High Forage Yield Research Articles

Yield and Water Use of Siberian Wildrye with Ridge and Furrow Planting in Northern China

Siberian wildrye (Elymus sibiricus L.) is a perennial grass that is widely planted in semiarid northern China, but yield is often low due to insufficient soil water supply. Field experiments were conducted from 2009 to 2011 to study the effects of ridge and furrow planting (RFP) on yield, evapotranspiration, and water use efficiency (WUE) of Siberian wildrye grassland under rainfed conditions. The treatments included bare flat bed planting (FB), bare ridge with bare furrow (BRB), bare ridge with naked oat (Avena nuda L.) straw mulch in furrow (BRM), plastic mulch on ridge with bare furrow (MRB), and plastic mulch on ridge with straw mulch in furrow (MRM). In the RFP system, the ridge and furrow were each 30 cm wide. Total forage yield with MRB and MRM each year was 46 to 111% and 50 to 135% greater, respectively, than with FB (2580 kg ha–1 yr–1). These two treatments also increased total WUE each year by 79 to 121% and 80 to 150%, respectively, compared with FB (10.8 kg ha–1 mm–1 yr–1). The BRB and BRM treatments increased total forage yield by 47 and 81% and total WUE by 51 and 81%, respectively, compared with FB only in 2010. The addition of straw mulch did not result in a further increase in total yield or WUE. Therefore, the MRB planting system will be recommended in Siberian wildrye production for achieving relatively high forage yield and WUE.

Assessing the drought tolerance variability in Mediterranean alfalfa (Medicago sativa L.) genotypes under arid conditions

This work investigated the variability in drought tolerance under arid conditions of Mediterranean alfalfa genotypes with the overall aim to assess the main criteria that are associated with the relative tolerance and to discover the most tolerant ecotypes. For this, 16 alfalfa genotypes originating from seven countries of the Mediterranean basin were tested in an experimental station in south of Tunisia. The trial was conducted under two irrigation treatments. The first was normally irrigated by providing an amount of water corresponding to the potential evapotranspiration of the crop, and in the second with water deficit which was applied by stopping the irrigation during 8 weeks in summer. A significant decrease was observed under water deficit for biomass production, leaf stem ratio and water use efficiency. The sensitive index, in stress treatment, varies between 13.8% and 46.2% for dry yield. Results showed that some genotypes exhibited high-forage yield potential even in the presence of stress, mainly Amerist, Sardi10 and Siriver. Proline accumulation in leaves was greater in water-stressed plants, while the K+ osmo-regulatory role was not definite. High biomass production, accumulation of proline and constancy of K+ in leaves are the most important criteria for tolerant alfalfa.

Agronomic Performance and Beef Cattle Nutrition Suitability of Forage Oat Varieties Grown in the Peace Region of Alberta, Canada

The economic value of cereal forage for feeding beef cattle is dependent on both its yield and feeding value (i.e., crude protein, minerals, detergent fiber, energy, digestibility and animal performance). The objective of this study was to identify oat varieties grown in the Peace Region of Alberta, Canada, with superior forage yield and feed quality for beef cattle production. Nine oat varieties were compared in field experiments from 2009 to 2011. Significant differences between the tested oat varieties were observed for the plant height, forage dry matter (DM) yield and several of the protein, fiber, macro minerals, micro minerals, energy and digestibility parameters. Three of the 4 taller oat varieties (Murphy, Foothill, CDC Baler and Waldern) also ranked high in DM. Based on the DM data, Murphy and AC Mustang were identified as the high forage yield potential varieties in the study area. However, most of the quality indicators, used for grouping the varieties, indicated that the low potential DM group (probably due to the presence of CDC SO-I) appeared to have slightly better forage quality than the high and the medium potential forage DM yield groups. The tested oat varieties had sufficient levels of some nutrition parameters but not for some others. Because of these inconsistencies, some form of commercial mineral supplement would be required to optimize the health, growth and reproduction of beef cattle. The implications of the results obtained in this study in relation to beef cattle production system are highlighted.

