Avaliação de substratos para a produção de mudas de tomate e pepino

Objetivou-se, com este trabalho, avaliar mudas de pepino e de tomateiro em relação a diferentes composições de substratos orgânicos, formulados com composto de resíduos do abate de aves, podas de árvores e areia. Os experimentos foram realizados em bandejas com 200 células, em blocos casualizados. Para mudas de tomateiro, os tratamentos foram: T0 (Plantmax® HT); T1 (composto); T2 (composto + areia, proporção 3:1 peso); T3 (composto + areia, proporção 1:1 peso) e T4 (composto + areia, proporção 1:3 peso). Para mudas de pepino, os tratamentos foram: T0 (Plantmax® HA) e as mesmas composições de substratos orgânicos adotadas para as de tomate. Avaliaram-se a emergência de plântulas (EP), o comprimento de raiz (CR), a massa seca de raiz (MSR) e da parte aérea (MSPA). Os substratos T0 e T4, que proporcionaram emergência rápida das plântulas de tomateiro, propiciaram maior CR. Mas os valores de CR nesses subtratos não diferiram daqueles observados em T2 e T3, aos 20 dias após a emergência (DAE). Houve aumento da MSPA do tomateiro, cultivado em T4, em relação à dos cultivados em T0 e T3. A MSR do tomateiro, em T2, T3 e T4, foi superior à observada em T0 e T1. Para a MSPA do pepino, aos 30 DAE, houve acúmulo de massa seca das plantas cultivadas em T3 e T4, em relação à dos tratamentos T0 e T1. Em relação à MSR, os substratos à base de composto proporcionaram resultados superiores aos de T0, destacando-se T3 e T4. Assim, para produção de mudas de pepino, recomendam-se os substratos T3 e T4 e, para tomateiro, o substrato T4.

Emergência e desenvolvimento de mudas de tomate IPA 6 em substratos, contendo esterco ovino

A busca por substratos alternativos, que possam substituir produtos comerciais na produção de mudas de tomate, é de fundamental importância para a redução dos custos nessa fase inicial da cultura. Objetivou-se, com esta pesquisa, avaliar a qualidade de mudas de tomate industrial IPA 6, produzidas com substratos à base de esterco ovino. O experimento foi conduzido em viveiro da Universidade Federal Rural de Pernambuco, Unidade Acadêmica de Serra Talhada, de 16 de fevereiro a 30 de março de 2012. Utilizou-se o delineamento inteiramente casualizado, com quatro repetições. Os tratamentos avaliados foram: T1 - [substrato comercial]; T2 - [esterco ovino + areia (1:1)]; T3 - [esterco ovino + areia (2:1)]; T4 - [esterco ovino + areia (3:1)]; T5 - [esterco ovino + solo (1:1)]; T6 - [esterco ovino + solo (2:1)]; T7 - [esterco ovino + solo (3:1)]; T8 - [esterco ovino + areia + solo (1:1:1)];T9 - [esterco ovino + areia + solo (2:1:1)]; T10 - [esterco ovino + areia + solo (3:1:1)]. Os indicadores de emergência avaliados foram: percentagem, índice de velocidade e tempo médio de emergência. Analisaram-se as seguintes características de desenvolvimento: número de folhas, altura de plântula, diâmetro de caule, comprimento de raízes, massa da matéria seca da parte aérea e das raízes. O substrato comercial proporcionou melhor vigor de mudas de tomate IPA 6. Por outro lado, o uso do esterco ovino mais solo (2:1), para compor substratos alternativos constituiu-se opção viável para a produção de mudas desse cultivar.

Chemical treatment of papaya seeds aiming at long-term storage and control of damping off

Damping off is a nursery disease of great economic importance in papaya and seed treatment may be an effective measure to control. The aim of this work was to evaluate the quality of papaya seeds treated with fungicides and stored under two environmental and packaging conditions. Additionally, the efficiency of fungicide treatments in the control of damping-off caused by Rhizoctonia solani was evaluated. Papaya seeds were treated with the fungicides Captan, Tolylfluanid and the mixture Tolylfluanid + Captan (all commercial wettable powder formulations). Seeds of the control group were not treated. The seeds were stored for nine months in two conditions: packed in aluminum coated paper and kept at 7 ± 1ºC and in permeable kraft paper and kept in non-controlled environment. At the beginning of the storage and every three months the seed quality (germination and vigor tests), emergence rate index, height, dry mass and damping of plants in pre and post-emergence (in contaminated substrate and mycelia-free substrate) were analyzed. Both storage conditions as well as the fungicide treatments preserved the germination and seed vigor. In the infested substrate, seedling emergence was favored by fungicides, but in post-emergence, fungicides alone did not control the damping off caused by R. solani. Symptoms of damping off were not observed in the clean substrate. The results showed that the fungicide treatments may be used to pretreat papaya seed for long-term storage and commercialization.

