The through chain approach to livestock production places increased emphasis on on-farm management systems for addressing pesticide residues. The current risk management paradigm assumes the user of animal feeds has the ability to assess, or at least profile, risks to trade in animal commodities associated with feeding livestock material containing residues of pesticides. The paper details some approaches that may be used by livestock producers, focusing on simple calculations, and summarises available information needed as inputs. Calculated factors for the transfer of pesticides from feed to animal commodities (transfer factors) are summarised for about 150 pesticides.
{"title":"Estimating the residue transfer of pesticides in animal feedstuffs to livestock tissues, milk and eggs: a review","authors":"D. Maclachlan, R. Bhula","doi":"10.1071/EA07196","DOIUrl":"https://doi.org/10.1071/EA07196","url":null,"abstract":"The through chain approach to livestock production places increased emphasis on on-farm management systems for addressing pesticide residues. The current risk management paradigm assumes the user of animal feeds has the ability to assess, or at least profile, risks to trade in animal commodities associated with feeding livestock material containing residues of pesticides. The paper details some approaches that may be used by livestock producers, focusing on simple calculations, and summarises available information needed as inputs. Calculated factors for the transfer of pesticides from feed to animal commodities (transfer factors) are summarised for about 150 pesticides.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"589-598"},"PeriodicalIF":0.0,"publicationDate":"2008-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07196","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58793101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Holroyd, V. J. Doogan, M. Jeffery, J. Lindsay, B. Venus, G. Bortolussi
This experiment tested the hypothesis that relocating cattle is detrimental to their growth. The study examined the effect of having relocated cattle mixed with, or segregated from, the local acclimatised cattle at the destination property. Bos indicus cross steers (120) were allocated to three groups and were relocated, in two separate cohorts, 980 km from northern Queensland to improved pastures in central Queensland. At the start of Phase 1, the control group (C) was moved 3 months before the other two groups. The remaining two groups grazed native pastures; one group was supplemented (SR) to increase growth rate similar to that expected from improved pasture in central Queensland and the other was not supplemented (R). At the end of Phase 1, C was significantly (P < 0.05) heavier than SR, which was significantly (P < 0.05) heavier than R. At the start of Phase 2, the SR and R groups were relocated and after transportation the R and SR groups lost 12 kg or 4.4% of liveweight and 18 kg or 5.7% of liveweight, respectively; this weight loss was recovered after 5 days. All steers were reallocated to segregated (SEG) or mixed (MIX) treatment groups forming six treatments (SEG.C, SEG.R and SEG.SR and MIX.C, MIX.R and MIX.SR). There were no significant differences in liveweights within the SEG treatments by 57 days or within the MIX treatments by 106 days after relocation. There were few if any significant differences in the plasma constituents and differential leucocyte counts of the steers and most results were within physiologically normal ranges. We conclude on the basis of these results and of other experiments that the anecdotal poor performance of cattle after relocation appears to be unfounded.
{"title":"Relocation does not have a significant effect on the growth rate of Bos indicus cross steers","authors":"R. Holroyd, V. J. Doogan, M. Jeffery, J. Lindsay, B. Venus, G. Bortolussi","doi":"10.1071/EA07154","DOIUrl":"https://doi.org/10.1071/EA07154","url":null,"abstract":"This experiment tested the hypothesis that relocating cattle is detrimental to their growth. The study examined the effect of having relocated cattle mixed with, or segregated from, the local acclimatised cattle at the destination property. Bos indicus cross steers (120) were allocated to three groups and were relocated, in two separate cohorts, 980 km from northern Queensland to improved pastures in central Queensland. At the start of Phase 1, the control group (C) was moved 3 months before the other two groups. The remaining two groups grazed native pastures; one group was supplemented (SR) to increase growth rate similar to that expected from improved pasture in central Queensland and the other was not supplemented (R). At the end of Phase 1, C was significantly (P < 0.05) heavier than SR, which was significantly (P < 0.05) heavier than R. At the start of Phase 2, the SR and R groups were relocated and after transportation the R and SR groups lost 12 kg or 4.4% of liveweight and 18 kg or 5.7% of liveweight, respectively; this weight loss was recovered after 5 days. All steers were reallocated to segregated (SEG) or mixed (MIX) treatment groups forming six treatments (SEG.C, SEG.R and SEG.SR and MIX.C, MIX.R and MIX.SR). There were no significant differences in liveweights within the SEG treatments by 57 days or within the MIX treatments by 106 days after relocation. There were few if any significant differences in the plasma constituents and differential leucocyte counts of the steers and most results were within physiologically normal ranges. We conclude on the basis of these results and of other experiments that the anecdotal poor performance of cattle after relocation appears to be unfounded.