Showing papers in "Australian Journal of Experimental Agriculture in 1993"
TL;DR: Field trials were conducted in 2 seasons at 13 sites on neutral to alkaline soils in Western Australia, to compare the growth and seed yield of 6 winter grain legume species, finding the relationship between seed yield and rainfall was complicated by transient waterlogging and fungal disease.
Abstract: Field trials were conducted in 2 seasons at 13 sites on neutral to alkaline soils in Western Australia, to compare the growth and seed yield of 6 winter grain legume species: field pea (Pisum sativum L.), chickpea (Cicer arietinum L.), faba bean (Vicia faba L.), lentil (Lens culinaris Medik), narrow leaf lupin (Lupinus angustifolius L.), albus lupin (L. albus). In a dry year (1991), overall site mean seed yield was highest for field pea (1.35 t/ha), then faba bean (1.22 t/ha) and narrow leaf lupin (0.85 t/ha). Chickpea, lentil line ILL5728, and albus lupin produced an average seed yield of 0.64 t/ha. Rainfall in 1992 was above average and seed yields of all species except field pea were higher than in 1991. Heavy rainfall in winter and spring caused transient waterlogging at several sites, affecting growth and seed yield of most species. Faba bean responded positively to the increase in rainfall and produced exceptional seed yields of >4 t/ha at 3 sites. Mean seed yield was highest for faba bean, at 2.87 t/ha, then narrow leaf lupin (1.19 t/ha), chickpea (1.1 t/ha), and field pea (1.0 t/ha). Field pea performed poorly at several sites due to its susceptibility to transient waterlogging and black spot disease (caused by Mycosphaerella pinoides). Albus lupin and lentil line ILL5728 produced similar seed yields (0.78 t/ha). Lentil cvv. Laird (1991) and Kye (1992) had low seed yields due to poor adaptation. Seed yield differences between species at various locations were not simply related to any soil chemical parameters or to depth to clay. On a calcareous soil of pH(CaC12) 8 at Dongara, the growth of narrow leaf lupin was severely affected and the crop failed. Days to flowering varied between species; faba bean was earliest to flower (76 days), then field pea. Faba bean and field pea (particularly in 1991) generally produced the most dry matter, both early and at final harvest. The relationship between seed yield and rainfall was complicated by transient waterlogging and fungal disease (e.g. black spot in field pea) at many sites. Seed yield was significantly positively related to final dry matter production but not to harvest index.
96 citations
TL;DR: The data suggest that in the higher rainfall region of north-eastern Victoria, a spike density of about 500 spikes/m2 is required to optimise wheat yields.
Abstract: A 3-year study was conducted to measure the effect of sowing time and seeding rate on the development and yield of wheat (Triticum aestivum L.) grown under high-yielding conditions in north-eastern Victoria. A range of wheat cultivars with different development responses, including 'winter' types, was used in 2 experiments in each season. High grain yields for dryland wheat were measured in the first 2 seasons (1985-86), and in 1985, near-optimal water use efficiencies (>18 kg/ha. mm effective rainfall) were obtained. In the third season (1987) grain yield was limited by adverse climatic conditions-in the me- and post-anthesis period. In each season, grain yield declined with delay in sowing time. In 1985 there was a loss of 200-250 kg grain/ha for each week's delay in sowing time. In 1987, yield loss with delayed sowing was 50-110 kg grain/ha. In each season, cultivars with late or midseason maturity development gave the highest mean yields, and the use of these maturity types allowed earlier sowing, in mid April. However, with late sowing of wheat there was a trend for early maturity types to give higher yields, and so the use of 2 wheat cultivars with distinct maturity development responses to climate is recommended. If only 1 wheat cultivar is to be used, then a late maturity type is recommended. Higher wheat yields were also obtained as spike density increased, as a result of higher seeding rates. Our data suggest that in the higher rainfall region of north-eastern Victoria, a spike density of about 500 spikes/m2 is required to optimise wheat yields.
62 citations
TL;DR: It was demonstrated that grain feeding had an effect on changing bovine fat colour, and although p- carotene was predominant in serum, both p-carotene and lutein contributed to the yellowness in bovines carcass fat.
Abstract: One hundred Brahman cross steers were removed from pasture and fed a high grain diet for a finishing period of 0, 35, 70, 105, or 175 days. The steers were then slaughtered and assessed for subcutaneous fat depth, fat colour, meat colour, marbling, and p-carotene and lutein concentrations in the fat and serum.The average liveweight gain was 0.7 kg/day. After35 days of grain feeding, fat colour was significantly(P<0.05) decreased from 3.9 to 2.4 when assessed using grading chips ranging from 0 (polar white) to 9 (creamy yellow). There was a trend to a further decline in fat colour over longer finishing periods (1.7 at 105 days and 2.0 at 175 days), although 1 steer had a fat colour core of 6 at 70 days and 1 at 105 days slaughter, and another had a score of 4 at 175 days. Steers fed for175 days had higher marbling but darker meat than those fed for the other finishing periods (P<0.05).Subcutaneous fat depth at 105 and 175 days (17.3 mm) was greater than at 35 and 70 days (14.5 mm) and significantly (P<0.05) greater than at the initial slaughter (12.5 mm).Fat colour was correlated (in the subcutaneous and intermuscular fat, respectively) with p-carotene (r = 0.61 and 0.55) and lutein (r = 0.53 and 0.52) concentrations, and in the serum, with p-carotene (r = 0.49) concentration. Objective assessment of fat colour, the Minolta b* value, was also correlated (in the subcutaneous and intermuscular fat, respectively) with p-carotene (r = 0.85 and 0.80) and lutein (r = 0.74 and 0.73) concentrations and was correlated with p-carotene (r = 0.61) concentrations in the serum. It was s demonstrated that grain feeding had an effect on changing bovine fat colour, and although p-carotene was predominant in serum, both p-carotene and lutein contributed to the yellowness in bovine carcass fat.
