Plant Pathology Commons^™

Selection For Improved Saccharification Efficiency In Alfalfa Stems Assessed By Enzyme-Released Glucose, Annick Bertrand, Yves Castonguay, Réal Michaud, Marc-Olivier Duceppe

IGC Proceedings (1977-2023)

Alfalfa (Medicago sativa L.) has a high potential for sustainable bioethanol production, particularly because of its low reliance on N fertilizer (Samac et al. 2006). Genetic improvement for the accumulation of readily fermentable non-structural carbohydrates (NSC) and the saccharification of structural carbohydrate (SC) could significantly increase ethanol conversion rate. Genetic gains for these traits are tributary to the availability of screening techniques for the precise identification of superior genotypes with increased potential for the production of fermentable carbohydrates.

When assessing the genetic variability of parameters linked to cellulosic ethanol production (concentrations of NSC and SC), our results showed …

Three Dimensional (3d) Reconstruction Of Subterranean Clover, Helen G. Daily, Jianming Guo, Xavier R. R. Sirault

IGC Proceedings (1977-2023)

Three dimensional (3D) plant reconstructions, extended to four dimensions with the use of time series and accompanied by visual modelling, is being used for a number of purposes including the estimation of biovolume and as the basis for functional structural plant modelling (FSPM). This has been successfully applied to crop species such as cotton (Paproki et al. 2012). Measuring the growth pattern and arrangement of a pasture sward is a difficult task but can be used as an indirect measure of other variables of interest, such as growth rate, light interception, nutritional quality, herbivore intake, etc. (Laca and …

Simulating Tall Fescue Pasture Growth In Argentina, Horacio Berger, Claudio F. Machado, Mónica G. Agnusdei, Brendan R. Cullen

IGC Proceedings (1977-2023)

Tall fescue (Festuca arundinacea Schreb) pastures have the potential to maintain high production rates under limiting climate conditions, especially in dry summers, improving the seasonal distribution of forage growth and year round production (Tharmaraj et al. 2008). The purpose of this work was to test the ability and flexibility of the DairyMod biophysical pasture-simulation model (Johnson et al. 2008), to predict herbage mass accumulation (HMA), of tall fescue pastures from Argentina under several environmental conditions that included different seasons, nitrogen fertilizer application levels and irrigation.

Physiological Characterization Of Cut-To-Cut Yield Variations Of Alfalfa Genotypes Under Controlled Greenhouse Conditions, Defeng Li, Baoluo Ma, Chengzhang Wang, Pufang Li

IGC Proceedings (1977-2023)

In a temperate region, alfalfa (Medicago sativa) crops are usually harvested 3-6 times per annum. The biomass yields of first and second cuts in the spring are generally the high-est. However, in subsequent cuts the biomass yields decline, with the final 1 or 2 cuts producing the lowest yields (Wang et al. 2009). This seasonal reduction in alfalfa biomass yields could be associated with prevailing changes in environmental factors such as rainfall and heat stress or due to biological characteristics of alfalfa crop itself. In this study, alfalfa was grown under controlled greenhouse conditions with suitable temperature, …

Biomass Yield And Nutritive Quality Of Panicum Maximum In The Natural Pastures During The Dry Season In Abeokuta, Nigeria, Adetayo B. Adekeye, Olufemi S. Onifade, Jimoh A. Olanite, Olubukola A. Isah

IGC Proceedings (1977-2023)

Panicum maximum Jacq. is among the prominent grass species in the grazing lands of the South-western part of Nigeria. An understanding of cutting management to find out the best agronomic practices that will improve the yield and nutritive value of these grass species, especially in the dry season formed the focus of this research work. The objective of the research is therefore to evaluate the effects of cutting height and interval on the dry matter yield (DMY), digestibility and chemical composition of P. maximum in the natural pasture during the dry season.

