Conservação de maracujá-doce pelo uso de cera e choque a frio

Estudou-se o efeito do choque a frio e da cera, na conservação pós-colheita do maracujá-doce (Passiflora alata Dryander), verificando as principais alterações físicas e químicas durante o armazenamento. Os frutos, colhidos no estádio pré-climatérico, foram desinfetados com hipoclorito de sódio e em seguida, submetidos aos tratamentos: testemunha; cera Sta fresh (1:2); choque frio (-2°C por 2 horas) + cera Sta fresh (1:2); choque frio (-2°C por 2 horas). Os frutos foram avaliados a cada 6 dias quanto a perda de peso, textura, rendimento de suco, sólidos solúveis totais e acidez total titulável. Após 30 dias a 9°C e 85-90% UR, pode-se concluir que o tratamento mais adequado à conservação do maracujá-doce foi o que utilizou a cera Sta Fresh. Os tratamentos com choque a frio e com choque a frio + cera não foram eficientes para manutenção da qualidade pós-colheita do maracujá-doce.

Adubação nitrogenada e substratos na produção de mudas de maracujazeiro doce

Com o objetivo de avaliar diferentes substratos e doses de nitrogênio na produção de mudas de maracujazeiro doce, conduziu-se um experimento no Setor de Fruticultura do Departamento de Agricultura da Universidade Federal de Lavras (UFLA). Foram estudadas cinco doses de nitrogênio 0; 400; 800; 1600 e 3200 mg de N/dm³ e duas composições de substratos: A (composto orgânico + areia + solo na proporção de 1:1:3 em volume) e B (Plantmax® + areia + solo na proporção de 1:1:3 em volume ). Foi utilizado o delineamento experimental em blocos casualizados em esquema fatorial 5 x 2, com quatro repetições e cinco plantas por parcela. Foi observado que doses elevadas de adubação de cobertura com N podem promover efeitos depressivos nas mudas. E que o melhor substrato foi o B, contendo: Plantmax® + areia + solo na proporção de 1:1:3 em volume.

Larvicultura de trairão (Hoplias lacerdae) em água doce e água salinizada

O experimento foi conduzido com o objetivo de desenvolver técnicas de manejo durante a larvicultura de trairão, realizando cultivos em água doce ou ligeiramente salinizada, utilizando náuplios de Artemia como alimento vivo. No início da alimentação exógena, oito dias após a eclosão, as larvas foram contadas e estocadas em 12 recipientes com volume útil de 1,5 L cada, dotados de sistema de aeração, numa densidade de 10 larvas/L, distribuídos dentro de três tanques de 130 L, contendo água com temperatura controlada (29,5ºC). Os tanques foram totalmente cobertos com lona plástica preta, mantendo o ambiente interno escuro, e descobertos somente para os manejos diários. As larvas foram submetidas a três tratamentos: cultivo em água doce; em água a 2 de salinidade; e em água a 4 de salinidade. Cada tratamento teve quatro repetições. A alimentação foi fornecida nas proporções diárias de 300 náuplios de Artemia/larva, do primeiro ao quinto dia, de 600 náuplios de Artemia/larva, do sexto ao décimo dia e de 900 náuplios de Artemia/larva, do décimo primeiro ao décimo quinto dia, divididos em três refeições. Ao final do experimento, foram avaliadas a sobrevivência, o crescimento (comprimento e peso), a taxa de crescimento específico e a taxa de resistência ao estresse. Após 15 dias de tratamento, não foram verificadas diferenças significativas entre os resultados das variáveis analisadas. As condições de cultivo mostraram-se eficientes, possibilitando altas taxas de sobrevivência (valores médios superiores a 91,6%), sendo a Artemia um alimento atrativo. Os níveis de salinidade utilizados não afetaram o desenvolvimento das larvas e alevinos.

