Canopy Characteristics and Growth Rate of Bahiagrass Monoculture and Mixtures with Rhizoma Peanut

Understanding relationships among canopy light interception (LI), canopy height and structure, and leaf area index (LAI) informs management decisions and can improve efficiency of forage-livestock systems. In a long-term experiment in Florida, USA, we assessed the LI, LAI and sward height relationships of rhizoma peanut (Arachis glabrata Benth., RP)-bahiagrass (Paspalum notatum Flügge) mixed swards compared with bahiagrass monoculture to determine whether changes in canopy structure affect herbage accumulation (HA) rate due to changes in radiation use. Treatments were arranged in a semi-factorial, split-plot design (r=4). Bahiagrass monoculture and bahiagrass-RP mixtures were whole-plot treatments. Sub-plot treatments were an undefoliated control, forage clipped to 5 cm when LAI \u3e 3, and forage clipped to 5 cm when LAI \u3e 3 and fertilized immediately after with 20 kg N ha-1. During 2021, LI, LAI and canopy height were measured weekly using a LiCOR LAI-2200 and a rising plate meter (platemeters g1000), respectively. The proportion of bahiagrass and RP in total herbage mass was determined for each treatment in July 2021. Herbage accumulation rate was calculated as HA during the regrowth period divided by days between clipping events. The relationship of LI and LAI was assessed with a negative exponential model. Relationships of cumulative LAI and sward height and days after clipping were determined using regression analysis. Incorporating RP into bahiagrass increased LI at shorter sward height compared with bahiagrass monoculture due to a greater LAI mm-1 of sward height (190-220 vs. 150-160 mm). Fertilized mixtures achieved LAI95 faster than bahiagrass monoculture, however, changes in mixture canopy structure did not result in greater radiation-use efficiency compared with fertilized bahiagrass monoculture. Herbage accumulation rate decreased for mixtures containing more than 30% RP. Application of this information can improve the efficiency of grazing systems and maximize HA of bahiagrass-RP mixtures, either under rotational or continuous stocking

Evaluation of Limpograss (\u3cem\u3eHemarthria altissima\u3c/em\u3e) Breeding Lines under Different Grazing Managements

Limpograss (Hemarthria altissima (Poir.) Stapf et C.E. Hubb.) is a stoloniferous, warm-season perennial grass from South Africa. It is frequently used to extend the grazing season in poorly drained soils of subtropical regions (Quesenberry et al. 2004). The cold tolerance of limpograss allows it to grow at temperatures below which other commonly used warm-season grasses (e.g. bermudagrass) remain productive. Use of limpograss has helped to reduce forage shortfall during winter, therefore, reducing feeding costs. In the past 30 years, the area planted to limpograss in Florida, USA has grown faster than that of any other forage grass species. It is estimated that over 0.2 million ha are planted to limpograss (Quesenberry et al. 2004). Recent University of Florida research with limpograss has focused on developing new hybrids which incorporate the persistence of the most widely used cultivar ‘Floralta’ with the digestibility of ‘Bigalta’. Preliminary clipping and grazing trials evaluated 50 breeding lines and identified 5 lines (designated 1, 4F, 10, 32 and 34) with superior performance. With an overall program goal of identifying the best limpograsses for cultivar release, the specific objective of this experiment was to investigate the forage productivity and sward canopy characteristics of these 5 breeding lines, compared to Floralta, in response to different grazing management strategies

Breeding Small Grains as a Forage, Silage and Cover Crop for the Southern Coastal Plain (USA) in a Changing Climatic Environment

Forage breeding of small grains in the southern Coastal Plains region of the U.S. mimic many other countries experiencing climate changes and breeding strategies should be similar for improving small grains grown for forage, silage or as cover crops. Significant focus on improvements in stress-adaptation has encouraged members of the SunGrains cooperative to cross, evaluate and develop experimental lines with inherent adaptation to climatic conditions including heat stress, drought tolerance, short-day and long-day forage production periods, and flooded conditions for events with storm-related, short-term durations. Many new cultivars, grown throughout the southeastern U.S. have resulted from breeding selection under abiotic and biotic stresses, adapted to climate change and related concerns, such as disease and insect pests

Use of Limpograss as an Alternative Feed During the Fall Forage Gap in Beef and Dairy Systems in Central and North Florida

In central and North Florida, the use of limpograss [Hemarthria altissima (Poir.) Stapf & C. E. Hubb.] for beef and dairy operations is limited and its potential use is not well documented. Two on-farm projects have been conducted in Central and North Florida to explore the use of limpograss as an alternative conserved forage during late fall and winter. The potential use of this forage as baleage for dairy farmers and as stockpiling for livestock producers would offer another alternative to reduce feed costs and fill the forage gap in the area when typical warm-season forages go dormant. In addition, the on-farm limpograss establishment would serve as dissemination for the limpograss planting material. Four dairy farms in Central and North Florida were enrolled in the study to evaluate two cultivars of limpograss for their potential when conserved as baleage. Four 0.2 ha strips were planted per farm, two for each variety (‘Kenhy’ and ‘Gibtuck’). The strips were arranged in a randomized complete block design, with two replicates in each location. Before wrapping the harvested forage for baleage, samples were taken to evaluate crude protein (CP) and in vitro digestible organic matter concentration (IVDOM). In addition, samples of fresh baleage at 60 and 90 d were analyzed for fermentation profile (pH, organic acids, and ammonia). Four beef cattle farms in North Florida allowed us to plant 1 ha of ‘Gibtuck’ for stockpiling evaluating the nutritive value at 30, 60, 90, and 120 days. Each plot was replicated four times and allocated in a randomized complete block design. The fermentation profile from the bales does not show differences between cultivars (P \u3e 0.05) and the pH is lower than 5 indicating that the fermentation process was successful. The CP and IVDOM of the stockpiling limpograss were different among the treatments (P \u3c 0.001)

Zika virus replication in the mosquito Culex quinquefasciatus in Brazil.