Pattern Of Hard Seed Breakdown In Some Annual Self-Reseeding Legumes Under Mediterranean Field Conditions, Claudio Porqueddu, Antonello Franca, Rita A. M. Melis, Leonardo Sulas, Giovanni A. Re

IGC Proceedings (1977-2023)

In the last decade a new generation of annual pasture legumes was released and introduced in the seed market for the Australian ley systems. In Sardinia (Italy), despite good agronomic performances in the first year, several of these new varieties showed low autumn re-establishment, reducing their competitiveness against native species and depressing any attempt for a long term pasture improvement (Porqueddu et al. 2010). Hardseedness may influence legume persistence. A study on the pattern of hard seed breakdown on some self-reseeding annual pasture legumes was carried out.

Perennial Legume Swards For Organic Farming System In Lithuania, Jonas Šlepetys, Alvyra Slepetiene

IGC Proceedings (1977-2023)

The economic and ecological benefits of forage legumes are well known. While perennial legumes can be useful in various aspects (Ledgard 2001), some legumes have short persistence in swards (Frame et al.1998; Vaiciulyte and Bacenas 2008) which is undesirable for organic farms where no mineral nitrogen is applied. Early flowering red clover (Trifolium pratense), which is the most common legume in Lithuania, has high yields only in the first – second years of use. In the third year, it often disappears completely.

In Lithuania, fodder galega (Galega orientalis) is the most long lived legume exhibiting …

Ryegrass Seeding Rate Alters Plant Morphology And Size--Possible Implications For Pasture Persistence, Julia M. Lee, Errol R. Thom, David F. Chapman, Kate T. Wynn, C. Deanne Waugh, Laura Rossi

IGC Proceedings (1977-2023)

Poor persistence of perennial ryegrass (Lolium perenne L.) is a major dairy industry issue in New Zealand and Australia. New ryegrass seed is often drilled at 18-30 kg/ha, although previous research indicated that pastures drilled at 10-12 kg/ha can be just as productive (Frame and Boyd 1986; Praat et al. 1996). High seeding rates increase competition between developing seedlings for light, water and nutrients, reduce plant size (Harris 1990) and potentially survival.

The experiment reported here investigated the effect of plant density (created by differences in seeding rate) on plant morphology and survival. The hypothesis was that plants …

Trifolium Occidentale: A Valuable Genetic Resource For White Clover Improvement, Syed Wajid Hussain, Warren M. Williams

IGC Proceedings (1977-2023)

Trifolium occidentale Coombe is a stoloniferous, diploid (2n=2x=16) perennial clover indigenous to Portugal, Spain, France, and the British Isles. It grows in relatively dry coastal habitats, in sand dunes and on shallow pocket of soil (Coombe 1961; Coombe and Morisset 1967). As the species grows naturally in saline, dry habitats, it is potentially a source of drought tolerance genes that could be used for the improvement of white clover (Trifolium repens L.) cultivars. Although T. occidentale is reported to be one of the progenitors of white clover (Williams et al. 2012), the 2x forms of T. occidentale cross …

Dry Matter Yield Of Perennial Ryegrass Cultivars Under Mechanical Cutting And Animal Grazing, Patrick A. Cashman, Trevor J. Gilliland, Michael O’Donovan, Marion Beecher, Mary Mcevoy

IGC Proceedings (1977-2023)

Perennial ryegrass evaluation trials are essential to identifying and promoting the most productive cultivars for use at farm level to maximise sward productivity (Grogan and Gilliland 2011). Cultivar testing is predominantly conducted under simulated grazing trials to predict dry matter yield (DMY) performance under animal grazing. Previous studies have shown a high correlation in DMY between these two defoliation methods (Camlin and Stewart 1975; Creighton et al. 2010). In contrast, Binnie and Chestnutt (1991) demonstrated that swards grazed by animals had higher DMY performance than those exposed to simulated grazing managements. Animal pressures such as pulling, treading and nutrient …

Fodder Yield And Quality Of Lucerne (Medicago Sativa) Grown As Pure Stands And In Mixture With Oats (Avena Sativa), Mustard (Brassica Campestris) And Ryegrass (Lolium Perenne) Under Different Cutting Managements, Balwinder Kumar, U. S. Tiwana, Ajaib Singh

IGC Proceedings (1977-2023)

