Embrapa Environment

Jaguariúna, Brazil

Embrapa Environment

Jaguariúna, Brazil
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Oelofse M.,Copenhagen University | Hogh-Jensen H.,University of Aarhus | Abreu L.S.,Embrapa Environment | Almeida G.F.,Federal University of São Carlos | And 3 more authors.
Ecological Economics | Year: 2010

Based on three case studies in China and Brazil, this paper explores the terms of access for farmers' participation in certified organic agriculture (OA) and investigates the influence of adoption on productivity, nutrient budgets, income and labour use. Small-scale farmers converting to OA require substantial external production-related, marketing and certification support. Access to OA was strongly dependent upon the type of support available to farmers. Organization based on a contract-farming model resulted in OA only being an option available to a narrow group of farmers, whilst OA initiated by a farmer cooperative provided better access. Gross output was significantly higher for oranges, whilst for the other crops gross output was similar. However, organic farmers in China felt that adoption had improved prices, incomes and market access. Farmers' perception of improved incomes is probably due to improved market access coupled with either a large production base, production intensification and production diversification. This study demonstrates that organization of farmers, and the manner in which this is structured, is crucial for external support to have an effect. Thus, OA may be a development path for small farmers if the supporting structures are provided at a small financial interest rate. © 2010 Elsevier B.V.

Soares J.R.,Agronomic Institute of Campinas | Cantarella H.,Agronomic Institute of Campinas | Vargas V.P.,Agronomic Institute of Campinas | Carmo J.B.,Federal University of São Carlos | And 3 more authors.
Journal of Environmental Quality | Year: 2015

The environmental benefits of producing biofuels from sugarcane have been questioned due to greenhouse gas emissions during the biomass production stage, especially nitrous oxide (N2O) associated with nitrogen (N) fertilization. The objective of this work was to evaluate the use of nitrification inhibitors (NIs) dicyandiamide (DCD) and 3,4 dimethylpyrazole phosphate (DMPP) and a controlled-release fertilizer (CRF) to reduce N2O emissions from urea, applied at a rate of 120 kg ha-1 of N. Two field experiments in ratoon cycle sugarcane were performed in Brazil. The treatments were (i) no N (control), (ii) urea, (iii) urea+DCD, (iv) urea+DMPP, and (v) CRF. Measurements of N2O fluxes were performed using static chambers with four replications. The measurements were conducted three times per week during the first 3 mo and biweekly afterward for a total of 217 and 382 d in the first and second seasons, respectively. The cumulative N2O-N emissions in the first ratoon cycle were 1098 g ha-1 in the control treatment and 1924 g ha-1 with urea (0.7% of the total N applied). Addition of NIs to urea reduced N2O emissions by more than 90%, which did not differ from those of the plots without N. The CRF treatment showed N2O emissions no different from those of urea. The results were similar in the second ratoon: the treatment with urea showed N2O emissions of 0.75% of N applied N. Application of NIs resulted in a strong reduction in N2O emissions, but CRF increased emissions compared with urea. We therefore conclude that both NIs can be options for mitigation of greenhouse gas emission in sugarcane used for bioenergy. © American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Kruk N.S.,Technical Institute of Aeronautic | Vendrame I.F.,Technical Institute of Aeronautic | Da Rocha H.R.,University of Sao Paulo | Chou S.C.,National Institute for Space Research | Cabral O.,Embrapa Environment
Theoretical and Applied Climatology | Year: 2010

The accurate estimate of the surface longwave fluxes contribution is important for the calculation of the surface radiation budget, which in turn controls all the components of the surface energy budget, such as evaporation and the sensible heat fluxes. This study evaluates the performance of the various downward longwave radiation parameterizations for clear and all-sky days applied to the Sertãozinho region in São Paulo, Brazil. Equations have been adjusted to the observations of longwave radiation. The adjusted equations were evaluated for every hour throughout the day and the results showed good fits for most of the day, except near dawn and sunset, followed by nighttime. The seasonal variation was studied by comparing the dry period against the rainy period in the dataset. The least square linear regressions resulted in coefficients equal to the coefficients found for the complete period, both in the dry period and in the rainy period. It is expected that the best fit equation to the observed data for this site be used to produce estimates in other regions of the State of São Paulo, where such information is not available. © 2009 Springer-Verlag.