Variation in yield, forage quality and morphological traits of red clover (Trifolium pratense L.) breeding populations and cultivars

The main objectives of this study were 1) to estimate variation in yield, forage quality and morphological traits of newly developed red clover (Trifolium pratense L.) breeding populations of different origin, 2) to compare their yield potential with foreign cultivars, 3) to determine the relationship between studied traits and 4) to identify and select the most promising populations for future breeding work. Eight red clover breeding populations of different origin (OPCD-2, RCOP-1,3,4,5,6,7,8 created within the framework of the forage crops breeding program at the Agricultural Institute Osijek, Croatia) and eight foreign cultivars (‘Liepsna’, ‘Kamaniai’, ‘Nosovskij 5’, ‘Pallas’, ‘Astred’, ‘Redquin’, ‘Milvus’, ‘Amos’) were evaluated for thirteen morpho-agronomic and forage quality traits. Field experiment was designed as a randomised complete block with three replications over two consecutive years (2008 and 2009) at the Agricultural Institute Osijek, Croatia. The studied breeding populations/cultivars of red clover significantly varied in yields of green mass and dry matter, plant height, number of internodes, density of hairs, width and length of central leaflet, shape of medial leaflet, leaf to stem ratio, content of crude protein and relative feed value. Croatian breeding populations RCOP-3, OPCD-2 and RCOP-1 had significantly higher total yields of green mass (from 98.50 to 111.82 t ha -1 ) and dry matter (from 22.61 to 25.64 t ha -1 ) compared to the observed yields of other populations and foreign cultivars of red clover, which indicates their high genetic potential for yield. Besides the high forage yield, those breeding populations achieved favourable values of quality and other analyzed morphological traits, and they are representing valuable germplasm for further selection work and improving of our breeding program and/or application for plant cultivar registration. Positive correlations were found between forage yields and plant height, number of internodes and between width and length of central leaflet, and these properties were positively correlated with each other. Most quality traits were in negative correlation with yield and other observed morpho-agronomic traits.

Chemical composition, in vitro digestibility and kinetics of fermentation of whole-crop forage from 18 different varieties of oat (Avena sativa L.)

The aim of this study was to compare the yield of forage and the yield of digestible organic matter as well as chemical composition and kinetics of fermentation of forage produced from 18 different varieties of oat (Avena Sativa L.) grown under the same agronomic condition. Dry matter and organic matter digestibility were determined using in vitro two-stage method and gas production technique was used to measure the kinetics of fermentation of forage from different varieties. Yield of forages varied significantly from 15.6 to 26.3 ton ha−1 DM. LGorskij 1026 variety had the highest forage yield. The content of crude protein, neutral detergent fibre (NDF), acid detergent fibre (ADF) and acid detergent lignin (ADL) were significantly (P<0.01) different among varieties of oat used in this study. There were significant (P<0.01) differences among varieties in terms of in vitro dry matter digestibility (IVDMD) and organic matter digestibility (IVOMD) and metabolisable energy (ME) from 18 varieties of oat forage. Possum and LGorskij 1026 varieties had the highest and lowest IVOMD, respectively (67/4 vs. 54/9%). The ME varied from 5.76 to 7.13 MJ kg−1 DM. The mean value of digestible organic matter (DOM) yield was 10.8 ton ha−1. LGorskij 1026 variety had the highest DOM (13.3 ton ha−1). Significant difference was observed in the potential gas production (A), constant rate (c) and lag time among different varieties. The fractional rate of gas production (c, h−1) ranged from 0.029 to 0.040. The result emphasised that in any evaluation of oat varieties, not only yield and digestibility but also kinetics of digestion or fermentation should be taken into consideration.

