Earth Sciences Commons^™

Using Recurrent Phenotypical Selection To Improve Drought Tolerance Of Red Clover, M. Sahin, S. Reid, E. Sahin, S. Ates, S. Elias, David B. Hannaway

IGC Proceedings (1997-2023)

Red clover is one of the most important forage legumes in the world. It is utilized extensively in European and North American farming systems. Approximately, 4 million hectares of red clover are grown globally each year for forage production, soil improvement, and as a pollen and nectar source for pollinators (Riday, 2010). In North America, red clover is widely used in temperate regions for pasture, hay, and silage in combination with grasses for soil improvement and as a pollen and nectar source for bumblebees (Bombus). In the northwest, it is also grown for seed production (Anderson et al., 2016) with …

Brs Sarandi: A New Andropogon Gayanus Cultivar For Tropical Pastures, Marcelo A. Carvalho, C. E. F. Lazarini, Allan K. B. Ramos, Gustavo J. Braga, Claudio T. Karia

IGC Proceedings (1997-2023)

BRS Sarandi is adapted to low and medium fertility soils. It has a medium-high height, with a semi-erect growth habit and a high total number of tillers. The annual productivity of dry matter is 11 t ha-1, concentrated in the rainy season (90%). Of the total DM produced, 60% are leaves. The levels of crude protein (CP), in vitro dry matter digestibility (IVDMD), neutral detergent fiber (NDF) and acid detergent fiber (ADF) are, on average, 8.7, 56.5, 66.7 and 38.2%, respectively. . The average daily weight gain was 0.7 kg/head/day, the gain per was and 1.7 kg ha-1 day with …

Participatory Development Of A Forage Grass Cultivar, Michael D. Casler, P. G. Pitts, P. C. Bilkey, C. A. Rose-Fricker

IGC Proceedings (1997-2023)

Perennial forage grasses exist in both nature and agriculture as a highly heterogeneous mixture of genotypes. Extreme environments, fluctuating environments, and severe managements can impose selection pressures that will result in loss of unadapted genotypes. Mortality of unadapted genotypes leads to dominance of fewer highly adapted genotypes which may be useful as superior germplasm in other similar environments.

Thoughts On Breeding For Increased Forage Yield, E. C. Brummer

IGC Proceedings (1997-2023)

Most forage crops have not experienced yield gains as impressive as those observed in annual grains crops such as maize (Zea mays L); in fact, yield improvement in lucerne appears to have stopped in the Midwestern USA (Riday and Brummer, 2002). I contend that much of this disparity can be explained by a failure of breeders to pursue long term recurrent selection programs within populations to capitalize on small, incremental improvements in yield over time. Many selection programs last only two or three cycles, resulting in a germplasm or cultivar release. Either no further selection is attempted or the …

Genetic Mapping In Tetraploid Alfalfa: Results And Prospects, E. C. Brummer, J. G. Robins, B. Alarcón Zúñiga, D. Luth

IGC Proceedings (1997-2023)

Among the difficulties of improving forages is their perennial nature, which necessarily requires long selection cycles to fully evaluate genotypes. Further, traits of particular importance—yield and winter hardiness—are difficult to assess on single plants, necessitating evaluation of progeny, which is both time consuming and expensive. Because of this, yield of many forages, and particularly alfalfa, has not improved substantially over the past 25 years (Riday and Brummer, 2002). Winter hardiness often has a negative correlation with autumn growth, although some evidence suggests this is not always true (Brummer et al., 2000). One way to overcome some of these limitations …

Review Of Urochloa Breeder’S Toolbox With The Theory Of Change And Stage Gate System Approach, E. Sweitzer, L. Hernandez, D. Florian, A. Notenbaert, S. Burkart, J. Arango, J. Cardoso, M. Peters, V. Castiblanco

IGC Proceedings (1997-2023)

Livestock production in the global south is at crossroads as there is a demand to increase Animal Source Foods to address hunger and pressure to lighten the environmental footprint often associated with livestock production. To satisfy both needs, the use of technologies that improve animal performance, while reducing land use and net Greenhouse Gas emissions produced by animals is essential. One of such technologies are Urochloa forage grasses.

Urochloa forage grasses are well known for their rusticity and their ability to grow in soils of low fertility and high aluminum content. These characteristics allow Urochloa to grow in areas temporally …

Warm-Season Legumes – Challenges And Constraints To Adapting Warm-Season Legumes To Transition Zone Climates With Examples From Arachis, G. M. L. Assis, José C. B. Dubeux Jr.

IGC Proceedings (1997-2023)

Grass pastures in monoculture are the predominant system in transition zone climates, where warm-season perennial grasses are usually cultivated. Mixed grass-legume pastures are worldwide recognized for having advantages over pure stands, including pasture longevity, N input from biological fixation, efficient nutrient cycling, and greater animal production. The genus Arachis encompasses important and successful warm-season forage legume species cultivated in mixed pastures or in pure stands. Arachis pintoi and Arachis glabrata are potential tropical forage species that can be used in transition zone climates. Mixed pastures with these legumes have been shown to be resilient systems, able to withstand short-term perturbations, …

Temperate/Tropical Transition Zones: A Hotspot For Breeding Forages With Climate Resiliency, Kenneth H. Quesenberry, Esteban F. Rios, Kevin E. Kenworthy

IGC Proceedings (1997-2023)