62 citations
TL;DR: Isolates of the race 4 VCG 0129 from Lady finger plantations were pathogenic to Cavendish cultivars in glasshouse tests, and was found attacking Bluggoe in North Queensland.
Abstract: Isolates of Fusarium oxysporum f. sp. cubense from wilted banana plants in Queensland and New South Wales were characterised for vegetative compatibility. Six vegetative compatibility groups VCGs) were identified. Race 1 (VCGs 0124, 01241.5, 0125) was widespread, being detected in northern and southern Queensland as well as northern New South Wales. Race 2 (VCG 0128) was found attacking Bluggoe in North Queensland. Race 4 (VCGs 0120, 0129, 01211) was detected in Cavendish plantations in southern Queensland and in Lady finger plantations in New (South Wales and southern Queensland. Isolates of the race 4 VCG 0129 from Lady finger plantations were pathogenic to Cavendish cultivars in glasshouse tests.
58 citations
TL;DR: Rotational strategies for weed control are likely to be effective in delaying or minimising the development of herbicide resistance, particularly where the average seed bank life time, as shown for wild oats in this study, is short.
Abstract: The effects of crop rotation, tillage practice, and herbicide use on the population dynamics of wild oats (Avena fatua and A. sterilis ssp. ludoviciana) were studied in a field experiment in northern New South Wales. In the third and fourth years of a continuous wheat rotation, cultivated fallow using tines increased wild oat density and reduced grain yield compared with a no-tillage fallow. Tillage did not affect the vertical distribution of wild oat seeds in the soil, and about 80% of wild oat seeds were in the top 5 cm of soil in both tillage treatments. The seed reservoir at the end of the experiment was smaller under a no-tillage fallow regime. The half-life of wild oat seeds in the soil was about 6 months, and rotation of wheat with sorghum was the most effective means of reducing the wild oat seed reservoir. Rotational strategies for weed control are also likely to be effective in delaying or minimising the development of herbicide resistance, particularly where the average seed bank life time, as shown for wild oats in this study, is short. Annual use of either tri-allate or flamprop-methyl in 4 successive wheat crops did not prevent a massive build-up of wild oat seed. The poor performance of herbicides was partly attributed to below-average rainfall in autumn and early winter in 1985 and 1986. However, wild oats are well adapted to continuous cropping with wheat, where recruitment of 34% of the soil seed reservoir maintained the population despite the use of selective herbicides. The results of this experiment indicate that a continuous wheat rotation using herbicides to control wild oats is likely to be much less effective in reducing the wild oat seed reservoir.
51 citations
TL;DR: In this paper, the authors investigated the relationship between spectral reflectance and early biomass production in barley and wheat and assessed the feasibility of using spectral reflectances techniques in cereal breeding programs.
Abstract: High early biomass production has been suggested as a useful selection criterion for improving cereal yields in mediterranean environments. Current methods for measuring biomass production in cereal plots involves destructive sampling which is not suitable for routine use by plant breeders where large numbers of samples are to be screened. The measurement of spectral reflectance using ground-based remote sensing techniques has the potential to provide a nondestructive estimate of plant biomass production. This field study investigated the relationship between spectral reflectance and early biomass production in barley and wheat and assessed the feasibility of using spectral reflectance techniques in cereal-breeding programs. Spectral reflectance measurements (0.40-2.5 ¦m wavelengths) were made before stem elongation for barley and wheat grown in separate experiments at Wongan Hills, Western Australia. Cereal biomass was closely associated with spectral reflectance in the visible (0.44-0.66 ¦m) and mid infrared (1.50-1.80 ¦m and 2.00-2.40 ¦m) regions, but not in the near infrared (0.71-1.10 ¦m). The poor correlation between reflectance in the near infrared region and biomass production was due to the low amounts of biomass present and the high reflectivity of the sandplain soils at these wavelengths. The close associations in the visible and mid infrared regions provides promise for use in estimation of cereal biomass, but further research is required to refine the technique for use in large scale breeding programs.
48 citations
TL;DR: A comparison of this model with a laboratory-based model showed good correlation for 3 soils, but the laboratory method underestimated the field lime requirement of solodic soil.
Abstract: Lime requirement curves based on relative yield and pH data for 4 soil types were derived to estimate the amount of lime required to reach maximum yield for wheat, triticale, barley, and canola. Simple equations expressing lime requirement as a function of soil pH accounted for >90% of the variation in applied lime on 3 soil types (red brown earth, red podsolic, podsolised red earth). When aluminium and manganese (0.01 mol CaCl2/L extracted) were included in these equations, either individually or together, they did not improve the relationship significantly for these 3 sites; however, manganese significantly improved the predictability of lime for solodic soil. A comparison of this model with a laboratory-based model showed good correlation for 3 soils (red brown earth, red podsolic, podsolised red earth), but the laboratory method underestimated the field lime requirement of solodic soil.
