Preliminary selection of acerola genotypes in Brazil

Introduction. Breeding studies for acerola (Malpighia glabra) improvement aim at obtaining plants that produce fruits with uniform chemical and physical attributes, including high levels of vitamin C, which can provision the market with fresh fruit and frozen pulp. High variability in fruit quality is observed in Brazilian acerola crops, especially those propagated by seeds. In this context, the objective of our research was to evaluate the physical and chemical characteristics of Brazilian acerola genotype fruits. Materials and methods. Sixteen acerola genotypes were studied in Jaboticabal, São Paulo State, Brazil. A completely randomized design with sixteen treatments and six replications was adopted. Each treatment was represented by one genotype. Several parameters related to fruit quality, such as width, length, weight, pulp percentage, soluble solids (SS), titratable acidity (TA), [SS / TA] ratio and vitamin C content, were evaluated in fruits of the acerola genotypes. The results were submitted to variance analyses, the Tukey test and cluster analysis. Results and discussion. There was a statistical difference between the acerola genotypes studied. Three of them stood out as natural sources of vitamin C. In spite of fruit size, two acerola genotypes were found to have potential for fresh fruit production. In a general form, genotypes that presented a high [SS / TA] ratio had low vitamin C content. Conclusion. The acerola genotypes studied in Jaboticabal presented high variability, forming eleven groups in relation to fruit quality parameters. © 2007 Cirad/EDP Sciences All rights reserved.

Dinâmica da regeneração do subsolo de áreas degradadas dentro do bioma Cerrado

The objective of this research was to evaluate the physical and chemical conditions of revegetated subsoil in degraded areas in a Cerrado biome and to verify which plants promote better conditions for soil recovery. The research was conducted in the remaining area of the hydroelectrical plant site at Ilha Solteira (SP). The experimental design was a completely randomized with five treatments and three replications. The treatments consisted of: natural regeneration area, brachiaria area, Pinus sp. area, exposed soil area and Cerrado grassland (used as control). The following soil characteristics were appraised: porosity; density, stability of aggregates, infiltration rate, temperature, exchangeable cations, organic matter, pH and potential acidity. The results show that Pinus is not a good species to recover the chemical attributes of the subsoil. The revegetated areas need to be improved in their physical attributes to allow a better development of the vegetation. Brachiaria and the natural regeneration were the most promising treatments, presenting results similar to natural Cerrado.

Atributos químicos e físicos de um solo tratado com biossólido industrial e cultivado com milho

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Determination of the quality index of a Paleudult under sunflower culture and different management systems

Soil is an essential resource for life and its properties are susceptible to be modified by tillage systems. The impact of management practices on soil functions can be assessed through a soil quality index. It is interesting to assess soil quality in different soil types. Therefore, the aim of this study was to determine the soil quality index of a Paleudult under different management conditions and sunflower culture. The experiment was carried out in Botucatu (SP, Brazil), in an 11-year non-tilled area used for growing soybean and maize during summer and black oat or triticale in winter. Four management systems were considered: no-tillage with a hoe planter (NTh), no-tillage with a double-disk planter (NTd), reduced tillage (RT) and conventional tillage (CT). Soil samples were taken from the planting lines at harvest time. To determine the soil quality indices, following the methodology proposed by Karlen and Stott (1994), three main soil functions were assessed: soil capacity for root development, water storage capacity of the soil and nutrient supply capacity of the soil. The studied Paleudult was considered a soil with good quality under all the observed management systems. However, the soil quality indices varied between treatments being 0.64, 0.68, 0.86 and 0.79 under NTh, NTd, RT and CT, respectively. Physical attributes such as resistance to penetration and macroporosity increased the soil quality index in RT and CT compared to NTh and NTd. The soil quality indices obtained suggested that the evaluated soil is adequate for sunflower production under our study conditions. In view of the SQI values, RT is the most suitable management for this site since it preserves soil quality and provides an acceptable sunflower yield. © 2011 Elsevier B.V.

Influência de diferentes sistemas de cultivo nos atributos físicos e no carbono orgânico do solo

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Atributos físicos do solo em diferentes condições de cobertura vegetal em área de plantio direto

The use of cover crops in the soil causes changes in soil attributes influencing in a series of hydro-physical processes, which also modify the ability of soil to support the many activities that it is intended. Thus, the objective of this study was to evaluate the effect of cover crops on physical attributes of the soil. For this, an experiment was carried out on a Typic Hapludox, Jaboticabal State, Brazil, using cover crops of millet, sunn hemp, jack bean, lab-lab and black velvet bean in no-tillage and fallow area (spontaneous vegetation). The characteristics evaluated were the bulk density, macroporosity, microporosity, total porosity, aggregate stability, penetration resistance and organic matter. The incorporation of cover crops has proved to be a beneficial practice for the physical attributes of the soil, allowing a greater aggregate stability compared to fallow in the depth of 0-0.05 m. All cover crops presented values of soil penetration resistance below the critical value of 2 MPa.

