Adubação nitrogenada do consórcio milho/braquiária para manutenção do sistema plantio direto no cerrado Sul-Matogrossense

Como alternativa para aumento da produtividade dos sistemas de produção agrícola, surgiu o Sistema de Integração Lavoura-Pecuária. Desta maneira, o presente trabalho objetivou avaliar para o consórcio milho/Brachiaria submetido a doses de N em cobertura, em um Latossolo Vermelho distroférrico do sul do Estado do Mato Grosso do Sul nas condições de integração lavoura/pecuária, o seguinte: 1) os teores nutricionais e as leituras do índice de clorofila foliar (ICF) em folhas de milho, assim como os respectivos componentes da produção e a produtividade de grãos, objetivando caracterizar a melhor dose de N para o consórcio, e 2) em relação às espécies de Brachiaria, após o consórcio, com o objetivo de nortear a manutenção do SPD pesquisado, efetuaram-se avaliações da produtividade de fitomassa, dos teores nutricionais, da composição bromatológica e da taxa de decomposição da palhada, durante os anos agrícolas 2008/2009 e 2009/2010, na Fazenda de Ensino, Pesquisa e Extensão, da Faculdade de Engenharia - Unesp, Campus de Ilha Solteira, com histórico de oito anos sob SPD. O delineamento experimental utilizado foi o de blocos casualizados, com quatro repetições, em esquema fatorial 2 x 5, sendo duas espécies de Brachiaria (brizantha e ruziziensis) e cinco doses de N (uréia) em cobertura (0, 50, 100, 150 e 200 kg ha-1). A Brachiaria brizantha, no consórcio com o milho, foi a espécie menos competitiva. A adubação nitrogenada utilizada nessa consorciação, até a dose de 200 kg ha-1 de N, incrementou a nutrição, o crescimento, os componentes da produção e a produtividade de grãos do milho. Dessa forma, a adubação nitrogenada deve ser recomendada para o consórcio, e não isoladamente para as culturas. Embora tenha havido uma maior produtividade de massa seca da B. brizantha, a B. ruziziensis apresentou melhor composição bromatológica e...

Distribuição ecológica e dinâmica populacional do camarão barriga branca Nematopalaemon schmitti (Holthuis, 1950) (Caridea, Palaemonidae) na região de Macaé-RJ, Brasil

Pós-graduação em Ciências Biológicas (Zoologia) - IBB

Efeito da reidratação nos aspectos ecofisiológicos da Copaifera langsdorffii Desf

Pós-graduação em Ciências Biológicas (Botânica) - IBB

Estudo da ocorrência de cianobactérias no reservatório de Nova Avanhandava-SP por meio da inferência do pigmento ficocianina

Pós-graduação em Ciências Cartográficas - FCT

Sugarcane tolerance to ratoon eradication with glyphosate determined by physiological responses

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Portable meters for nutritional assessment in plants of gerbera fertigated with electrical conductivity levels

Rapid tests to assess the nutritional status of plants gerbera can make easier the decision of any adjustments in the fertilization of the substrate. The study was conducted to evaluate nutritionally fertigated gerbera plants with increasing levels of electrical conductivity (EC), using portable meters nitrate and potassium, and chlorophyll. For this, two experiments were conducted. A randomized block design with five levels of EC (0.5, 2.0, 3.5, 5.0 and 6.5 dS m-1) and four replications was used. Cherry cultivar was used in the first experiment. In the second experiment, two cultivars (Cherry and Salmon Rose) were used. In the first experiment, the sap of the leaves was subjected to rapid testing of N-NO3- (equipment Cardy Horiba C -141). N-NO3- and K+ (C-131) were determined in the substrate solution. The intensity of the green leaf, in the second experiment was evaluated with portable Chlorophyll Meter. The N content in the indicator leaf in the first and N and K contents in the plant in the second experiment were determined. Rapid tests are presented as good indicators of the level of N-NO3- and K+ in plant tissue, with the advantages of convenience and speed of determination, facilitating monitoring of fertilization of the substrate by producers and technicians.