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"608-614"},"PeriodicalIF":0.0,"publicationDate":"2008-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58792448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two batches of sorghum infected with ergot were incorporated into nutritionally balanced grower and finisher diets that contained 0, 5 or 10 mg alkaloid/kg (0, 4 or 8 mg dihydroergosine/kg), or 10 mg alkaloid/kg (8 mg dihydroergosine/kg) plus 1% zeolite. The contents of ergot sclerotia in the 10 mg/kg diets were ~2% in one batch and 4% in the other; the latter batch had a heavy secondary fungal infection of Cerebella sp., which tends to limit alkaloid accumulation. These diets were each fed to four male and four female pigs as they grew from 20 to 90 kg. There were no deleterious effects on growth, feed intake and conversion even with lower plasma prolactin of 0.1 µg/L in ergot-fed pigs compared with ~1 µg/L in the control pigs. Zeolite did not counteract the ergot reduction of prolactin and had no effect on performance. Male pigs were then slaughtered, but females continued to be fed the diets for a further 3 months, when they were brought into oestrus and artificially inseminated. One month after pregnancy was confirmed, they were slaughtered and fertility was assessed. There were no significant differences in the numbers of corpora lutea or embryos between pigs fed ergot and control diets.
{"title":"Tolerance of pigs to sorghum ergot (Claviceps africana) during growth and finishing, and effect on conception of replacement gilts","authors":"J. Kopinski, B. Blaney, J. Downing","doi":"10.1071/EA07326","DOIUrl":"https://doi.org/10.1071/EA07326","url":null,"abstract":"Two batches of sorghum infected with ergot were incorporated into nutritionally balanced grower and finisher diets that contained 0, 5 or 10 mg alkaloid/kg (0, 4 or 8 mg dihydroergosine/kg), or 10 mg alkaloid/kg (8 mg dihydroergosine/kg) plus 1% zeolite. The contents of ergot sclerotia in the 10 mg/kg diets were ~2% in one batch and 4% in the other; the latter batch had a heavy secondary fungal infection of Cerebella sp., which tends to limit alkaloid accumulation. These diets were each fed to four male and four female pigs as they grew from 20 to 90 kg. There were no deleterious effects on growth, feed intake and conversion even with lower plasma prolactin of 0.1 µg/L in ergot-fed pigs compared with ~1 µg/L in the control pigs. Zeolite did not counteract the ergot reduction of prolactin and had no effect on performance. Male pigs were then slaughtered, but females continued to be fed the diets for a further 3 months, when they were brought into oestrus and artificially inseminated. One month after pregnancy was confirmed, they were slaughtered and fertility was assessed. There were no significant differences in the numbers of corpora lutea or embryos between pigs fed ergot and control diets.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"672-679"},"PeriodicalIF":0.0,"publicationDate":"2008-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58797611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many plant species with agronomic potential have been introduced for livestock forage and have subsequently become weeds of natural ecosystems, or ‘environmental weeds’. Stringent border quarantine procedures introduced by Australia in 1997 ensure few high weed risk species are now imported into the country; however, there are no protocols for assessing and managing weed risk in use on a national scale ‘post-border’ (i.e. once a plant species is in the country). Environmental weed risk management in forage improvement programs aims to minimise the risk that new species and cultivar introductions will be invasive in natural ecosystems. We describe an environmental weed risk assessment (EWRA) model specifically aimed at assessing the weed potential of exotic and native forage species. The EWRA model predicts and ranks species for weed risk by assessing invasiveness, impacts and potential distribution. Assessments are based on published evidence, experimental observations and intuitive responses from experienced pasture researchers, in collaboration with weed experts. This model specifically addresses the need for environmental weed risk management in forage improvement programs.
