Plant Pathology Commons^™

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 …

Sward Structural Characteristics Of Perennial Peanut Genotypes As Affected By Harvest Frequency, Aliedson S. Ferreira, Carlos G. S. Pedreira, Carla M. Marassatto

IGC Proceedings (1977-2023)

Despite the high potential of tropical forage species, herbage production, nutritive value and animal productivity in Brazilian livestock production systems are lower than what can be obtained from both a biological and operational point of view (Pedreira and Mello 2000, Da Silva and Sbrissia 2000). Even with these limitations, the livestock industry is often able to sustain high productivity levels (animal product per hectare) by using good animal genetics and supplementation. Reducing production costs, however, will likely depend on the identification and incorporation of a high-quality forage resource, in terms of both improving diet quality of grazing animals and sustaining …

Morphophysiological Adaptations Of Brachiaria Humidicola Cultivars Under Grazing, Rodrigo A. Barbosa, Pedro N. C. Amaral, André F. Sbrissia, Thiago T. Camara

IGC Proceedings (1977-2023)

Pastures of Brachiaria humidicola are broadly used in Brazil, especially in soils with low fertility and poor drain-age (Valle et al. 2010). Currently, 3 cultivars are commercially available: Tully, Llanero and BRS Tupi (available since 2012). Despite the extensive use of this species, research has focused primarily on aspects related to herbage and animal production, while only a few studies aimed at understanding morphological adaptations of the plants when subjected to grazing and contrasting environmental conditions.

Therefore, the aim of this work was to evaluate some morphological traits of 2 B. humidicola cultivars when continuously stocked during 2 seasons …

Vegetative Propagation Of Stylosanthes Scabra, Alexandre C. L. De Mello, Adeneide C. Galdino, José C. B. Dubeux Jr., Mércia V. F. Dos Santos, Mário De A. Lira Jr., Felipe M. Saraiva, Mário De A. Lira, Márcio V. Da Cunha

IGC Proceedings (1977-2023)

One way to multiply genetically desirable plants in a more uniform manner is to use vegetative propagation, such as using plant cuttings. This technique multiplies a single plant into several, in an easy low-cost system (Fachinello et al. 2005), so it is useful in plant breeding. This technique may be enhanced through the use of hormonal regulators, with indolebutyric acid (IBA) being most frequently used, because of its stability in hydroalcoholic solution, low sensitivity to biological degradation and good establishment of adventitious roots (Fachinello et al. 1995). In spite of its large-scale use for fruit production, the technique …

Effects Of Two Intake Levels Of Leucaena Leucocephala On Rumen Function Of Sheep, Marcos Barros-Rodríguez, Javier Solorio-Sánchez, Carlos Sandoval-Castro, Athol V. Klieve, Eduardo Briceño-Poot, Luis Ramírez-Avilés, Rafael Rojas-Herrera

IGC Proceedings (1977-2023)

Ruminant production systems based on grass pastures often produce poor animal performance as expressed by growth or reproductive rates. The nutrient imbalance affecting rumen function is due to their low energy and protein intake. The incorporation of leguminous forages such as Leucaena leucocephala, in the diet of ruminants, can stimulate rumen function by providing protein-rich forage (Barros-Rodriguez et al. 2012). This increases the availability of compounds such as ammonia, amino acids and peptides as well as branched short-chain fatty acids, which are produced as a result of degradation of proteins. These substances promote fibre breakdown by acting as ruminal …

Survey Of Pasture Species And Management, Manure Management, Milk Production And Reproduction On Pasture-Based Dairy Farms In Florida And Georgia, Usa, F. Du, K. D. Gay, M. E. Sowerby, Y. C. Newman, C. R. Staples, R. C. Lacy, A. De Vries

IGC Proceedings (1977-2023)