Indirect effect of neem oil on Podisus nigrispinus (Hemiptera, Pentatomidae): biology and predatory capacity

This study evaluated the effects on the development and predatory capacity of Podisus nigrispinus fed on Spodoptera frugiperda that have ingested different concentrations of neem oil. The predatory capacity of Podisus nigrispinus was assessed, separating nymphs (fourth instar) and adults (males and females). The treatments consisted of S. frugiperda larvae reared in neem oil aqueous solutions (0.077, 0.359 and 0.599%), deltamethrin EC 25 (0.100%) and control arranged in a completely randomized design, with ten replicates. Insects were offered three larval densities (one, three and six), in the third or fourth instars. The predated larvae were examined at 24 and 48 hours after the beginning of the experiment. Biological parameters of Podisus nigrispinus were evaluated in groups of ten second-instar nymphs transferred to pots, in five replicates. Insects were offered 2-6 third and/or fourth-instar larvae reared in the same neem oil concentrations in a completely randomized design. The following parameters were evaluated: duration of each nymph stage (days), nymph mortality (%), weight of fifth-instar nymphs (mg), sex ratio, weight of males and females (mg) and longevity of unfed adults (days). The predatory capacity of nymphs and adults of Podisus nigrispinus was influenced by the neem oil at the concentrations of 0.359% and 0.599% in the highest density. The concentration of 0.359% lengthened the nymphal stage and the concentration of 0.599% reduced the weight of males.

Produção de massa de tomate com maior conteúdo de pró-vitamina A: avaliação microbiológica, físico-química e sensorial

A deficiência de vitamina A é um grande problema de saúde pública e um dos grupos mais vulneráveis a essa deficiência são as crianças em idade pré-escolar. Existem medidas de intervenção que podem ser adotadas como forma de preveni-la ou reduzi-la, sendo uma delas o enriquecimento de alimentos. O objetivo deste trabalho foi produzir massa de tomate com fontes naturais de carotenoides pró-vitamínicos A, oriundos de três diferentes concentrações de suco de cenoura, e caracterizar as formulações em relação à análise microbiológica (bactérias lácticas, bolores e leveduras, clostrídios butíricos e termófilos "flat-sour"), análise físico-química (pH, sólidos solúveis e carotenoides) e análise sensorial (teste de aceitação com escala hedônica e intenção de compra). Os resultados mostraram que todas as formulações foram aprovadas no teste microbiológico, durante 90 dias de armazenamento. Quanto às análises físico-químicas, verificou-se aumento significativo do pH, nas três formulações, enquanto o teor de sólidos solúveis manteve-se inalterado, durante os três meses, em cada um dos produtos. Apesar da degradação significativa ao longo do tempo, foi possível aumentar o conteúdo de carotenoides nas massas de tomate com suco de cenoura, nas formulações. Além disso, as formulações foram consideradas, sensorialmente, como boas, pelos provadores. Considerando-se o teor de carotenoides encontrados e a impressão sensorial, as formulações podem ser uma estratégia de prevenção ou de redução da carência de vitamina A.

Silicon in plant disease control

All essential nutrients can affect the incidence and severity of plant diseases. Although silicon (Si) is not considered as an essential nutrient for plants, it stands out for its potential to decrease disease intensity in many crops. The mechanism of Si action in plant resistance is still unclear. Si deposition in plant cell walls raised the hypothesis of a possible physical barrier to pathogen penetration. However, the increased activity of phenolic compounds, polyphenol oxidases and peroxidases in plants treated with Si demonstrates the involvement of this element in the induction of plant defense responses. The studies examined in this review address the role of Si in disease control and the possible mechanisms involved in the mode of Si action in disease resistance in plants.

Postharvest biological control of brown rot in peaches after cold storage preceded by preharvest chemical control 1

ABSTRACT Pathogenic fungi cause skin darkening and peach quality depreciation in post harvest. Therefore, alternative techniques to chemical treatment are necessary in order to reduce risks to human health. The aim of this study was to evaluate the effect of the application of Trichoderma harzianum in association with different fungicides applied before harvest to 'Eldorado' peaches for brown rot control and other quality parameters during storage. The treatments consisted of five preharvest fungicide applications (control, captan, iprodione, iminoctadine and tebuconazole) associated with postharvest application of T. harzianum, after cold storage (with and without application), in three evaluation times (zero, two and four days at 20 °C), resulting in a 5x2x3 factorial design. The application of T. harzianum only brought benefits to the control of brown rot when combined with the fungicide captan, at zero day shelf life. After two days, there was a greater skin darkening in peaches treated with T. harzianum compared with peaches without the treatment, except for peaches treated with the fungicide iprodione and T. harzianum The application of T. harzianum during postharvest showed no benefits for the control of brown rot, however, the association with fungicides reduced the incidence of Rhizopus stolonifer during the shelf life.

