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As the number of livestock increased in the years following English colonisation of Australia in 1788, the need for nutritious fodder, including lucerne (Medicago sativa), grew. One of the first diseases found on lucerne was a leaf spot which was collected in 1879 by George Bancroft, a physician and naturalist, in a suburb of Brisbane. The Queensland Government Botanist Frederick Manson Bailey sent a specimen to the prominent English mycologists Miles Joseph Berkeley and Christopher Edmund Broome who in 1883 formally described and named the fungus Sphaerella destructiva. That fungus is now known as Pseudopeziza medicaginis , the causal agent of common leaf spot of lucerne. It was one of over 300 fungi that were included in a 1880 paper co-written by the Reverend Julian Tenison-Woods and Frederick Bailey. At that time almost all of these fungi which had been collected in Australia were identified by overseas mycologists, particularly Berkeley and Broome. It can be argued that their 1880 paper was the first significant one published in Australia which focussed on fungi. Just a decade or so later Australian scientists, in particular Daniel McAlpine, were describing new fungal taxa on their own. Among the fungi recorded in a paper published in the 1880 Proceedings of the Linnaean Society of New South Wales was Sphaerella destructiva , now Pseudopeziza medicaginis , the cause of common leaf spot of lucerne. The paper, co-authored by the naturalist Reverend Julian Tenison-Woods and the Queensland Government Botanist Frederick Manson Bailey was the first known comprehensive list of Australian fungi published by Australian residents. It is a milestone in the evolution of mycology and plant pathology studies in Australia. Photograph by H. H. Baily. [ABSTRACT FROM AUTHOR]

Here, we review the research undertaken since the 1950s in Australia's grain cropping regions on seed-borne virus diseases of cool-season pulses caused by alfalfa mosaic virus (AMV) and cucumber mosaic virus (CMV). We present brief background information about the continent's pulse industry, virus epidemiology, management principles and future threats to virus disease management. We then take a historical approach towards all past investigations with these two seed-borne pulse viruses in the principal cool-season pulse crops grown: chickpea, faba bean, field pea, lentil, narrow-leafed lupin and white lupin. With each pathosystem, the main focus is on its biology, epidemiology and management, placing particular emphasis on describing field and glasshouse experimentation that enabled the development of effective phytosanitary, cultural and host resistance control strategies. Past Australian cool-season pulse investigations with AMV and CMV in the less commonly grown species (vetches, narbon bean, fenugreek, yellow and pearl lupin, grass pea and other Lathyrus species) and those with the five less important seed-borne pulse viruses also found (broad bean stain virus, broad bean true mosaic virus, broad bean wilt virus, cowpea mild mottle virus and peanut mottle virus) are also summarized. The need for future research is emphasized, and recommendations are made regarding what is required. [ABSTRACT FROM AUTHOR]

Context: Barley grass (Hordeum spp. L.) is an annual, invasive grass weed of southern Australian crops and pastures, frequently associated with weight loss and carcass damage in sheep due to its sharp seeds. Knowledge gaps exist regarding optimal density thresholds for effective control to reduce impacts on animal production. The value of integrated weed management (IWM) over individual control options for reducing barley grass populations in pasture is also unknown. Aims: We aimed to develop a model for simulating the population dynamics of barley grass within lucerne (Medicago sativa L.) pastures of southern Australia and to test the hypothesis that combining herbicides with mowing will be more effective for removing barley grass seedbanks over time than individual control measures. Methods: The model was developed within Microsoft Excel and adapted from other annual grass models. The model takes a Monte Carlo approach to simulate control impacts on weed seedbanks over 10 years using five weed-control density thresholds. It was parameterised using data from recent experiments and available literature. Key results: The most effective long-term control strategy for barley grass occurred with a density threshold of 5 seedlings m−2 by combining early and late herbicide applications, and by combining early and late herbicides with mowing, reducing the seedbank by 86% and 89%, respectively. Conclusions: Simulation results showed that IWM programs were more effective than individual control options in reducing the barley grass seedbanks over 10 years, particularly at low weed densities (≤50 seedlings m−2). Implications: Incorporation of this model into a bioeconomic grazing systems model will be valuable for determining the economic impacts and optimal weed-control strategies for minimising the effects of barley grass seed contamination in lamb production systems. Barley grass is an invasive weed in southern Australia, with sharp seeds that can penetrate the flesh of grazing sheep, affecting production and animal welfare. Using a simulation modelling approach, this study compared the efficacy of single versus combined weed management strategies on barley grass populations within a lucerne pasture over 10 years. Combined control practices were found superior for reducing seed production, and the reported approach will enable the selection of optimal control strategies for reducing impacts on livestock production. [ABSTRACT FROM AUTHOR]

Context: Improving the stability of legumes in grasslands in the face of variable seasonal conditions is key to mitigating risks posed by drought. Aims: We assessed the persistence of a range of legume species and cultivars in order to inform legume choice for pasture improvement and identify priority species for further development. Methods: Twenty field experiments in four series were conducted at sites with contrasting seasonal and soil characteristics in the 'high-rainfall' (560–920 mm long-term average) Tablelands and Monaro regions of New South Wales, Australia. Legumes were grown as pure swards and assessed periodically for seedling density, plant frequency and dry matter for up to 5 years. Key results: Legume dry matter production was positively correlated with plant frequency. However, most legumes persisted poorly at most sites, particularly on soils of lower fertility. Subterranean clover (Trifolium subterraneum) cv. Goulburn was the best performing cultivar of that species across sites on the Southern Tablelands and Monaro. Yellow serradella (Ornithopus compressus) cvv. Avila and Yellotas showed promising persistence, particularly under drought conditions. White clover (T. repens) was the most broadly adapted of the perennial legumes across a range of soils, but persistence was still inadequate at many sites. Lucerne (Medicago sativa) was approximately twice as productive as the next-most productive species when soil conditions suited its growth, but it failed to persist on acidic, low-fertility soils. Conclusions: Serradella species (yellow and French, O. sativus) and white clover, in conjunction with subterranean clover, offer the best near-term prospects for diversifying legume productivity and resilience under variable seasonal conditions in tableland environments. Implications: An increased focus on phenology and seed characteristics is suggested to improve the persistence of annual and facultative perennial legume species in grasslands. Serradella and white clover are identified as the highest priorities for cultivar development for tableland environments of south-eastern Australia. This study evaluated the stability and persistence of a range of legume species and cultivars to identify viable options for grasslands of south-eastern Australia. Yellow and French serradella, white clover and subterranean clover were identified as priority species because they are already, or are close to being, viable options for use in grasslands. An increased focus on phenology and seed characteristics is suggested to improve the persistence of white clover and serradella in grasslands. [ABSTRACT FROM AUTHOR]

Context: An accession of the annual legume Trigonella balansae Boiss. & Reuter. has been selected for commercial release in Australia. Aims: As part of a duty-of-care assessment, we tested the hypothesis that sheep grazing the trigonella accession will have liveweight, condition scores and wool production similar to those of sheep grazing two widely adopted annual legumes, subterranean clover (subclover, Trifolium subterraneum L. cv. Dalkeith) and French serradella (Ornithopus sativus Brot. cv. Erica). We also hypothesised that sheep grazing the three legumes will have similar meat quality and health, as indicated by blood plasma panel analysis. Methods: Wethers (n = 6) grazed plots (n = 4) of three pasture species. Liveweight, condition scores and wool growth were measured, and a subset of animals were subject to blood sampling to assess health. Consumer sensory taste analysis was used to assess meat eating quality from two sheep per plot. Forage biomass, dry-matter digestibility, crude protein, fibre, mineral content and isoflavones were measured across the plant's lifecycle. Key results: There were no significant differences in liveweight, wool growth, wool yield or condition score that were associated with pasture species during the grazing period. There were differences in dry-matter digestibility, minerals and crude protein content of the pastures over time. As trigonella matured, it did not meet the minimum sulfur, phosphorus, manganese, molybdenum and copper requirements for mature sheep. We found some differences in indications of animal health; however, there were no significant systematic detrimental differences between sheep grazing trigonella and the other two species. In total, 2 of 24 individual sheep grazing trigonella had more than two plasma indicators of liver damage. There were no differences in meat tenderness, juiciness, flavour and overall consumer acceptability. Conclusions: The data supported the hypotheses. Under the conditions of this experiment, the pasture legumes had the same relative feeding value. Some care must be taken in interpreting the outcome as the trigonellacomprised only 18% of the dry matter on offer at the termination of grazing. Implications: Results of this study will be considered during the commercialisation process for T. balansae. Trigonella balansae is a novel species that is being domesticated for use in Australian pasture systems. As part of a duty of care experiment, we compared productivity, health and meat quality of sheep grazing the novel Trigonella accession with sheep grazing French serradella and subterranean clover. While there were some differences in pasture composition, plant nutritional value and animal health, Trigonella did not vary significantly from other species in terms of feeding value. [ABSTRACT FROM AUTHOR]