Assis M.C.,Embrapa Environment | Mello-Silva R.,University of Sao Paulo
Phytotaxa | Year: 2016

Five species of Alstroemeria from caatinga in Brazil are presented. Three of them are endemic to this vegetation, including a new species, A. stramonia, here described. We provide descriptions, illustrations, comments, and a key to the species. © 2016 Magnolia Press.

Costa L.B.,Federal University of Lavras | Rangel D.E.N.,University of Paraíba Valley | Morandi M.A.B.,Embrapa Environment | Bettiol W.,Embrapa Environment
Biological Control | Year: 2013

Clonostachys rosea is effective to control of Botrytis cinerea on strawberry, although is highly susceptible to ultraviolet radiation and has reduced ability to antagonize a pathogen in solar radiation conditions. The objective of this work was to evaluate the ability of an isolate of C. rosea, previously selected for its tolerant to UV-B radiation, to control B. cinerea on strawberry leaves in controlled experiments. Leaf discs of 1cm diameter were placed on Petri dishes and each received 20μL of a C. rosea LQC 62 concentrations (104, 105, and 106conidiamL-1). They were then exposed to UV-B irradiance 600mWm-2 (0, 2.1, 4.2, and 6.3kJm-2), and after radiation, half of the discs were inoculated with an aliquot of 10μL B. cinerea (105conidiamL-1). The colonization of fungi on the leaf disc was measured with diagrammatic scale formation of conidiophores. The presence and sporulation of C. rosea on leaf disc was influenced by the dose of UV-B radiation and the conidial concentration of antagonist. The incidence and severity of B. cinerea on leaf discs were inversely correlated to presence and sporulation of C. rosea. The growth of the pathogen was higher in the lower C. rosea concentration. The highest concentration of C. rosea (106conidiamL-1) reduced the incidence and severity by 91% and 98% of B. cinerea on strawberry leaf discs. The UV-B radiation reduced the ability of C. rosea to control B. cinerea. The higher dose of UV-B reduced the presence and sporulation of C. rosea by 20% and 42%, respectively. Consequently, the incidence of B. cinerea increased twice and the severity was three-folder higher. Taken together this data means that, for the development of biological control agents based products, the effect of UV-B should be considered on the efficacy studies. © 2013 Elsevier Inc..

Costa L.B.,Federal University of Lavras | Rangel D.E.N.,University of Paraíba Valley | Morandi M.A.B.,Embrapa Environment | Bettiol W.,Embrapa Environment
World Journal of Microbiology and Biotechnology | Year: 2012

Sensitivity to UV-B radiation is one of the main limitations of biological control of plant pathogens in the field. The effect of UV-B radiation on germination and leaf tissue colonization by the biological control agent Clonostachys rosea was evaluated. There were variations among C. rosea strains in sensitivity to UV-B radiation. The most tolerant strain (LQC62) had relative germination of about 60 % after irradiation of 4. 2 kJ m-2. The deleterious effects of UV-B radiation on C. rosea colonization were overcome by higher conidial concentration. In addition, the tolerance of C. rosea conidia was higher when irradiated over leaf disks compared to agar media, and this is very important information to determine the dose and spray strategies for applying C. rosea in the field. © 2012 Springer Science+Business Media B.V.