47 citations
TL;DR: An 'across the fence' comparison of farmer paddocks with nearby virgin bush sites was made at 3 locations, to measure the effects of lupins and subterranean clover based pastures on the chemical properties of the soil as mentioned in this paper.
Abstract: An 'across the fence' comparison of farmer paddocks with nearby virgin bush sites was made at 3 locations, to measure the effects of lupins and subterranean clover based pastures on the chemical properties of the soil. Estimated rates of acidification in the 0-60 cm depth were 0.29-0.55 kmol H+/ha.year for wheat-lupin paddocks and 0.16-0.2 1 kmol H+/ha .year for pasture paddocks. A significant proportion of this acidification occurred below 20 cm, particularly in the lupin paddocks (up to 70% of the total). Severe water repellency had developed at 1 location that had produced 30 lupin crops with the occasional wheat crop. Despite these detrimental effects, lupins maintained soil mineral nitrogen and organic matter contents and electrical conductivities similar to those in pasture paddocks, even though the soils in the lupin rotations had been sown to wheat more frequently.
45 citations
TL;DR: Colour image analysis, using a Matrox digitiser, was more accurate than visual estimates or black and white imaging systems in discriminating between rusted and healthy leaf tissues in colour transparency photographs of rusted coffee leaves.
Abstract: Using disease diagrams, visual assessments of coffee leaf rust from Papua New Guinea overestimated severity by >2 times when >20% leaf area was rusted. Nevertheless, a significant linear relationship was established between visual and planimeter assessments of coffee rust severity. Colour image analysis, using a Matrox digitiser, was more accurate than visual estimates or black and white imaging systems in discriminating between rusted and healthy leaf tissues in colour transparency photographs of rusted coffee leaves. Electronic flash photography of rusted coffee leaves produced images with reflections from the waxy leaf surface which made it difficult to discriminate between healthy tissues and the background.
44 citations
TL;DR: The feasibility of estimating, with acceptable precision, temperate and tropical pasture mass in a subtropical environment was evaluated and regression equations were developed based on calibrations against shoot DM and are only applicable to well-managed and highly utilised pastures.
Abstract: The feasibility of estimating, with acceptable precision, temperate and tropical pasture mass in a subtropical environment was evaluated. For the tropical grasses kikuyu (Pennisetum clandestinum) and setaria (Setaria ancepts), 3 different pasture meters were calibrated against 1 of 3 dry matter (DM) estimates. Temperate pastures (predominantly Lolium perenne and Trifolium repens) were evaluated using the Ellinbank rising plate meter (RPMl) calibrated against DM to ground level. A single regression equation was developed for syegrass-white clover pasture from data pooled within season over first- and second-year swards. The s.e. of estimate (s.e.e.) for assessing tropical grass pasture mass using RPMl was similar to that for a heavier Ellinbank meter and substantially lower than that for the electronic pasture probe. Using RPMl, separate regression equations were required for early (November-February) and late (March-May) season determinations for both kikuyu and setaria. The regression equations were based on calibrations against shoot DM (>5 cm stubble height for kikuyu and 6 cm for setaria) and are only applicable to well-managed and highly utilised pastures. Calibrations of all pasture meters over all months to green DM (senescent leaf and stem removed) gave a lower s.e.e. than total DM (kikuyu 138 v. 177 kg DM/ha, n = 171; setaria 211 v. 224 kg DM/ha, n = 177) whilst shoot DM gave a more substantial reduction in s.e.e. (kikuyu 95 v. 147 kg DM/ha; setaria 140 v. 193 kg DM/ha).
43 citations
TL;DR: In this article, methionine supplements were given directly into the abomasum of Merino wethers grazing either improved or native pasture at Armidale, New South Wales.
Abstract: Seven experiments are reported in which methionine supplements were given directly into the abomasum of Merino wethers grazing either improved or native pasture at Armidale, New South Wales. In 4 experiments where initial wool growth was 0.4-0.8 mg/cm2.day of clean dry wool, significant increases in wool growth (at 2.4 g methionine/day in 3 experiments and 0.6-4.8 g/day in the fourth) and fibre diameter were obtained when methionine was given once daily in capsules. In the fourth experiment the response to methionine was quadratic, with a maximum at 2.4 g/day. In the remaining 3 experiments, where initial wool growth was >1.1 mg/cm2.day, no significant response to methionine was obtained, whether it was given once daily or infused continuously.
TL;DR: In 1991, a survey was distributed to 251 potato growers in South Australia to determine major diseases, insect and other invertebrate pests, and chemicals used to control them, but of these, 24 individuals were no longer growing potatoes.