Species resiliency to climate change is critical for sustainability of grassland agricultural systems. Transition zones between temperate and tropical climates (between 27 and 31° N and S latitude) with variable annual frost/freeze events have proven to be ideal zones for identification of species with variable climate adaptation. This paper will identify these regions around the globe and show how these regions offer distinct advantages in terms of selection for abiotic and biotic stresses, and thus resiliency to changing climate. Programs located in these regions have the advantage of exposure to alternating extreme warm and cold temperatures, drought and flood conditions, …

Breeding Perennial Warm-Season Grasses For The Subtropical Belt In South America, Carlos A. Acuña

IGC Proceedings (1997-2023)

Perennial warm-season grasses share several agronomic characteristics, such as marked seasonal growth, cold susceptibility and photoperiod sensitivity. Breeding efforts in South America have been focused on attempting to improved cool-season growth, cold tolerance and also adaptation to the alternation of flooding and drought periods. Warm-season grasses also have in common that most of them are polyploid and some have very low fertility. Apomixis is also a common trait among these species. For polyploid species with limited seed yield, which commonly have stolons or rhizomes, F₁ hybrids are created and released as cultivars. Acroceras macrum and Hemarthria altissima will be …

The Master Tasks Of Forage Breeding In China, Guowen Cui, Gang Li, Huiqing Liu

IGC Proceedings (1997-2023)

No abstract provided.

Polyploidization Of Sexual Diploid Brachiaria Decumbens For Intraspecific Hybridization, Cacilda B. Valle, C. Simioni, Liana Jank, Rosangela M. S. Resende

IGC Proceedings (1997-2023)

No abstract provided.

Selection Of Panicum Maximum Genotypes Under Different Shade Levels, Liana Jank, M. M. Gontijo Neto, V. A. Laura, Rosangela M. S. Resende, Cacilda Borges Do Valle

IGC Proceedings (1997-2023)

No abstract provided.

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 (1997-2023)

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 …

Selecting New Brachiaria Humidicola Hybrids For Western Brazilian Amazon, Giselle M. L. De Assis, Cacilda B. Valle, Carlos M. S. De Andrade, Judson F. Valentim

IGC Proceedings (1997-2023)

Brachiaria humidicola is a perennial and stoloniferous forage grass, with excellent adaptation to infertile soils and waterlogging. Producers in northern Brazil have become interested in this species, especially after the degradation of large areas of lowly permeable soils sown with B. brizantha cv. Marandu, which is highly intolerant of soil waterlogging (Andrade and Valentim 2006). However, since only 3 cultivars of B. humidicola are registered in Brazil (Mapa 2013), there is a need to develop new cultivars adapted to the range of environmental conditions experienced. Recently, Embrapa Beef Cattle obtained intraspecific hybrids of B. humidicola that need to be evaluated …

Brs Mandobi: A New Forage Peanut Cultivar Propagated By Seeds For The Tropics, Giselle M. L. De Assis, Judson F. Valentim, Carlos M. S. De Andrade

IGC Proceedings (1997-2023)

Forage peanut (Arachis pintoi) is a forage legume of relatively recent use in beef and dairy cattle feeding. Although it is native exclusively to Brazil, the first cultivar, Amarillo, was released in Australia in 1987. Forage peanut has a great number of favourable attributes for establishing grass-legume mixtures, which guarantee the persistence and high yields of high quality forage in cultivated pastures. Therefore, studies with this species have intensified in many tropical regions of the world (Assis and Valentim 2009). In the state of Acre, western Brazilian Amazon, 137,000 ha are cultivated with forage peanut, cv. Belmonte, benefiting …

Animal Production From New Panicum Maximum Genotypes In The Amazon Biome, Brazil, Carlos M. S. De Andrade, Luis H. E. Farinatti, Hemython L. B. Do Nascimento, Andressa De Q. Abreu, Liana Jank, Giselle M. L. De Assis

IGC Proceedings (1997-2023)

The Panicum maximum breeding program coordinated by the Brazilian Agricultural Research Corporation - Embrapa has been evaluating and selecting genotypes under different soil and climatic conditions, with the objective to release new cultivars adapted to the diverse regions of Brazil. For the Amazon biome, small-plot experiments carried out in Acre between 2003 and 2005 allowed the selection of some promising genotypes (Valentim and Andrade 2005; Valentim et al. 2006; Andrade and Valentim 2009), with higher potential for forage growth than cultivars on the market. The objective of this work was to compare 2 new P. maximum genotypes with cv. …

Agronomic And Nutritional Evaluation Of Intraspecific Crosses In Brachiaria Decumbens, Simony A. Mendonça, Sanzio C. L. Barrios, Ulisses J. De Figueiredo, Geovani F. Alves, Cacilda B. Valle

IGC Proceedings (1997-2023)

Brachiaria decumbens cv. Basilisk is the single most important forage grass used for pastures in the tropics. This cultivar has exceptional adaptation to acid soils, vigorous growth, ease of establishment, and good forage value throughout the year, but these favourable characteristics are counteracted by its susceptibility to insect pests such as spittlebug. Breeding to produce improved cultivars within this species was impossible until 2009 due to the lack of compatible sexual ecotypes. With the success of somatic chromosome duplication of sexually reproducing diploid plants of B. decumbens (Simioni and Valle 2009), intraspecific crosses with natural apomictic tetraploid accessions were finally …