{"title":"An environmental weed risk assessment model for Australian forage improvement programs","authors":"L. Stone, M. Byrne, J. Virtue","doi":"10.1071/EA07117","DOIUrl":"https://doi.org/10.1071/EA07117","url":null,"abstract":"Many plant species with agronomic potential have been introduced for livestock forage and have subsequently become weeds of natural ecosystems, or ‘environmental weeds’. Stringent border quarantine procedures introduced by Australia in 1997 ensure few high weed risk species are now imported into the country; however, there are no protocols for assessing and managing weed risk in use on a national scale ‘post-border’ (i.e. once a plant species is in the country). Environmental weed risk management in forage improvement programs aims to minimise the risk that new species and cultivar introductions will be invasive in natural ecosystems. We describe an environmental weed risk assessment (EWRA) model specifically aimed at assessing the weed potential of exotic and native forage species. The EWRA model predicts and ranks species for weed risk by assessing invasiveness, impacts and potential distribution. Assessments are based on published evidence, experimental observations and intuitive responses from experienced pasture researchers, in collaboration with weed experts. This model specifically addresses the need for environmental weed risk management in forage improvement programs.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"568-574"},"PeriodicalIF":0.0,"publicationDate":"2008-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07117","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58791155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Nichols, A. D. Craig, M. Rogers, T. Albertsen, S. Miller, D. Mcclements, S. Hughes, M. D’Antuono, B. Dear
Herbage production and persistence of 42 annual pasture legumes from 33 species were measured at five sites across southern Australia. Medicago polymorpha L. was highly productive on soils, particularly those not prone to waterlogging, with soil surface (0–10 cm soil depth) salinity [estimated by electrical conductivity (ECe)] levels in summer of up to 36 dS/m, whereas M. truncatula Gaertn. was productive on ECe levels of at least 11 dS/m. Trifolium michelianum Savi and T. resupinatum L. were highly productive on soils subject to waterlogging, but only where 0–10 cm summer ECe levels were less than 8 dS/m. No commercial species were adapted to highly saline (0–10 cm summer ECe levels >8 dS/m), waterlogged sites. However, Melilotus siculus (Turra) Vitman ex B.D. Jacks. has the potential to fulfil this role, provided an appropriate Rhizobium strain can be selected. Mixtures of species and cultivars should be sown to account for high spatial variability for salinity and waterlogging. Traits for annual legume success in saline landscapes include salinity and waterlogging tolerance in germinating seedlings and mature plants, early flowering, hardseededness and delayed softening of hard seeds. Establishment of regenerating seedlings is associated with the timing of hardseed softening in relation to rainfall events capable of leaching topsoil salts. It is proposed that salinity measurements to determine annual legume suitability for winter-dominant rainfall areas are made in summer or early autumn, when at their highest levels. Transects along salinity and waterlogging gradients are suggested as an alternative method to traditional plots for genotype evaluation.
{"title":"Production and persistence of annual pasture legumes at five saline sites in southern Australia","authors":"P. Nichols, A. D. Craig, M. Rogers, T. Albertsen, S. Miller, D. Mcclements, S. Hughes, M. D’Antuono, B. Dear","doi":"10.1071/EA07167","DOIUrl":"https://doi.org/10.1071/EA07167","url":null,"abstract":"Herbage production and persistence of 42 annual pasture legumes from 33 species were measured at five sites across southern Australia. Medicago polymorpha L. was highly productive on soils, particularly those not prone to waterlogging, with soil surface (0–10 cm soil depth) salinity [estimated by electrical conductivity (ECe)] levels in summer of up to 36 dS/m, whereas M. truncatula Gaertn. was productive on ECe levels of at least 11 dS/m. Trifolium michelianum Savi and T. resupinatum L. were highly productive on soils subject to waterlogging, but only where 0–10 cm summer ECe levels were less than 8 dS/m. No commercial species were adapted to highly saline (0–10 cm summer ECe levels >8 dS/m), waterlogged sites. However, Melilotus siculus (Turra) Vitman ex B.D. Jacks. has the potential to fulfil this role, provided an appropriate Rhizobium strain can be selected. Mixtures of species and cultivars should be sown to account for high spatial variability for salinity and waterlogging. Traits for annual legume success in saline landscapes include salinity and waterlogging tolerance in germinating seedlings and mature plants, early flowering, hardseededness and delayed softening of hard seeds. Establishment of regenerating seedlings is associated with the timing of hardseed softening in relation to rainfall events capable of leaching topsoil salts. It is proposed that salinity measurements to determine annual legume suitability for winter-dominant rainfall areas are made in summer or early autumn, when at their highest levels. Transects along salinity and waterlogging gradients are suggested as an alternative method to traditional plots for genotype evaluation.