Advances in improving tolerance to waterlogging in Brachiaria grasses

An inter-institutional and multi-disciplinary project to identify Brachiaria genotypes, which combine waterlogging tolerance with high forage yield and quality, for use in agricultural land in Latin America with poor drainage, is underway. The aim is to improve meat and milk production and mitigate the impacts of climate change in the humid areas of Latin America. Researchers at the International Center for Tropical Agriculture (CIAT) have developed a screening method to evaluate waterlogging in grasses. Using this method, 71 promising hybrids derived from the species, Brachiaria ruziziensis , B. brizantha and B. decumbens , were evaluated. Four hybrids with superior waterlogging tolerance were identified. Their superiority was based on greater: green-leaf biomass production, proportion of green leaf to total leaf biomass, green-leaf area, leaf chlorophyll content and photosynthetic efficiency; and reduced dead-leaf biomass. These hybrids, together with previously selected hybrids and germplasm accessions, are being field-tested for waterlogging tolerance in collaboration with National Agricultural Research Institutions and farmers from Colombia, Nicaragua and Panama.

Yield and Stand Persistence of Switchgrass as Affected by Cutting Height and Variety

Switchgrass (Panicum virgatum L.) is a high-yielding forage species with low input demands on marginal soils. However, long-term response of prominent varieties to cutting heights is not well documented. To examine varietal type and cutting height impacts, three varieties of switchgrass (‘Cave-in-Rock’, ‘Kanlow’, and ‘Alamo’) that were established in 1992 for a previous study were evaluated in Knoxville, TN, from 2008 to 2011. Switchgrass plots were harvested at 10-, 20-, 30-, and 41-cm cutting heights in a two-cut system (June and September annually) to determine if lower harvest height affected forage yield and stand persistence. Plots were visually rated during the final year (2011) to assess stand vigor. Interactions were detected for total yield by cutting height and year (P < 0.05); shorter cutting heights appeared to negatively impact yields in subsequent years and the highest cutting height resulted in lower yields. However, there were no varietal yield responses to cutting heights. Shorter cutting height treatments (10 and 20 cm) had reduced Alamo and Kanlow presence (P < 0.05) by the end of the 4-yr study period. Consequently, lower switchgrass cutting heights (10 and 20 cm) may maximize short-term forage yield; however, stand persistence may be compromised long term, especially in lowland varieties.

Response of a new and a commonly grown forage sorghum cultivar to limited irrigation and planting density

Increasing scarcity of water for irrigation is one of the major challenges for forage producers in all arid and semi-arid regions. Selecting drought tolerant forage species such as sorghum (Sorghum spp. L.) over corn, as a common forage crop, could be a viable option to cope with the limited available water for irrigation and increasing the productivity in such climates. A two-year experiment was conducted during the 2009 and 2010 growing seasons to determine if limited irrigation regimes and different plant densities may produce high-yielding forage sorghum with acceptable forage quality. The experiment was arranged in a three-replicated split-plot factorial design with three irrigation regimes including optimum irrigation (when evaporation reached 70mm, using evaporation pan class “A”), moderate drought stress (100mm), and severe drought stress (130mm) as main plots. A common sorghum cultivar (Speedfeed) and a newly released cultivar (Pegah) were factorially combined with three plant densities (150,000, 200,000, and 250,000plantsha−1), as sub-plots. Results of this study indicated that forage dry matter and forage quality parameters were significantly influenced by irrigation regimes, plant densities, and cultivars. Increasing water stress from optimum irrigation (Ir70) to moderate (Ir100) and low irrigation (Ir130) resulted in 20 and 34% less forage dry matter yield. Protein yield was also lower when applying moderate and severe drought stress than with the optimum irrigation regime, whereas some forage quality parameters including crude protein, dry matter digestibility, water soluble carbohydrates, dry matter intake, relative feed value, and net energy for lactation improved when limited irrigation was imposed. Highest protein yield (1688kgha−1) was obtained from the combination of optimum irrigation regime and lowest plant density, whereas forage produced in moderate stress and low plant density was richer in relative feed value. Speedfeed outyielded Pegah cultivar and produced higher protein yield.

