Avaliação de dois diferentes meios de cultura para o desenvolvimento de biopesticidas à base de Bacillus thuringiensis e sua aplicação em larvas de Aedes aegypti

The bacteria Bacillus thuringiensis var. israelensis (Bti) generates certain toxins with pesticide action, which can be used on the control of transmissible diseases by culicides, specially Aedes aegypti, the dengue vector. This biopesticide has been produced by submerged fermentation and, in Brazil, this production has been made by very little research centers and, more recently, by a unique small enterprise. For the implementation of a viable vectors control program through biopesticides, some studies about culture media are essential in order to join efficiency and low costs. In this way, agroindustrial wastes or by-products have been used as a nutrient source for the culture media production. In this study, corn steep liquor, a corn industrial processing by-product and tryptose, both with/without sugar addition, were compared as culture media. Cellular growth was evaluated by optical density at 620 nm, spore production by total viable cell count and LC50 by bioassays against 4th instar larvae. Among the four examined substrates, the medium composed by glucose plus corn steep liquor presented the best spore production and bioassay results.

Assessment of the genotoxicity of two agricultural residues after processing by diplopods using the Allium cepa assay

Agroindustrial by-products and residues from treatment of sewage sludge have been recently recycled as soil amendments. This study was aimed at assessing toxic potential of biosolid, obtained from a sewage treatment plant (STP), vinasse, a by-product of the sugar cane industry, and a combination of both residues using Allium cepa assay. Bioprocessing of these samples by a terrestrial invertebrate (diplopod Rhinocricus padbergi) was also examined. Bioassay assembly followed standards of the Brazilian legislation for disposal of these residues. After adding residues, 20 diplopods were placed in each terrarium, where they remained for 30 days. Chemical analysis and the A. cepa assay were conducted before and after bioprocessing by diplopods. At the end of the bioassay, there was a decrease in arsenic and mercury. For the remaining metals, accumulation and/or bioavailability varied in all samples but suggested bioprocessing by animals. The A. cepa test revealed genotoxic effects characterized by different chromosome aberrations. Micronuclei and chromosome breaks on meristematic cells and F1 cells with micronuclei were examined to assess mutagenicity of samples. After 30 days, the genotoxic effects were significantly reduced in the soil + biosolid and soil + biosolid + vinasse groups as well as the mutagenic effects in the soil + biosolid + vinasse group. Similar to vermicomposting, bioprocessing of residues by diplopods can be a feasible alternative and used prior to application in crops to improve degraded soils and/or city dumps. Based on our findings, further studies are needed to adequately dispose of these residues in the environment. © 2013 Springer Science+Business Media Dordrecht.

Control de la chinche de los pastos Collaria scenica (Hemiptera: Miridae) con nematodos entomopatógenos en invernadero

We studied the efficacy of infective juveniles (IJ) of Steinernema sp. strain JCL024 and Heterorhabditis sp. strain SL0708 on adults and nymphs of Collaria scenica under greenhouse conditions. Five doses were evaluated (2, 16, 78, 160 IJ) cm-2 leaf) for each nematode. The experiment was evaluated for 21 days every 24 hours, making mortality counts and assessment of damage on Kikuyo grass. The bugs showed 100% mortality after 15 days. Each bug produced an average of 13,000 IJ/6 days. As for the damage did not reach level 2 within 21 days prior to treatment without nematodes that damage introduced 3 with necrosis and apical leaf curl. Thus, Steinernema sp. strain JCL024 and Heterorhabditis sp. strain SL0708 exercised control bug on the grass and kept under the level of damage to the foliage.

Analysis of efficiency and rationality in a sugar-alcohol mill using hyperboloid a-load and potency

Brazil is the world's largest producer of sugar cane and which in the state of São Paulo concentrate the greatest amount of sugar cane field of the country. The sugar-alcohol sector has the capacity to produce sufficient thermal and electrical energy to be used in their process of production and commercialize of surplus in electricity distribution network. Therefore it is necessary to evaluate the energy efficiency and rationality within the mill. Accordingly this research proposed analyze the sugar-alcohol mill's sectors globally and individually, located in the west center of the São Paulo state, using the valuation methodology employed by the Agência Nacional de Energia Elétrica (ANEEL) in the industries that do not have systems of cogeneration. In this analysis, the hyperboloids of load and potency were applied based on the indexes of potency factor and load factor that allow estimate the efficiency and rationality. © 2013 IEEE.

Respostas fisiológicas de cultivares de cana-de-açúcar a herbicidas seletivos

The use of selective herbicides to control weeds has caused different responses in cultivars of sugar cane, and some products affect physiological characteristics and reduce the photosynthetic activity. This study aimed to evaluate the physiological traits in cultivars of sugar cane under the effect of applying post-emergence herbicides. The test was developed in Jau, SP. The experimental design was randomized blocks in factorial scheme 5 x 4 (cultivar x herbicide) with four replications. SP81-3250, RB855156, RB855453, RB867515, IACSP95-5000 were grown in this studied. Herbicides clomazone (1200 g i.a.ha-1); commercial mixture of clomazone + ametryn (1000 + 1500 g i.a.ha-1) and ametryn (3000 g i.a.ha-1) and a control were applied at 30 days after planting. Cultivars IACSP95-5000 and RB867515 were less affected physiologically and can be considered selective to these herbicides. The application of clomazone and ametryn affected negatively the traits maximum photochemical efficiency of photosystem II (Fv/Fm), SPAD index and photosynthetic pigments, but the mixture of these herbicides caused higher reductions, indicating to be the more aggressive to the cultivars.

Eficácia do herbicida mesotrione aplicado no sistema de cana crua

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Seletividade do herbicida saflufenacil aplicado em pós-emergência em dez variedades de cana-de-açúcar na condição de soca

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Tolerância de Digitaria ciliaris, Digitaria horizontalis e Digitaria nuda à herbicidas usados em cana-de-açúcar

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Eficácia da mistura de glifosato a outros maturadores na cana-de-açúcar (Saccharum spp.)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Thiametoxam em cana-de-açúcar manejada com maturadores

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Caracterização espectral e espacial de áreas infestadas por nematóides e Migdolus fryanusem em cultura canavieira

Pós-graduação em Ciências Cartográficas - FCT

Identificação do teor de nitrogênio foliar em cana-de-açúcar no estágio inicial de crescimento utilizando infravermelho próximo e sistemas inteligentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeitos de doses subletais do imidaclopride no cérebro, ventrículo e túbulo de Malpighi de Apis melifera africanizada

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos das doses subletais de fipronil para abelhas africanizadas (Apis mellifera L.), por meio de análises morfológicas e comportamentais

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

A escória de siderurgia como material corretivo e a interação com a adubação nitrogenada em cana-de-açúcar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)