A system for environmental monitoring of hydroelectric reservoirs in Brazil

Environmental monitoring of aquatic systems is an important tool to support policy makers and environmental managers' decisions. Long-term, continuous collection of environmental data is fundamental to the understanding of an aquatic system. This paper aims to present the integrated system for environmental monitoring (SIMA), a long-term temporal series system with a web-based archive for limnological and meteorological data. The following environmental parameters are measured by SIMA: chlorophyll-a (µgL-1), water surface temperature (ºC), water column temperature by a thermistor string (ºC), turbidity (NTU), pH, dissolved oxygen concentration (mg L-1), electric conductivity (µS cm-1), wind speed (ms-1) and direction (º), relative humidity (%), shortwave radiation (Wm-2) and barometric pressure (hPa). The data were collected in a preprogrammed time interval (1 hour) and were transmitted by satellite in quasi-real time for any user within 2500 km of the acquisition point. So far, 11 hydroelectric reservoirs are being monitored with the SIMA buoy. Basic statistics (mean and standard deviation) and an example of the temporal series of some parameters were displayed at a database with web access. However, sensor and satellite problems occurred due to the high data acquisition frequency. Sensors problems occurred due to the environmental characteristics of each aquatic system. Water quality sensors rapidly degrade in acidic waters, rendering the collected data invalid. Data is also rendered invalid when sensors become infested with periphyton. Problems occur with the satellites' reception of system data when satellites pass over the buoy antenna. However, the data transfer at some inland locations was not completed due to the satellite constellation position. Nevertheless, the integrated system of water quality and meteorological parameters is an important tool in understanding the aquatic system dynamic. It can also be used to create hydrodynamics models of the aquatic system to allow for the study of meteorological implications to the water body.

Produtividade do milho em condições de diferentes manejos do solo e de doses de nitrogênio

Research has been conducted to identify the best nitrogen (N) rate for maize in most diverse types of soil management. However, there is no agreement on the results, once the dynamic of N is influenced by soil management and cover crops. This study evaluated dry mass production and nutrient uptake by cover crops, agronomic parameters and grain yield of maize in response to soil management and N rates. Field trials were carried out in Selvíria, Mato Grosso do Sul State, Brazil, in the growing seasons of 2009/2010 and 2010/2011, on a clayey Rhodic Haplustox (20º 20' S and 51º 24' W, 340 m asl). Thirty-six treatments were established with four replications, in a randomized blocks design, with the combination of cover crops (millet, Crotalaria juncea and millet + Crotalaria juncea), soil management systems (tillage with chisel plow + lightweight disking, heavy disking + lightweight disking, and no-tillage) and topdressing N rates (0, 60, 90 e 120 kg ha-1 - urea as source). Maize hybrid DKB 350 YG® was used and N applied at stage V5 (fifth expanded leaf). A linear increase with the increase of N rates was observed for chlorophyll leaf index, leaf N content, ear length and diameter, and grain weight and yield. Previously grown sunn hemp and millet + sunn hemp grown, associated with 120 kg ha-1 N for maize, induced a higher grain yield after two growing seasons.

Respostas fisiológicas de genótipos de Eucalyptus grandis x E. urophylla à disponibilidade hídrica e adubação potássica

