Calagem, adubação e nutrição mineral de Anonáceas

Among the edaphic factors, those related to acidity are the ones that affect productivity, especially in tropical regions. For culture the Annonaceae, no research results that indicate the proper base saturation, nor the determination of doses, times, application methods and sources of nutrients for orchards Annonaceae in training and production in order to promote sustainability and higher yields. Given the importance and potential of commercial exploitation of Annonaceae in Brazil and, considering the limited available scientific information on liming, fertilization and nutrition of fruit plants of this family, some research has to be carried out urgently due to the effects of nutrients on productivity, fruit quality, post-harvest, tolerance to pests and diseases, etc.

Controle de doenças fúngicas e de danos por frio em pós-colheita de lima ácida Tahiti

The Tahiti lime appears very susceptible to attack by post-harvest diseases, primarily by the fungi Penicillium and Phomopsis, and also because of its high sensitivity to storage at low temperatures. In order to reduce such damage, the present study aimed to verify the efficiency of heat treatment and disinfection of pathogens in the prevention of post-harvest chilling injury of this cultivar and to compare this treatment with other products using the conventional fungicides. The heat treatments were studied with hot-water temperatures ranging between 48 and 56° C. Water at room temperature was used as a control treatment. After treatment, the fruits were kept under cold temperature at 10° C and RH 90% for about 45 days. For comparison, three other treatments were carried out simultaneously, one using imazalil, one with baking soda, and a third with sodium carbonate, these three products being applied by baths in cold water. Two groups of fruit were evaluated, one treated by immersion considering pathogens coming from the field and another by inoculation with spores of the previously isolated pathogens. For the evaluation of physical and chemical parameters of fruits, determinations were made of the skin color, texture, weight loss, size, juice yield, soluble solids, total acidity and vitamin C content. The determination of the sensitivity of the fruit to cold was made by their exposure at temperatures inducing cold damage. The design was a randomized block design with nine treatments, analyzed by the Statgraphics statistical package. Heat treatments, especially at 52° C, were shown to be more promising in the control of pathogenic fungi and cold damage, surpassing the conventional fungicides. No changes were found in the intrinsic and extrinsic parameters in relation to the application of the different treatments.

Nutritional balance and yield for green manure orange trees

Intercropping could efficiently prevent soil nutrient losses caused by extensive agriculture. The present study aimed to assess the effect of green manure on the nutritional status of orange trees cultivar 'Pera' (Citrus sinensis (L.) Osbeck). The plants were grafted on 'Cravo' lime trees and were then planted in a 7x4m space. Four different treatments corresponding to the evaluated green manures were employed: jack bean (JB) (Canavalia ensiformis DC), lablab (LL) (Dolichos lablab L.), pigeon pea (PP) (Cajanus cajan L. Millsp), and Brachiaria (BQ) (Brachiaria brizantha Hochst ex A. Rich. Stapf) as control. The experimental design was in randomized blocks, in split-plot time, with six replicates, with four treatments (green manures) and two plants per evaluation. The nutritional status was assessed by using the DRIS method (Diagnosis and Recommendation Integrated System); the yield and the macro and micronutrient levels contained in green manures and in the control was also determined. The nutritional diagnosis indicated that, in the two years of experiment, plants treated with green manure showed better nutritional balance index compared to Brachiaria. This suggests that, over time, green manure can lead to better nutritional balance. Pigeon pea treatment showed the highest yields, compared to control, in the two evaluated crop cycles (2004/05 and 2005/06).

Determination of reactivity rates of silicate particle-size fractions

The efficiency of sources used for soil acidity correction depends on reactivity rate (RR) and neutralization power (NP), indicated by effective calcium carbonate (ECC). Few studies establish relative efficiency of reactivity (RER) for silicate particle-size fractions, therefore, the RER applied for lime are used. This study aimed to evaluate the reactivity of silicate materials affected by particle size throughout incubation periods in comparison to lime, and to calculate the RER for silicate particle-size fractions. Six correction sources were evaluated: three slags from distinct origins, dolomitic and calcitic lime separated into four particle-size fractions (2, 0.84, 0.30 and <0.30-mm sieves), and wollastonite, as an additional treatment. The treatments were applied to three soils with different texture classes. The dose of neutralizing material (calcium and magnesium oxides) was applied at equal quantities, and the only variation was the particle-size material. After a 90-day incubation period, the RER was calculated for each particle-size fraction, as well as the RR and ECC of each source. The neutralization of soil acidity of the same particle-size fraction for different sources showed distinct solubility and a distinct reaction between silicates and lime. The RER for slag were higher than the limits established by Brazilian legislation, indicating that the method used for limes should not be used for the slags studied here.

Aplicação de corretivos de acidez do solo na implantação do sistema plantio direto

Pós-graduação em Agronomia (Agricultura) - FCA

Culturas de cobertura, residual de nitrogênio e reaplicação de calcário em sistema plantio direto: cultura da soja

Pós-graduação em Agronomia - FEIS

Atributos da solução e do solo de cerrado após aplicação de resíduo da extração de celulose

Pós-graduação em Agronomia - FEIS

Properties of Mortar Using Cubes, Prism Halves, and Cylinder Specimens

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The influence of citrus rootstocks on the relationship between the mite Brevipalpus phoenicis and citrus leprosis disease

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

Cana-de-açúcar hidrolisada para vacas em lactação

Pós-graduação em Zootecnia - FCAV

Emissão de CO2 do solo associada à calagem em área de conversão de laranja para cana-de-açúcar

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

Fitodisponibilidade de metais utilizando ácidos orgânicos após sucessiva aplicação de resíduos no solo

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

Nutrient accumulation and biomass production of alfafa after soil amendment with silicates

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

Interação fungo micorrízico arbuscular e adubação fosfática no crescimento e absorção de nutrientes pelo porta-enxerto limoeiro Cravo

Estudou-se o efeito da inoculação com fungo micorrízico arbuscular (FMA), Glomus etunicatum, Glomus clarum, ou Scutelospora heterogama, e da adição de fósforo solúvel (15, 30, 45, 60, 120 e 240 mg de P kg-1 de terra) sobre as variáveis altura, número de folhas, diâmetro do caule, massas vegetais aérea e radicular, teores de nutrientes nas folhas e colonização micorrízica no porta-enxerto limoeiro Cravo (Citrus limonia (L.) Osbeck). Os FMAs, Glomus etunicatum e Glomus clarum, e doses crescentes de fósforo exerceram efeitos significativos sobre essas variáveis. O efeito da inoculação sobre as variáveis de crescimento vegetal foi mais acentuado nos tratamentos com adição de 30 a 60 mg de P kg-1 de terra. Para o teor de P foliar, o efeito da inoculação foi mais acentuado nos tratamentos adicionados de 120 a 240 mg de P kg-1 de terra. A inoculação com estes FMAs aumentou a eficiência do limoeiro Cravo em absorver nutrientes, tanto que as variáveis estudadas em plantas inoculadas na ausência de adubação fosfática superaram às de plantas não inoculadas em substrato adicionado de 240 mg de P kg-1 de terra.

Characterization and properties of elephant grass ashes as supplementary cementing material in pozzolan/Ca(OH)(2) pastes

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