Determination of physical, chemical and biological attributes with individual analyses is inadequate for improving the understanding of soil conditions as a function of land-use change (LUC) in comparison to the natural state of soil. For a more accurate soil condition diagnostic, it is necessary to consider various indicators related to these characteristics, which requires the use of multivariate statistical analysis. The aim of this work was to characterize, through multivariate analysis, different types of LUCs in an Oxisol as a function of the physical, chemical and biological attributes and to clarify the relationship of these attributes with the quality of the soil in comparison to these attributes in natural soil conditions, in the southern Amazon in Brazil. The land uses evaluated in the municipality of Alta Floresta, state of Mato Grosso (MT), Brazil, were native amazon forest (ma), degraded pasture (pd), managed renewed pasture (pn), permanent preservation area in recovery (app), crop area (rice), forage sugarcane (ca) and reforested area with eucalyptus (eu). To characterize the physical and chemical soil attributes, samples were collected in each land-use area, at depths of 0-0.10 and 0.10-0.20 m, and the determination of soil microbial activity (biological attributes) was evaluated at a depth of 0-0.10 m. The interrelationship between the analyzed attributes was described by multivariate techniques, which included hierarchical and non-hierarchical cluster analyses, principal component analysis, canonical correlation, and structural equation modeling. The multivariate approach for the analysis of soil attribute data was efficient in the identification of anthropogenic actions on areas in comparison to natural conditions. Together, the cluster analysis and principal components analysis identified two groups that differed mainly in terms of anthropic operations of soil tillage and liming. The land use that was most similar to the natural condition was degraded pasture, which was mainly due to K and H + Al contents, soil microporosity and soil basal respiration. Structural equation modeling indicated that the latent factor soil chemical attributes had three times greater interference (-0.5828) than the latent factor soil physical attributes (0.1735) on the latent factor soil biological attributes. Therefore, anthropic actions, especially the liming, modified soil acidity conditions, affecting the microorganisms of its flora and changing the native fungal community of the soil that was evaluated. large areas, mainly through the inadequate conversion of natural environments into agricultural areas (Fonseca et al., 2007; Rojas et al., 2016). The main impact of LUC is on in the soils, which are directly responsible for the sustainability and productivity of natural and agricultural ecosystems (Castilho et al., 2016; Novak et al., 2017; Sanabria et al., 2016). Studying the physical, chemical and biological attributes of soil in different applications and comparing these attributes to those in areas

RESUMO:As plantas daninhas, de forma geral, causam transtornos e prejuízos para diversos agricultores.O capim-navalhão (Paspalum virgatum) tem se destacado como uma agressiva planta daninha de pastagens em diversas regiões, especialmente em áreas de solo mais úmido. A sua baixa palatabilidade, grande produção de semente, tolerância a diferentes condições de estresse ambiental, e principalmente sua semelhança morfológica, fisiológica e bioquímica com as gramíneas forrageiras dificultam seu controle. O conhecimento da capacidade germinativa das sementes de plantas daninhas pode gerar subsídios para a adoção de práticas de manejo, visando reduzir sua população em ambiente agrícola ou de criações.O presente trabalho objetivou estudar os aspectos germinativos das sementes de capim-navalhão, visando avaliar a superação de dormência de suas sementes nos seguintes tratamentos: escarificação química utilizando ácido sulfúrico (H 2 SO 4 ), por 1, 5 e 15 minutos; embebição em água em temperatura ambiente por 2, 4, 8 e 16 horas; embebição em hipoclorito de sódio por 1, 5, 10 e 15 horas; e armazenamento em temperatura elevada (40 ºC) por 0, 23, 28, 33 e 38 dias. Assim, nas condições experimentais deste estudo, o uso de escarificação química proporcionou a maior percentagem e índice de velocidade germinativa de sementes de P. virgatum, assim como o método de armazenamento em temperatura elevada (40 ºC), especificamente por 23 e 33 dias.Temperaturas elevadas, tais como ocorrem no solo podem contribuir para a quebra de dormência das sementes capim-navalhão, assemelhando-se ao ato dos ruminantes ao se alimentarem das partes da gramínea, passando pelo trato digestivo,que possui efeito semelhante ao do ácido sulfúrico, contribuindo assim para que ocorra a quebra de dormência e,posteriormente disseminam as sementes da espécie. Palavras chave: Paspalum virgatum.planta daninha.Germinação.temperatura elevada.hipoclorito de sódio.