Legume-cereal mixtures are important protein and carbohydrate sources for livestock and provide a balanced chemical composition for livestock feeding along with higher green forage yields than the pure stands (Berdahl et al. 2001; Albayrak and Ekiz, 2005). Lucerne is the most important rabi legume crop of Punjab grown under limited irrigation conditions and provides succulent, palatable and nutritious fodder to dairy animals. The fodder yield of first cut of lucerne is very low so it is usually grown in mixture with oats and or mustard. The information on the mixtures of lucerne and suitable cutting times is scant. This …

Hybrid And Perennial Tetraploid Ryegrasses Are At Least As Productive And Persistent As Perennial Diploids In Dryland Conditions In Northern Tasmania, Pedro M. Evans, Eric J. Hall

IGC Proceedings (1977-2023)

Perennial ryegrass Lolium perenne is the preferred grass for fertile conditions and high rainfall areas or those with irrigation. Persistence of ryegrass can become a problem in drier and warmer areas (Fraser 1994). Even in high rainfall areas of south eastern Australia receiving between 550 and 750 mm of annual rainfall, loss of perennial ryegrass within a few years from sowing is a common problem (Waller and Sale 2001).

This work aimed to examine the ability of a range of lines and cultivars of ryegrass to produce and persist under dryland conditions and rotational grazing by sheep in northern Tasmania, …

Tedera: From A Promising Novel Species To A Commercial Pasture Option For Mediterranean Southern Australia, Daniel Real, Chris Oldham, Matthew N. Nelson, Janine Croser, Marie-Claire Castello, Steve Gherardi, John Finlayson, Clinton K. Revell, Aneeta Pradhan, Graham O'Hara, Enrique Correal

IGC Proceedings (1977-2023)

Tedera (Bituminaria bituminosa var. albomarginata and var. crassiuscula) is a traditional forage species used for centuries in the Canary Islands (Méndez and Fernández 1990), that has increasingly attracted interest from researchers in regions with Mediterranean-type climates from Spain, Italy, Israel, Greece, Portugal, Morocco, Turkey and Australia. In 2000, Australian pasture researchers started a large and systematic screening process that evaluated about 720 species of exotic and native legumes, grasses and herbs for adaptation and productivity in Mediterranean and temperate environments (Real et al. 2011). Tedera was one of the few novel perennial legumes to show potential for …

Genetic Maps Of Diploid Orchardgrass (Dactylis Glomerata L.), Wengang Xie, Xinquan Zhang, Linkai Huang, Peng Yan

IGC Proceedings (1977-2023)

Orchardgrass (Dactylis glomerata L.) is indigenous to Eurasia and northern Africa. It has been naturalized on nearly every continent and is one of the top four economically important perennial forage grasses grown worldwide (Stewart and Ellison 2010). It has been used widely as forage due to its quality, biomass production and good shade tolerance. Despite its various agricultural uses, little information is available for functional and comparative genetic analysis and concomitant genetic improvement of this species. To date, a number of linkage maps have been constructed for forage grasses such as perennial ryegrass (Lolium perenne L.) (Jones et …

Breeding Forage Legumes To Complement Warm Season Perennial Grass Pastures In The Us Southern Region, Gerald R. Smith, F. M. Rouquette Jr.

IGC Proceedings (1977-2023)

Perennial warm-season grass pastures, primarily bermudagrass (Cynodon dactylon [L] Pers..)) and bahia grass (Paspalum notatum Flugge)),, cover approximately 12 million hectares in the US southern region (US Census of Agric. 2002). These grasses are used for grazing, hay production or both. Bermuda grass and bahia grass are dormant from late fall until early spring with some variation in total dormancy period depending on seasonal conditions and latitude. Cool-season forage legumes can be over-seeded in the fall before the perennial grasses become dormant, providing winter grazing and nitrogen for the pasture system. The legumes sown in these grasslands are …

Adaptability And Extension Activity Of Dwarf Napiergrass In Southern Kyushu And Elsewhere Since Its Introduction To Japan 15 Years Ago, Yasuyuki Ishii, Dong-Jin Kang, Asuka Yamano, Sachiko Idota, Kiichi Fukuyama

IGC Proceedings (1977-2023)