Context: High international demand for goat meat and high prices for goat in Australia have resulted in a transition from opportunistic harvesting to more managed production systems for Rangeland goats. There is limited information available to establish feeding strategies to maximise growth rates of Rangeland goats within these developing managed production systems. Aims: The aim of these experiments was to determine the response to supplements and the metabolisable energy requirements for maintenance and liveweight gain of young entire male Rangeland goats. Methods: Dose–response relationships to various supplements were established in two experiments with young entire male Rangeland goats. In Experiment 1, 54 goats were allocated to rolled-wheat grain, rolled-sorghum grain, or lucerne pellet supplements offered from 0 (control) to 24 g dry matter/kg liveweight.day. In Experiment 2, 24 goats were allocated to a commercial starch-based pellet offered from 0 (control) to ad libitum. In both experiments, goats were held in individual pens and offered their daily supplement allowances with ad libitum access to Mitchell grass hay and drinking water for 70 days. Key results: Total intake (30 to 32 g dry matter/kg liveweight.day) increased in a linear fashion with an increasing intake of all supplements. Maximum intake of rolled-wheat, rolled-sorghum, lucerne pellets and the commercial starch-based pellet supplements ranged from 18 to 22 g dry matter/kg liveweight.day. Unsupplemented goats lost liveweight (−20 to −32 g/day), while supplemented goats gained liveweight (0 to 126 g/day) in a linear fashion with an increasing supplement and metabolisable energy intake for all supplements, with the highest response in goats supplemented with the commercial starch-based pellets. Estimated metabolisable energy requirements to maintain liveweight (372 kJ/kg liveweight0.75.day) and for liveweight gain (35 kJ/g) of the goats were the same in both experiments. Conclusion: Liveweight gain increased in a linear fashion with metabolisable energy intake, with the maximum rates of liveweight gain occurring when starch-based supplement intake was approximately 20 g dry matter/kg liveweight.day. Implications: Supplementation with starch-based rations will increase liveweight gain and decrease age at turn-off of young entire male Rangeland goats; however, the local availability and cost of these supplements need to be considered. High prices for goats in Australia due to high international demand has resulted in a transition from opportunistic harvesting to more managed production systems for Rangeland goats. There is limited information available to establish feeding strategies to maximise growth rates of goats within these managed production systems. The present paper demonstrates that the highest rates of liveweight gain of young male Rangeland goats is when they are offered a high energy supplement. [ABSTRACT FROM AUTHOR]

Acacia is the largest genus of flowering plants in Australia, occurring in all terrestrial habitats. Black acacia (Acacia mearnsii De Wild) is adapted to different geographical areas of the world. Its forage can be used in the feeding of ruminants using different alternatives (hay, silage, silvopasture, protein bank, meal or fresh forage) to reduce costs of low and mediumscale livestock farming. The present work is a descriptive-analytical review of the available scientific literature with the purpose of contributing to the update on the potential of Acacia negra as feed for ruminants. The methodology consisted in the compilation of scientific articles and publications of scientific, academic and technological institutions on the object of study. The results focused on: Origin and distribution, Taxonomy and plant characteristics, Crop characteristics, Forage production, Nutritive value and Effects of forage consumption in ruminants. The review concluded that A. mearnsii adapts to diverse ecosystems and under low-input conditions shows rapid growth and acceptable forage production, which, together with its protein content, make it an option for small and medium producers. This allows lowering production costs by reducing the consumption of concentrates or alfalfa (Medicago sativa L.), without affecting production yields, mainly due to its high tannin content (main secondary metabolite), which favors the flow of amino acids from the diet from the rumen to the duodenum, among other beneficial effects on animal health and reproduction. [ABSTRACT FROM AUTHOR]

Prospects for improving the productivity of species mixtures in transitions between phases by changing row configuration at sowing were examined in two series of field experiments in rain-fed, semi-arid environments in south-eastern Australia. The first series explored how the choice of cover crop and use of alternate drill row configurations affected establishment and yields of sward components in the transition from a cropping into a pasture phase. Cover-crop species included wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), c anola (Brassica napus L.) a nd l upins (Lupinus augustifolius L.), e ach s own i n m ixed o r a lternate d rill r ows w ith l ucerne (Medicago sativa L.) and subterranean clover (Trifolium subterraneum L.). The second series of experiments examined the productivity implications when returning from the pasture phase back into cropping following 10 contrasting pastures sown to various combinations of lucerne, subterranean clover or phalaris (Phalaris aquatica L.) sown in mixed, alternate (1:1) or double skip (1:2) row configurations in the absence of cover crops. All experiments were sown on a 0.25-m row spacing. In the transition into the pasture phase, grain yields of cover crops in the mixed drill row treatment were similar to those achieved by crops grown in the absence of pasture species but were reduced by an average of 24% in the alternate drill row configuration. Canola and lupin crop biomass were lower, compared with wheat and barley, leading to increased pasture yields in year 1, highlighting an opportunity for increased use of these species as cover/companion crops in semi-arid environments. Pasture yields beyond year 1 were reduced by ~20% in the alternate drill row treatments compared with where species were sown in mixed drill rows, with greater yield differences under more favourable growing conditions. This response largely reflected yield reductions in lucerne where it was concentrated in fewer drill rows. The alternate drill row configuration increased the abundance of subterranean clover in year 1, but this species remained a minor component of all swards beyond the establishment year. In the transition into the cropping phase, effects on grain quality could only be attributed to row configuration of the previous pasture to the extent that row configuration changed pasture composition. Grain size was smallest and protein concentration highest where previous pastures contained both lucerne and subterranean clover without phalaris. Taken together, there was little advantage in total productivity attributable to spatially separating species in drill rows at sowing. [ABSTRACT FROM AUTHOR]

Australia has tropical, summer dominant rainfall in the north transitioning to temperate, winter dominant rainfall in the south. Temperate pasture species with a cool season growth pattern are commonly grown in the south, but tropical pasture species that are highly productive and responsive to summer rainfall, may also have a role in southern pasture systems with climate change. Determine the value of replacing temperate pastures with tropical pastures; and assess the emergence success of tropical grasses in response to historic climate change in eastern Australia. The AusFarm model was used to test replacing lucerne (Medicago sativa L.) (L); annual ryegrass (Lolium rigidum L.)/subterranean clover (Trifolium subterraneum L.) (RC); or lucerne/annual ryegrass/subterranean clover (LRC) with tropical pasture at varying rates of inclusion at five locations across the subtropical-temperate transition zone. The emergence success of tropical grasses with a bare fallow, short fallow and increased ground cover management was also tested. The modelling covered two periods, the Far Climate (1960–1990) and the Near Climate (1990–2020). Tropical pastures had higher plant growth in late summer-early autumn when temperate pastures are less active. Pasture growth decreased from the Far to the Near Climate period across all sites. The pastures with L lost the most production over this period, with minimal change in other pasture types. Supplementary feeding was reduced at all sites with the inclusion of tropical pastures. The cost of supplementary feeding from the Far to the Near Climate increased by $20/ha with increased variability between years, which in-turn decreased gross margin by an average of $26/ha. Tropical pastures improved profitability on average by $24/ha (11%), but with different responses between environments. At the low rainfall sites (Condobolin and Leeton) there was a substantial benefit when tropical grass-clover (TC) pasture replaced L, but at the higher rainfall sites (Cowra and Wagga Wagga) the benefit was replacing RC with TC. There was a gradient of successful emergence from very high (>90%) in the north, to reduced opportunities in the south (<45%), and marginal influence of sowing management. Adding tropical pastures to grazing systems with temperate pastures increased summer-autumn growth, the animal requirements met by pasture, and gross margins. Profitability of livestock systems decreased with climate change, but this can be overcome by optimising pasture composition. Fewer years are favourable for establishment of tropical pastures in more temperate environments, therefore establishment strategies need to be adjusted and field tested. • Tropical pastures have potential in temperate grazing systems due to climate change. • Tropical pastures increased plant growth over summer when temperate pastures are less active. • Tropical pastures decreased supplementary feeding and increased gross margin. • Poor establishment conditions limit the use of tropical grasses in temperate environments. • Profit of livestock systems decreased with climate change but less so with tropical pastures. [ABSTRACT FROM AUTHOR]