Mandioca e Resíduos das Farinheiras na Alimentação de Ruminantes: pH, Concentração de N-NH3 e Eficiência Microbiana

O objetivo do presente trabalho foi avaliar a concentração de N-NH3, o pH do líquido ruminal e a eficiência de síntese microbiana de rações que continham diferentes fontes energéticas: milho (MI), milho + casca de mandioca desidratada (MC), raspa de mandioca (RM) e farinha de varredura de mandioca (FV). Foram utilizados quatro novilhos da raça Holandesa (270 kg), portadores de cânulas ruminal e duodenal, distribuídos em um delineamento Quadrado Latino 4x4. A cinza insolúvel em ácido foi utilizada como indicador do fluxo duodenal e fecal. Não houve efeito das rações experimentais no pH ruminal. No entanto, menor concentração de N-NH3 foi observada para a ração com FV. O fluxo duodenal de matéria orgânica e nitrogênio e a composição química das bactérias ruminais não foram influenciados pelas rações experimentais. A maior eficiência microbiana aparente foi obtida para a ração com FV. Nas condições do presente experimento a FV, possivelmente apresentou uma melhor sincronização com a fonte protéica (farelo de soja), diminuindo a perda de nitrogênio na forma de N-NH3 e aumentando a eficiência microbiana.

STUDY OF AMNONIFYING BACTERIA BEHAVIOR IN THE LAKES CARIOCA AND D-HELVECIO (RIO-DOCE-VALLEY-MG)

The study of the amnonifying bacteria behavior in the lakes Carioca and D. Helvecio, which belong to the natural lacustrine system of the Rio Doce Valley - Minas Gerais - Brazil, during the period from March to November, showed a similar seasonal variation in both lakes, with higher population density in March and November (raining period) and lower density in May, July and September (dry period). The vertical variation was also relatively similar for both lakes, were during the thermal stratification the distribution was regular along the water column, while during the period of thermal stratification the populational density was remarkably different at different depths. The characterized ammonifying types to the genera Acinetobacter, Moraxella and Proteus, which in culture reveal high amnonifying activity with values which have reached 30,8 mug/l of ammonia per population unity (105 bacteria/ml).

Produção e qualidade de raiz tuberosa de cultivares de batata-doce no Oeste do Paraná

The objective of this work was to evaluate sweet potato cultivars with starch processing capability, on two cultivation periods, in the western region of Parana (Brazil). Sweet potato was grown at Marechal Candido Rondon, Parana State (24 degrees 33'40 '' S and 54 degrees 4'12 '' W), at a mean annual temperature between 14 and 28 degrees C. The experiment was designed in complete randomized blocks, in a factorial scheme of 4 cultivars (CNPH 003, CNPH 004, Brazlandia Roxa, and Brazlandia Rosada) and 2 cultivation periods (115 and 183 days), with four repetitions. The evaluated parameters were the root productivities (t ha(-1)) and the physical and chemical root composition (humidity, pH, acidity, starch, total soluble sugars and fibers). Data was submitted to all analysis of variance (Anova) and the means were compared by the Tukey test at 5% of probability, Results indicated that sweet potato yield at the cultivars was higher during the 183 day cultivation period (average of 9.14 t ha(-1)) than during the 115 day cultivation period (average of 4.25 t ha(-1)). Thus the CNPH 003 cultivar seems to be a better indication for starch extraction, due to the lowest fiber content in the root, the driest mass content and the largest yield of starch per area.

Características físico-químicas, cozimento e produtividade de mandioca cultivar IAC 576-70 em diferentes épocas de colheita.

The instability of cassava culinary quality is a problem in the market. This work had the purpose of evaluating the interference of the productivity, rain precipitation and physical-chemical characteristics on the cooking time of the IAC 576-70 cultivar, from the 6(th) to the 12(th) month after the planting. The physical parameters evaluated were: difficulty in peeling (easy, medium, and hard), difficulty in cutting in long, thin sticks with a manual machine, being those cut in a subjective way. In the analysis of the cooked root, the percentage of water absorbed into the cassava pieces, the color, white points formed inside the pieces of cassava, gel formation around the pieces of cassava, and cooking time were evaluated. The pH, acidity, moisture, ashes, fibers, ether extract, protein, reducing sugars, and starch of the roots were also monthly evaluated. From the results obtained in the present work, it may be concluded that the cassava IAC 576-70, when planted in July, in Botucatu-SP area, must be harvested at the age of nine months, without damage to the productivity, starch level and root cooking, and the harvest could be extended up to ten months. The producers should follow the sum of precipitation index ten days before the harvest, and this value should be the smallest as it may be and the producers should not harvest when this value is more than 100 mm, in order not to hinder the cooking of the root.