Conduziu-se este trabalho, com o objetivo de estudar as respostas fisiológicas de cinco genótipos de eucalipto à disponibilidade hídrica e adubação potássica. As mudas foram plantadas em vasos preenchidos com sete litros de um Neossolo Quartzarênico, com baixo teor natural de potássio (0,2 mmol c.dm-3 K), e submetidas a dois regimes de irrigação (RI1 - diário e RI2 - irrigação suspensa até o aparecimento de sintomas iniciais de murcha), sem (K0) e com suprimento de potássio (K1 - 200 mg.dm-3 K2O), em casa de vegetação. Avaliou-se a taxa fotossintética (A), condutância estomática (gs), transpiração (E), índice de conteúdo de clorofila (ICC), conteúdo relativo de água (CRA), eficiência fotoquímica (Fv/Fm), eficiência intrínseca (EUAintr) e instantânea no uso da água (EUAinst) e potencial hídrico foliar (Ψf). O experimento foi estabelecido no delineamento de blocos ao acaso, em esquema fatorial 5 x 2 x 2 (5 genótipos, 2 regimes de irrigação e 2 níveis de adubação potássica), com cinco repetições. À exceção da eficiência fotoquímica, as demais características apresentaram alterações significativas no regime RI2, com redução nos valores de A, gs e E e aumento em ICC e EUAinst. O suprimento de potássio nas plantas do RI2 proporcionou maiores valores de A, gs, E e CRA. Dos genótipos avaliados, o G1 é o mais resistente e o G2 o mais sensível à deficiência hídrica. Conclui-se que a adubação potássica pode amenizar os efeitos negativos da deficiência hídrica nos estádios iniciais de crescimento de eucalipto.

Carotenogênese em células de Haematococcus pluvialis induzidas pelos estresses luminoso e nutricional

The objective of this work was to evaluate the responses of Haematococcus pluvialis cells to the carotenogenesis induction process, under light and nutrition stress. Cells were acclimated during 15 days in WC medium, with aeration with synthetic, filtered atmospheric air and flow rate of 100 mL min-1, light intensity of 50 µmol photons m-2 s-1, photoperiod of 12 hours, and temperature of 23ºC. The following two treatments were compared: cultivation under the described conditions, but with increase of light intensity up to 350 µmol photons m-2 s-1 ; and cultivation under the same conditions as the previous treatment, but with aeration containing 4% CO2. The treatments were done in triplicate, during ten days. With the addition of CO2 and the increment in lighting, an increase was observed in the carotenoids/chlorophyll ratio and cell biomass. Cells stopped dividing on the second day of stress, when nitrate became limiting, and significantly increased their biovolume. The excretion of organic carbon and the concentration of astaxanthin increase in response to the addition of CO2. Stress by light intensity combined with CO2 addition optimizes carotenogenesis in H. pluvialis and increases astaxanthin production.

Effects of some parameters in upscale culture of Haematococcus pluvialis Flotow

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

Efeitos da deriva de clomazone, aplicado isoladamente ou em mistura com ametryn, sobre características produtivas de laranjeira 'Hamlin'

This experiment aimed to evaluate the effect of increasing clomazone (sprayed alone or in mixture with ametryn) drift simulation on quantitative and qualitative aspects of orange production when applied at two developmental plant stages: flowering and initial fruit development (fruits 2 cm diameter or smaller). Increasing drifts of clomazone, in two formulations, and clomazone in mixtures with ametryn were tested. Fruit morphological features, fruit color, flower and fruit abortion and leaf chlorophyll content were evaluated. Simulated drift similar to the recommended dose of clomazone and clomazone plus ametryn caused fruit abortion in citrus at the stage of fruits 2 cm diameter or smaller. Lower drift doses did not result in fruit abortion. Fruit diameter reduction was observed with drift off above 25% of clomazone alone recommended rate and 50% when in mixture with ametryn or in microcapsule formulation. Clomazone drift at 50% of the recommended rate (alone or in mixture with ametryn ) caused clorotic and necrotic spots in the fruit peel. Drift did not affect juice quality in any of the treatments tested.

Adubação nitrogenada e aplicação de herbicidas como reguladores de crescimento em grama esmeralda

Pós-graduação em Agronomia - FEIS

Qualidade de sementes, teor de nitrogênio e expressão gênica em genótipos de milho inoculados com Azospirillum brasilense

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Diagnose da composição nutricional e eficiência de fertilizantes nitrogenados na cultura do milho

Pós-graduação em Agronomia (Produção Vegetal) - FCAV