Tropical perennial grasses are an important forage option in the frost prone, summer dominant rainfall zone in eastern Australia. These pastures commonly lack a companion legume and are, at best, irregularly fertilised with nitrogen; therefore, their production potential is not realised. We conducted a study during 2012–16 to evaluate the productivity and persistence of a range of cultivars/lines of eight tropical and two temperate perennial legumes in mixes with digit grass (Digitaria eriantha cv. Premier) at two sites (Bingara and Manilla) in the northern inland region (North-West Slopes) of New South Wales. The sites were subjected to dry conditions during the assessment period, with the Bingara site receiving <25th percentile rainfall for 2 years of the study. Lucerne (Medicago sativa) was the most productive companion legume, with mixes producing 16–18 and 38–46 t dry matter (DM)/ha at the Bingara and Manilla sites respectively. Cultivars of Desmanthus spp. were less productive, with the best performing in mixes producing 13 and 21–23 t DM/ha at Bingara and Manilla respectively. These cultivars were also persistent and readily recruited new seedlings. Their persistence was similar or superior to lucerne, which appeared to be declining, especially at the Manilla site. Mixes of burgundy bean (Macroptilium bracteatum) and digit grass produced 14–17 t DM/ha at the sites but DM tended to decline during the course of the experiment, especially at the Manilla site. Stylosanthes spp. and Chamaecrista rotundifolia had poor persistence, generally failing within 1–2 years of sowing. Therefore, we recommend lucerne and Desmanthus virgatus cvv. Marc and JCU 2 as suitable perennial legumes in mixes with digit grass during drought conditions. Tropical perennial grasses are an important forage option in the frost prone, summer dominant rainfall zone in eastern Australia, but their production potential is not realised owing to lack of nitrogen fertility. We evaluated a range of tropical and temperate perennial legume species in mixes with digit grass in the northern inland region of New South Wales over 4 years with below average rainfall. Under these conditions, lucerne and Desmanthus virgatus were the most productive and persistent species. [ABSTRACT FROM AUTHOR]

Context: Liveweight gains (LWGs) of lambs grazing lucerne (Medicago sativa L.) in the mixed-farming zone of Australia commonly do not match predicted rates of growth. It has been suggested that this could be due to sodium (Na) deficiency or an imbalance in the crude protein : metabolisable energy ratio (CP : ME). Aims: This research aimed to determine whether sodium concentration in lucerne is below requirements for growing lambs and whether supplementation with salt (NaCl) and/or barley grain would increase LWG of lambs grazing lucerne. Methods: Pluck-samples were collected along a transect in 65 paddocks containing lucerne pasture in southern Australia. Herbage that most likely represented the animal diet was 'plucked', avoiding the less digestible plant parts. Two replicated grazing experiments using different cohorts of lambs compared LWG of unsupplemented lambs with lambs given supplements of salt and/or barley. Key results: The survey of lucerne pastures found that Na concentrations were below published requirements (0.07 g Na/kg DM) for growing lambs in 85% of samples collected from dryland lucerne pastures, but were above lamb requirements in 95% of samples collected from lucerne pastures gown under spray irrigation, which suggests a degree of salinity in the irrigation water. Supplementation with salt or barley did not affect LWG of lambs in Experiment 1, and residual feed on-offer did not differ among treatments. Salt increased LWG by 14% in Experiment 2 (292 g/lamb.day vs 256 g/lamb.day in those without access to salt; P = 0.03), with a return on investment of 1220%. Supplementation with whole barley did not increase (P > 0.05) LWG of lambs grazing lucerne. Barley supplementation resulted in higher residual feed on-offer in Experiment 2, suggesting a substitution of barley for lucerne. Mean LWG in Experiment 1 (192 g/lamb.day) was lower than in Experiment 2 (274 g/lamb.day), suggesting that the lack of response to salt supplementation in Experiment 1 may have been due to lamb growth rates being restricted by other factors such as reduced leaf availability and diet quality. Conclusions and implications: Results of the survey and grazing experiments confirm that Na concentration of dryland lucerne in southern Australia is commonly below lamb requirements. Producers should consider Na supplementation for lambs grazing dryland lucerne pastures as a way to increase lamb growth rates. Lucerne is a high-quality forage for finishing lambs. A survey of pastures in southern Australia identified that dryland lucerne may be low in sodium; however, lucerne pastures growing under spray irrigation are less likely to be deficient. Supplementation of lambs grazing high-quality lucerne with salt can increase lamb growth rates, whereas supplementation with barley grain does not. [ABSTRACT FROM AUTHOR]

Context: Biserrula (Biserrula pelecinus L.) is a relatively new legume species in Australia that has been shown to maintain higher quality forage late in the season than subterranean clover (Trifolium subterraneum L.). Aim: This study investigated the suitability of lucerne (Medicago sativa L.), subterranean clover and biserrula, or a choice of both biserrula and subterranean clover, for finishing White Dorper and White Suffolk × Merino lambs during spring. Methods: An experiment was established near Wagga Wagga, NSW, in 2013 in a randomised complete block design with three replicates and four pasture treatments grazed by lambs during late spring and early summer. Liveweight, carcass weight and GR fat depth of White Dorper and White Suffolk × Merino lambs grazing lucerne, subterranean clover, biserrula or a choice of subterranean clover plus biserrula were compared. Key results: Lambs grazing lucerne had significantly (P < 0.05) higher final liveweight, carcass weight and GR fat depth than lambs grazing other pasture treatments. After 61 days of grazing, mean liveweight of lambs grazing lucerne, subterranean clover and subterranean clover plus biserrula was higher than of lambs grazing biserrula monoculture. In vitro digestible organic matter digestibility and crude protein content indicated that lambs grazing biserrula should have achieved growth rates at least as high as lambs grazing subterranean clover. Sheep genotype and pasture type affected final liveweight. Final liveweight was higher for White Dorper lambs when grazing the subterranean clover plus biserrula treatment than the subterranean clover monoculture (45.6 vs 44.5 kg; P < 0.05) but was similar for White Suffolk × Merino lambs grazing these treatments (47.3 vs 47.2 kg; P > 0.05). Conclusions: Provision of a companion species or mixture of species when lambs graze biserrula during late spring to summer appears to offer benefits for lamb growth rate over this period. Utilising pastures that maintain high quality later in the season can allow higher finished weights for lambs grazing pasture. Biserrula forage maintained higher digestibility and crude protein levels later in the season than subterranean clover; however, growth rates were lower for lambs grazing biserrula than other pastures during late spring. Provision of a companion species or mixture of species when lambs graze biserrula during late spring to summer appears to offer benefits for lamb growth rate over this period. [ABSTRACT FROM AUTHOR]

Context: Finishing lambs on pasture and specialist forages is a commonly used production system in southern Australia; however, there is little information properly comparing multiple pasture options for lamb production. Aim: We aimed to compare growth rates of lambs when grazing traditional pastures, novel legumes, or a herb–legume mixture. Methods: Six pasture and forage treatments were sown in three replicate 0.4-ha plots and with access to irrigation. Treatments were French serradella (Ornithopus sativus Brot.), bladder clover (Trifolium spumosum L.), forage brassica (Brassica napus L.), lucerne (Medicago sativa L.), lucerne + phalaris (Phalaris aquatica L.), and arrowleaf clover (Trifolium vesiculosum Savi) + chicory (Cichorium intybus L.). The last two treatments were sown in a 1 : 1 alternate sowing-row (tyne) arrangement. All plots were grazed concurrently from 15 October to 2 December 2014, each plot with a mixed-sex group of 13 weaned lambs: five White Dorper, three White Suffolk × White Dorper and five White Suffolk × Merino lambs. During the grazing period, lambs were weighed each week following an overnight curfew. Starting liveweight (mean ± s.d.) was 32.4 ± 5.5 kg. At the completion of the grazing period, lambs were slaughtered and carcass traits recorded. Key results: Lambs grazing arrowleaf clover + chicory had the highest average daily growth rates (ADG) (245 g/lamb.day) and those grazing lucerne + phalaris the lowest (119 g/lamb.day). There was a lag in ADG for the forage brassica treatment over the first 14 days of grazing, and lamb growth plateaued for the bladder clover treatment toward the end of the trial. Overall, ADG for the forage brassica and bladder clover treatments was similar to that for lucerne. Lambs grazing French serradella had similar ADG to 18 November compared with those grazing other treatments, except arrowleaf clover + chicory; however, lambs grazing French serradella were withdrawn from the experiment on 26 November after losing weight. The genotype × treatment interaction was significant for final liveweights, with White Suffolk × White Dorper lambs having higher predicted final liveweight on the arrowleaf clover + chicory pasture (45.2 kg) than White Dorper (43.8 kg) and White Suffolk × Merino (44.0 kg) lambs, and higher liveweight on lucerne than White Suffolk × Merino lambs (42.6 vs 41.4 kg). White Dorper lambs had a higher overall sale value owing to their higher dressing percentage. The proportion of lambs reaching the finished weight target was higher for arrowleaf clover + chicory (0.96) than for any other treatment. Conclusions and implications: Using a forage option that maintains high levels of production and quality later in spring can increase the proportion of lambs reaching target weights and the final sale weight of lambs. Pastures that allow high lamb growth rates and maintain quality later in the season will improve the efficiency of production and producer returns. This study compared lamb production when grazing traditional and novel pastures, and showed that lambs grazing a mixture of arrowleaf clover and chicory had higher final liveweights and produced heavier carcasses than those grazing alternatives such as lucerne, bladder clover and French serradella. Producers can select a specialist pasture for increasing lamb production in late spring. [ABSTRACT FROM AUTHOR]

