81 research outputs found
Carbon and water footprints in Brazilian coffee plantations - the spatial and temporal distribution
The future of many coffee growing regions, such as Brazil, depends on strategies to allow the minimization of the negative impacts of climate change. Still the own contribution of coffee cultivation for global warming is largely unknown. Water and carbon footprints are concepts that indicate the potential negative impact of a specific product, underlining which part of the process is the major responsible for it. In this context, the objective of this study was to quantify and spatialize the water and carbon footprints from coffee crop in different regions of Brazil, and to find the proportional weight of coffee production in the total emission of CO2 and water consumption in the context of Brazilian agriculture. For this end, water and carbon footprints were estimated and spatialized for Brazilian regions along 10 productive seasons (from 2004/2005 to 2014/2015), based on data of plantation area (ha) and coffee production (tons of beans). It is concluded that the estimates of annual carbon and water footprints were 19.791 million t CO2-equivalent and 49,284 million m3 of water, with higher values from the Southeast region. This corresponded to a moderate (ca. 5%) value for the emissions of greenhouse gases, but a relevant water footprint in the context of Brazilian agricultureinfo:eu-repo/semantics/publishedVersio
Ciências sociais e ambientais rural: principais temas e perspectivas analíticas.
Este trabalho tem por finalidade fazer um balanço dos estudos ambientais rurais sob a perspectiva das ciências sociais. Para isso, em primeiro lugar, realiza-se uma análise da trajetória dos movimentos sociais, identificando-se as principais questões ambientais emergentes na ótica dos atores do mundo rural. Num segundo momento, agrupam-se os temas privilegiados pelos pesquisadores para, em seguida, apontar as principais perspectivas analíticas em curso
Stomatal and Non-Stomatal Leaf Responses during Two Sequential Water Stress Cycles in Young Coffea canephora Plants
This research was funded by Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ, Brazil) granted to E.C. (200.957/2022), together with fellowships awarded to D.F.B., W.P.B. and L.Z.C. (E-26/200.327/2020, E-26/200.172/2021, and E-26/203.158/2023). The research was additionally funded by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES, Brazil) with fellowships granted to G.A.R.S., C.M.A., A.R.S., L.C.S.B. and L.F.T.B. (88887.968322/2024-00, 88887.903335/2023-00, 88887.671147/2022-00, 88887.704841/2022-00, and 88887.822657/2023-00), by Fundação de Amparo à Pesquisa e Inovação do Espírito Santo (FAPES, Brazil) by fellowship awarded to M.R. (2022–M465D), and National Council for Scientific and Technological Development (CNPq, Brazil) by fellowship awarded to E.C (304470/2023-6).
© 2024 by the authors.
Licensee MDPI, Basel, Switzerland.Understanding the dynamics of physiological changes involved in the acclimation responses of plants after their exposure to repeated cycles of water stress is crucial to selecting resilient genotypes for regions with recurrent drought episodes. Under such background, we tried to respond to questions as: (1) Are there differences in the stomatal-related and non-stomatal responses during water stress cycles in different clones of Coffea canephora Pierre ex A. Froehner? (2) Do these C. canephora clones show a different response in each of the two sequential water stress events? (3) Is one previous drought stress event sufficient to induce a kind of “memory” in C. canephora? Seven-month-old plants of two clones (’3V’ and ‘A1’, previously characterized as deeper and lesser deep root growth, respectively) were maintained well-watered (WW) or fully withholding the irrigation, inducing soil water stress (WS) until the soil matric water potential (Ψmsoil) reached ≅ −0.5 MPa (−500 kPa) at a soil depth of 500 mm. Two sequential drought events (drought-1 and drought-2) attained this Ψmsoil after 19 days and were followed by soil rewatering until a complete recovery of leaf net CO2 assimilation rate (Anet) during the recovery-1 and recovery-2 events. The leaf gas exchange, chlorophyll a fluorescence, and leaf reflectance parameters were measured in six-day frequency, while the leaf anatomy was examined only at the end of the second drought cycle. In both drought events, the WS plants showed reduction in stomatal conductance and leaf transpiration. The reduction in internal CO2 diffusion was observed in the second drought cycle, expressed by increased thickness of spongy parenchyma in both clones. Those stomatal and anatomical traits impacted decreasing the Anet in both drought events. The ‘3V’ was less influenced by water stress than the ‘A1’ genotype in Anet, effective quantum yield in PSII photochemistry, photochemical quenching, linear electron transport rate, and photochemical reflectance index during the drought-1, but during the drought-2 event such an advantage disappeared. Such physiological genotype differences were supported by the medium xylem vessel area diminished only in ‘3V’ under WS. In both drought cycles, the recovery of all observed stomatal and non-stomatal responses was usually complete after 12 days of rewatering. The absence of photochemical impacts, namely in the maximum quantum yield of primary photochemical reactions, photosynthetic performance index, and density of reaction centers capable of QA reduction during the drought-2 event, might result from an acclimation response of the clones to WS. In the second drought cycle, the plants showed some improved responses to stress, suggesting “memory” effects as drought acclimation at a recurrent drought.publishersversionpublishe
Recurrent mass selection for upright plant architecture in common bean
Plant with a more upright architecture offers many advantages to farmers. Recurrent mass selection (RS) programs for carioca type common bean have been implemented for the purpose of obtaining new lines that will generate the high yields that are associated with upright plant archi tecture. This study aimed to assess the efficiency of recurrent mass selection (RS) for upright plant architecture in common bean (Phaseolus vulgaris) and the effect of RS on grain yield and to verify whether or not there is still variability in the population that favors continuing selection programs, using information obtained from progenies evaluated in cycle five (CV) and cycle eight (CVIII) of the RS program. Mass selection for more upright plants was performed visually in the "S0" generation before flowering. Progenies S and Swere evaluated in 2009 (CV) and 2011 (CVIII). Heritability (h²;) and RS progress were estimated using adjusted means. After eight selection cycles, the population subjected to RS still had enough genetic variability to achieve continued success through recurrent selection. The RS progress was 1.62 % per cycle for the growth habit scores and 6.81 % for grain yiel
ANÁLISE DE EXPERIMENTOS EM LÁTICE QUADRADO COM ÊNFASE EM COMPONENTES DE VARIÂNCIA: II. ANÁLISE CONJUNTA
Eficiência Reprodutiva e Produtiva em Rebanhos Leiteiros Comerciais Monitorados por Sistema Informatizado
Allohexaploid pearl millet x elephantgrass population potential for a recurrent selection program
- …