생태형이 다른 귀리품종의 파종기별 조사료 생산성 및 사료가치

Most oats are used for livestock feed in the world. This experiment was conducted at Iksan city of Korea from 2007 to 2008. The objective of this study was to select eminent oat (Avena sativa L.) cultivars with high-yielding and a quality for forage adaptable in each planting seasons. Experimental design was split-plot design with three replications. A split plot design was used with seeding date on the main plots and other treatments fully randomized in sub-plots. A factorial arrangement of treatments included three different ecotypes cultivars, winter type (Sanmhan, Donghan and Chohan), summer type (High-speed, Darkhorse, and Swan), and naked oats near to spring type (Daeyang, Choyang, and Sunyang) and twelve seeding dates (twice a month from March to November). Plant height, dry matter yield, and percent TDN was significantly affected by seeding dates, cultivars, and the interaction of cultivars seeding dates. There was a decrease in plant height, dry matter yield, and percent total digestible nutrients (TDN) as seeding was delayed from early March to late June and it also from early September to early November. The winter type oat cultivars such as Samhan, Donghan, and Chohan adapted to fall seeding and early summer harvest, while summer type cultivars such as High-speed, Darkhorse, and Swan showed high productivity either to summer seeding and mid-fall harvest or to spring seeding and early summer harvest. Naked type cultivars, Choyang and Daeyang, showed high forage yield by spring and summer seeding except for fall seeding because of cold damage. Summer type oat cultivars such as High-speed, Darkhorse, and Swan can supplement high forage production in spring. TDN yield showd the most at seeding in October 10 (780 kg ), followed at seeding in March 23 (627 kg ).

Plant growth promoting bacteria in Brachiaria brizantha

Brachiaria brizantha is considered one of the preferred fodders among farmers for having high forage yield and large production of root mass. The association of beneficial bacteria with these grasses can be very valuable in the recovery of the pasture areas with nutritional deficiency. With the aim of studying this possibility, we carried out the sampling of soil and roots of B. brizantha in three areas (Nova Odessa-SP, São Carlos-SP and Campo Verde-MT, Brazil). Seventy-two bacterial strains were isolated and used in tests to evaluate their biotechnological potential. Almost all isolates presented at least one positive feature. Sixty-eight isolates produced analogues of indole-3-acetic acid, ten showed nitrogenase activity when subjected to the method of increasing the concentration of total nitrogen (total N) in the culture medium and sixty-five isolates showed nitrogenase activity when subjected to acetylene reduction technique. The partial sequencing of 16S rRNA of these isolates allowed the identification of seven main groups, with the prevalence of those affiliated to the genus Stenotrophomonas (69%). At the end, this work elected the strains C4 (Pseudomonadaceae) and C7 (Rhodospirillaceae) as promising organisms for the development of inoculants due to their higher nitrogenase activity.

Produção de forragem de gramíneas anuais semeadas no verão

No Rio Grande do Sul, a base forrageira para bovinos de corte e de leite é constituída, basicamente, por pastagens de gramíneas perenes de verão, com bom valor nutritivo (VN) durante a primavera e parte do verão, quando manejadas adequadamente. Entretanto, a forragem no outono e inverno tem baixa concentração de nutrientes, o que ainda é agravado pelas geadas. Um experimento com dois anos de avaliação com parcelas divididas no delineamento em blocos casualizados, com três repetições, comparou rendimento, distribuição de forragem e valor nutritivo em três épocas de semeadura (janeiro, fevereiro e março), alocadas nas parcelas principais, e cinco genótipos (milheto comum, capim-sudão ou aveia de verão, teosinto e os híbridos de sorgo BRS 800 e AG 2501C) nas subparcelas. As duas primeiras épocas de semeadura resultaram em maior rendimento de forragem (mais de 6,0Mg ha-1 de MS) que a semeadura de março, com elevado valor nutritivo (&gt;15% PB). Os sorgos forrageiros foram mais produtivos que capim-sudão e teosinto. Milheto, capim-sudão e teosinto têm maior afilhamento que os sorgos forrageiros híbridos. Milheto tem maior teor de PB (20%) e menor de FDA (35%) nas lâminas foliares quando comparado aos sorgos e teosinto. É possível minimizar a crise forrageira conhecida como vazio forrageiro outonal com a semeadura em múltiplas datas de forrageiras anuais de verão, até o final de fevereiro na região do Planalto Médio do RS e estender o período de pastejo em até 60 dias, em período em que as pastagens perenes de verão têm baixa oferta de forragem ou baixo valor nutritivo e as forrageiras anuais de inverno não estão estabelecidas.