BACKGROUND: The European earwig, Forficula auricularia (L.) (Dermaptera: Forficulidae), is regarded as an important beneficial in many orchard environments but has the potential to be a plant pest in other systems, including to grain crops. Due to its agricultural importance, the lifecycle of F. auricularia has been widely studied in North America and Europe. However, much less is known in the southern hemisphere, including Australia where F. auricularia has been present for over 170 years. RESULTS: To elucidate the lifecycle of F. auricularia, we monitored five sites in grain-growing areas of southern Australia using two different trap types. Adults were found year-round, but most prevalent from late-spring to mid-winter. First instars were typically found from mid to late winter. Second, third and fourth instars occurred from winter through to late spring. The seasonal development of F. auricularia in Australia may be much earlier than observed in comparable North American studies. Degree day modelling highlights variation in development times across the active season for F. auricularia across our sites. CONCLUSION: Forficula auricularia is well adapted to the Australian grain growing environments. The timing of egg hatching aligns closely with crop emergence, juveniles then develop alongside the crop, and adult development occurs by harvest time in late spring. These findings are important given that many of these crops (canola, lucerne, pulses) are vulnerable to attack by F. auricularia during emergence and development. They also suggest a phenotypic capacity of this species to adapt different phenology after introduction into a novel environment. [ABSTRACT FROM AUTHOR]

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Lucerne (alfalfa, Medicago sativa L.) is grown extensively worldwide owing to its high forage biomass production and nutritional value. Although this crop is characterised as being tolerant to drought, its production and persistence are affected by water stress. Selection of genotypes of high yield potential and persistence after a long period of drought is a major objective for lucerne-breeding programmes in Mediterranean environments. This selection could be enhanced and accelerated by the use of physiological and productivity traits and their estimation through remote-sensing methods. A set of nine cultivars of lucerne from Australia and the USA were assessed in four locations in Mediterranean central-south Chile. Several physiological and productivity traits were evaluated: forage yield (FY), stomatal conductance (gs), water potential (WP), leaf area index (LAI), nitrogen (N) content, and isotope composition (δ13C and δ18O) of the dry matter. Spectral-reflectance data were used to estimate the traits through spectral-reflectance indices (SRIs) and multivariate regression methods. For the SRI-based estimations, the R² values for each assessment were <0.65. However, traits such as LAI, WP, gs, and N content showed higher R² values when data from the different assessments were combined. Regression-based estimation showed prediction power similar to or higher than the SRI-based approaches. The highest R² value was for δ13C (0.78), but for most traits the combination of data from different assessments led to higher trait estimation, with respective R² values for LAI, FY, WP and gs of 0.67, 0.71, 0.63 and 0.85. Among regression methods, the best estimation was achieved by using support vector machine regression. The use of spectral-reflectance data collected at field level and multivariate regression models has great potential to estimate physiological and productivity traits in lucerne under water deficit and could be useful in lucerne-breeding programmes. [ABSTRACT FROM AUTHOR]

In recent decades several pasture legumes have been available in southern Australia as potential alternatives to the most widely used annual pasture legume Trifolium subterraneum. Little is known about their soil phosphorus (P) requirements, but controlled environment experiments indicate that at least some may differ in their P fertiliser requirements. In this study, pasture legume varieties, including T. subterraneum as the reference species, were grown at up to four sites in any one year over a 3-year period (in total, seven site × year experiments) to measure herbage growth responses in spring to increased soil P availability. A critical soil test P concentration (corresponding to 95% maximum yield) was estimated for 15 legumes and two pasture grasses. The critical soil P requirements of most of the legumes did not differ consistently from that of T. subterraneum , indicating their soil fertility management should follow the current soil test P guidelines for temperate Australian pastures. However, the critical P requirement of Medicago sativa was higher than that of T. subterraneum , but remains ill-defined because extractable soil P concentrations in these experiments were often not high enough to permit a critical P estimate. Three forage crop legumes (Trifolium incarnatum , Trifolium purpureum , Trifolium vesiculosum) and two pasture legumes (Ornithopus compressus , Ornithopus sativus) had lower critical soil test P concentrations. It may be feasible to manage pastures based on these species to a lower soil test P benchmark without compromising yield. Extractable phosphorus concentrations of soil corresponding to near-maximum pasture legume growth can be used as benchmarks for soil phosphorus management in temperate grass–legume pastures. In this study, the soil phosphorus requirements of alternative pasture legumes used in southern Australia were assessed and compared with that of the widely used legume Trifolium subterraneum. The results indicate that published soil test phosphorus benchmarks for T. subterraneum are appropriate for many alternative legumes, but also demonstrate that some can be fertilised to lower benchmark concentrations without compromising yield. [ABSTRACT FROM AUTHOR]

Species composition is limiting production in >65% of pastures in Tasmania, Australia—a situation not unique to Tasmania. There are many reasons for degradation and poor persistence of improved pastures, with species selection crucial. Selection currently relies on producers making an assessment based on experience, external advice from agronomists and seed merchants, and experimental trial data. This project sought to assess the benefit of using fine-scale soils data and long-term rainfall data to determine the suitability of pasture species at a farm level across >3 Mha of agricultural land in Tasmania. Suitability rules were developed for perennial ryegrass (Lolium perenne L.) and lucerne (Medicago sativa L.) involving growth responses to soil characteristics (pH, soil depth, electrical conductivity, drainage, and coarse fragments) and average annual rainfall. Suitability classes were defined as well suited, suitable, moderately suitable, and unsuitable, with additional subclasses to account for soil limitations that could be mitigated through management. Soil grids were generated using digital soil mapping techniques from ~6500 new and existing site data sources spread across Tasmania. Rainfall data from 539 Bureau of Meteorology rainfall-recording sites were modelled using regression kriging interpolation. Soil pH was found to be a major constraint on lucerne, with 61.3% of the land area having a pH <5.7. Ameliorating the soil with lime could reduce this constraint to 33.5% of the land area. Drainage was another major constraint on lucerne suitability, with 37.8% of land constrained by imperfectly or poorly drained soils. Improving drainage by installing surface or underground drains could reduce the affected area to 22.1%. The mapping showed that perennial ryegrass was constrained by soil pH, with 38.2% of land having a pH <5.5. However, liming could reduce this constraint to just 9.6%. Accurate identification of the likely constraints on pasture production and persistence before sowing and choice of appropriate species and management intervention will result in fewer failed sowings and greater productivity. The feasibility of expanding this approach is being assessed for a larger area of south-eastern Australia and across a wider range of pasture species. Selecting pasture species suitable for particular soil and climate conditions is a critical step in growing productive and persistent pastures. Fine-scale soil and rainfall data were used for spatial evaluation of the suitability of growing perennial ryegrass and lucerne across agricultural land in Tasmania, with soil pH and drainage identified as key constraints. Fine-scale mapping can help to identify constraints and prioritise land suited to amelioration, or support the selection of other pasture species adapted to these conditions. [ABSTRACT FROM AUTHOR]

Managing agricultural pests that use multiple host plant species is a challenge when individuals move between host plants in natural vegetation and agricultural environments. The green mirid (Creontiades dilutus) Stål (Hemiptera: Miridae) is endemic to Australia and routinely invades cotton from local uncultivated vegetation, but may also originate from remote locations in the arid continental interior. This bug is polyphagous and highly mobile, which contributes to its pest status in cotton L. (Malvaceae) systems as well as its persistence in arid environments with sparsely distributed ephemeral host plants. The aim of this study was to evaluate how C. dilutus individuals use a variety of host species across remote arid regions and highly managed agricultural landscapes. Structured field surveys spanning vast areas across the Simpson Desert in the arid heart of Australia, as well as subcoastal cotton production systems, were designed to evaluate host use across environments that share few plant species. High numbers of C. dilutus were collected from Cullen australasicum (Schltdl.) J.W.Grimes (Fabaceae) (perennial hosts) and Goodenia cycloptera R.Br. (Goodeniaceae) (ephemeral hosts) in the desert following rain. In agricultural environments, C. dilutus bugs were mostly found on irrigated Medicago sativa L. (Fabaceae) (lucerne), and to a lesser extent Melilotus indicus (L.) All. (Fabaceae) near rivers. Significantly, bugs were on these plants prior to the planting of cotton across all environments surveyed. These data allow inferences relating host use, host abundance, and insect migration to one another to understand the connection that C. dilutus bugs have between arid and agricultural environments. [ABSTRACT FROM AUTHOR]