¿Entes de regulación o control? Imprecisiones del "moderno" esquema de regulación: reflexiones y enseñanzas del caso argentino

Este artículo analiza las particularidades del "moderno" esquema de regulación de los servicios públicos de infraestructura, que se extendió a partir de los procesos de privatización del último cuarto del siglo XX. Diferenciándose de la arquitectura institucional vigente durante el período de prestación estatal (regulación "endógena"), los entes reguladores emergen como el elemento neurálgico de este nuevo esquema. Sin embargo, como se desprende de la experiencia argentina, estos organismos han sido dotados de ambiguas atribuciones regulatorias e inapropiados diseños institucionales, quedando trunca su capacidad real de regulación. A raíz de la difusa delimitación de misiones y funciones e - incluso - frente a las imprecisiones teóricas en la materia, este artículo precisa el alcance de la intervención de los distintos actores del sistema de prestación y regulación: empresas prestadoras, entes reguladores, poderes del Estado (Ejecutivo y Legislativo) y usuarios y consumidores. En este sentido, trabaja sobre los diseños institucionales más apropiados para que los entes desarrollen efectivas capacidades de regulación. El análisis se ejemplifica a partir de la experiencia privatizadora argentina - nacional y subnacional - en los servicios de agua potable y saneamiento y distribución de electricidad.

Accountability and co-production of information and control: social observatories and their relationship with government agencies

Abstract:Through the development of a proposal to categorize accountability into four stages - classical, cross-sectional, systemic, and diffused -, this article aims to identify characteristics of co-production of information and socio-political control of public administration in the work of Brazilian social observatories in relationship with government control agencies. The study analyses data from 20 social observatories and, particularly, three experiences of co-production of information and control, based on a systemic perspective on accountability and a model with four categories: Political and cultural; valuing; systemic-organizational, and production. The conclusions summarize characteristics of these practices, specific phases in the accountability processes, as well as the potentialities and challenges of co-production of information and control, which not only influences, but it is also influenced by the accountability system.

Chagas' disease and social security: a case-control study in an urban area, Goiás, Brazil

One hundred and twenty subjects with Chagas' cardiopathy and 120 non-infected subjects were randomly selected from first time claimants of sickness benefits in the National Institute of Social Security (INPS) in Goiás. Cases of Chagas' cardiopathy were defined based on serological test, history of residence in an endemic area and, clinical and/or electrocardiogram (ECG) alterations suggestive of Chagas' cardiomyopathy. Controls were defined as subjects with at least two negative serological tests. Case and controls were compared in the analysis for age, sex, place of birth, migration history, socio-economic level, occupation, physical exertion at work, age at affiliation and years of contribution to the social security scheme, clinical course of their disease and ECG abnormalities. Chagas' disease patients were younger than other subjects and predominantly of rural origin. Non-infected subjects presented a better socio-economic level, were performing more skilled activities and had less changes of job than cases. No important difference was observed in relation to age at affiliation to INPS. About 60% of cases have claimed for benefits within the first four years of contribution while among controls this proportion was 38.5%. Cases were involved, proportionally more than controls, in "heavy" activities. A risk of 2.3 (95%CL 1.5 - 4.6) and 1.8 (95%CL 1.2- 3.5) was obtained comparing respectively "heavy" and "moderate" physical activity against "light". A relative risk of 8.5 (95%CL 4.9 - 14.8) associated with the presence of cardiopathy was estimated comparing the initial sample of seropositive subjects and controls. A high relative risk was observed in relation to right bundle branch block (RR = 37.1 95%CL = 8.8 - 155.6) and left anterior hemiblock (RR = 4.4, 95%CL = 2.1 - 9.1).

The epidemiology and control of schistosomiasis mansoni where Biomphalaria tenagophila is the snail host

The epidemiology and control of schistosomiasis mansoni in the Municipality of Pedro de Toledo (State of S. Paulo, Brazil) since 1980, has been studied. In 1980 the prevalence evaluated by stool exams (Kato-Katz method) was 22.8% and no statistical difference at 5.0% level was observed between rural and urban zones. The intensity of infection was low (58.5 eggs/g of faeces); the highest prevalence and intensity of infection rates were observed within the group of from 5 to 29 years of age, respectively. The transmission of schistosomiasis usually occurred during leisure time. The majority of the carriers of the parasite were asymptomatic. Of the B. tenagophila examined only 0.4% were found to be infected. The control programme has been intensified from 1981 on resulting in a sharp decrease in the prevalence from 22.8% in 1980 to 6% at the present time. This result shows that, in spite of the control programme there is a residual human prevalence. A beginning has been made on the investigation into the possible causes of this residual prevalence (6.0% was maintained through out 1987).

Susceptibility of Aedes aegypti larvae to temephos and Bacillus thuringiensis var israelensis in integrated control

The susceptibility of field collected Aedes aegypti larvae was evaluated in terms of median lethal time (LT50) and final mortality, when treated with temephos, Bacillus thuringiensis var israelensis as well as mixtures of these two agents. Third instar larvae were shown to be more susceptible than early and late fourth instar ones to the entomopathogen. Survival of some individuals when exposed to temephos suggest possible resistance. Temporal synergism in early fourth instar larvae was detected when they were exposed to mixtures of Bti-temephos. The possibility of this integrated treatment is commented on.