Abstract: In 1991, a survey was distributed to 251 potato growers in South Australia to determine major diseases, insect and other invertebrate pests, and chemicals used to control them. The overall response rate was 48%, but of these, 24 individuals were no longer growing potatoes. The results were summarised for the State and by district (Adelaide Hills, Adelaide Plains, Murray Lands, South East). The most prevalent diseases encountered by respondents in all districts were target spot caused by Alternaria solani, and rhizoctonia canker caused by Rhizoctonia solani. Other diseases of concern to growers included late blight caused by Phytophthora infestans, seed piece decay caused by various pathogenic and saprophytic microorganisms, common scab caused by Streptomyces scabies, and leaf roll caused by potato leaf roll virus. The most commonly used fungicides for disease control were chlorothalonil (33-42% of respondents), mancozeb (30%), and cupric hydroxide (11-13%). The most commonly used seed treatments for control of seed piece decay were mancozeb (51 % of respondents), tolclofos methyl (24%), and lime (20%). Green peach aphid (Myzus persicae), potato aphid (Macrosiphum euphorbiae), potato moth (Phthorimaea operculella), and jassids and leafhoppers (Jassidae, Cicadellidae) were the pests of greatest concern to the growers. Others included Rutherglen bug (Nysius vinitor), redlegged earth mite (Halotydeus destructor), and thrips (Thripidae). The most commonly used insecticides were ethamidophos (40% of respondents), monocrotophos (22-28%), and dimethoate (7-13%).
TL;DR: The effect of 3 stubble management regimes (burning after harvest, incorporation with a disc plough, retention on the surface) on the incidence of infection of wheat with Fusarium graminearum Schw.
Abstract: The effect of 3 stubble management regimes (burning after harvest, incorporation with a disc plough, retention on the surface) on the incidence of infection of wheat with Fusarium graminearum Schw. Group 1 was studied for 5 seasons at 2 sites at Moree, New South Wales. One site had high initial incidence (site A) and the other low initial incidence (site B). There were no differences in incidence of infection between retained and incorporated treatments. Stubble burning reduced the increase in incidence of infection in 2 of 5 years at site A and 3 of 4 years at site B. Failure of control in other years was attributed to susceptible weed hosts and poor burns. When stubble was retained on the plots at site B that had been burnt, incidence of infection in the next season increased to a level not significantly different from the retained or incorporated treatments. Incidence of infection at the fourth consecutive wheat crop at both sites was close to the maximum recorded, which was 92% at site A and 65% at site B. There was no evidence of a decline in incidence by the time of the most recent season assessed (eighth year of continuous wheat cultivation at site A, and sixth year at site B). In most years, the differences in yield between treatments were not significant.
TL;DR: Cervical insemination is cheaper and simpler than the laparoscopic method, and this warrants the development of an improved technique for the consistent, deep deposition of frozen-thawed semen through the cervix in a high proportion of does.
Abstract: Artificial insemination (AI) allows individual bucks to be exploited widely and so is a potentially useful tool for the rapid genetic improvement of fibre goats. In Australia, where there is a desire by farmers to improve the productivity of their goats, AI may best be adopted under extensive grazing conditions using control of ovulation to allow efficient and accurate timing of the deposition of frozen-stored semen. Although ovulatory activity is influenced by the manipulation of environmental factors, the time of ovulation is synchronised most accurately by the combined use of intravaginal progestagens and pregnant mares' serum gonadotrophin. However, the costs of these exogenous hormones remain high, which justifies investigation of alternative methods to control ovulation. Bucks show strong seasonality in the quality and quantity of their sperm production, and so there is limited time in which semen may be collected for storage and AI, but this can be extended by optimising nutrition and management. There appears to be no improvement in the fertility of stored semen when seminal plasma, which contains egg yolk coagulating enzyme, is removed and an extender containing only a low concentration of egg yolk is used for dilution. Simple methods have been developed for 1-step dilution and freezing of buck semen. However, the post-thawing viability of spermatozoa frozen in pellets on dry ice is higher than for semen frozen in straws in liquid N2 vapour, although straws are preferred for commercial trade. For frozen-thawed semen, fertility after laparoscopic insemination is high, whereas the fertility after cervical insemination is considerably lower but improves by the deeper placement of semen into the reproductive tract. Does are best inseminated 5-10 h before the expected time of ovulation. A dose as low as 1 x 106 motile spermatozoa may be used for laparoscopic insemination of thawed semen that was previously diluted at rates (semen: diluent) of 1:2 to 1:23. However, for the cervical method, a low dilution rate of 1:2 allows a sufficiently small, highly concentrated dose of at least 120 x 106 motile frozen-thawed spermatozoa t o be deposited into the reproductive tract of the doe. Cervical insemination is cheaper and simpler than the laparoscopic method, and this warrants the development of an improved technique for the consistent, deep deposition of frozen-thawed semen through the cervix in a high proportion of does.
TL;DR: A fixed cutting frequency of 5 weeks throughout the year is an acceptable management compromise for all lucerne cultivars, combining high dry matter and N yields with acceptable levels of foliar N and root reserves.
Abstract: The use of fixed interval or growth stage (crown bud elongation) cutting management for lucerne was studied for cultivars with dormancy characteristics ranging from highly winter-active to winter-dormant. Fixed cutting intervals ranged from 3 to 8 weeks and were imposed on irrigated stands in a subtropical environment. Persistence, dry matter yield, weed yield, nitrogen (N) concentration and yield, and root reserves were measured over a 2-year period. For cultivars from all dormancy classes, persistence was highest with either 5- or 6-weekly cutting, while dry matter yield was maximised with 5-weekly cutting. Nitrogen concentration was highest with 3-weekly cutting but N yield was greatest under 4-weekly cutting. Root reserves were not maintained unless the cutting interval was extended beyond 7 weeks. Growth stage cutting produced equivalent yields and persistence but lower N concentrations and root reserves than the best fixed interval cutting treatment. There was no evidence that cultivars of different dormancy classes require different cutting management to obtain optimum performance. Therefore, a fixed cutting frequency of 5 weeks throughout the year is an acceptable management compromise for all lucerne cultivars, combining high dry matter and N yields with acceptable levels of foliar N and root reserves. Although the more complex management decisions associated with growth stage cutting appear unwarranted, dry matter yield could be maximised by using a flexible cutting schedule which matched cutting interval with growth rate (4 weeks in summer and 7 weeks in winter).