Forty-seven lucerne varieties/lines were examined to quantify their morphological, production characteristics, and nutritive values in southeastern Australia. The experiment was established in 2015 with a randomized complete block design and four replications. The morphological and production characteristics were measured from January to October 2017, and nutritive values were measured in February 2017. The results showed that the cultivars differed significantly (P < 0.01) in morphological, production characteristics, and nutritive values. Total herbage yield was highest for Haymaster 7 (14,186 kg/ha) and lowest for Qingshui (5927 kg/ha). Plant height was highest for Cropper 9.5 (31.4 cm) and lowest for Qingshui (14.5 cm). SF 714QL had the greatest branch number (44.7 branches/15 cm row segment). AV1001 had longest leaf (2.3 cm) and greatest leaf area (16.68 cm2/10 leaves) whereas Force 10 and SARDI 10 SERIES 2 had widest leaves (1.3 cm). AV1005 had the highest leaf-to-stem ratio (5.64). Crude protein (CP) content was highest for SARDI 10 SERIES 2 (15.1%) and lowest for SF 714QL (8.0%). AV12 was highest in crude fat (4.5%). Neutral detergent fiber (NDF) content was lowest in Stamina 5 (33.5%). Acid detergent fiber (ADF) content was lowest in Gannong 4 (29.3%). Relative feed value (RFV) was highest in Force 11 (193.0%). Calcium (Ca) content was highest for Titan 5 (1.8%). Phosphorous content was highest for AV1 and Gannong 6 (0.1%). Overall, Cropper 9.5, SARDI 10 SERIES 2, Haymaster 9, Titan 9, SF 714QL, Kaituna, Haymaster 7, AV1001, AV1002, and WL925HQ performed well based on their comprehensive scores. Abbreviations: CP - crude protein; CF - crude fat; NDF - neutral detergent fiber; ADF - acid detergent fiber; Ca - calcium; P - phosphorus; RFV - relative feed value. [ABSTRACT FROM AUTHOR]

Lucerne (Medicago sativa) has not been a significant part of the feedbase of the Murray-Dairy Region of Australia. However, under future climate regimes, which are indicating an overall decline in rainfall as well as water available for irrigation of pastures, lucerne is emerging as a potential forage species because of its adaptability, productivity and resilience. A large-scale field experiment was conducted at Tatura, Victoria, Australia, over four years to determine the dry matter (DM) production and nutritive characteristics of lucerne under a range of limiting and non-limiting irrigation management practices. Nine irrigation treatments were imposed that ranged from full irrigation to no irrigation in either a single, or over consecutive, irrigation seasons. Plots were harvested using plant-based criteria over the irrigation season and DM production and nutritive characteristics were determined. DM production generally increased as the total water supply (irrigation plus rainfall plus changes in soil water) increased, with the fully irrigated treatments producing significantly more DM than the treatments where the irrigation water had been restricted. Mean annual DM digestibility concentration was 66% of DM and was not affected by treatment. Similarly, mean crude protein concentration, which was 22% of DM, was also not affected by treatment. There was no consistent effect of restricted irrigation on the neutral detergent fibre concentration of the lucerne plants. These results suggest that in seasons where irrigation is restricted because of limited water supply, the reduction in lucerne productivity is not associated with a penalty in forage nutritive characteristics, with lucerne able to provide sufficient nutrients to form a large proportion of the total diet for a high-producing dairy cow. A large-scale field experiment was conducted to determine the effect of limiting and non-limiting irrigation treatments on the dry matter production and nutritive characteristics of lucerne. Dry matter production generally increased as the total water supply increased; however, neither mean dry matter digestibility concentration nor mean crude protein concentration were affected by irrigation treatment. There was no consistent effect of restricted irrigation on the neutral detergent fibre concentration of the lucerne plants. [ABSTRACT FROM AUTHOR]

Seed distributors market lucerne to farmers based on the supposed winter activity of those cultivars. This study determines the amount of between-cultivar variation, in cultivars available to farmers, in annual dry matter production and seasonality of that dry matter production when grown in dryland grazing areas of south east Australia. Forty-seven cultivars of lucerne, that spanned the range of winter activity ratings, were defoliated every 6 weeks for a period of nearly four years at two contrasting dryland sites. At each site, annual and seasonal dry matter growth was measured over three yearly periods. The variation between cultivars was examined using models with random between-cultivar effects. At both sites and in most years, within the Australian commercial cultivars, the higher (97.5% quantile) annual growth cultivars had about 20–30% greater annual growth than the lower (2.5% quantile) annual growth cultivars. Whilst variation between cultivars in seasonality of growth was statistically detectable, the main feature was the small magnitude of this between cultivar variation. We suggest that dryland farmers in temperate regions (similar to south-east Australia) should make purchasing decisions of lucerne cultivar based on annual production, pest and disease resistance, persistence and grazing tolerance, and mostly ignore differences in seasonality of production. [ABSTRACT FROM AUTHOR]

In recent years, livestock producers have widely sown tropical perennial grasses, such as digit grass (Digitaria eriantha), in the frost-prone summer dominant rainfall zone of eastern Australia. Tropical grasses require substantial nitrogen inputs to maintain water productivity and forage quality. Perennial legumes offer a potential nitrogen source for these perennial grasses when sown in a mixed sward. Lucerne (Medicago sativa) is the perennial legume most widely sown in grazing systems in south-eastern Australia. In this study, conducted over the period 2014–2018, we compared the soil water dynamics and rainwater productivity of pure stands of digit grass (fertilized with applied nitrogen), lucerne, desmanthus (Desmanthus virgatus) and leucaena (Leucaena leucocephala) and binary mixtures of digit grass (not fertilized with applied nitrogen) with each legume. We found that often growing season actual evapotranspiration (ET a) was similar among the treatments (P > 0.05), but rainwater productivity (kg DM/ha.mm) and proportion (%) of legume herbage mass were not (P < 0.05). Our results showed that the lucerne-digit grass mix was equally productive and efficient as fertilized digit grass (P > 0.05), particularly in the latter three seasons. However, lucerne dominated the herbage mass (c. > 67% legume). Leucaena production was delayed by frost and severely impacted by competition with digit grass, and generally underperformed both lucerne and desmanthus. This observation did always not hold when alfalfa mosaic virus (AMV) impacted desmanthus in specific seasons. Our experiment has shown that a mixed sward of lucerne-digit grass is highly productive and offered high rainwater productivity. Both desmanthus and leucaena, in mixes with digit grass, provided useful contributions of legume herbage mass, in specific seasons and under specific conditions, but both underperformed overall compared with lucerne. • Tropical perennial grasses can be highly productive but require a nitrogen supply. • Companion legumes can supply nitrogen to the grass and increase forage quality. • We compared rainwater productivity of digit grass and binary mixes with perennial legumes. • Growing season total evapotranspiration was often similar, but rainwater productivity was not. • Lucerne-digit grass was highly productive and offered high rainwater productivity. [ABSTRACT FROM AUTHOR]

Abstract: Dairying in the southern Murray–Darling Basin accounts for about 25% of Australia''s annual milk production, and relies on irrigation for pasture production. Border-check irrigation is the predominant method of irrigation used in the region, however subsurface drip irrigation (SDI) could be an alternative. We present an economic evaluation of converting from border-check to subsurface drip irrigation for grazed perennial pasture, and a comparison of border-check and subsurface drip irrigation for fodder lucerne (alfalfa, Medicago sativa) production. Costs and potential savings/benefits associated with these systems are identified, and a 10-year, discounted net cash flow analysis performed for each scenario. Our results indicate that it is only in situations where a substantial increase in pasture consumption is achieved (2.8tDM/ha/yr), valued at $300/tDM, with concurrent water savings of 2.0ML/ha/yr, valued at $250/ML, each year for 10 years, that it is predicted that the internal rate of return is large enough to justify the SDI system investment for grazed perennial pastures. The sensitivity of the investment to various combinations of additional lucerne conservation (for hay and silage) and water savings indicate that installation of SDI for a lucerne hay/silage production system could be a profitable investment if combinations equivalent to 3tDM/ha/yr of lucerne, valued at $400/tDM, coupled with 30% water savings, valued at $150/ML, each year for 10 years, could be achieved. The capital cost associated with installing such a system limits the feasibility of adopting this technology at the present time. Further research is required to quantify potential perennial pasture and lucerne dry matter production gains and water savings associated with this technology. [Copyright &y& Elsevier]

Interactions between annual grass and perennial legume species when they are grown together under drought and limited phosphorus (P) availability are likely to be very important for pasture productivity, but are not well understood. Therefore, the objective of this study was to compare the interactions of drought and species combination on growth, nutrition, hydraulic lift and photosynthesis of the Australian native legume Cullen australasicum and the exotic legume Medicago sativa when grown with the exotic annual ryegrass ( Lolium rigidum) with poorly soluble FePO as the source of P. Plants were grown for 22 weeks in monoculture and in legume-grass mixtures in 1-m tall pots filled with river sand. Two moisture treatments were applied, drought (top 70 cm of soil allowed to dry after 16 weeks of establishment) and control (field capacity). In monoculture, shoot dry weight (DW) pot of L. rigidum was higher than that of C. australasicum and M. sativa. In the mixtures, compared with the monocultures, an increase in shoot DW pot for L. rigidum and a decrease for both C. australasicum and M. sativa resulted in a relative yield total >1. Citrate was the main carboxylate in the rhizosphere of all species, except for the drought-treated L. rigidum in monoculture and mixtures, for which malate was the main constituent. Both C. australasicum and M. sativa had higher concentrations of Ca, Mg, S, Cu, Zn, Mn and Mo in their leaves than did L. rigidum. Hydraulic lift was not detected in M. sativa and C. australasicum; likely reasons are discussed. Photosynthetic rate was similar for all species, but L. rigidum had tighter stomatal control. C. australasicum survived longer under drought than did M. sativa. In conclusion, L. rigidum out-competed the legumes. The legumes provided benefits to the growth of L. rigidum through solubilising P, but not through hydraulic lift. In addition, L. rigidum conserved moisture through tight stomatal control and produced an extensive root system to take up water and nutrients efficiently. [ABSTRACT FROM AUTHOR]