Consórcio de espécies nativas da floresta estacional semidecidual com mandioca (Manihot sculenta Crantz) para restauração de mata ciliar

Intercropping of trees and annual crops could be an important alternative for promoting forest restoration in small farms. The objective of this study was to evaluate the intercropping of cassava (Manihot sculenta Crantz) with native trees for restoration of natural forest in riparian areas in the western São Paulo State, Brazil. The experimental design was randomized blocks with six replications for comparing two restoration systems: pure afforestation and afforestation intercropped with cassava. It was evaluated the variables related to seedling development (height, crown diameter, crown cover, and height/crown diameter ratio), mortality and the economic impact were assessed for using cassava. No differences were found between treatments for any dendrometrical variable and mortality. Economic impact of the intercroppoing treatment was positive because costs for establishment of intercropped system were partially reduced by the income from the cassava crop, which covered 32% of total costs. Cassava income made final costs 19% lesser than restoration in the pure afforestation system.

Thermal structure, heat content and stability of two lakes in The National Park of Rio Doce Valley (Minas Gerais, Brazil)

The thermal structure, heat content and stability were studied in Lakes Dom Helvécio and Carioca during an annual cycle. It was found that the maximum heat content, stability and work of the wind in Lake Dom Helvécio correspond to two, four and four times, respectively, the values for the Lake Carioca. These difference can be attributed to morphometric differences in the lakes. A long-term record of heat content and stability for lake Carioca is also presented. Diel variations were studied in summer and winter. The tropicality of the lakes is discussed and compared with other lacustrine systems. © 1989 Kluwer Academic Publishers.

Extra̧ão de Macro e Micronutrientes Pela Parte Aérea de Erva-Doce EM Fuņão de Calagem e Aduba̧ão com Esterco de Cama de Frango

A greenhouse experiment was conducted in the Soil Science Department of the Botucatu College of Agricultural Sciences (UNESP), Brazil, using a Dark Red Latosol in 25 L pots. The soil was limed to 50 and 70% of base saturation; and doses 0, 10, 20, 30 and 40 t ha-1 of chicken manure were applied, in December of 1999. The experimental design was completely randomized blocks with a factorial arrangement 5x2, 10 treatments and three replications. This work was carried to evaluate leaf number, height plants, fresh and dry weight by aerial part of sweet fennel, and macronutrients and micronutrients removal. The organic fertilization affected the accumulation of N, P, K, S, B and Mn; liming affected the nutrient uptake, except for the Ca, Mg, S and Fe; the interaction of factors affected K, Mg and Mn.

Influência de cultivares de batata-doce resistentes e suscetíveis a Euscepes postfasciatus fairmaire (Coleoptera: Curculionidae) sobre o parasitismo, sobrevivência e a biologia de Catolaccus grandis burks (Hymenoptera: Pteromalidae)

The influence of four resistant and two susceptible genotypes of sweet potato to Euscepes postfasciatus Fairmaire on parasitism and biology of Catolaccus grandis Burks were evaluated under laboratory conditions. Six sweet potato roots of each genotype were infested with E. postfasciatus adults during 40 days. After this period the larvae were taken, weighted and encapsulated in parafilm. Five larvae were offered in free choice and no choice tests to C. grandis pregnant females for 12h. Five replications were used. The parasitized larvae and the eggs of the parasitoid were counted. Three daily observations were made to determine the developmental time of phases and parasitoid survival. C. grandis females can distinguish E. postfasciatus larvae reared on susceptible and resistant roots, prefering to parasitize larvae reared on susceptible roots. C. grandis survival was higher when the parasitoid was reared on larvae originated from susceptible roots and the number of emerged females was higher on larvae reared on hosts originated from susceptible roots.

