RESUMO Devido à importância socioeconômica do feijoeiro no Brasil, estudos que permitem estabelecer condições favoráveis ao não comprometimento da lavoura com o mofo-branco tornam-se vitais para a agricultura brasileira, haja vista os enormes prejuízos causados por este fungo, , razão por que se objetivou, neste trabalho, avaliar a incidência e severidade do mofo-branco na cultura do feijoeiro-comum (Phaseolus vulgaris L.), cultivar Madrepérola, submetido a diferentes turnos de rega, densidades de plantio e aplicação de fungicida. A pesquisa foi conduzida em Viçosa, nos anos 2011 e 2012. Na análise estatística foi utilizado o esquema de parcelas sub-subdivididas. Nas parcelas foi alocado o efeito do fungicida (com ou sem fungicida), nas subparcelas os turnos de rega (3, 6, 9 e 12 dias) e nas sub-subparcelas as densidades de plantio (6, 9, 12 e 15 plantas por metro linear), no delineamento experimental em blocos casualizados, com três repetições. A variação do turno de rega não colaborou significativamente para o controle do mofo-branco. Recomenda-se a utilização de menores densidades de plantio a fim de minimizar os danos ocasionados pela doença. A utilização do fungicida foi o principal método de controle do mofo-branco nos dois anos consecutivos.

ABSTRACT Due to the socioeconomic importance of common bean in Brazil, studies that allow establishing favorable conditions for not compromising the crop with white mold, in view of the enormous damages caused by this fungus, become vital to Brazilian agriculture. Therefore, the aim of this study was to evaluate the incidence and severity of white mold in common bean (Phaseolus vulgaris L.), cultivar ‘Madrepérola’, subjected to different irrigation intervals, planting densities and fungicide application. The research was conducted in Viçosa-MG, Brazil, in the years 2011 and 2012. The statistical analysis used the split-split-plot scheme. The fungicide applications (with or without fungicide) were allocated to plots, the irrigation intervals (3, 6, 9 and 12 days) to sub-plots and planting densities (6, 9, 12 and 15 plants per linear meter) to sub-subplots, in a randomized block design with three replicates. The variation of the irrigation intervals did not contribute significantly to the control of white mold. It is recommended to use lower planting densities in order to minimize the damages caused by the disease. The use of the fungicide was the main method of white mold control in two consecutive years.

RESUMO A escolha do método mais apropriado para estimar a evapotranspiração depende da disponibilidade de dados meteorológicos, do nível de precisão exigido e do custo de aquisição dos equipamentos. Para tal estimativa, o Irrigâmetro é de simples operação, preciso e economicamente viável aos produtores rurais, haja vista que colabora para a aplicação da lâmina de água necessária às culturas, evitando o consumo desnecessário de energia e a degradação do meio ambiente, além de aumentar a produtividade e melhorar a qualidade das culturas. Neste contexto, objetivou-se, por esta pesquisa, estimar a evapotranspiração de referência utilizando o Irrigâmetro, para as condições climáticas do Sul do Estado do Tocantins. O delineamento experimental foi inteiramente casualizado com Irrigâmetros operando com sete alturas da água no evaporatório do aparelho, representando os tratamentos, e três repetições. A evapotranspiração de referência foi obtida pelo método de Penman-Monteith – FAO 56. Para as condições climáticas analisadas, a altura da água recomendada no evaporatório do aparelho para estimar a evapotranspiração de referência na primavera é 3,4 cm; no verão, 4,0 cm; no outono, 3,8 cm e no inverno, 2,3 cm.

ABSTRACT The choice for the most appropriate method to estimate evapotranspiration depends on the availability of meteorological data, required level of precision and cost of equipment acquisition. For this estimate, the Irrigameter is simple to operate, precise and economically viable to farmers. In addition, it collaborates in the application of the necessary water depth to crops, thus avoiding unnecessary energy consumption, environmental degradation, and increasing crop yield and improving crop quality. In this context, the objective of this research was to estimate the reference evapotranspiration using the Irrigameter, for the climatic conditions of the Southern Tocantins state, Brazil. The experimental design was completely randomized with Irrigameters operating with seven water heights in the evaporator, as treatments, with three replicates. The reference evapotranspiration was obtained by FAO-56 Penman-Monteith method. For the analyzed climatic conditions, the water height in the evaporator recommended to estimate the reference evaporation in the spring is 3.4 cm; summer, 4.0 cm; fall, 3.8 cm; and winter, 2.3 cm.