This study aimed to determine the optimal plant density of lucerne for maximum pasture productivity combined with enhanced environmental outcomes in a Mediterranean climate. Lucerne was sown at different seeding rates (1, 2, 4 or 8 kg ha) at two sites (Esperance and Katanning); productivity and soil water extraction was compared with an annual pasture over 4 years. Lucerne plant densities 5-6 months after seeding in 2002 ranged from 8 to 39 plants m at both sites. Initial lucerne plant densities at the Esperance site were stable from 2002 until late 2004, and then began to decline, especially at the higher densities. The decline was associated with an extended dry spell. At the Katanning site, the decline was slower but constant from mid 2004 onwards with similar rates of decline for each treatment. Lucerne densities >20 plants m at both sites produced more dry matter than lower plant densities (10 plants m) in most years. At both sites the proportion of lucerne in the total biomass increased with higher plant densities but generally at the expense of the proportion of subterranean clover. Lucerne at densities of 10 plants m at Katanning had up to 30-53 mm higher soil water content to a depth of 2.6 m during summer and early autumn compared with that of >20 plants m. However, the differences between lucerne plant densities were smaller than the difference between lucerne and annual pasture (up to 120 mm). At Esperance the plant available soil water was limited and there were no differences between lucerne treatments. We conclude that in the 430-450 mm annual rainfall zone of south-western Australia, the higher the lucerne plant density (up to 40 plants m) in the first summer after establishment the more productive the pasture is in most years, the higher the proportion of lucerne in the total biomass and depending on the site the drier the soil profile. A drier soil profile can potentially reduce the spread of salinity. [ABSTRACT FROM AUTHOR]

Background and aims: Medicago sativa L. is widely grown in southern Australia, but is poorly adapted to dry, hot summers. This study aimed to identify perennial herbaceous legumes with greater resistance to drought stress and explore their adaptive strategies. Methods: Ten herbaceous perennial legume species/accessions were grown in deep pots in a sandy, low-phosphorus field soil in a glasshouse. Drought stress was imposed by ceasing to water. A companion M. sativa plant in each pot minimised differences in leaf area and water consumption among species. Plants were harvested when stomatal conductance of stressed plants decreased to around 10% of well watered plants. Results: A range of responses to drought stress were identified, including: reduced shoot growth; leaf curling; thicker pubescence on leaves and stems; an increased root:shoot ratio; an increase, decrease or no change in root distribution with depth; reductions in specific leaf area or leaf water potential; and osmotic adjustment. The suite of changes differed substantially among species and, less so, among accessions. Conclusions: The inter- and intra-specific variability of responses to drought-stress in the plants examined suggests a wide range of strategies are available in perennial legumes to cope with drying conditions, and these could be harnessed in breeding/selection programs. [ABSTRACT FROM AUTHOR]

Abstract: Evaluating the potential scale of adoption of a technological innovation or management practice at the farm business scale can help gauge the potential size of an industry for the purposes of prioritising resources for research and development. In this paper we address the question of quantifying the potential area of adoption of a perennial pasture, lucerne (Medicago sativa L.), in dryland mixed farming systems in Australia. Lucerne pastures play a significant role in dryland farming systems in the wheat-sheep zone of southern and western Australia. While there are benefits of integrating lucerne into cropping systems there will inevitably be additional costs, and the scale of adoption of lucerne will depend largely on the increase in farm profit resulting from the introduction of lucerne. Whole-farm economic models of representative farms in the Australian wheat-sheep belt were used to determine the key drivers for the scale of adoption of lucerne. For a particular farming system the optimal area of lucerne which maximises whole-farm profit is found to depend on production, price and cost conditions. Generally, no more than 30% of a farm was allocated to lucerne according to those conditions and location of the farm. For most scenarios examined the response of profit was flat around the optimal area. This implies that lucerne could be grown on areas greater than the optimum, in order to reduce groundwater recharge (and thereby reduce the risk of dryland salinity), without greatly reducing whole-farm profit. The optimal area of lucerne in all regions was limited by the area of suitable soil types and proportion of lucerne in the most profitable lucerne-crop sequences. At all price levels assumed in this study lucerne remained as part of the optimal enterprise mix for all farm types examined. Lucerne productivity was also a major determinant of the optimal area of lucerne. The sensitivity of profit to changes in winter and/or summer production varied between regions and for different livestock enterprises. The differences were driven by the timing of energy demands and supply of feed in individual farming systems. In all regions the optimal area and profitability of lucerne varied with livestock enterprise. The analyses showed that changing from wool production to meat production enabled greater economic benefit to be realised from lucerne. This was consistent across farm types and demonstrated the value of lucerne as a source of high quality feed for finishing prime lambs in summer. The results of this study demonstrate that lucerne is profitable in a range of environments on a significant proportion of the farm area, but that this area is small relative to that required to significantly influence in its own right the environmental issue of salinity. [Copyright &y& Elsevier]

Phosphorus (P) deficiency is a major problem for Australian agriculture. Development of new perennial pasture legumes that acquire or use P more efficiently than the current major perennial pasture legume, lucerne ( Medicago sativa L.), is urgent. A glasshouse experiment compared the response of ten perennial herbaceous legume species to a series of P supplies ranging from 0 to 384 µg g−1 soil, with lucerne as the control. Under low-P conditions, several legumes produced more biomass than lucerne. Four species ( Lotononis bainesii Baker, Kennedia prorepens F.Muell, K. prostrata R.Br, Bituminaria bituminosa (L.) C.H.Stirt) achieved maximum growth at 12 µg P g−1 soil, while other species required 24 µg P g−1. In most tested legumes, biomass production was reduced when P supply was ≥192 µg g−1, due to P toxicity, while L. bainesii and K. prorepens showed reduced biomass when P was ≥24 µg g−1 and K. prostrata at ≥48 µg P g−1 soil. B. bituminosa and Glycine canescens F.J.Herm required less soil P to achieve 0.5 g dry mass than the other species did. Lucerne performed poorly with low P supply and our results suggest that some novel perennial legumes may perform better on low-P soils. [ABSTRACT FROM AUTHOR]

Lucerne ( Medicago sativa L.) helps to prevent soil salinisation in the Western Australian Wheatbelt by reducing recharge to saline water tables. There is broad consensus, though, that it is not sufficiently profitable to motivate producers to plant it at the intensity at which considerable off-site benefits would be conferred. This paper employs a multiple-phase optimal control model to explore the value of this perennial pasture for the management of herbicide-resistant annual ryegrass ( Lolium rigidum Gaud.) in a crop–pasture rotation, given the difficulty of observing this value in practice. The availability of selective herbicides for efficient weed control is found to determine whether or not it is profitable to adopt lucerne pasture under optimal management. Herbicide resistance requires producers to employ costly, non-selective treatments for in-crop weed control. Thus, it motivates the adoption of perennial pasture in which cost-effective forms of control can be implemented. Moreover, this result is robust to feasible changes in the current economic environment. [ABSTRACT FROM AUTHOR]

1. The spatial heterogeneity of predator populations is an important component of ecological theories pertaining to predator–prey dynamics. Most studies within agricultural fields show spatial correlation (positive or negative) between mean predator numbers and prey abundance across a whole field over time but generally ignore the within-field spatial dimension. We used explicit spatial mapping to determine if generalist predators aggregated within a soybean field, the size of these aggregations and if predator aggregation was associated with pest aggregation, plant damage and predation rate. 2. The study was conducted at Gatton in the Lockyer Valley, 90 km west of Brisbane, Australia. Intensive sampling grids were used to investigate within-field spatial patterns. The first row of each grid was located in a lucerne field (10 m from interface) and the remaining rows were in an adjacent soybean field. At each point on the grid the abundance of foliage-dwelling and ground-dwelling pests and predators was measured, predation rates [using sentinel Helicoverpa armigera (Hübner) egg cards] and plant damage were estimated. Eight grids were sampled across two summer cropping seasons (2000/01, 2001/02). 3. Predators exhibited strong spatial patterning with regions of high and low abundance and activity within what are considered to be uniform soybean fields. Ground-dwelling and foliage-dwelling predators were often aggregated in patches approximately 40 m across. 4. Lycosidae (wolf spiders) displayed aggregation and were consistently more abundant within the lucerne, with a decreasing trap catch with distance from the lucrene/soybean interface. This trend was consistent between subsequent grids in a single field and between fields. 5. The large amount of spatial variability in within-field arthropod abundance (pests and predators) and activity (egg predation and plant damage) indicates that whole field averages were misleading. This result has serious implications for sampling of arthropod abundance and pest management decision-making based on scouting data. 6. There was a great deal of temporal change in the significant spatial patterns observed within a field at each sampling time point during a single season. Predator and pest aggregations observed in these fields were generally not stable for the entire season. 7. Predator aggregation did not correlate consistently with pest aggregation, plant damage or predation rate. Spatial patterns in predator abundance were not associated consistently with any single parameter measured. The most consistent positive association was between foliage-dwelling predators and pests (significant in four of seven grids). Inferring associations between predators and prey based on an intensive one-off sampling grid is difficult, due to the temporal variability in the abundance of each group. 8. Synthesis and applications. This study demonstrated that generalist predator populations are rarely distributed randomly and field edges and adjacent crops can have an influence on within-field predator abundance. This must be considered when estimating arthropod (pest and predator) abundance from a set of samples taken at random locations within a field. [ABSTRACT FROM AUTHOR]