No presente trabalho, foi avaliado o efeito da salinidade sobre a germinação de sementes e desenvolvimento pós-seminal de Ochroma pyramidale através de três agentes osmóticos (NaCl, CaCl2 e KCl), em dois experimentos. No primeiro, foi avaliado o estresse salino na germinação em esquema fatorial de 3 x 6, utilizando NaCl, CaCl2 e KCl, e seis potenciais osmóticos (0,0; -0,1; -0,2; -0,4; -0,6 e -0,8 MPa). No segundo experimento, estudou-se o crescimento inicial de plântulas, utilizando os mesmos agentes osmóticos, em quatro potenciais osmóticos (0,0; -0,1; -0,2 e -0,3 MPa), no delineamento inteiramente ao acaso esquema fatorial 3 x 4. O efeito da salinidade interferiu na germinação de sementes O. pyramidale, havendo redução à medida que os potenciais se tornaram mais negativos à produção de massa seca de plântula, percentual de germinação e velocidade do processo germinativo. No potencial osmótico de -0,8 MPa, ocorreu inibição total, evidenciando que o CaCl2 apresentou um efeito inibitório mais acentuado que o NaCl, seguido pelo KCl. No desenvolvimento de plantas, o NaCl provocou maior sensibilidade, comparando-se ao CaCl2 nos maiores potenciais osmóticos.Palavras-chave: Pau-de-balsa; germinabilidade; potencial osmótico; estresse salino. EFFECT OF SALINITY IN THE GERMINATION AND DEVELOPMENT OF Ochroma pyramidale SEEDLINGS ABSTRACT: In the present study, the effect of salinity on seed germination and post-seminal development of Ochroma pyramidale was evaluated through three osmotic agents (NaCl, CaCl2 and KCl) in two experiments. In the first experiment, salt stress in germination was evaluated in a factorial scheme 3 x 6, using NaCl, CaCl2 and KCl; and six osmotic potentials (0.0, -0.1, -0.2, -0.4, -0.6 and -0.8 MPa). In the second experiment, the initial development of plants, using the same osmotic agents, was studied in four osmotic potentials (0.0; -0.1; -0.2 and -0.3 MPa), in a completely randomized design 3 x 4 factorial scheme. The effect of salinity interfered on the germination of O. pyramidale seeds, with reduction as the potentials became more negative for the production of dry seedling mass, percentage of germination and germination speed. In the osmotic potential of -0.8 MPa, total inhibition occurred, evidencing that CaCl2 had a stronger inhibitory effect than NaCl, followed by KCl. In the development of plants, NaCl caused greater sensitivity when compared to CaCl2 in the highest osmotic potentials.Keywords: Pau-de-Balsa wood; germinability; osmotic potential; saline stress.

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The aim of this research was to evaluate the fungitoxicity of high dilutions of tectonic (Tectona grandis) extract in mycelial growth, sporulation and germination of the fungus Colletotrichum gloeosporioides. In a completely randomized design with six dynamizations of the pyroligneous extract (3, 9, 15, 21, 27 and 33 CH) and three controls (distilled water, mother tincture, 30% hydroalcoholic solution) with four replicates each. All treatments were diluted to 0.1% in BDA medium. Mycelial growth rate index, relative percentage of mycelial development (PRD%), inhibition of sporulation and spore germination (%) were evaluated. The treatments did not differ among them for mycelial growth, percentage of spore germination and IVCM. The PRD and sporulation variables varied according to the dynamization, with a maximum reduction of 7% in PRD (33 CH) and a 70% increase in sporulation (3 and 21 CH). The dynamized pirolenous extract did not present expressive fungitoxicity in the growth, sporulation and germination of C. gloeosporioides.