Southern Kyushu is well suited to the cultivation of tropical grasses due to its warm climate, history of herbage production, and extensive areas of abandoned arable land. In 1996, a C4-tropical dwarf variety of a late-heading (DL) napiergrass (Pennisetum purpureum Schumach) was introduced from the USA into southern Kyushu via Thailand. Since 2004, DL napiergrass has been evaluated for its production potential, overwintering ability, and suitability for grazing. In Miyazaki, napiergrass exhibits superior sustainability, persisting for more than 5 years without annual renovation. The species shows excellent overwintering ability in coastal areas and is resilient to pathogens and insects. …

Ninety Years Of Perennial Forage Grass Breeding For The Canadian Prairie Provinces, Bruce E. Coulman, Paul G. Jefferson

IGC Proceedings (1977-2023)

The majority of Canadian beef production takes place in the three prairie provinces of western Canada and seeded pasture and hay land provides a large proportion of the feed for these cattle. This region is characterized by low to moderate rainfall (300-500 mm annually) and extremely cold winters; thus, forage species grown must have high tolerance to cold and drought. Perennial grass breeding for the region began in 1922 and has continued for ninety years in two programs. Major seeded grass species were introduced into Canada from Eurasia. Significant developments from this program include: the development of Fairway crested wheatgrass …

Widening The Adaptation Of White Clover By Incorporation Of Valuable New Traits From Wild Clover Species, Warren M. Williams, Isabelle M. Verry, Syed Wajid Hussain, H. A. Ansari, K. H. Widdup, N. W. Ellison, Shirley N. Nichols

IGC Proceedings (1977-2023)

Although white clover (Trifolium repens) is the most widely used legume in grazed pastures of temperate and sub-tropical regions, it is severely restricted in genetic diversity for adaptive traits to low soil fertility and other stress environments, including drought. The objective of this research was to transfer traits for wider adaptation from other clover species by hybridisation. Eight Trifolium species with contrasting adaptations were shown by DNA sequence phylogenetics to be closely related to white clover. Interspecific hybridisation was undertaken among these species using embryo rescue, and an array of partially fertile F1 hybrids was obtained. Population development …

Commercialisation And Impacts Of Pasture Legumes In Southern Australia–Lessons Learnt, Clinton K. Revell, Michael A. Ewing, Daniel Real, Phillip G. H. Nichols, Graeme A. Sandral

IGC Proceedings (1977-2023)

Forage legumes are a key feature of temperate grasslands in southern Australia, valued for their ability to increase animal production, improve soil fertility and fix atmospheric nitrogen. Of the 36 temperate annual legume and 11 temperate perennial legume species with registered cultivars introduced or domesticated in Australia over the last 100 years, a third have made a major contribution to agriculture, a third have modest use and a third have failed to make any commercial impact. Highly successful species include subterranean clover, barrel medic, white clover, lucerne, French serradella and balansa clover. Species were assessed on the scale of their …

Global Impact Of Sown Temperate Pastures On Productivity And Ecosystem Stability–What Progress Have We Made?, E. Charles Brummer

IGC Proceedings (1977-2023)

Twenty years ago, in 1993, we published one of the first two alfalfa genetic linkage maps. At the time, hopes ran high that genetic marker technologies would revolutionize selection, making the development of superior cultivars both easier and faster. The objective of this paper is to critically examine forage improvement since that time and to suggest ways to more fully capitalize on those initial hopes in the future. Marker studies have been conducted around the world, identifying quantitative trait loci (QTL) for the major agronomically important traits, including biomass yield, nutritive value, disease resistance, abiotic stress tolerance, and others. But …

Structural Characteristics Of Porto Rico Stargrass (Cynodon Nlemfuensis) Pastures Under Different Frequencies And Severities Of Defoliation, Carlos Augusto Brandão De Carvalho, Sergio Trabali Camargo Filho, Domingos Sávio Campos Paciullo, Pablo Giliard Zanella, Elisa Cristina Modesto, Priscila Beligoli Fernandes

IGC Proceedings (1977-2023)

