Marta dos Santos Freire Ricci

Infestação natural de moscas frugívoras (Diptera: Tephritoidea) em café arábica, sob cultivo orgânico arborizado e a pleno sol, em Valença, RJ

Frugivorous flies have been acquiring great economic importance in coffee crop because they cause premature dropping of coffee beans and significantly decrease the quality of the beverage. The coffee plant is also a natural reservoir of Tephritidae species that infest fruits of economic importance. This study evaluated the influence of the shaded and unshaded coffee systems, under organic management, on the natural infestation of fruits of Coffea arabica L. var. Icatu Amarelo by frugivorous flies. An experiment in completely randomized design was carried out in Valenca, RJ, Brazil, with two treatments (shaded coffee with Musa sp. and Erithrina verna Vell. and unshaded coffee monoculture) and four replicates. A 1kg-sample of maturing fruits per plot was harvested in Mach 2004 to evaluate infestation and identify the flies. The mean infestation index was significantly higher in the shaded coffee system. Four species of Tephritidae (Ceratitis capitata (Wiedemann), Anastrepha fraterculus (Wiedemann), Anastrepha obliqua (Macquart) and Anastrepha sororcula Zucchi), and six of Lonchaeidae (Neosilba pendula (Bezzi), Neosilba pseudopendula (Korytkowski and Ojeda), Neosilba certa (Walker), Neosilba glaberrima (Wiedemann), Neosilba n.sp.9 and Neosilba n.sp.10) were recovered from coffee fruits. Nine parasitoid species were obtained, six belonging to Braconidae (Asobara anastrephae (Muesebeck), Doryctobracon areolatus (Szepligeti), Doryctobracon brasiliensis (Szepligeti), Utetes anastrephae (Viereck), Opius bellus Gahan and Opius sp.), and three to Figitidae (Aganaspis pelleranoi (Brethes), Dicerataspis flavipes (Kieffer) and Odontosema anastrephae Borgmeier). The total percent parasitism was 8.8% and 12.4% in the shaded and unshaded coffee systems, respectively.Frugivorous flies have been acquiring great economic importance in coffee crop because they cause premature dropping of coffee beans and significantly decrease the quality of the beverage. The coffee plant is also a natural reservoir of Tephritidae species that infest fruits of economic importance. This study evaluated the influence of the shaded and unshaded coffee systems, under organic management, on the natural infestation of fruits of Coffea arabica L. var. Icatu Amarelo by frugivorous flies. An experiment in completely randomized design was carried out in Valença, RJ, Brazil, with two treatments (shaded coffee with Musa sp. and Erithrina verna Vell. and unshaded coffee monoculture) and four replicates. A 1kg-sample of maturing fruits per plot was harvested in Mach 2004 to evaluate infestation and identify the flies. The mean infestation index was significantly higher in the shaded coffee system. Four species of Tephritidae (Ceratitis capitata (Wiedemann), Anastrepha fraterculus (Wiedemann), Anastrepha obliqua (Macquart) and Anastrepha sororcula Zucchi), and six of Lonchaeidae (Neosilba pendula (Bezzi), Neosilba pseudopendula (Korytkowski and Ojeda), Neosilba certa (Walker), Neosilba glaberrima (Wiedemann), Neosilba n.sp.9 and Neosilba n.sp.10) were recovered from coffee fruits. Nine parasitoid species were obtained, six belonging to Braconidae (Asobara anastrephae (Muesebeck), Doryctobracon areolatus (Szépligeti), Doryctobracon brasiliensis (Szépligeti), Utetes anastrephae (Viereck), Opius bellus Gahan and Opius sp.), and three to Figitidae (Aganaspis pelleranoi (Brèthes), Dicerataspis flavipes (Kieffer) and Odontosema anastrephae Borgmeier). The total percent parasitism was 8.8% and 12.4% in the shaded and unshaded coffee systems, respectively.

Cyperus rotundus control by solarization

ABSTRACT Soil solarization by means of polyethylene cover sheets was tested for the control of Cyperus rotundus weed infestation. Following solarization, which lasted for a period of approximately three months, the field was cultivated with carrots and dwarf green beans. Solarization was shown to provide a highly significant reduction of the weed population and to increase carrot yield. As for green beans, soil treatment was less effective and yield was not affected. In the solarized plots no weeding was needed during the vegetable crops cycle whereas the untreated plots required hand weeding within the first month from sowing. Soil solarization significantly reduced ant and earthworm numbers but had no effect on millipede population. Soil microbial biomass carbon (SMBC) was affected by solarization. However, actinomycete and bacterial populations, including nitrogen- fixing bacteria, showed no obvious pattern related to soil solarization.

Effects of Low Incoming Turbulence on the Flow around a 5 : 1 Rectangular Cylinder at Non-Null-Attack Angle

The incompressible high Reynolds number flow around the rectangular cylinder with aspect ratio 5 : 1 has been extensively studied in the recent literature and became a standard benchmark in the field of bluff bodies aerodynamics. The majority of the proposed contributions focus on the simulation of the flow when a smooth inlet condition is adopted. Nevertheless, even when nominally smooth conditions are reproduced in wind tunnel tests, a low turbulence intensity is present together with environmental disturbances and model imperfections. Additionally, many turbulence models are known to be excessively dissipative in laminar-to-turbulent transition zones, generally leading to overestimation of the reattachment length. In this paper, Large Eddy Simulations are performed on a 5 : 1 rectangular cylinder at non-null-attack angle aiming at studying the sensitivity of such flow to a low level of incoming disturbances and compare the performance of standard Smagorinsky-Lilly and Kinetic Energy Transport turbulence models.

