72 research outputs found
Técnicas de produção de sementes florestais.
Este trabalho apresenta informações sobre técnicas de seleção, extração, beneficiamento, secagem e armazenamento de sementes florestais, a fim de obter sementes de boa qualidade.bitstream/item/100452/1/Cot205-sementesflorestais.pd
Técnicas de produção de sementes florestais.
Este trabalho apresenta informações sobre técnicas de seleção, extração, beneficiamento, secagem e armazenamento de sementes florestais, a fim de obter sementes de boa ualidade.bitstream/item/24812/1/Cot-205.pd
Caracterização de dez áreas com café conilon arborizado na Zona da Mata de Rondônia.
A presente pesquisa faz parte de um projeto maior de manejo da lavoura cafeeira arborizada e objetivou identificar as principais espécies utilizadas na arborização de áreas com cafeeiro Robusta nos município de Rolim de Moura e Nova Brasilândia do Oeste. A pesquisa foi desenvolvida em dez propriedades, cinco por município, e constou da aplicação de um questionário sócio-econômico, no qual foram levantadas a área total de cada propriedade, área com café Robusta, área com a(s) espécie(s) arborizadora, número de plantas, produtividade e idade do cafeeiro. Em Rolim de Moura a área total das propriedades avaliadas com cafeeiro Robusta arborizado é de 7,9 ha, a produtividade média varia de 10 a 100 sacas/ha, a idade do cafeeiro varia de 5 a 15 anos. No município de Nova Brasilândia a área total com café nas propriedades analisadas é de 15, 58ha, produtividade variando de 9 a 85 sacas/ha, a idade do cafeeiro varia de 5 a 21 anos
Salt-magma interactions influence intrusion distribution and salt tectonics in the Santos Basin, offshore Brazil
Many sedimentary basins host thick evaporite (salt) deposits. Some of these basins also host extensive igneous intrusion networks. It thus seems inevitable that, in some locations, magma will interact with salt. Yet how interaction between these materials may influence salt tectonics or magma emplacement, particularly at the basin‐scale, remains poorly understood. We use 3D seismic reflection data from the Santos Basin, offshore Brazil to image 38 igneous intrusions spatially related to thick Aptian salt. Based on identified seismic–stratigraphic relationships, we suggest sill emplacement likely occurred during the late Albian‐to‐Santonian. We show intra‐salt sills are geometrically similar to but laterally offset from supra‐salt sills. We suggest ascending magma was arrested by the salt in some areas, but not others, perhaps due to differences in evaporite lithology. Our mapping also reveals most sills occur within and above the presalt Merluza Graben, an area characterized by Albian‐to‐Neogene, salt‐detached extension. In adjacent areas, where there are few intrusions, salt deformation was driven by post‐Santonian diapir rise. We suggest emplacement of hot magma within evaporites above the Merluza Graben enhanced Albian‐to‐Santonian salt movement, but that crystallization of the intrusion network restricted post‐Santonian diapirism. Our work indicates salt–magma interaction can influence salt tectonics, as well as the distribution of magma plumbing systems, and thus could impact basin evolution
Agregação do solo cultivado com gramíneas e leguminosas solteiras e consorciadas na região de Rolim de Moura - Ro.
O trabalho objetivou avaliar a estabilidade de agregados em Latossolo Vermelho Amarelo com textura franco argilosa, utilizado com gramíneas e leguminosas em cultivo solteiro e consorciado. O delineamento experimental foi blocos ao acaso em parcela subdividida contento oito tratamentos principais e três secundários em 04 repetições. Os parâmetros analisados foram, diâmetro médio ponderado dos agregados via úmida (DMPAu) e via seca (DMPAs), índice de estabilidade de agregados (IEA) através da relação DMPAu/DMPAs e niveis de matéria orgânica do solo. O Consórcio Brachiaria brizantha + amendoim é mais eficiente na formação de agregados estáveis em água nos primeiros 10 cm de profundidade e o milho solteiro, nos outros 20 cm a Brachiaria brizantha, amendoim, Panicum maximum em cultivo solteiro e o consórcio Panicum maximum + amendoim foram pouco influentes na formação de agregados estáveis em água
Detection of Mitochondrial COII DNA Sequences in Ant Guts as a Method for Assessing Termite Predation by Ants
Termites and ants contribute more to animal biomass in tropical rain forests than any other single group and perform vital ecosystem functions. Although ants prey on termites, at the community level the linkage between these groups is poorly understood. Thus, assessing the distribution and specificity of ant termitophagy is of considerable interest.We describe an approach for quantifying ant-termite food webs by sequencing termite DNA (cytochrome c oxidase subunit II, COII) from ant guts and apply this to a soil-dwelling ant community from tropical rain forest in Gabon. We extracted DNA from 215 ants from 15 species. Of these, 17.2% of individuals had termite DNA in their guts, with BLAST analysis confirming the identity of 34.1% of these termites to family level or better. Although ant species varied in detection of termite DNA, ranging from 63% (5/7; Camponotus sp. 1) to 0% (0/7; Ponera sp. 1), there was no evidence (with small sample sizes) for heterogeneity in termite consumption across ant taxa, and no evidence for species-specific ant-termite predation. In all three ant species with identifiable termite DNA in multiple individuals, multiple termite species were represented. Furthermore, the two termite species that were detected on multiple occasions in ant guts were in both cases found in multiple ant species, suggesting that anttermite food webs are not strongly compartmentalised. However, two ant species were found to consume only Anoplotermes-group termites, indicating possible predatory specialisation at a higher taxonomic level. Using a laboratory feeding test, we were able to detect termite COII sequences in ant guts up to 2 h after feeding, indicating that our method only detects recent feeding events. Our data provide tentative support for the hypothesis that unspecialised termite predation by ants is widespread and highlight the use of molecular approaches for future studies of ant-termite food webs
Evidence for increasing global wheat yield potential
Wheat is the most widely grown food crop, with 761 Mt produced globally in 2020. To meet the expected grain demand by mid-century, wheat breeding strategies must continue to improve upon yield-advancing physiological traits, regardless of climate change impacts. Here, the best performing doubled haploid (DH) crosses with an increased canopy photosynthesis from wheat field experiments in the literature were extrapolated to the global scale with a multi-model ensemble of process-based wheat crop models to estimate global wheat production. The DH field experiments were also used to determine a quantitative relationship between wheat production and solar radiation to estimate genetic yield potential. The multi-model ensemble projected a global annual wheat production of 1050 +/- 145 Mt due to the improved canopy photosynthesis, a 37% increase, without expanding cropping area. Achieving this genetic yield potential would meet the lower estimate of the projected grain demand in 2050, albeit with considerable challenges
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