between the fertiliser band and seed.Toxicity symptoms were noted on 7-day-old plants grown in the non-limed treatment; in contrast, plants grown in the CaCO3 treatment did not show these symptoms during the whole growth period. In comparison with the non-limed treatment, CaCO3 addition markedly lowered the ammonium and P concentration in soil solution extracted from soil between the fertiliser band and the seed. Although a lower Ca concentration was measured in the vicinity of the DAP band in the non-limed than in the limed treatment, Ca in non-limed soil was still sufficiently high to prevent deficiency in plants, implying that there might be no ground for the association of an injurious effect of DAP and Ca deficiency as suggested in other studies. Around 2.8 mg Al/L soil solution was detected in the non-limed treatment, but liming with CaCO3 reduced Al concentration in all soil sections, especially those with the high rooting density. Therefore, a possibility that Al toxicity was related to the DAP toxicity in non-limed soils cannot be excluded, considering that even higher Al would have existed in the soil solution in the vicinity of the fertiliser band during the first couple of days. In conclusion, the causal factors associated with DAP toxicity might be high concentration of ammonium and free ammonia resulting from hydrolysis of DAP, and high P and possibly high Al concentrations.
Simulating fababean development, growth, and yield in Australia
Authors: Turpin J. E. , Robertson M. J. , Haire C. , Bellotti W. D. , Moore A. D. , Rose I.
Published: March 2003

The capability to simulate fababean (Vicia faba L.) production across the range of environments in which it is grown in Australia provides a tool for assessing agronomic and management options for the crop. This paper describes the building and testing of a model of fababean (cv. Fiord) development and growth, designed for use in the cropping systems simulator, APSIM. Parameters describing leaf area expansion, radiation interception, biomass accumulation and partitioning, root growth, water use, and nitrogen accumulation were sourced from the literature or developed from experiments conducted by the authors. In addition, parameters defining phenological development in response to temperature and photoperiod were derived from a comprehensive dataset of times to flowering and maturity.Routines for pre-flowering phenology predicted time to flowering ranging from 43 to 94 days with a root mean squared deviation (RMSD) of 4.3 days. Post-flowering development could not be satisfactorily predicted using thermal time alone; analysis of the collated data suggested that the lengths of some post-flowering phases were related to photoperiod. With incorporation of a photoperiod effect on post-flowering development, time from sowing to maturity was simulated with an R2 of 92% and an RMSD of 6.7 days.The model was tested over a diverse range of latitudinal and climatic conditions within Australia, using data from experiments in which sowing date, crop density, and water supply varied. Observed grain yield (n = 42) varied from 500 to 5600 kg/ha. In general, observed biomass and yield patterns within a growing season were reproduced well. Simulated grain yield explained 87% of the variance in observed yields (RMSD = 466 kg/ha). Apart from demonstrating the capability of the model over a wide range of growing conditions, the tests highlighted a number of areas for future improvement, including accounting for lodging, variation in harvest index under wet conditions, and accurate simulation of the response of leaf area expansion to mild levels of water deficit.
Habitats, morphological diversity, and distribution of the genus Vigna Savi in Australia
Authors: Lawn R. J. , Watkinson A. R.
Published: March 2003

Vigna is an agriculturally important genus containing several important species used as pulses, forages, vegetable, or cover crops. The genus is represented in Australia by 5 species, 4 indigenous (V. radiata, V. vexillata, V. luteola, V. marina) and 1 endemic (V. lanceolata). A germplasm collection has been assembled comprising >400 accessions of the 5 Vigna species from Australia and offshore and seed committed to storage as the CSIRO National Vigna collection. For a large number of accessions, herbarium sheets have also been prepared either from field or glasshouse-grown plants and lodged with the Qld Herbarium, Brisbane. This paper describes the structure of the collection and, for each of the 5 species and major regional variants, summarises provenance information on their geographic distribution, habitat, soil type, and associated species. Within the Australian tropics/subtropics, the Vigna species collectively occupy a diverse range of grassland habitats extending from the foreshore to the central desert. Of the 5 species, the endemic V. lanceolata is the most diverse in terms of distribution, habitat, and morphology. Geographic gaps in the collection are noted and priorities for future collection suggested.