Ensiled sorghum and soybean as ruminant feed in the tropics, with emphasis on Cuba

AbstractThe concept is presented of combined cultivation of legumes and sorghum–maize and their use as conserved ruminant feed in tropical regions, with special reference to Cuba. Good yields are obtained during the rainy season through intercropping (alternate rows of either sorghum or maize and soybean). When followed by ensiling, this provides high‐quality ruminant feed for the tropical dry season. Soybean compensates for the low crude protein content of sorghum, whereas sorghum allows good silage quality in combination with legumes. The paper reviews and updates recent studies assessing combined sorghum–soybean cultivation and ensiling as well as determination of their feed value. The high nutritive quality and forage potential when these crops are intercropped demonstrate that silage from these plants can be used successfully in ruminant diets in Cuba and other tropical areas. Perspectives for new studies in this field are suggested, particularly with legume species that are more adapted to specific tropical regions and/or with higher forage yield. In addition, it is suggested that there is a need to assess the supplementation impact on meat and milk production at the farm level, as well as its environmental impact, when ruminants are fed combined silages from whole plants of sorghum–legumes.

The Effects of Fe, Mn and Zn Foliar Application on Yield, Ash and Protein Percentage of Forage Sorghum in Climatic Condition of Esfahan

Improving forage yield and quality remains a major concern of the producer. Among the various ways of supplying nutrient to the crops, the efficient utilization of nutrients by the plants is made through foliar application. Foliar application had significant effect on plant height, the number of leaf, the number of tiller, LAI, fresh forage yield, dry leaf yield, dry stem yield, total dry yield, dry leaf weight/dry stem weight ration and ash percentage. Application methods of micronutrients are very important to attain the best absorption. The results of this study demonstrated that, Fe, Zn and Mn had positive effect on yield and quality of forage sorghum. The highest plant height, LAI, Fresh forage yield, dry leaf and stem yield, total dry yield and dry leaf weight/dry stem weight was obtained in Zn+Fe+Mn application. The highest number of tiller was related to combination of Zn and Mn. The maximum ash percentage and appropriate protein percentage also was achieved in application of Zn+Fe+Mn. So, on the basis of the results, it seems that application Zn+Fe+Mn was suitable to gain high forage yield and gain to high quality.

Produção de biomassa de cultivares de aveia sob diferentes manejos de corte

No sistema de integração lavoura-pecuária, o manejo inadequado da aveia pode resultar em baixo rendimento de biomassa. O objetivo deste trabalho foi avaliar o efeito do manejo de cortes na produção de biomassa, em cinco cultivares de aveia com potencial de uso no sistema de integração lavoura-pecuária. O delineamento adotado foi o de blocos completos casualizados, em esquema de parcelas subdivididas, com quatro repetições. As parcelas foram representadas pelas cultivares de aveia Preta Comum, IAPAR 61, IPR 126, FAPA 2 e FUNDACEP FAPA 43. A cultivar Preta Comum apresenta ciclo curto e as demais ciclo longo. As subparcelas foram representadas pelos seguintes sistemas de corte: corte único no florescimento, um corte na fase vegetativa e outro no florescimento, dois cortes na fase vegetativa e outro no florescimento e três cortes na fase vegetativa e outro no florescimento. As cultivares de ciclo longo (IAPAR 61, IPR 126, FAPA 2 e FUNDACEP FAPA 43) alcançaram alta produção de forragem, sem comprometer a posterior produção de palhada para a cobertura do solo, evidenciando aptidão para utilização no sistema de integração lavoura-pecuária. O manejo com três cortes no estádio vegetativo maximiza a produção de forragem, no entanto, para a produção de palhada, o melhor desempenho das cultivares foi obtido no manejo com até dois cortes na fase vegetativa, ou corte único no florescimento.