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"518-535"},"PeriodicalIF":0.0,"publicationDate":"2008-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07167","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58792573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Medicago sativa L. is the most widely sown perennial forage legume in farming systems of southern Australia. However, M. sativa lacks adaptation to winter waterlogged conditions. This constraint has highlighted the need for new perennial forage legumes adapted to winter waterlogged conditions and to locations where the summer is too dry for the survival of Trifolium repens L. and T. fragiferum L. To explore new perennial legume options suitable for these circumstances, 10 species of Lotus were evaluated for waterlogging tolerance including: two accessions of L. corniculatus L., four accessions of L. tenuis Waldst. & Kit., two accessions of L. pedunculatus Cav., two accessions of L. australis Andrew, three accessions of L. creticus L., three accessions of L. glaucus Sol., one accession of L. cruentus Court., one accession of L. argyrodes R.P. Murray, one accession of L. campylocladus Webb & Berthel and one accession of L. latifolius Brand. These were compared with the M. sativa cultivar Sceptre. The ability to grow in waterlogged conditions, and to recover, was assessed in a pot experiment conducted over 19 weeks. The Lotus species most tolerant of waterlogging were L. corniculatus, L. tenuis and L. pedunculatus. Each of these species developed aerenchyma, adventitious roots, surface roots and split stems at the base to improve oxygen transport into the roots. Significant intra-species variation was also found within each of the three tolerant species, highlighting the opportunity for genetic improvement. By comparison, the remaining Lotus species were susceptible to waterlogging and showed poor recovery, whereas M. sativa Sceptre partially recovered after waterlogging.
{"title":"Waterlogging tolerance and recovery of 10 Lotus species","authors":"D. Real, J. Warden, G. Sandral, T. Colmer","doi":"10.1071/EA07110","DOIUrl":"https://doi.org/10.1071/EA07110","url":null,"abstract":"Medicago sativa L. is the most widely sown perennial forage legume in farming systems of southern Australia. However, M. sativa lacks adaptation to winter waterlogged conditions. This constraint has highlighted the need for new perennial forage legumes adapted to winter waterlogged conditions and to locations where the summer is too dry for the survival of Trifolium repens L. and T. fragiferum L. To explore new perennial legume options suitable for these circumstances, 10 species of Lotus were evaluated for waterlogging tolerance including: two accessions of L. corniculatus L., four accessions of L. tenuis Waldst. & Kit., two accessions of L. pedunculatus Cav., two accessions of L. australis Andrew, three accessions of L. creticus L., three accessions of L. glaucus Sol., one accession of L. cruentus Court., one accession of L. argyrodes R.P. Murray, one accession of L. campylocladus Webb & Berthel and one accession of L. latifolius Brand. These were compared with the M. sativa cultivar Sceptre. The ability to grow in waterlogged conditions, and to recover, was assessed in a pot experiment conducted over 19 weeks. The Lotus species most tolerant of waterlogging were L. corniculatus, L. tenuis and L. pedunculatus. Each of these species developed aerenchyma, adventitious roots, surface roots and split stems at the base to improve oxygen transport into the roots. Significant intra-species variation was also found within each of the three tolerant species, highlighting the opportunity for genetic improvement. By comparison, the remaining Lotus species were susceptible to waterlogging and showed poor recovery, whereas M. sativa Sceptre partially recovered after waterlogging.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"480-487"},"PeriodicalIF":0.0,"publicationDate":"2008-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07110","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58791427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Nichols, M. Rogers, A. D. Craig, T. Albertsen, S. Miller, D. Mcclements, S. Hughes, M. D’Antuono, B. Dear
Herbage production and persistence of 24 perennial legumes from 20 species and 19 perennial grasses from 10 species were measured at five sites across southern Australia that differed in annual rainfall and extent of salinity and waterlogging. At Cranbrook, Western Australia, a site with occasional waterlogging and a summer salinity [estimated by electrical conductivity (ECe)] of 6.9 dS/m in the surface 10 cm of soil, strawberry clover (Trifolium fragiferum L.) and Lotus uligonosis Schkuhr produced 2.7 t/ha in the second year and had the highest legume plant frequencies in year 3, while herbage production of L. tenuis Waldst. & Kit. ex Willd. and L. corniculatus L. was not significantly lower. No grasses produced more than 0.3 t/ha in the second year, but tall wheatgrass (Thinopyrum ponticum (Podp.) Z.-W. Liu & R.