Three field experiments involving wheat, lucerne or cotton were established at different sites in the semiarid cropping regions of northern Australia, to test whether the deep placement of P fertiliser improved P availability, compared to the conventional practice of placing the fertiliser beside or adjacent to the seed. At Mulga View, near St George in southern Queensland on a red Kandosol soil with a Colwell soil test value of 19 mg P kg soil-1 in the top 10 cm, there was no response to 10 kg P ha-1 applied in the 5-7 cm layer. However, increasing the depth of placement of 10 kg P ha-1 from 5-7 to 10-15 cm resulted in increased shoot growth and grain yield of spring wheat (Triticum aestivum) by 43 and 30%, respectively. A further grain yield increase of 43% to 3.2 t ha-1 resulted when the deep P rate was increased from 10 to 40 kg P ha-1. At Roma, in southern Queensland, on a grey/brown Vertosol with a Colwell soil test value of 15 mg P kg soil-1, there was no difference in the winter growth of lucerne (Medicago sativa) when P fertiliser had been applied at 5-7 cm depth at rates of 10 and 40 kg P ha-1. Shoot dry matter yields were around 2 t ha-1. However dry matter yields increased significantly to 2.6 and 3.7 t ha-1 when 10 and 40 kg P ha-1, respectively were applied at the 10-15 cm depth. The third experiment was carried out on a grey Vertosol at Kununurra in Western Australia. Significant increases in the yield of seed cotton (Gossypium hirsutum) occurred when 50 kg P ha-1 was applied at depth (10-15 and 25-30 cm), compared with the conventional placement at 7-10 cm, with maximum yield response to deep placement occurring with DAP, and the minimal response with MAP. The cotton was grown on raised beds and the crop was irrigated according to district practice. The response to deep P at all sites was attributed to the rapid drying of the soil surface layers, reducing the availability of soil or fertiliser P in these layers. The deep fertiliser P remained available during the growing season and alleviated the P deficiency that appears to be a feature of these soils when the surface layers become dry. [ABSTRACT FROM AUTHOR]

Soil acidity is one of the limiting factors affecting the production and sustainability of pastures and crops in many parts of the world. An on-farm experiment was conducted in Australia to investigate the cultivar variation in alfalfa (lucerne) (Medicago sativa L.) with respect to soil acidity and response to applied lime. The experimental site was a brown sandy clay loam with a soil pH of 4.8 (1:5 calcium chloride). Ten cultivars (Hunter River, Hunterfield, Sceptre, Aurora, Genesis, Aquarius, Venus, PL90, PL55, and breeding line Y8804) were tested at two levels of lime (0 and 2 t ha-1). Lime application significantly increased the root growth, nodulation, leaf retention, leaf to stem ratio, herbage yield, and crude protein content of alfalfa. Liming had a significant effect on elemental composition of alfalfa shoots. Aluminum (Al) concentration was reduced from 93 mg kg-1 DM in nil lime treatment to 45 mg kg-1 DM in +lime treatment. Similarly, manganese (Mn) and iron (Fe) shoot concentrations were reduced from 74 mg kg-1 DM and 92 mg kg-1 DM to 59 mg kg-1 DM and 76 mg kg-1 DM, respectively. Liming significantly improved the calcium (Ca) concentration of shoots, while there was a little effect on phosphorus (P) and zinc (Zn) concentrations of alfalfa shoots. Cultivars had differential response to lime application. Response to lime application was greater in Y8804 and Aurora alfalfa where yield increased by 32% and 31%, while yield increase was 11–22% in other cultivars. Cultivars also differed significantly in root growth, nodulation, leaf drop, leaf to stem ratio, crude protein content, and elemental composition of shoots. Cultivars with better performance in no liming treatment had comparatively lower shoot Al, Mn, and Fe concentrations compared with other cultivars. [ABSTRACT FROM AUTHOR]

The phenotypic diversity and productivity of a diverse alfalfa (M. sativa subspp.) panel of cultivars, landraces and wild relatives with putative drought tolerance were evaluated in two Mediterranean environments (central Chile and Southern Australia). In Chile, 70 accessions were evaluated in rainfed conditions and in Australia 30 accessions under rainfed and irrigated conditions, during three growing seasons. Large phenotypic variation was observed among and within subspecies for NDVI, stem length, intercepted PAR and forage yield. Principal component analysis indicated that the first two principal components (PC) accounted for 84.2% of total variance; fall dormancy, taxa, and breeding status were closely related to the agronomical performance of alfalfa accessions. Forage yield varied largely among accessions across years and locations. A linear relationship was found between annual forage yield and annual water added to the experiments (R2 = 0.60, p < 0.001). The GxE analysis for forage yield allowed the detection of the highest yielding accessions for each of the two mega-environments identified. The accessions CTA002 and CTA003 showed greater forage yield in both Chile and Australia environments. It is concluded that new breeding lines derived from crosses between cultivated alfalfa (M. sativa subsp. sativa) and wild relatives belonging to the primary (M. sativa subsp. falcata) and tertiary (M. arborea) gene pool, achieve outstanding agronomical performance in drought-prone environments. [ABSTRACT FROM AUTHOR]

Within 6 years of the first devastating appearance of the spotted alfalfa aphid, Therioaphis trifolii, on Medicago sativa (lucerne) crops in Australia in 1977, the pest ceased to be an economic problem. At first the aphid reached high levels of infestation on virtually every crop of irrigated lucerne cut each season, but following the introduction and release of three exotic hymenopterous parasites of the aphid, the frequency and level of infestations declined. Other possible causes of the decline were considered but none of them could satisfactorily account for it. The capacity of the aphid to infest and increase on susceptible lucerne remains unchanged. The drought, which developed concurrently with the decline and may have reduced source populations on non-irrigated lucerne plants thus lowering immigration rates into irrigated crops, broke in 1983 with no indication of aphid resurgence since. Insecticide use, although high at first, decreased rapidly with the reduction in infestations. Relative to the rate of decline, the replacement of aphid-susceptible lucerne with aphid-resistant varieties proceeded slowly to reach only 10% in I981 and 26% in 1984. The majority of lucerne grown in Australia is still susceptible to the aphid. Although native predatory insects became numerous in aphid-infested crops, they did not reduce aphid numbers sufficiently consistently to account for the decline. Of the hymenopterous parasites, only one, Trioxys complanatus, became generally widespread and numerous throughout the lucerne-growing areas of Australia. Parasitization by T. complanatus increased from one lucerne growth cycle to the next and higher levels were associated with aphid infestations that did not increase to damaging levels. Observed reductions in the proportion of apterous adult female aphids in field populations were consistent with estimates of parasitization by T. complanatus. When the properties of the aphid and parasite, as measured in the laboratory, were assembled into a simulation model of their interacting life systems on irrigated lucerne crops, outputs from the model closely matched the observed field data. Furthermore, the simulated population at harvest from initial lucerne growth cycles, when used as input for other runs of the model, resulted in good simulations of aphid and parasite populations in subsequent cycles in the same season. It is concluded that Therioaphis trifolii on irrigated lucerne crops was biologically controlled by the introduced hymenopterous parasite Trioxys complanatus. The short-term (say 5-year) value of the biological control, in terms of the reduction in the cost of insecticide applications needed to prevent loss and spoilage of the N.S.W. lucerne-hay crop, has probably been of the order of 1 million dollars a year. In terms of reduced urgency for replanting with aphid-resistant varieties, the value was similar. Over the whole of Australia, the value would be proportionally greater. Although T. complanatus was known to be less effective at high summer temperatures, this did not prevent an overall reduction in immigration rates, although some alates still infest many crops. [ABSTRACT FROM AUTHOR]