Inbreeding and fertility in Egyptian clover, Trifolium alexandrinum

Selection for manual tripping (MT) was effective in improving self-fertility (SF) in all populations and generations over original parents. Selection for MT was accompanied by improving fertility of open pollinated (OP) populations. Self-seed set (ST) was very poor. Some individual selections set seeds up to 88% in MT materials. The enigma of fertility, sterility and absence of inbreeding depressions in berseem was discussed. This was explained as inbreeding tolerance, due to selection for good vigor accompanying inbreeding. The results indicated that selection for high MT seed set could be accompanied by selection for good forage yield. An approach was suggested to develop new composite varieties characterized by high seed fertility and high forage yield. Improved selections for seed production was mainly due to profuse flowering and more flowers/ inflorescence, whereas improved forage yield was mainly due to more tillers / plant and to less degree of plant height. An approach was outlined to produce new composites with high seed setting and good forage. T. alexandrinum is self-compatible, but needs tripping to stimulate self seeds. This is mainly due to the relative position of male and female organs and the presence of bubbles on stigma. Molecular characterization revealed polymorphic differences between Io and selected inbred. Key words: Trifolinm alexandrinum, fertility, yield, tripping, compatibility, inbreeding.

Alfalfa forage digestibility, quality and yield under future climate change scenarios vary with Sinorhizobium meliloti strain

Elevated CO2 may decrease alfalfa forage quality and in vitro digestibility through a drop in crude protein and an enhancement of fibre content. The aim of the present study was to analyse the effect of elevated CO2, elevated temperature and Sinorhizobium meliloti strains (102F78, 102F34 and 1032 GMI) on alfalfa yield, forage quality and in vitro dry matter digestibility. This objective is in line with the selection of S. meliloti strains in order to maintain high forage yield and quality under future climate conditions. Plants inoculated with the 102F34 strain showed more DM production than those inoculated with 1032GMI; however, these strains did not show significant differences with 102F78 plants. Neutral or acid detergent fibres were not enhanced in plants inoculated with the 102F34 strain under elevated CO2 or temperature and hence, in vitro dry matter digestibility was unaffected. Crude protein content, an indicator of forage quality, was negatively related to shoot yield. Plants inoculated with 102F78 showed a similar shoot yield to those inoculated with 102F34, but had higher crude protein content at elevated CO2 and temperature. Under these climate change conditions, 102F78 inoculated plants produced higher quality forage. However, the higher digestibility of plants inoculated with the 102F34 strain under any CO2 or temperature conditions makes them more suitable for growing under climate change conditions. In general, elevated CO2 in combination with high temperature (Climate Change scenario) reduced IVDMD and CP content and enhanced fibre content, which means that animal production will be negatively affected.

Effect of sulphur fertilizer on sulphur uptake and forage yield of Brassica juncea in condition of different regimes of irrigation

To study the effect of irrigation and sulphur on Indian mustard, a field experiment was conducted at Indian Agricultural Research Institute, New Delhi during crop season of 2007-2008 and 2008-2009. The experiment was carried out in split plot design with three replications. The treatments consisted of three levels (no irrigation, one irrigation at 45 days after sowing (DAS) and two irrigations at 45 DAS and 90 DAS) of irrigation in main plots, and four levels (0, 15, 30 and 45 kg S/ha) of sulphur in sub-plots. The results showed that in both the years of experimentation, application of two irrigations significantly increased plant height and number of primary and secondary branches per plant over one irrigation, which resulted in significantly higher dry matter accumulation and forage yield with two irrigations as compared to one irrigation. Also, application of two irrigations being on par with one irrigation, significantly increased sulphur content in forage over no irrigation, which resulted in increased sulphur uptake by crop in both the years of study. The increasing level of sulphur increased plant height, dry matter accumulation. Application of 45 kg S/ha produced more number of primary branches than control during both the years of study and other levels of sulphur remained on par with each other, whereas number of secondary branches/plant increased significantly with increasing level of sulphur up to 30 kg/ha in both the years of study. Forage yield of mustard increased significantly with the successive increase in the level of applied sulphur in both the years. Sulphur content in forage and sulphur uptake increased significantly with increasing level of sulphur. Key words: Indian mustard, irrigation, fertilizer, forage yield, sulphur uptake.