RESUMO A rúcula é uma hortaliça que tem ganhado cada vez mais destaque na alimentação, sendo rica em potássio, enxofre, ferro, ômega-3 e vitaminas A e C. É uma cultura que possui, como fatores limitantes para sua produção, a disponibilidade de água e de nutrientes, contexto no qual se objetivou, neste trabalho, avaliar a produção da rúcula submetida a diferentes lâminas de irrigação e doses de adubação potássica. O experimento foi conduzido entre agosto e setembro de 2015. O delineamento experimental utilizado foi o inteiramente casualizado, no esquema de parcelas subdivididas. As parcelas foram representadas pelas lâminas de irrigação L1, L2, L3 e L4 (25, 50, 75 e 100% da evapotranspiração da cultura, respectivamente), e as subparcelas pelas doses de potássio K1 e K2 (200 e 400 kg ha-1, respectivamente). Embora a maior produtividade tenha sido obtida com a maior lâmina de irrigação e maior dose de potássio, recomenda-se o cultivo da rúcula com a menor lâmina e menor dose, haja vista o maior valor de eficiência do uso da água para este tratamento.

ABSTRACT Arugula is a vegetable that has gained more highlight in the consumption, being rich in potassium, sulfur, iron, omega-3 and vitamins A and C. Availability of water and nutrients are limiting factors for production of this crop. In this context, the objective of this study was to evaluate the production of arugula subjected to different irrigation depths and potassium fertilization. The experiment was conduct between August and September 2015. The experimental design was completely randomized in split-plot scheme. Irrigation depths L1, L2, L3 and L4 (25, 50, 75 and 100% of crop evapotranspiration, respectively) represented the plots and potassium doses K1 and K2 (200 and 400 kg ha-1, respectively) represented the subplots. Although the highest yield was obtained with highest irrigation depth and highest potassium dose, it is recommended the cultivation of arugula with the lowest irrigation depth and the lowest potassium dose, considering the higher value of water use efficiency for this treatment.

Our objective is to evaluate the habitat preference of freshwater snails in relation to environmental factors and the presence of the competitor snail Melanoides tuberculatus. In the first phase, snails was collected at 12 sites. This sampling sites presented a degree of organic input. In the second phase 33 sampling sites were chosen, covering a variety of lotic and lentic environments. The snail species found at Guapimirim, state of Rio de Janeiro, displayed a marked habitat preference, specially in relation to the physical characteristics of each environment. Other limiting factors for snail distribution at the studied lotic environments were the water current velocity and the amount of organic matter, mainly to Physa marmorata, M. tuberculatus, and Biomphalaria tenagophila. The absence of interactions between M. tuberculatus and another snails could be associated to the distinct spatial distribution of those species and the instability of habitats. This later factor may favor the coexistence of M. tuberculatus with B. glabrata by reduction of population density. In areas of schistosomiasis transmission some habitat modification may add to the instability of the environment, which would make room for the coexistence of M. tuberculatus and Biomphalaria spp. In this way, some of the usual measures for the control of snail hosts would prevent the extinction of populations of Biomphalaria spp. by M. tuberculatus in particular habitats.

The aim of this study was to determine the toxicity of niclosamide (Bayluscide ®) on Melanoides tuberculata and Biomphalaria glabrata under laboratory conditions. The latter species is the intermediate host of Schistosoma mansoni (Sambon 1917). M. tuberculata was successfully used as competitor of B. glabrata in biological control programs in French West Indies. Both molluscicide and biological control using M. tuberculata have proved to be successful in reducing the population density of B. glabrata. The associated use of molluscicide in this area would be an effective measure if M. tuberculata were less susceptibility to the molluscicide than B. glabrata. Three hundreds individuals each of B. glabrata and of M. tuberculata, collected in Sumidouro, State of Rio de Janeiro, were used in the experiment. The molluscs were exposed to 14 different concentrations of niclosamide as recommended by the World Health Organization. Probit analysis was used to determine the LC 50 and LC 90. The LC 50 and LC 90 values for B. glabrata were 0.077 mg/l and 0.175 mg/l, respectively and the LC 50 and LC 90 values for M. tuberculata were 0.082 mg/l and 0.221 mg/l respectively. As the lethal concentrations of niclosamide were approximately the same to both species, this could be a disadvantage when controlling B. glabrata with niclosamide in an area of M. tuberculata occurrence. It migth therefore be preferable to utilize the latex extracted from the Euphorbia splendens, which presented a much higher efficiency for B. glabrata than to M. tuberculata.