TL;DR: In this paper, the authors investigated the reasons for post-harvest organ fall in Geraldton waxflower (Chamelaucium unciizatum Schauer) and found that an 11kg compression load, equivalent to the lidding of a carton, caused flower fall amounting to 1% of the fresh mass of 420-g bunches.
Abstract: Possible reasons for, and prevention of, postharvest floral organ fall in Geraldton waxflower (Chamelaucium unciizatum Schauer) were studied. An 11-kg compression load, equivalent to the lidding of a carton, caused flower fall amounting to 1% of the fresh mass of 420-g bunches. Fungal development also resulted in flower abscission. Healthy flowers produced little ethylene (e.g. 0.05 μL/kg.h), while infected flowers produced much more (e.g. 7.71 μL/kg.h) and were shed. Treatment with fungicide (iprodione + mancozeb) and antiethylene compounds [e.g. silver thiosulfate (STS) pulse, Purafil sorbant] reduced flowerfall in packaged flowers. Cut sprigs which suffered severe water deficit also shed flowers. In cv. Elegance, drying to −3.61 MPa elevated ethylene production (e.g. 1.35 μL/kg.h). Flowerfall induced by water deficit could be reduced by pretreatment with a STS pulse (0.5 mmol Ag+L for 15-22 h at 0°C or 4 mmol Ag+L for 20-30 min at about 20°C). Pretreatment with a naphthaleneacetic acid dip (50 mg/L for 1 min at room temperature) shortened the vase life of Elegance.
TL;DR: When added after weight and fat depth in regression models, muscle score significantly increased the coefficient of determination in all cases, with an associated decrease in the residual standard deviation.
Abstract: Summary. Domestic trade weight steers (149) were assessed visually for subcutaneous fat and then given a live muscle score based on the thickness and convexity of their shape relative to frame size, having adjusted for subcutaneous fat. After slaughter, carcasses were given visually assessed carcass muscle scores based on the same critera. Fat depths at the P8 site and 12-13th eye muscle area were measured. Half of each carcass was boned-out into primal joints with subcutaneous fat trimmed to 6 rnrn. The weights of these joints plus meat trim (85% visual lean) were added to obtain the weight of saleable meat. The weight of fat trimmed from the carcass, primal joints, and meat trimmings during the bone-out process was added to obtain weight of fat trim. The assessors did not give steers with a greater subcutaneous fat depth better muscle scores when scoring for muscle and intermuscular fat. There was a negative correlation between live muscle score and P8 fat depth (-0.37), and no significant correlation between carcass muscle score and P8 fat depth. The associations between muscle score and yield of saleable meat were investigated using multiple regression techniques, with fat depth and muscle score sequentially added after weight in the model. The coefficient of determination and the residual standard deviation were compared at each stage. For saleable meat yield (kg), liveweight and carcass weight were the main contributors to the variation explained by the models fitted. For saleable meat yield as a percentage of carcass weight, most of the variation accounted for by the models fitted was explained by fat depth, muscle score, and eye muscle area. When added after weight and fat depth in regression models, muscle score significantly increased the coefficient of determination in all cases, with an associated decrease in the residual standard deviation. The effect was strongest for percentage of saleable meat. At the same weight and fat depth, animals or carcasses with better muscle scores produced more saleable meat.
TL;DR: Indirect selection and pattern analysis were used to examine the magnitude and form of genotype x environment (GE) interactions for sugar yield in sugarcane clones in southern Queensland and suggest that more emphasis should be placed on sampling a greater number of locations than on the testing of clonal ratooning ability within locations to improve the chances of obtaining both broadly and specifically adapted sugarCane varieties.
Abstract: To develop a strategy to improve the efficiency of selection, indirect selection and pattern analysis were used to examine the magnitude and form of genotype x environment (GE) interactions for sugar yield in sugarcane clones in southern Queensland. Clone x location interactions were the predominant source of clone X environment interactions and were much larger than clone x crop-year and clone x location x crop-year interactions. Both the indirect selection study and the pattern analysis emphasised the relative magnitude of these sources of interactions. Pattern analysis strongly associated crop classes at each location, and indirect selection analysis emphasised an opportunity to exploit correlated genetic advance between crop classes within a location. These suggest that more emphasis should be placed on sampling a greater number of locations than on the testing of clonal ratooning ability within locations. This would improve the chances of obtaining both broadly and specifically adapted sugarcane varieties.
TL;DR: Four long-term citrus rootstock trials established at Irymple, in the Sunraysia district of Victoria, were tested for leaf nutrient composition in each of 2 years, finding no evidence of a negative relationship between uptake of N and C1 by citrus rootstocks.