Higashikawa F.S.,Federal University of Lavras | Silva C.A.,Federal University of Lavras | Bettiol W.,Embrapa Environment
Revista Brasileira de Ciencia do Solo | Year: 2010

Due to human activity, large amounts of organic residue are generated daily. Therefore, an adequate use in agricultural activities requires the characterization of the main properties. The chemical and physical characterization is important when planning the use and management of organic residue. In this study, chemical and physical properties of charcoal, coffee husk, pine-bark, cattle manure, chicken manure, coconut fiber, sewage sludge, peat, and vermiculite were determined. The following properties were analyzed: N-NH4 +, N-N03 -, and total concentrations of N, P, S, K, Ca, Mg, Mn, Zn, Cu, and B, as well as pH, Electrical Conductivity (EC) and bulk density. Coffee husk, sewage sludge, chicken manure and cattle manure were generally richer in nutrients. The EC values of these residues were also the highest (0.08 - 40.6 dS m-1). Peat and sewage sludge had the highest bulky density. Sodium contents varied from 0 to 4.75 g kg-1, with the highest levels in chicken manure, cattle manure and sewage sludge. Great care must be taken when establishing proportions of organic residues in the production of substrates with coffee husk, cattle or chicken manure or sewage sludge in the calculation of the applied fertilizer quantity in crop fertilization programs.

De S. Dos Santos M.,São Paulo State University | Ghini R.,Embrapa Environment | Fernandes B.V.,V and M Florestal Ltda | Silva C.A.,Federal University of Lavras
Australasian Plant Pathology | Year: 2013

The increased atmospheric carbon dioxide concentrations expected in the coming decades will result in changes in host-pathogen interactions. The present study aimed to evaluate the effect of high concentrations of CO2 in the air on the development of Ceratocystis wilt in two Eucalyptus clones (a hybrid of Eucalyptus urophylla and a cross between E. urophylla x E. camaldulensis). The clonal plantlets were cultivated under CO2 concentrations of 394 ± 10 μmol/mol (environmental condition), 553 ± 15 μmol/mol and 878 ± 70 μmol/mol in a controlled environment for 70 days and inoculated with Ceratocystis fimbriata conidia. In the treatments with 553 and 878 μmol/mol, the plants of both clones had greater growth (215 % and 219 % increases in leaf area and 22 % and 24 % in stem diameter, respectively), a longer incubation period (65 % for both CO 2 concentrations) and less disease severity (48 % and 78 % reduction, respectively) on average compared with the plants cultivated at 394 μmol/mol. The carbon content of the leaves was greater at the higher CO 2 concentrations; however, there was no difference in the C content of the stems and roots. The nitrogen content of the leaves, stems and roots were lower in the environments with higher CO2 concentrations. The results show that an increased CO2 concentration can reduce the severity of Ceratocystis wilt and stimulate the growth of Eucalyptus clonal plantlets. © 2013 Australasian Plant Pathology Society Inc.

Ghini R.,Embrapa Environment | Bettiol W.,Embrapa Environment | Hamada E.,Embrapa Environment
Plant Pathology | Year: 2011

Tropical and plantation crops include important crops for food security and alternative energy resources. Even so, there are few studies on the impact of climate change on diseases of these crops. Findings from previous studies concerning some climate-change effects on diseases of coffee, sugarcane, eucalyptus, cassava, citrus, banana, pineapple, cashew, coconut and papaya have been summarized to provide a context. By reviewing available methods to evaluate the impact of climate change on diseases of tropical and plantation crops, we present trends for some diseases and their management strategies, identify critical gaps in knowledge, and suggest experimental and analytical approaches to advance knowledge. As the projected climate conditions will probably vary greatly in the future from continent to continent and from developed to developing countries, studies must be conducted under tropical regions considering their specific environmental conditions. Multifactor studies under realistic field situations, such as free air CO2 enrichment with increasing CO2 and O3 concentrations incorporating spectral reflectance measures in situ for realistic assessment of plant growth, are a way forward. Effects of a changing climate on chemical and biological controls are discussed in the context of changing global outlook on environmental demands for the future. © 2011 The Authors. Plant Pathology © 2011 BSPP.

Ghini R.,Embrapa Environment
Acta Horticulturae | Year: 2014

Climate change, intense globalization and the need to increase the sustainability of agricultural activity are major challenges for effective soil disinfestation. The impact of climate change on the soil biota, the geographical distribution of soilborne pathogens, and adaptation strategies are discussed. These challenges underscore the importance of adopting preventive measures in soilborne pathogens control and of holistic approaches that integrate physical, chemical and biological control.

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