-C. Wang) was the most persistent. At Girgarre, Victoria, another site with occasional waterlogging and a summer ECe of 8.0 dS/m, phalaris (Phalaris aquatica L.) produced 8.5 t/ha in the second year, while production of tall wheatgrass and perennial ryegrass (Lolium perenne L.) was not significantly lower. Sulla (Hedysarum coronarium L.) was the only legume that produced more than 1 t/ha. Phalaris, tall wheatgrass and sulla had the highest densities in the third year. At Duranillin (Western Australia) and Keith (South Australia), which both experienced extensive winter waterlogging and had summer ECe >30 dS/m, puccinellia (Puccinellia ciliata Bor) and tall wheatgrass were the only grass or legume species that persisted beyond the first summer. Puccinellia was the only species to produce useful quantities of herbage (1.0 t/ha) in year 3 at Duranillin. No perennial grasses or legumes produced more than 0.35 t/ha in either year 2 or year 3 at Tammin, Western Australia, the lowest rainfall site (330 mm mean annual rainfall) with summer ECe of 10.9 dS/m. Genotypic differences within sites were indicated for several species, suggesting opportunities to develop cultivars better adapted to saline soils
{"title":"Production and persistence of temperate perennial grasses and legumes at five saline sites in southern Australia","authors":"P. Nichols, M. Rogers, A. D. Craig, T. Albertsen, S. Miller, D. Mcclements, S. Hughes, M. D’Antuono, B. Dear","doi":"10.1071/EA07168","DOIUrl":"https://doi.org/10.1071/EA07168","url":null,"abstract":"Herbage production and persistence of 24 perennial legumes from 20 species and 19 perennial grasses from 10 species were measured at five sites across southern Australia that differed in annual rainfall and extent of salinity and waterlogging. At Cranbrook, Western Australia, a site with occasional waterlogging and a summer salinity [estimated by electrical conductivity (ECe)] of 6.9 dS/m in the surface 10 cm of soil, strawberry clover (Trifolium fragiferum L.) and Lotus uligonosis Schkuhr produced 2.7 t/ha in the second year and had the highest legume plant frequencies in year 3, while herbage production of L. tenuis Waldst. & Kit. ex Willd. and L. corniculatus L. was not significantly lower. No grasses produced more than 0.3 t/ha in the second year, but tall wheatgrass (Thinopyrum ponticum (Podp.) Z.-W. Liu & R.-C. Wang) was the most persistent. At Girgarre, Victoria, another site with occasional waterlogging and a summer ECe of 8.0 dS/m, phalaris (Phalaris aquatica L.) produced 8.5 t/ha in the second year, while production of tall wheatgrass and perennial ryegrass (Lolium perenne L.) was not significantly lower. Sulla (Hedysarum coronarium L.) was the only legume that produced more than 1 t/ha. Phalaris, tall wheatgrass and sulla had the highest densities in the third year. At Duranillin (Western Australia) and Keith (South Australia), which both experienced extensive winter waterlogging and had summer ECe >30 dS/m, puccinellia (Puccinellia ciliata Bor) and tall wheatgrass were the only grass or legume species that persisted beyond the first summer. Puccinellia was the only species to produce useful quantities of herbage (1.0 t/ha) in year 3 at Duranillin. No perennial grasses or legumes produced more than 0.35 t/ha in either year 2 or year 3 at Tammin, Western Australia, the lowest rainfall site (330 mm mean annual rainfall) with summer ECe of 10.9 dS/m. Genotypic differences within sites were indicated for several species, suggesting opportunities to develop cultivars better adapted to saline soils","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"536-552"},"PeriodicalIF":0.0,"publicationDate":"2008-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07168","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58792113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Increasing the proportion of the landscape planted to deep-rooted perennial pasture species is recognised as one of several remedial actions required for the control of dryland salinity in southern Australia. The widespread use of perennials in farming systems is limited at present by the lack of well-adapted perennials that can be grown to reduce recharge in a landscape where drought, soil acidity, temporary waterlogging, infertile soils and unrestricted grazing prohibit the use of many species. The range of plants adapted to salinity also needs to be expanded to stabilise and ameliorate soils already degraded by rising watertables and to increase the profitability of grazing discharge regions within the landscape. This paper describes the steps involved in a national forage screening and breeding program initiated by the Cooperative Research Centre (CRC) for Plant-based Management of Dryland Salinity1, seeking to expand the range of perennial and or salt-tolerant forage plants that can be incorporated into farming systems of southern Australia. It describes the target environments, soil constraints, farming systems and the criteria being considered when assessing the potential of new plants, including assessment of the weed risk posed by introducing new species. This paper forms an introduction to a special issue which presents the outcomes of the pasture species field evaluation and plant breeding program conducted by the CRC.