Abstract: Four long-term citrus rootstock trials (navel orange, mandarin, Valencia orange, and lime soil trial) established at Irymple, in the Sunraysia district of Victoria, were tested for leaf nutrient composition in each of 2 years. Scion or rootstock significantly influenced leaf nutrient composition in orange and mandarin trees in all 4 trials. Poncirus trifoliata and citrange rootstocks and Ellendale tangor scion resulted in high to moderate leaf N, P, and K concentrations, while Symons sweet orange rootstock and Dancy mandarin gave low leaf nitrogen (N), phosphorus (P), and potassium (K) concentrations. Potassium concentrations of navel and Valencia oranges on rough lemon rootstock were lower than on most of the other rootstocks tested. For all rootstocks, however, leaf N, P, and K concentrations were in the high range in the navel orange and Valencia orange trials, while leaf K concentrations were in the high range in the mandarin trial. Citrange rootstocks and Ellendale scion also had higher concentrations of leaf magnesium (Mg), while Symons sweet orange, Cox sweet orange, and Rangpur lime had lower leaf Mg concentrations than other rootstocks and scions. In the Valencia rootstock trial, rough lemon and Rangpur lime induced the highest leaf sulfur concentrations, while citrange rootstocks gave the lowest. Soil depth in the lime soil trial influenced foliar P and K levels in Valencia orange trees but these differences were small. In all trials, rootstock, but not scion, strongly influenced chloride (Cl) concentrations of citrus leaves. Poncirus trifoliata rootstock accumulated high concentrations of Cl, and the citrange rootstocks moderate, while Cleopatra mandarin rootstock showed consistently low leaf C1 concentrations in all trials. Rough lemon rootstock was not consistently good at excluding C1, and Rangpur lime showed good C1 exclusion only in the Valencia rootstock trial. There was no evidence of a negative relationship between uptake of N and C1 by citrus rootstocks. Poncirus trifoliata had a lower uptake of sodium (Na) in the Valencia rootstock trial, while Cleopatra and Emperor mandarin rootstocks showed slightly higher leaf Na levels than most other rootstocks tested. The 2 citranges, mandarin, rough lemon, and Rangpur lime rootstocks induced higher boron (B) concentrations in leaves of navel orange compared with other rootstocks but they were still in the adequate range for citrus (Reuter and Robinson 1986), while sweet orange rootstocks had lower levels. Emperor mandarin scion on all rootstocks tested had the lowest B levels. Concentrations of iron and copper were rarely influenced by scion or rootstock. Rootstock significantly influenced leaf manganese (Mn) and zinc (Zn) levels in a number of trials, but scion effects were minor. In comparison with all other rootstocks, rough lemon induced higher Mn levels in some cases; sweet orange rootstocks gave higher leaf Zn levels in other cases; while Rangpur lime induced higher Mn and Zn levels in trees grown in the lime soil trial. In the first 3 trials, concentrations of Zn and Mn were low in many of the rootstocks and scions, indicating a need for a second micronutrient spray per growing season.
TL;DR: The association between visually assessed muscle scores on live steers and their carcasses, eye muscle area, and the yield of saleable and lean meat was determined on 156 steers of mixed breeds and there was a negative correlation between P8 fat depth and both live and carcass muscle score.
Abstract: Summary. The association between visually assessed muscle scores on live steers and their carcasses, eye muscle area, and the yield of saleable and lean meat was determined on 156 steers of mixed breeds (mean carcass weight 282 kg, mean P8 fat depth 13 mm). The contribution of subcutaneous and intermuscular fat to differences in saleable meat yield was also investigated. There was a negative correlation between P8 fat depth and both live (I. = -0.21) and carcass muscle score (r. = -0.31); therefore, the assessors were not scoring fatter steers as having better shape. The correlation between live and carcass muscle scores was 0.79. The correlation between carcass muscle score and eye muscle area was 0.58. When live muscle score, carcass muscle score, or eye muscle area was included in regression models already containing weight and fat depth, there was a significant (P<0.001) increase in the amount of variation in saleable and lean meat yield explained by the models. At the same liveweight and fat depth, a change in live muscle score from C (moderately muscled) to B (well muscled) was accompanied by an increase of 1.7% in saleable meat and 2.2% in lean meat, when these were expressed as a percentage of carcass weight. The equivalent change in carcass muscle score in carcasses of the same weight and fat depth was accompanied by an increase of 1.9% in saleable meat and 2.4% in lean meat. The increased weight of saleable meat was not due to an increase in the dissected fat content of the meat. Weight of subcutaneous fat decreased as muscle score increased (P<0.01). There was no significant association between the amount of intermuscular fat and either live or carcass muscle score (1. = -0.075 and -0.18, respectively).
TL;DR: Results suggest that dwarf and extra-dwarf off-types could be readily separated from the taller Cavendish cultivars Williams, New Guinea Cavendish, and Grande Naine.