Traditionally, most dairy farms in the south-eastern United States confine cows to barns or on pasture lots year-round and feed stored forages and concentrated feeds (Fontaneli et al. 2005). Often, much of the feed is purchased, however, the cost of purchased feed and fuel has risen rapidly in the last 5 years (NASS 2009). In addition, a significant amount of capital is tied up in buildings, machinery and manure management systems on the farms. For these reasons, many dairy farmers have shown an interest in or started transitioning to pasture-based dairy systems (Ricks and Hardee 2012). The management practices …

Breeding Strategies For Brachiaria Spp. To Improve Productivity–An Ongoing Project, Geovani F. Alves, Ulisses J. De Figueiredo, Antônio D. Pandolfi Filho, Sanzio C. L. Barrios, Cacilda B. Valle

IGC Proceedings (1977-2023)

Two strategies have been used in the breeding of Brachiaria (syn. Urochloa) to produce new cultivars. The first involves exploring the natural variability existing in nature, which is the selection of ecotypes, mostly apomicts, from the diversity in germplasm banks. This strategy proved efficient originally and the cultivars in use in Brazil were derived in this way, but progress with this strategy is limited in the medium to long term.

Dry Matter Intake By Beef Steers On Piatã Palisadegrass (Brachiaria Brizantha Cv. Brs Piatã) Pasture, Denise B. Montagner, Valéria P. B. Euclides, Teresa C. M. Genro, Nayana N. Nantes

IGC Proceedings (1977-2023)

Beef production in Brazil is primarily based on tropical pastures and 85% of these pastures are Brachiaria brizantha cv. Marandu. Such a monoculture could prove disastrous if some pest or disease emerged. With the goal of further diversifying pastures and contributing to the sustainability of the pasture production system, B. brizantha cv. BRS Piatã was released by the Brazilian Agricultural Research Corporation (Embrapa). Little is known about the characteristics of this cultivar in relation to grazing management and plant-animal interactions. Dry matter (DM) intake by grazing animals is influenced by the structural characteristics of tropical grasses (Stobbs 1973, 1975), and …

Agronomic Evaluation Of 324 Intraspecific Hybrids Of Brachiaria Decumbens In Brazil, Rogério G. Mateus, Sanzio C. L. Barrios, Ulisses J. De Figueiredo, Cacilda B. Valle

IGC Proceedings (1977-2023)

Brachiaria decumbens cv. Basilisk is the most planted pasture grass in the tropics owing to its adaptation to poor and acid soils, typical of the tropics, plus good animal performance. This cultivar was responsible for a radical change of scenario in central Brazil in the early 1970s and is the only cultivar available commercially. Efforts to breed this species have been recent, as the successful somatic chromosome duplication of sexually reproducing diploid plants of B. decumbens was accomplished only in 2009 (Simioni and Valle 2009). Subsequently, intraspecific crosses with natural apomictic tetraploid accessions were carried out. Breeding is needed since …

Effect Of Season And Year Of Evaluation In The Selection Of Brachiaria Humidicola Hybrids, Ulisses J. De Figueiredo, José A. R. Nunes, Cacilda B. Valle, Sanzio C. L. Barrios, Geovani F. Alves

IGC Proceedings (1977-2023)

Brachiaria humidicola is well adapted to infertile and acid soils with poor drainage or temporary flooding (Keller-Grein et al. 1996). It is widely used in Brazil in wetlands and areas of marginal land characterised by waterlogged soils. During the evaluation stages of the breeding program of this species, genotypes are generally tested using consecutive cuts within different seasons for at least 2 years. The ‘Cerrado’ region, where most animal production takes place in Brazil, has 2 well defined seasons: spring-summer with warm weather and rain; and autumn-winter with cooler, dry weather. Thus, owing to environmental variation, especially related to …

Effects Of Irrigation And Season On Performance Of Grazed Pastures Of Brachiaria Brizantha Cv. Mg5, Rita De C. R. Carvalho, Wellington W. Rocha, Bruno S. Pires, César T. Piza, Luziney D. Silva, Paulo R. V. Leite, Eliel A. Ferreira

IGC Proceedings (1977-2023)