{"title":"The search for new pasture plants to achieve more sustainable production systems in southern Australia","authors":"B. Dear, M. Ewing","doi":"10.1071/EA07105","DOIUrl":"https://doi.org/10.1071/EA07105","url":null,"abstract":"Increasing the proportion of the landscape planted to deep-rooted perennial pasture species is recognised as one of several remedial actions required for the control of dryland salinity in southern Australia. The widespread use of perennials in farming systems is limited at present by the lack of well-adapted perennials that can be grown to reduce recharge in a landscape where drought, soil acidity, temporary waterlogging, infertile soils and unrestricted grazing prohibit the use of many species. The range of plants adapted to salinity also needs to be expanded to stabilise and ameliorate soils already degraded by rising watertables and to increase the profitability of grazing discharge regions within the landscape. This paper describes the steps involved in a national forage screening and breeding program initiated by the Cooperative Research Centre (CRC) for Plant-based Management of Dryland Salinity1, seeking to expand the range of perennial and or salt-tolerant forage plants that can be incorporated into farming systems of southern Australia. It describes the target environments, soil constraints, farming systems and the criteria being considered when assessing the potential of new plants, including assessment of the weed risk posed by introducing new species. This paper forms an introduction to a special issue which presents the outcomes of the pasture species field evaluation and plant breeding program conducted by the CRC.","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":"387-396"},"PeriodicalIF":0.0,"publicationDate":"2008-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1071/EA07105","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58790859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Scott, M. Ewing, R. Williams, A. Humphries, N. Coombes
A rapid (7 day) solution-based screening test was developed using 15 annual Medicago cultivars and one M. sativa. Based on a relative root regrowth after exposures to aluminium (Al), Zodiac (M. murex), Orion (M. sphaerocarpos) and the M. polymorha cultivars Santiago, Cavalier and Serena had the greatest Al tolerance. Herald (M. littoralis) and Rivoli (M. tornata) were most sensitive. Ranking for Al tolerance from the solution culture correlated well (r = 0.80) with ranking for tolerance of the 16 genotypes grown in an acidic soil (unlimed pHCa 4.1). We screened 17 Australian populations of lucerne (M. sativa) using a 24 h ‘pulse’ of 75 µmol/L Al, and a three day ‘recovery’ of 10 µmol/L Al. We identified and recovered plants with a root regrowth of ≥5 mm in all 17 populations with selection intensities of 2 to 4%. Four of these selected populations (Aurora, UQL-1, A513 and TO2-011) were polycrossed within each population to produce four populations of seed from the cycle 1 selections. The length of root regrowth under Al stress was improved for all four populations of cycle 1 selection (P ≤ 0.001; from 2.6 mm for the original populations to 6.3 mm for the cycle 1 selections). In a subsequent experiment the cycle 2 selections from Aurora, UQL-1 and TO2-011 had significantly greater root regrowth than both the cycle 1 selections (P ≤ 0.001; 8.3 cf. 6.6 mm) and the unselected populations (3.0 mm). The selections from TO2-011 appeared to have greater improvement in the average length of root regrowth after 2 cycles of selection. Selected germplasm was more tolerant than GAAT in our evaluation. Based on estimation of realised heritability, it seemed likely that higher selection intensities would give more rapid improvements in tolerance. Our studies have not investigated the physiological basis of any tolerance of Al which we observed.
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{"title":"Foreword to 'Sustainable Pastures in Marginal Environments'","authors":"K. Goss","doi":"10.1071/EA07370_FO","DOIUrl":"https://doi.org/10.1071/EA07370_FO","url":null,"abstract":"","PeriodicalId":8636,"journal":{"name":"Australian Journal of Experimental Agriculture","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2008-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"58797850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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