Alfalfa (Medicago sativa L.) is a major forage crop of family Fabaceae and is frequently cultivated in Egypt. The present study is concerned with the genetic discrimination of fifteen alfalfa cultivars from three different countries (Egypt, Australia, and USA) using two molecular approaches: inter-retrotransposon-amplified polymorphism (IRAP) markers and two chloroplast DNA barcodes matK and the trnH in addition to the analysis of fifteen morpho-agronomic traits. The genetic relatedness, based on analysis of IRAP marker polymorphism and produced using eleven primers by clustering via principal component analysis (PCA) and multivariate heatmap biostatistical methods differentiated the two Egyptian cultivars EGY1-Ismailia1 and EGY2-Nubaria1 from the three Australian and seven American cultivars, with some distinction of the cv. USA6-SW9720 and cv. AUS4-SuperFast. The results were also supported by the sequence analysis of the matK and the trnH genes on the genetic relatedness between eight cultivars. Moreover, it might be suggested that breeding lines from M. sativa cultivars may provide novel insights and a better understanding of the domestication of M. sativa genetic diversity. The classification of the eight cultivars, as revealed by morpho-agronomic traits, confirmed the close genetic relationship between the two Egyptian cultivars and indicated some resemblance between them and the AUS2-Siri Nafa, whereas the two American cultivars, USA1-Super supreme and USA4-Cuf101, were clearly isolated from a cluster of other three cultivars USA7-SW9628, USA8-Magna901, and USA9-Perfect. The results are useful sources of genetic information for future breeding programs in crop development and open new possibilities of producing M. sativa lines harboring high forage quality, productivity, and resistance to biotic and abiotic stresses. [ABSTRACT FROM AUTHOR]

Lucerne (Medicago sativa L.) persistence is important for farming systems in south east Australia. Defoliation of lucerne that is too frequent (arguably more than once every six weeks) reduces yield and accelerates stand decline. Three experiments were conducted in south east Australia (Burraja, New South Wales; Rutherglen and Hamilton, Victoria) to investigate different cutting regimes on lucerne persistence. At Burraja lucerne was cut 16 (lax) or 33 (severe) times over three years at different plant densities. At Rutherglen and Hamilton lucerne was cut every 21 days (short rotation), every 42 days (long rotation), when new shoots (2.5 cm long) emerged (new shoots) or cutting when new shoots emerged but allowing the lucerne to flower in autumn (new shoots flowering). It was hypothesised that the frequent cutting of lucerne would result in lower plant densities. At Burraja there was little difference between treatments at any density or assessment. At Hamilton, apart from the assessment in June 2016, there was no difference (p > 0.1) between treatments. At Rutherglen, there was no difference (p > 0.1) between treatments at any assessment although plant numbers declined in 2016 from waterlogging. The results provide evidence that lucerne has intrinsic mechanisms that protect it from cutting, often at short intervals, thus promoting its persistence over three to four-year periods. [ABSTRACT FROM AUTHOR]

Simple Summary: Pre-grazing pasture height has significant impact on intake rate and intake in grazing dairy herds, and the ideal pre-grazing pasture height varies between pasture species. Defining the ideal pre-grazing pasture height of lucerne pasture has potential to significantly increase milk production of cows on sub-tropical partial mixed ration (PMR) dairies in Australia. Pasture intake of dairy cows was highest when the pre-grazing pasture height of lucerne was 39 cm and a proportion of the pasture remained un-grazed, irrespective of the amount of mixed ration offered. The effect of lucerne (Medicago sativa L.) pre-grazing pasture height on pasture intake and milk production was investigated in a sub-tropical partial mixed ration (PMR) dairy system in south-east Queensland, Australia. The experiment involved a 26-day adaptation period followed by an eight-day measurement period during April and May 2018. Twenty-four multiparous Holstein-Friesian dairy cows were offered a mixed ration at either 7 (low) or 14 (high) kg dry matter (DM)/cow/day and allocated pastures at pre-grazing heights ranging from 23 to 39 cm. The targeted pasture intake was 14 and 7 kg DM/cow/day for cows offered the low and high mixed ration allowances respectively, with a total intake target of 21 kg DM/cow/day. Pasture structure did not limit pasture intake as the all groups left at least 12% of the allocated area ungrazed, and therefore could selectively graze pasture. There was no significant difference in intake between mixed ration levels, however intake had a positive linear relationship with pre-grazing pasture height. For every one cm increase in pasture height, intake increased by 0.3 kg DM/cow/day. Using a grazing strategy that ensures the some pasture remains ungrazed and the pre-grazing height of lucerne is approximately 39 cm above ground level will maximise pasture intake in sub-tropical PMR dairy systems. [ABSTRACT FROM AUTHOR]

Alfalfa plants in the field can display a range of virus-like symptoms, especially when grown over many years for seed production. Most known alfalfa viruses have RNA genomes, some of which can be detected using diagnostic assays, but many viruses of alfalfa are not well characterized. This study aims to identify the RNA and DNA virus complexes associated with alfalfa plants in Australia. To maximize the detection of RNA viruses, we purified double-stranded RNA (dsRNA) for high throughput sequencing and characterized the viromes of ten alfalfa samples that showed diverse virus-like symptoms. Using Illumina sequencing of tagged cDNA libraries from immune-captured dsRNA, we identified sequences of the single-stranded RNA viruses, alfalfa mosaic virus (AMV), bean leafroll virus, a new emaravirus tentatively named alfalfa ringspot-associated virus, and persistent dsRNA viruses belonging to the families Amalgaviridae and Partitiviridae. Furthermore, rolling circle amplification and restriction enzyme digestion revealed the complete genome of chickpea chlorosis Australia virus, a mastrevirus (family Geminiviridae) previously reported only from chickpea and French bean that was 97% identical to the chickpea isolate. The sequence data also enabled the assembly of the first complete genome (RNAs 1–3) of an Australian AMV isolate from alfalfa. [ABSTRACT FROM AUTHOR]

Lucerne (Medicago sativa L.) is valued by producers with integrated crop-livestock systems. The multiple benefits of periods of lucerne leys to either livestock or to crop production have been widely reported; however, the importance of managing lucerne leys to whole farm profit and production has not and is best suited to a whole of system modelling study. This paper reports a simulation study aimed at better understanding the mixed farming systems that include short-term (3-year) phases of lucerne: specifically, the effects of terminating lucerne leys at different times prior to cropping. Simulations of mixed farming systems with the same soil type, crop rotation and proportional land use were conducted along a rainfall transect in a temperate environment in south-eastern Australia. Spring versus summer termination of the lucerne ley prior to cropping in autumn were compared. Although farming systems where lucerne was terminated in spring had higher crop production (mostly because of increased N at sowing) than those where lucerne was terminated in summer, the opposite was true for livestock production. Livestock production was higher in systems with summer termination mostly because of higher ewe condition scores at mating. When these sometimes positive and sometimes negative effects were evaluated at the whole of farm scale, in cases except the low rainfall site, allowing the lucerne ley to grow as late as possible prior to cropping was the most profitable management strategy in medium to high rainfall systems as it resulted in more lambs that were sold at heavier weights and the systems were more profitable, less costly, more efficient and less risky than those where leys were terminated in spring. • The decision when to remove lucerne in leys requires a whole farm analysis. • Differences in removal dates at the farm level were small and yet significant. • Land in transition presents opportunities for increasing water and N use efficiency. • Summer termination of lucerne was overall more profitable, efficient and less risky. • Perennial legume pastures need to be seen as a whole-of-farm resource. [ABSTRACT FROM AUTHOR]

The genus Micromonospora has been found in nodules of several legumes and some new species of this genus were isolated from these plant organs. In this study we analysed the taxonomic diversity of Micromonospora strains isolated from alfalfa nodules in Spain and Australia on the basis of three phylogenetic markers, the rrs and gyrB genes and 16S-23S intergenic spacer (ITS). The genome analysis of selected strains representative of different clusters or lineages found after rrs , gyrB and ITS analyses confirmed the results obtained with these phylogenetic markers. They showed that the analysed strains belong to at least 18 Micromonospora species including previously described ones, such as Micromonospora noduli , Micromonospora ureilytica , Micromonospora taraxaci , Micromonospora zamorensis , Micromonospora aurantiaca and Micromonospora tulbaghiae. Most of these strains belong to undescribed species of Micromonospora showing the high taxonomic diversity of strains from this genus inhabiting alfalfa nodules. Although Micromonospora strains are not able to induce the formation of these nodules, and it seems that they do not contribute to fix atmospheric nitrogen, they could play a role related with the mechanisms of plant growth promotion and pathogen protection presented by Micromonospora strains isolated from legume nodules. [ABSTRACT FROM AUTHOR]

Use of forage brassicas (Brassica napus) and lucerne (alfalfa; Medicago sativa) as ruminant feeds has been linked to unacceptable flavors in sheepmeat. Lambs from low and high intramuscular fat sires were allocated to one of four finishing feeds-perennial ryegrass (Lolium perenne), lucerne, and two brassica forages-for a 6 week period. Grilled loins (Longissimus thoracis et lumborum) were subjected to chemical and sensory analysis by a trained panel and also evaluated by non-Chinese and Chinese background Australian consumers. Consumer liking was similar for both groups, and liking was highest for the brassica- and lucerne-finished lamb, especially from high intramuscular fat sires. No evidence of a distinctive lucerne- or brassica-induced flavor taint was measured by the trained panel or gas chromatography-mass spectrometry-olfactometry. The diets influenced the composition of lipids and branched-chain fatty acids in the subcutaneous fat, and the concentration of total branched-chain fatty acids was positively correlated with flavor and overall liking. Significantly higher levels of key aroma volatiles were measured in the higher fat samples.