Populações de minhocas em sistemas agroflorestais com café convencional e orgânico

Objetivou-se, neste estudo, determinar se as populacoes das minhocas sao alteradas em funcao do manejo do cafe (Coffea arabica) em Turrialba, CostaRica. Os seguintes sistemas de cultivo do cafe foram estudados: a pleno sol (PS) e sombreado com eritrina, Erythrina poeppigiana (E); terminalia, Terminalia amazonia (T) e casha, Chloroleucon eurycyclum (Ab). A hipotese foi de que o manejo orgânico do cafe e o fornecimento da serapilheira de melhor qualidade favoreceria a diversidade, a densidade e a biomassa das minhocas. As populacoes das minhocas foram alteradas, em funcao do manejo com insumos sinteticos ou orgânicos , sendo a densidade menor no cafe a pleno sol. Entre as especies utilizadas no sombreamento, a eritrina parece limitar a abundância das minhocas. Contudo, favorece a diversidade das mesmas, tendo sido registradas duas especies de minhocas com papeis ecologicos diferenciados, Pontoscolex corethrurus, endogeica e Metaphire californica, anecica; ao contrario dos demais tratamentos, onde somente foi encontrada a primeira especie, considerada cosmopolita com distribuicao pantropical.

Vegetative and productive aspects of organically grown coffee cultivars under shaded and unshaded systems

Although Coffea arabica species has its origin in the African understories, there is great resistance on the part of the Brazilian producers for growing this species under agroforestry systems as they fear that shading reduces production. This study aimed at evaluating some vegetative traits and the productivity of organically grown coffee (Coffea arabica L.) cultivars under shaded and unshaded systems. Twelve treatments consisting of two cultivation systems (shaded and unshaded) and six coffee cultivars were arranged in randomized blocks with four replicates, in a split-plot scheme. Shading was provided by banana (Musa sp.) and coral bean plants (Erythrinaverna). Shading delayed fruit maturation. Late maturation cultivars, such as the Icatu and the Obata, matured early in both cultivation systems, while medium and early maturation cultivars presented late maturation. Cultivation in the shaded system increased the leaf area and the number of lower branches, decreased the number of productive nodes per branch, and increased the distance between the nodes and the number of leaves present in the branches. Cultivation in the unshaded system presented greater number of plants with branch blight in relation to plants grown in the shade. The productivity of the cultivars was not different, at 30.0 processed bags per hectare in the shaded system, and 25.8 processed bags per hectare in the unshaded system. The most productive cultivars in the shaded system were the Tupi, the Obata, and the Catuai, while no differences between cultivars were obtained in the unshaded system.

Produção da cenoura e efeito na fertilidade do soloe nutrição decorrente da solarização do solopara controle da tiririca

Dentre os desafios do cultivo orgânico de hortalicas destaca-se o controle de plantas daninhas, devido a proibicao do uso de herbicidas. Entre as invasoras, a tiririca (Cyperus rotundus L.) e de dificil controle pela sua alta competitividade. A solarizacao e uma alternativa para desinfestacao do solo, a qual consiste em cobri-lo com plastico transparente, com bons resultados no controle da tiririca. A fim de avaliar a influencia do preparo e do revolvimento do solo sobre a eficiencia da solarizacao no controle da tiririca, bem como seu posterior efeito sobre o cultivo da cenoura, foi realizado um experimento na Fazendinha Agroecologica, em Seropedica (RJ). O experimento foi disposto em blocos ao acaso com tres repeticoes, em arranjo fatorial 2 x 3 mais uma testemunha adicional, sendo: 1) solo solarizado, preparado (com grade aradora) e revolvido 30 dias apos a solarizacao (manualmente com auxilio de uma enxada); 2) solo solarizado, preparado e revolvido aos 60 dias; 3) solo solarizado, preparado e nao revolvido; 4) solo solarizado, nao preparado e revolvido aos 30 dias; 5) solo solarizado, nao preparado e revolvido aos 60 dias; 6) solo solarizado, nao preparado e nao revolvido; solo nao solarizado, nao preparado e nao revolvido (testemunha). A solarizacao iniciou-se em 29/1/2002, e durou cem dias. A solarizacao reduziu em 86% a infestacao de tiririca no cultivo da cenoura. Ate 10 cm de profundidade, a temperatura do solo foi superior nas parcelas solarizadas, porem a 5 cm, a solarizacao foi mais eficiente quando associada ao preparo do solo, nao havendo efeito do revolvimento. A solarizacao aumentou os valores da biomassa microbiana e dos teores de Ca, Mg e P do solo. O desenvolvimento da cenoura foi influenciado pela solarizacao que resultou em maior produtividade.