Abstract: Summary. A method was developed for early detection of dwarf off-types from micropropagated bananas (Mwa sp., AAA Group, Cavendish subgroup). Selection of dwarfs was from glasshouse-grown plants, and although differences between dwarf and normal plants could be detected as early as 3 weeks from deflasking, discrimination was most effective at week 7, when the normal plants had reached a height of 18-20 cm. In order to develop selection criteria, known dwarf off-types and normal plants were micropropagated and established in a glasshouse. Measurements included plant height, petiole - length, lamina length and width, and distance between leaves. Petiole length, lamina length, and the petiole to lamina length ratio provided the most promising selection criteria, with the dwarfs having significantly (P<0.01) smaller petioles and leaves than the normal plants. Selection was most effective when the plants were growing vigorously and uniformly. When growth became limiting, selection was more difficult. This was particularly apparent in plants that required repotting into larger containers and in micropropagated bananas grown in nurseries under suboptimal conditions. Plants were grown in the field and observed at bunch emergence, to verify trueness to type and to eliminate the possibility that off-types may have arisen in the normal and dwarf populations. A survey of these selection criteria with other Cavendish cultivars of various statures was also completed and the results suggest that dwarf and extra-dwarf off-types could be readily separated from the taller Cavendish cultivars Williams, New Guinea Cavendish, and Grande Naine.
TL;DR: There was no evidence of improved maternal behavioural attributes associated with increasing age of ewe that were independent of previous experience in giving birth and rearing lambs.
Abstract: Behavioural factors associated with lamb mortality were examined in regard to the relative effects of age and parity in single-bearing Merino ewes. Primiparas tended to have longer labour and higher lamb mortality than multiparous ewes. Maternal behaviour in primiparas was characterised by more desertions, a smaller proportion that stood and started to groom their lambs immediately after birth, and a larger proportion with non-cooperative behaviour during the initial sucking attempts of the lamb. These traits, and a high incidence of malpresentations, were particularly marked in 5-year-old primiparas deliberately denied access to rams in previous seasons. There was no evidence of improved maternal behavioural attributes associated with increasing age of ewe that were independent of previous experience in giving birth and rearing lambs.
TL;DR: Partial resistance to the anthracnose pathogen Colletotriclzum gloeosporioides was characterised in 6 tetraploid accessions and cv.
Abstract: Partial resistance to the anthracnose pathogen Colletotriclzum gloeosporioides was characterised in 6 tetraploid accessions and cv. Verano of the tropical pasture legume Stylosanthes hamata. Four components of resistance (incubation period, latent period, spore production, weighted infection type) were determined and compared with those of the susceptible S. scabra cv. Fitzroy. There were significant differences between the accessions for all resistance components. The mechanisms of resistance in the 3 most resistant accessions appeared to be different, with accession 55830 having a longer incubation period but higher sporulation per day than either 92715 or 92412. Spore production, weighted infection type, and latent period were significantly (P<0.05) correlated with resistance of adult plants in the field (ADPC). The weighted infection type was useful in discriminating between accessions that had similar disease severity scores. A quantitative relationship was established between 2 components, latent period and spore production per day, and the ADPC, using a multiple regression analysis (r2 = 0.9). If verified using a large number of accessions, such analysis may be used to obtain an index of resistance that may predict resistance levels in the field based on the components.
TL;DR: The newly released cultivar Junee was well adapted to the environment; it was later maturing than the recommended cultivar Seaton Park but was able to maintain high seed reserves.
Abstract: The density, productivity, flowering characteristics, and seed reserves of 14 lines (10 cultivars and 4 experimental lines) of subterranean clover were observed over 5 years (1983-87) on a red earth soil at Wagga Wagga, New South Wales. Plant density increased from 149-318 plants/m2 in 1983 to 1975-13925 plants/m'n 1987. Herbage yields of all cultivars during autumn-winter were similar in most years except in July 1985 when Seaton Park was superior. Cultivars in the midseason or later flowering groups were more productive in late spring and better able to utilise the extended growing seasons that occur periodically in this environment. The mean time from emergence to 5% flowering of all cultivars was 168 days with March germination in 1985 but decreased to 13.5 days with May germination in 1986. The number of days to flowering at Wagga Wagga was highly correlated with maturity ranking at Perth (r2 = 0.92 in 1985 and? = 0.93 in 1986). In the first year, average seed set was 295 kg seed/ha. but by summer of the fourth year the seed pool ranged from 124 kg/ha for Clare to 1190 kg/ha for Nungarin, the earliest flowering cultivar. The quantity of hard seed that carried over to the next year varied significantly between cultivars, with Enfield, Woogenellup, and Clare having the least, and Nungarin, Northam, Dalkeith, and Daliak the most. Seed set was related to maturity ranking only in 1984, although root disease probably affected seed yields in 1985-86. The proportion of hard seed that carried over was much higher than expected, particularly in soft-seeded cultivars. The newly released cultivar Junee was well adapted to the environment; it was later maturing than the recommended cultivar Seaton Park but was able to maintain high seed reserves. Karridale, another new cultivar, maintained higher seed reserves than the older Mount Barker.
TL;DR: This review of plant analysis in Australia accuracy is discussed and the role of 'plant sap quick examines sample preparation, instrumentation, problem tests' in nutrient analysis is assessed.
Abstract: Summary. This review of plant analysis in Australia accuracy is discussed and the role of 'plant sap quick examines sample preparation, instrumentation, problem tests' in nutrient analysis is assessed. Results of a analytes, calibration, detection limits, and quality survey of Australian plant-testing laboratories are assurance. The issue of turnaround time v. analytical included.
TL;DR: Investigation in field experiments in the south-west of Western Australia found that lime pelleting was not generally required to maximise field pea growth or yield, but yield was affected by the inoculant Rhizobium strain.