An understanding of the effects of frequency and severity of defoliation on the sward structure of pastures is essential for identifying pasture management strategies that are more efficient in forage usage in tropical environments (Da Silva and Nascimento Jr 2007; Euclides et al. 2010). Some pasture species have not yet been investigated in this way, e.g. cultivars of Cynodon. The potential of this grass in tropical environments suggests that it should be given priority (Pedreira 2010). This study was designed to evaluate the effects of 2 frequencies (90 and 95% light interception) and severities (20 and 30 cm …

Effect Of Grazing Height On Marandu Pasture Production And Performance Of Soybean Grain-Supplemented Nellore Bulls, Andre L. S. Valente, Ricardo A. Reis, Sharadinny M. C. Dos Santos, Fernando H. M. De Souza, Telma T. Berchielli, Ana C. Ruggieri, Sabrina S. Santana, Juliana M. Serra

IGC Proceedings (1977-2023)

The Brazilian beef cattle industry is primarily based on the use of pastures. Grasses belonging to the genus Brachiaria are extremely important, regardless of whether the production system used is intensive or extensive.

Appropriate management of the system is vital for obtaining a high efficiency of resource usage. Adjustment of stocking rate to maintain optimum forage allowance and feeding of supplements are strategies for achieving these aims. Feeding of concentrates on pasture can result in increased carrying capacity and higher weight gains over unsupplemented systems.

The purpose of this study was to evaluate the effects of 3 different grazing heights …

Establishment Of Leucaena Leucocephala Cv. Tarramba In Eastern Indonesia, Jacob Nulik, H. Dahlanuddin, Debora Kana Hau, Charles Pakereng, Resti G. Edison, Dessy Liubana, S. P. Ara, Hayley E. Giles

IGC Proceedings (1977-2023)

The adaptability and productive value of Leucaena leucocephala cv. Tarramba (Tarramba) in eastern Indonesia has been observed since 2001 (Nulik et al. 2004), with many farmers and other stakeholders currently requesting seed for planting. Tarramba has greater forage and timber production, and psyllid tolerance than other commercial cultivars and locally grown leucaena. The variability of soils and climate in eastern Indonesia means that establishment techniques specific to the region are required to achieve maximum adoption and utilisation of Tarramba.

Potential Of Australian Bermudagrasses (Cynodon Spp.) For Pasture In Subtropical Australia, Andrew Hacker, Meena Puachuay, H. Max Shelton, Scott A. Dalzell, Haider Al Dabbagh, Margaret Jewell, Thinh Van Tran, The Ngo, Yi Zhou, Michael J. Halliday, Hayley E. Giles, Don S. Loch, Ian D. Godwin, Fukai Shu, Chris O’Brien, Will Pearce, William F. Anderson, Christopher J. Lambrides

IGC Proceedings (1977-2023)

In Australia, little work has been carried out on the improvement of tropical or subtropical pastures in recent years. There seems to be an increasing demand for pastures that can withstand heavy grazing, while producing high yields of high quality forage in the humid subtropical regions of Australia. Most graziers, who live in these areas, have small acreages, which they graze intensively. Cynodon spp. represent a potential source of grasses with these attributes. This study will evaluate the pasture potential of a large number of bermudagrass (Cynodon spp.) ecotypes collected from across Australia.

Selection Of Psyllid-Resistant Forage Varieties From An Inter-Specific Breeding Program Of Leucaena Leucocephala With L. Pallida, Scott A. Dalzell, Lachlan M. Robertson, Christopher J. Lambrides, James L. Brewbaker, Del Greenway, Mark Dieters, H. Max Shelton

IGC Proceedings (1977-2023)

Leucaena (Leucaena leucocephala) pastures for beef cattle production are productive and sustainable; however, susceptibility to the psyllid insect (Heteropsylla cubana) has limited expansion of current commercial cultivars into more humid areas (> 800 mm/yr) (Shelton and Dalzell 2007). Psyllids can also cause intermittent damage in lower rainfall regions during humid periods. The psyllid, which arrived in Australia in 1986, is a leaf-sucking insect specific to the Leucaena genus, feeding on the growing tips of susceptible cultivars (Bray 1994). Psyllid damage can reduce production by as much as 50-70% in humid regions and 20-50% in subhumid environments …