In Brazil, livestock production is based primarily on systems with continuously grazed natural or cultivated pastures (FAO 2009). Intensifying animal breeding, handling and knowledge strategies is necessary to obtain improvements in production indices for economically feasible and sustainable grazing systems (Cedeño et al. 2003). Beef cattle breeding on irrigated pasture, like all forms of intensive grazing, requires the use of forage species with high potential for production and quality, and Brachiaria brizantha cv. MG5 is considered a good option. This study aimed to evaluate the effects of irrigation on the performance of B. brizantha cv. MG5 grazed rotationally by …

Development Of Leucaena Mimosine-Degrading Bacteria In The Rumen Of Sheep In Myanmar, Aung Aung, Moe Thida Htun, Lwin Naing Oo, Mar Mar Kyi, Tin Ngwe

IGC Proceedings (1977-2023)

Myanmar has an agricultural base, and about 70% of people reside in rural areas. They depend for survival on agriculture and small-scale crop production, with ruminant livestock consuming fibrous agricultural residues. For optimal ruminant production, concentrates are needed as supplements to these residues. As concentrates are expensive, researchers are testing alternative protein sources like legumes, including foliage from leguminous trees such as leucaena (Leucaena leucocephala). Leucaena is the most widely used leguminous tree as a ruminant feed because it is rich in protein (~ 22%) and contains easily digestible fibre (23% neutral detergent fibre, 16.6% acid detergent fibre; …

Development, Isolation And Characterisation Of A New Non-Virulent Mimosine-Degrading Klebsiella Pneumoniae Strain From The Rumen Liquor Of German Steers By Using Ibt-Goettinger Bioreactor, Aung Aung, U. Ter Meulen, F. Gessler, H. Böhnel

IGC Proceedings (1977-2023)

The tropical legume Leucaena leucocephala (leucaena) has many uses, including: a potential source of firewood and timber; for soil erosion control (Dijkman 1950); to provide shade; to enhance soil fertility; and as a nutritious forage for animal feed (Ruskin 1977). It is widely used as forage for cattle in tropical agriculture (Shelton 1998). In Myanmar, leucaena is used as a protein source in urea-molasses multi-nutrient blocks for ruminants (Ni Ni Maw et al. 2004). However, the use of leucaena as ruminant feed is not without problems, because it contains mimosine, a toxic anti-nutritional factor limiting its use as animal …

Brs Paiaguás: A New Brachiaria (Urochloa) Cultivar For Tropical Pastures In Brazil, Cacilda B. Valle, Valéria P. B. Euclides, Denise B. Montagner, José R. Valério, Celso D. Fernandes, Manuel C. M. Macedo, Jaqueline R. Verzignassi, Luis A. Machado

IGC Proceedings (1977-2023)

Approximately half the world’s beef is produced in the tropics and subtropics, almost exclusively on pasture. While the world production of beef and veal increased 91% over the past 40 years, the increase in the tropics was 200%. Brazil has today the largest commercial cattle herd in the world (about 190 M head) and is the world's largest exporter of beef. The area of cultivated pasture increased from 30 to 100 Mha between 1970 and 1995 (IBGE 2006). This area has now stabilised or decreased despite the increase in beef production, which reflects the gain in area productivity. Part of …

Performance Of Nelore Cattle On Panicum Maximum Pastures In The Brazilian Cerrado, Giovana A. Maciel, Gustavo J. Braga, Roberto Guimarães Jr., Hélio A. De Araújo, Allan K. B. Ramos, Marcelo A. Carvalho, Lourival Vilela, Liana Jank

IGC Proceedings (1977-2023)

With the increased demand for meat products, associated with environmental concerns due to global climatic and land use changes, the need to efficiently use pasture and forage resources will increase (Boval and Dixon 2012). Efforts to breed and release new forage cultivars must incorporate these concerns, ensuring that introduced material is of high quality, especially under grazing (Euclides et al. 2008).

In this study, we aimed to evaluate the average daily weight gain and stocking rate of Nelore beef cattle grazing new genotypes of Panicum maximum during the rainy season in the Brazilian Cerrado.