Zika virus (ZIKV) is a flavivirus that has recently been associated with an increased incidence of neonatal microcephaly and other neurological disorders. The virus is primarily transmitted by mosquito bite, although other routes of infection have been implicated in some cases. The Aedes aegypti mosquito is considered to be the main vector to humans worldwide; however, there is evidence that other mosquito species, including Culex quinquefasciatus, transmit the virus. To test the potential of Cx. quinquefasciatus to transmit ZIKV, we experimentally compared the vector competence of laboratory-reared Ae. aegypti and Cx. quinquefasciatus. Interestingly, we were able to detect the presence of ZIKV in the midgut, salivary glands and saliva of artificially fed Cx. quinquefasciatus. In addition, we collected ZIKV-infected Cx. quinquefasciatus from urban areas with high microcephaly incidence in Recife, Brazil. Corroborating our experimental data from artificially fed mosquitoes, ZIKV was isolated from field-caught Cx. quinquefasciatus, and its genome was partially sequenced. Collectively, these findings indicate that there may be a wider range of ZIKV vectors than anticipated

Zika virus replication in the mosquito Culex quinquefasciatus in Brazil

Submitted by Kamylla Nascimento ([email protected]) on 2018-03-19T13:27:43Z No. of bitstreams: 1 PE - IAM - Zika virus replication in the mosquito Culex quinquefasciatus in Brazil.pdf: 2488944 bytes, checksum: 4d2eb5f1267900f3fa4522126876c476 (MD5)Approved for entry into archive by Kamylla Nascimento ([email protected]) on 2018-03-19T13:44:01Z (GMT) No. of bitstreams: 1 PE - IAM - Zika virus replication in the mosquito Culex quinquefasciatus in Brazil.pdf: 2488944 bytes, checksum: 4d2eb5f1267900f3fa4522126876c476 (MD5)Made available in DSpace on 2018-03-19T13:44:01Z (GMT). No. of bitstreams: 1 PE - IAM - Zika virus replication in the mosquito Culex quinquefasciatus in Brazil.pdf: 2488944 bytes, checksum: 4d2eb5f1267900f3fa4522126876c476 (MD5) Previous issue date: 2017Este trabalho foi parcialmente apoiado pela Fundação de Amparo à Pesquisa do Estado de Pernambuco (FACEPE, APQ-1608-2.13 / 15 e APQ-0085-2.13 / 16 à CFJA, APQ-345-2.13 / 13 a MAVMS e APQ-0078 -2.02 / 16 a GLW), o Conselho Nacional de Pesquisa e Desenvolvimento do Brasil (CNPq; concessão 441100 / 2016-3) eo Instituto Nacional de Alergia e Doenças Infecciosas dos Institutos Nacionais de Saúde (R01AI095514 e 1R21AI128931-01 a WSL) . A CFJA ea PAC foram apoiadas por bolsas de produtividade do CNPq.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil / Universidade Federal de Pernambuco. Centro Acadêmico do Agreste. Núcleo de Ciências da Vida. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Laboratório de Virologia e Terapia Experimental. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Laboratório de Virologia e Terapia Experimental. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Laboratório de Virologia e Terapia Experimental. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Núcleo de Estatística e Geoprocessamento. Recife, PE, Brasil.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.University of California-Davis. Department of Molecular and Cellular Biology. Davis, CA, USA.Fundação Oswaldo Cruz. Instituto Aggeu Magalhães. Departamento de Entomologia. Recife, PE, Brasil.Zika virus (ZIKV) is a flavivirus that has recently been associated with an increased incidence of neonatal microcephaly and other neurological disorders. The virus is primarily transmitted by mosquito bite, although other routes of infection have been implicated in some cases. The Aedes aegypti mosquito is considered to be the main vector to humans worldwide; however, there is evidence that other mosquito species, including Culex quinquefasciatus, transmit the virus. To test the potential of Cx. quinquefasciatus to transmit ZIKV, we experimentally compared the vector competence of laboratory-reared Ae. aegypti and Cx. quinquefasciatus. Interestingly, we were able to detect the presence of ZIKV in the midgut, salivary glands and saliva of artificially fed Cx. quinquefasciatus. In addition, we collected ZIKV-infected Cx. quinquefasciatus from urban areas with high microcephaly incidence in Recife, Brazil. Corroborating our experimental data from artificially fed mosquitoes, ZIKV was isolated from field-caught Cx. quinquefasciatus, and its genome was partially sequenced. Collectively, these findings indicate that there may be a wider range of ZIKV vectors than anticipated