Growth Of Bali Bulls On Rations Containing Sesbania Grandiflora In Central Lombok, Indonesia, H. Dahlanuddin, Baiq Tutik Yuliana, Tanda Panjaitan, Michael J. Halliday, H. Max Shelton

IGC Proceedings (1977-2023)

The demand for meat in Indonesia is currently growing by up to 8% per year, with beef cattle fattening identified as a major livestock industry (Purwantara et al. 2012). Bali cattle (Bos javanicus) account for almost 27% of total beef cattle in Indonesia; they are the predominant breed in the eastern islands and are highly favoured by smallholder farmers for their high fertility, low calf mortality and generally higher price at markets (Purwantara et al. 2012). Lombok in west Nusa Tenggara is one of the biggest suppliers of Bali cattle in Indonesia.

A major constraint to …

Animal Performance And Productivity Of A New Cultivar Of Brachiaria Brizantha, Valéria P. B. Euclides, Denise B. Montagner, Cacilda B. Valle, Nayana N. Nantes

IGC Proceedings (1977-2023)

Brazil has the competitive advantage of a very dynamic and cost-effective animal production system on pastures over other countries. The pursuit of more productive forages that will result in higher quality beef at a lower cost is justified. As Brachiaria is the most important forage genus utilised in Brazil, an intense search for new cultivars amongst collected and introduced ecotypes from Africa is underway. Following agronomic evaluation of this material in plots, 8 Brachiaria ecotypes were pre-selected. As part of Embrapa`s process of cultivar development, B. brizantha cv. Xaraés, characterised by high productivity (liveweight gain/area), was released in 2003, followed …

Performance Of Young Nellore Bulls Grazing Marandu Grass Pasture At Different Heights, Ricardo A. Reis, Andre L. S. Valente, Sharadinny M. C. Dos Santos, Fernando H. M. De Souza, Telma T. Berchielli, Ana C. Ruggieri, Sabrina S. Santana, Juliana M. Serra

IGC Proceedings (1977-2023)

Brazil is one of the largest beef cattle producers in the world with approximately 200 M head. The Industry relies predominantly on warm-season grass pastures, with approximately 90% of animals finished on pastures.

One of the main factors for the intensification of animal production systems based on pasture is appropriate management. Adjustment of stocking rate to maintain optimum forage allowance is essential. Studies on forage allowance have resulted in a better understanding of the response of forage crops and animals to changes in grazing intensity.

The purpose of this study was to evaluate management strategies for beef cattle systems grazed …

Seasonal Expression Of Apospory In Bahiagrass, Esteban F. Rios, Ann R. Blount, Kevin E. Kenworthy, Carlos A. Acuña, Kenneth H. Quesenberry

IGC Proceedings (1977-2023)

Flowering plants can reproduce sexually (outcrossing and/or selfing) and/or asexually. Sexual reproduction implies the successful completion of meiosis and double fertilisation for the formation of both the embryo and the endosperm. In contrast, gametophytic apomixis is an asexual mode of reproduction through seeds that involves parthenogenetic embryo development from a cytologically unreduced egg cell (2n). Apospory is the process by which unreduced gametophytes are formed after a series of mitotic divisions of somatic cells (2n) in the ovary. This occurs independently from the sexual meiotic process; and therefore, both sexual and apomictic pathways may coexist simultaneously. Apospory is inherited in …

Morphogenic Responses Of Two Brachiaria Genotypes In Response To Clipping Frequency, Ana Flávia G. Faria, Carlos G. S. Pedreira, Diego N. L. Pequeno, Liliane S. Silva, Damião W. Nguluve, Aliedson S. Ferreira

IGC Proceedings (1977-2023)

Tropical grasslands represent an important resource for the Brazilian cattle industry, which is heavily dependent on grazed pastures. Total pasture area in the country totals 196 M ha (23% of the country’s land area) (FAO 2013). The genus Brachiaria represents around 85% of cultivated pastures in Brazil (Moreira et al. 2009), 40% of which are established with B. brizantha cv. Marandu (Barbosa 2006). Mulato II is a new hybrid brachiaria grass cultivar which has been developed to improve agronomic characteristics, broaden the range of adaptation, and to ensure high forage production and nutritive value. It has also been viewed …