Avaliação da capacidade de uso da terra da bacia do córrego do cavalheiro - Analândia, SP

Environmental factors are important in agriculture and need to be considered for getting good degree of development and reasonable efficiency, by reducing their operating costs. To this end, land use shall be appropriated to the conditions offered by the physical elements of the landscape. By facing such questions, this paper aims is to present of mapping the ability of land use of the hydrographic basins Cavalheiro Stream basin (in the city of Analândia - São Paulo State - Brazil) which presents serious erosion problems. Besides it aims to assess if the current land use in this area is consistent with the identified land use ability. For this we have made a cartographic document that spatializes the various classes of usability and its main restrictions. The correlative analysis between that document and land use data showed that Cavalheiro Stream's current use is predominantly inappropriate with the usability of land, which was identified from the physical attributes of the studied area, except for a few sites that are used for forestry and pasture placed in Western, Eastern and Central-South.

Sistemas de manejo e atributos físico-hídricos de um Latossolo Vermelho cultivado com milho

The purpose of this experiment was to evaluate the hydro-physical attributes of the Red Oxisol cultivated with maize in Jaboticabal, São Paulo State, Brazil, under different systems of use and periods of adoption of managements. The experiment was arranged in a completely randomized design with split-plot arrangement, with six replications and the treatments were: six years of no-tillage system (SPD6), eight years of no-tillage system (SPD8), ten years of no-tillage system (SPD10), conventional tillage system (SPC) and an adjacent area of native forest (NF). The soil penetration resistance (PR), density, macroporosity, microporosity of the soil in layers of 0-0.05; 0.05-0.10 and 0.10-0.20 m, and the saturated hydraulic conductivity (Kθ) in 0.15 m depth were evaluated. It was found that the PR conditions were favorable for the cultivation to 0.20 m, indicating a structure preserved even after soil chiseling. Furthermore, the Kθ in the soil showed similar behavior between SPC and periods of SPD, although this was shown in a part of maize cycle, macroporosity values near 0.10 m3 m-3 and soil water tensions near 0.09 MPa.

Variabilidade espacial dos atributos físicos em um Argissolo Vermelho sob floresta

This study aim to evaluate the spatial variability of soil physical attributes in of Alfissol forest in Manicoré region, AM. The mapping of an agroforestry growing area of 70×70m was made using a regular grid sampling of 10 × 10m. In each grid, soil samples were collected at 0.0-0.2 and 0,40-0,60 m depth, with a total of 128 sample points. Physical analyses were made (texture, soil bulk and particles density, macro and microporosity, total porosity and aggregates stability in water). With the exception of DMG, DMP and class aggregates <1.00 mm had all the physical attributes spatial dependence structure ranging from moderate to weak. Values were above the range established in the mesh (12.00 to 45.56 m), enabling to make a basis for future studies in forest area. The physical attributes presented in kriging maps different spatial behavior, however there are relationships between these attributes shown by geostatistics proving that this is effective tool for studies in forest area.

Variabilidade espacial da resistência mecânica do solo à penetração e umidade do solo em área cultivada com cana-de-açúcar na região de Humaitá, Amazonas, Brasil

The mechanical resistance to penetration (RP) is an attribute indicator of compaction was influenced by soil moisture. The objective of this study was to evaluate the spatial variability of soil resistance to penetration and soil moisture on area under cultivation of sugar cane in the region of Humaitá, Amazonas, Brazil. We conducted a sampling grid of 70x70 m where points were scored at regular intervals of 10 m, a total of 64 points. Soil samples were collected at depths of 0.00 to 0.15 m, 0.15 to 0.30 I 0.30 to 0.45 m for determination of soil moisture and soil resistance to penetration in the field. After analysis of these data analyzes were descriptive statistics and geostatistics. We conclude that all the variables studied showed spatial dependence and range values were higher than stipulated by the sampling grid and the RP and soil moisture showed a spatial relationship where lower values of PR concentrated on smaller values of soil moisture.

Análise de imagens no estudo da porosidade em latossolo cultivado com batata (Solanum tuberosum L.) sob dois sistemas de irrigação

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Semeadura de braquiária em consorciação com milho em diferentes espaçamentos na integração agricultura-pecuária em plantio direto

Pós-graduação em Agronomia - FEIS

Comportamento de variedades de soja em condições de solo compactado e níveis de irrigação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Indicadores de qualidade de um Latossolo Vermelho após onze anos em sistemas de cultivos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Escoamento superficial e risco de erosão do solo na sub-bacia Jardim Novo Horizonte, Município de Ilha Solteira-SP

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)