Alien fishes in lakes of the Doce river basin (Brazil): Range, new occurrences and conservation of native communities

The present study shows the distribution of alien fish species in tropical lakes in the middle Doce river basin, southeastern Brazil, obtained from a rapid assessment program. The causes for their introductions were sport-fishing improvement in some specific lakes and aquaculture in the studied basin. Presently, these species have a wide distribution occurring in 41 of the 54 lakes studied, representing an actual threat to regional native fish community. The natural connection among lakes and streams during the rainy season and the dispersal mediated by local people are the main invasion agents for alien fishes. The success of these invaders is probably due to absence of pre-existing effective competitors or top-predators in the invaded communities. We consider that the eradication of alien fishes by means of the available management tools may be very difficult due to the large number of lakes invaded and to the wide spectrum of lake conditions and resources exploited by these alien species. We recommend the use of environmental education as a tool to stop the human-mediated dispersion of aliens and to improve conservation of native fish community in lakes where these alien species are not present yet. © 2004 Instituto de Ciências Biológicas - UFMG.

Erosão hídrica de Latossolo Vermelho muito argiloso relevo ondulado em área de pós-plantio de eucalipto no Vale do Rio Doce, região Centro Leste do Estado de Minas Gerais

The erosion caused by running water constitutes important cause of environmental degradation and productivity reduction, which justifies its evaluation in areas of eucalypt commercial plantations, mainly in ondulated slope conditions. The present study was intended to evaluate the influence of different management systems, in an undulated eucalypt pos-planting area, upon soil and water losses by erosion. The experiment was installed in a very clayey Red Latosol (Oxisol) under three eucalypt management systems (downhill planting with burning of crop residues - EDq; downhill planting with maintenance of crop residues on soil surface - ED; level planting with maintenance of crop residues on soil surface - EN), native forest (FN), bare soil (SD), and native pasture (PN). The soil and water losses evaluations were performed in standard plots installed in the field. All eucalypt systems presented very low values of soil losses in relation to the established tolerance limit, indicating the adequacy of these management systems concerning water erosion. The sustainability of these environments regarding erosion is indicated by the fact that soil losses in eucalipt were very close to those observed in native forest (reference).

Policultivo do camarão de água doce Macrobrachium amazonicum (Heller, 1862) com a Tilápia do Nilo (Oreochromis niloticus) alimentadas com rações peletizada e farelada

The objective of this work was to evaluate the influence of fresh water shrimp Macrobrachium amazonicum (Heller, 1862) in performance of Nile tilapia (Oreochromis niloticus) cultivated in polyculture system and feeding with ration pelleted and mashed. The work was realized in Centro de Pesquisa em Aqüicultura Ambiental-CPAA/IAP - Toledo/PR during 37 days. Were utilized like experimental unit 16 ponds excavated, covered with concrete but with bottom of soil with dimension the 4 x 3 m and useful volume the 3,5 m 3. Were utilized 30 tilapias e 150 shrimps for experimental unit distributed at an entirely randomized design with 4 treatments and 4 replications, where TF: tilapia feeding with ration mashed; TCF: tilapia and shrimp feeding with ration mashed; TP: tilapia feeding with ration pelleted; TCP: tilapia and shrimp feeding with ration pelleted. The density used were the 2,6 fishes/m 2 with medium initial weight the 5,58 ± 0,10 g and initial length the 5,56 cm, and the density of shrimp was the 13 shrimps/m 2 with initial length the 1,04 cm. The temperature was gauged daily, while the variables dissolved oxygen, pH and electrical conductivity, weekly. The quantity of ration supplied was the 10% of total biomass of fishes, with feed frequency the 4 times a day, being corrected weekly in function of the biometry. During the experimental period the medium values of temperature, dissolved oxygen, pH and electrical conductivity of the ponds water were 23,42 ± 0,83°C, 5,32 ± 0,52 mg/L, 7,02 ± 0,39, e 100,96 ± 1,81 μS/ cm respectively. Won't registering any influence of shrimp during the cultivation and the ration pelleted provide the better conversion alimentary and performance of tilapias.