Residues from renewable energy production: Their value for fertilizing pastures

Abstract A field study was conducted to investigate the potential of residues from renewable energy production for fertilizing pastures. Six treatments including manure or biogas sludge, each combined with wood ash at 0, 1 and 3 t ha −1 were applied at the same N equivalent (190 kg N ha −1 ). Three soil samplings and two cuttings were carried out within one growing season (4 months). Plots amended with biogas sludge had a higher EC and total N, those amended with wood ash at 3 t ha −1 scored higher soil pH, EC and C/N ratio. K concentrations increased in plots amended with biogas sludge. Basal respiration, microbial biomass, metabolic quotient and C mic /C org from the differently treated soils were not influenced neither by the nature of the organic waste nor the amount of wood ash added. The time of sampling (seasonal effects) was found to influence the soil pH, EC and all the microbial parameters. A higher forage yield and lower proportion of leguminous plants was observed for soil treated with anaerobic sludge. It may be concluded that the combination of anaerobic sludge and wood ash has a double positive effect, both on some selected soil chemical parameters as well as on total forage yield. The results obtained need to be confirmed in long term experiments, and the best practice for a combined application still needs to be worked out.

Molecular diversity and population structure of the forage grass Hemarthria compressa (Poaceae) in south China based on SRAP markers

Hemarthria compressa is one of the most important and widely utilized forage crops in south China, owing to its high forage yield and capability of adaptation to hot and humid conditions. We examined the population structure and genetic variation within and among 12 populations of H. compressa in south China using sequence-related amplified polymorphism (SRAP) markers. High genetic diversity was found in these samples [percentage polymorphic bands (PPB) = 82.21%, Shannon's diversity index (I) = 0.352]. However, there was relatively low level of genetic diversity at the population level (PPB = 29.17%, I = 0.155). A high degree of genetic differentiation among populations was detected based on other measures and molecular markers (Nei's genetic diversity analysis: G(ST) = 54.19%; AMOVA analysis: F(ST) = 53.35%). The SRAP markers were found to be more efficient than ISSR markers for evaluating population diversity. Based on these findings, we propose changes in sampling strategies for appraising and utilizing the genetic resources of this species.

Bridgeview alfalfa

Acharya, S. N. and Steppuhn, H. 2012. Bridgeview alfalfa. Can. J. Plant Sci. 92: 203–206. Bridgeview salt tolerant alfalfa (Medicago sativa L.) was developed by the Agriculture and Agri-Food Canada Research Centre, Lethbridge, Alberta in cooperation with the salt laboratory at Semiarid Prairie Agricultural Research Centre, Swift Current, Saskatchewan. This synthetic cultivar, tested as SC-A101 in the Western Forage Testing System (WFTest), was developed for improved seedling vigor and high forage yield under saline conditions. This cultivar yielded about 1% better than Beaver check in the WFTest over 36 location years. The pedigree of this cultivar consists of saline tolerant selections from Apica, AC Blue J, Barrier, Beaver, Heinrichs, Rangelander and Roamer alfalfa. This cultivar produced higher dry matter yield than Beaver in the third year of a test conducted in a naturally saline seep area in Vauxhall, AB. SC-A101 was found to perform significantly higher emergence, survival and biomass production than Rangelander alfalfa in an indoor test at salt levels higher than 16 dS m−8. Bridgeview was registered by CFIA on 2011 May 16 (Reg. No. 7018) and was licensed to SeCan for seed multiplication and distribution. This cultivar is well suited for hay production in western Canada.