Abstract: The requirement of field pea (Pisum sativum) for seed inoculation with Rhizobium and for lime pelleting of inoculated seed was investigated in field experiments in the south-west of Western Australia, especially at locations where inoculated field pea had been grown 2 years previously. At most sites with previous pea cropping, the nodulation, total dry matter and nitrogen, and grain yield of pea were not improved by seed inoculation or lime pelleting. At these sites soil populations of R. leguminosarum by. viciae at sowing were >103/g soil. Responses to inoculation were measured at sites where the soil was very acidic [pH(CaCl2) 90% sand + gravel), or where pea had not grown previously. There were fewer rhizobia at sowing at these locations. Lime pelleting was not generally required to maximise field pea growth or yield, but yield was affected by the inoculant Rhizobium strain.
TL;DR: The effect on yield of early sowing of wheat, and of sowing wheats with winter habit, was assessed from routine trials from 29 sites in south and central New South Wales from 1981 to 1990.
Abstract: The effect on yield of early sowing of wheat, and of sowing wheats with winter habit, was assessed from routine trials from 29 sites in south and central New South Wales from 1981 to 1990 Early-sown trials were largely sown from mid to late April and conventionally late trials from mid to late May Entries in early trials consisted of winter wheats or photoperiod-sensitive spring wheats, while photoperiod-insensitive spring wheats were sown in late trials There was a gradual change in trial entries over the period of study Although more variable than the late-sown trials, the early-sown trials had high yields over a wider range of sowing times and displayed less risk of frost damage On average, winter wheats had a 6% yield advantage over late-maturing spring wheats in early-sown trials Trials yielded 15% more when sown early than late In comparison with quick-maturing spring wheats, winter wheats did not appear to suffer a large yield penalty when sown late Yield of early-sown trials declined with sowing before or after the optimum sowing time of late April There was a large reduction in yield with sowings earlier than 20 April Yield of spring wheats declined from early May almost linearly with delay in sowing date
TL;DR: A simplified point method, the rod-point technique, for determining pasture botanical composition was assessed against 3 other popular methods, and it was over 100 times faster than the traditional cut and hand-separate technique for the same level of precision.
Abstract: A simplified point method, the rod-point technique, for determining pasture botanical composition was assessed against 3 other popular methods. It was over 100 times faster than the traditional cut and hand-separate technique for the same level of precision. The presence of bias in the rod-point technique was assessed by comparing its estimates with those obtained by the hand-separation method. The pasture was classified into 8 botanical components, and the rod-point technique was significantly different from the hand-separated method in 3 instances, but in each case so were the Levy-point and the dry-weight-rank methods or the dry-weight-rank method alone. The rodpoint technique is most useful in large grazing trials, on-farm pasture monitoring, and pasture surveys. It provides a simple alternative for estimating pasture composition, using low inputs of materials, time, and labour.
TL;DR: In this paper, two experiments were conducted at the Mallee Research Station, Walpeup, between 1985 and 1989 to evaluate the impact of conservation farming practices on wheat yields, and the results indicated that erosion control and potentially lower production costs associated with direct drilling and stubble retention can be achieved without loss of wheat yield in the Victorian Mallee.
Abstract: Two experiments were conducted at the Mallee Research Station, Walpeup, between 1985 and 1989 to evaluate the impact of conservation farming practices on wheat yields. The first experiment compared wheat crops established by direct drilling into a chemical fallow with those conventionally sown into a cultivated fallow. Over the 5 years, yields ranged from 1.31 to 3.24 t/ha, and there was no reduction in crop yield associated with chemical fallowing and direct drilling compared with the cultivated fallow. There was also no significant effect of the chemical fallow on the amount of water conserved in the soil at sowing, at depth 0-100 cm; the range was 206-274 mm water. The second experiment from 1987 to 1989 examined the effect of maintaining 4 rates of stubble (0, 0.5, 1.0, 2.0 t/ha) on the surface of a conventionally cultivated long fallow. Stubble maintained at 2 t/ha increased the amount of water stored in the soil at sowing, at depth 0-140 cm, by 16 mm in 1 year of 3. This increase in soil water availability was not reflected in increased crop yield. These findings indicate that erosion control and potentially lower production costs associated with direct drilling and stubble retention can be achieved without loss of wheat yield in the Victorian Mallee.
TL;DR: The responses of germination, emergence, and pre-emergent growth of narrow-leafed lupin (Lupinus angustifolius L.) to a range of soil temperatures and matric potentials were determined in 2 replicate experiments; absolute responses to temperature and water availability differed between experiments, but the patterns of the responses did not.
Abstract: The responses of germination, emergence, and pre-emergent growth of narrow-leafed lupin (Lupinus angustifolius L.) to a range of soil temperatures and matric potentials were determined in 2 replicate experiments with different seedlots and sowing techniques. Although absolute responses to temperature and water availability differed between experiments, the patterns of the responses did not. Optimum temperatures were close to 20¦C and base temperatures were 0-3¦C. At temperatures >23¦C, germination and growth were highly variable and hindered estimation of ceiling (maximum) temperatures; the lowest was about 30¦C for germination. Under optimum conditions, germination took 1-1.5 days and emergence from a depth of 4 cm took 4-4.5 days, equating to 75¦C. day (base temperature 2¦C). The minimum soil matric potential for growth was -1 to -2 MPa, and emergence was more sensitive to low matric potential than was germination. Hypocotyl extension was more sensitive than radicle extension to low matric potential, leading to relatively long roots at the time of emergence.