The biological control of Biomphalaria glabrata, intermediate host of Schistosoma mansoni, is one the accepted options to fight schistosomiasis. One of the most promising candidates to control B. glabrata is the snail Melanoides tuberculata, a potential competitor. However, the mechanisms of interaction between the two species are not clear. Our objective is to determine if M. tuberculata indeed compete with B. glabrata, using two laboratory experiments. In Experiment 1, we tested the effect of the presence of M. tuberculata on the fecundity and mortality rates of B. glabrata. In Experiment 2, we tested if there was a direct or indirect interaction between the two species. In Experiment 1, M. tuberculata was eliminated after the peak in reproductive activity of B. glabrata. In Experiment 2, B. glabrata produced more egg masses when raised with M. tuberculata. The conditions leading to this unexpected positive effect of M. tuberculata on the fecundity of B. glabrata need further clarification, but emphasize that detailed studies of the interaction between these species in the conditions of the local environment should be considered.

The use of the latex of Euphorbia splendens var. hislopii was considered as an effective control method for Biomphalaria glabrata in Sumidouro, Rio de Janeiro. However, the appearance and expansion of the snail Melanoides tuberculata since August 1997, with the concomitant reduction of the population of B. glabrata suggest that competitive exclusion might be taking place. Depending on the susceptibility of the thiarid to the E. splendens toxin, the natural control that is occurring could be interrupted by the employment of the latex if the planorbid were less susceptible to the toxin. The aim of this study is to investigate the molluscicidal activity of the latex on M. tuberculata. We used 420 M. tuberculata, from Sumidouro. Fourteen different latex concentrations were tested using World Health Organization general methodology. Probit analysis was used for LD90 and LD50 determination. The LD50 was 3.57 mg/l and LD90 was 6.22 mg/l. At the highest concentration (10 mg/l) there was no survival. No significant differences among replicas (chi2 = 8.31; gl = 13; p > 0.05) were found. The LD90 dose for M. tuberculata was 13.8 times greater than that for B. glabrata, so that the molluscicide in the presence of the thiarid may have a synergic effect on reduction of Biomphalaria populations.

Aspectos da ecologia de Tropidurus torquatus foram estudados mensalmente na restinga de Guriri, São Mateus, Norte do Espírito Santo, de fevereiro de 1996 a março de 1997. Foram coletados 108 exemplares com arma de pressão, sendo 45 machos, 56 fêmeas e 7 exemplares cujo sexo não foi identificado. O comprimento rostro-anal no total dos exemplares variou de 26,0 a 101,8 mm (média = 61,7 mm; DP = 15,1). O peso no total dos exemplares variou de 0,8 a 39,6 g (média = 14,6 g; DP = 10,4). Em freqüência de ocorrência, os itens alimentares que predominaram na dieta de T. torquatus foram as formigas (85,7%), coleópteros (32,4%), abelhas (31,4%), cupins (22,8%), aranhas (20,9) e flores (20,0%). Em relação à freqüência numérica, os itens alimentares que predominaram foram as formigas (41,2%) e cupins (40,8%). O número total de presas encontrado nos conteúdos estomacais de T. torquatus foi de 2.903. Este número no total dos exemplares variou de 1 a 268 (média = 27,6; DP = 36,2). Tropidurus torquatus é um predator do tipo senta-e-espera. O comportamento oportunístico desta espécie, cuja dieta inclui invertebrados, pequenos vertebrados (outros lagartos) e vegetais (flores e sementes), pode ser a explicação do sucesso deste lagarto em uma diversidade de hábitats.

Ecological aspects of the collared lizard, Tropidurus torquatus, were studied monthly in a sandy coastal plain of southeastern Brazil, from February 1996 to March 1997. We collected 108 specimens using a pressure gun, of which 45 were males, 56 females, and 7 specimens which sex was not possible to identify. The snout vent length (SVL) ranged from 26.0 to 101.8 mm (mean = 61.7 mm; SD = 15.1). Total weight varied from 0.8 to 39.6 g (mean = 14.6 g; SD = 10.42). Based on the frequency of occurrence, major food items found in the stomach contents of T. torquatus were: ants (85.7%), beetles (32.4%), bees (31.4%), termites (22.8%), spiders (20.9) and flowers (20.0%). Based on the relative number of prey ingested, main food items were: ants (41.2%), and termites (40.8%). Total number of prey found in the stomachs of the collared lizard was 2,903, which varied in individual stomachs from 1 to 268 (mean = 27.6; SD = 36.2). Most of the time T. torquatus is a sit-and-wait predator. Its opportunistic feeding behavior, including invertebrates, small vertebrates (other lizard species), and vegetables (flowers and seeds), may contribute to the success of this lizard in colonizing a diversity of habitats.