RESUMO: Este trabalho teve como objetivo determinar a interação competitiva de cultivares de sorgo sacarino com biótipos de papuã e de leiteiro. Os ensaios foram instalados em delineamento completamente casualizado, replicados quatro vezes. Os tratamentos foram dispostos em série substitutiva nas proporções de 100:0, 75:25, 50:50, 25:75 e 0:100%, o que equivaleu a 20:0, 15:5, 10:10, 5:15 e 0:20 plantas vaso-1 de sorgo sacarino (cultivares BRS 506, BRS 509 e BRS 511) com as plantas daninhas (papuã ou leiteiro). A área foliar (AF) e a massa seca (MS) das plantas de sorgo sacarino, do papuã e do leiteiro foram determinadas aos 50 dias após emergência das espécies. Os dados relativos às habilidades competitivas foram analisadas através do método da análise gráfica, construindo-se diagramas baseados nas produtividades ou variações relativas e totais. Determinaram-se também os índices de competitividade, coeficiente de agrupamento e agressividade, todos eles relativos. Ocorreu competição pelos mesmos recursos do meio entre os cultivares de sorgo sacarino e as plantas daninhas, com prejuízo mútuo às espécies envolvidas na comunidade. O leiteiro e o papuã modificaram de forma negativa a AF e a MS da cultura, demonstrando habilidade competitiva superior pelos recursos do ambiente. O leiteiro foi menos competitivo que os cultivares de sorgo sacarino, enquanto o papuã apresentou maior competitividade do que eles. Os maiores prejuízos para as variáveis AF e MS foram observados quando as espécies estiveram em competição interespecífica, em relação à competição intraespecífica.

ABSTRACT: The objective of this work was to determine the competitive interaction of sweet sorghum cultivars BRS 506, BRS509, and BRS 511 with biotypes of Alexandergrass and wild poinsettia. The adopted experimental design was the randomized block one, with four replications. Treatments were arranged in a substitution series by proportions of 100:0, 75:25, 50:50, 25:75, and 0:100%, corresponding to 20:0, 15:5, 10:10, 5:15 and 0:20 plant per pot of sweet sorghum (cultivars BRS 506, BRS 509 and BRS 511) withweeds (Alexander grass/wild poinsettia). The leaf area (LA) and dry matter (DM) of sweet sorghum, Alexandergrass and wild poinsettia plants were determined 50 days after emergence. Data about competitive abilities were analysed through the graphical analysis method, constructing diagrams based on yield or relative and total variations. Indices of relative competitiveness, clustering coefficient and aggressiveness were also determined; all of them were relative indices. There was competition for the same environmental resources between sweet sorghum cultivars and weeds, with mutual injury to the species involved in the community. Wild poinsettia and Alexandergrass negatively modified the LA and DM of the crop, demonstrating a greater competitive ability for the resources that are available in the environment. Wild poinsettia was less competitive than sweet sorghum cultivars, while Alexandergrass showed higher competitive ability than them. The highest losses for the LA and DM variables were observed when species were in interspecies competition rather than intraspecies competition.

Paracoccidioides brasiliensis and P. lutzii are fungi that cause paracoccidioidomycosis (PCM), the most prevalent systemic mycosis in South America. For serological diagnosis, although 43-kDa glycoprotein (gp43) is regarded as highly specific for PCM, the occurrence of false negative reactions in sera from patients infected with P. lutzii suggests that preparation with only one antigen is not recommended. Heat shock proteins are feasible alternatives as a second antigen because they are often highly immunogenic. In this study, we evaluated the usefulness of recombinant 60-kDa heat shock protein from P. brasiliensis (rPbHsp60) for the serological diagnosis of PCM. Using western blotting assay, we observed that 77.3% of the sera from PCM patients were positive to rPbHsp60, with 90.9% positivity to recombinant gp43 (rgp43). More importantly, sera from healthy subjects had 27% positivity to rPbHsp60 and none to rgp43. When rPbHsp60 was used in ELISA, we did not observe significant differences between the reactions with sera from PCM patients and healthy subjects, while the difference was clearly evident when the antigen was rgp43. Furthermore, rPbHsp60 was recognized by sera from patients with histoplasmosis, aspergillosis, sporotrichosis or tuberculosis in an ELISA test. These results show that rPbHsp60 is not a good antigen for PCM diagnosis.

Avaliou-se a potencialidade larvicida do extrato-bruto etanólico (EBE) da casca do caule de Sapindus saponaria sobre Rhipicephalus sanguineus. Para o cálculo das concentrações letais (CL) foram preparadas soluções com diferentes concentrações do EBE dissolvido em água destilada. Foram utilizadas larvas em jejum com 14 a 21 dias, obtidas pela incubação de teleóginas, coletadas em ambientes infestados, freqüentados por cães de vários bairros de Goiânia. Os bioensaios foram realizados em uma câmara biológica para testes com acaricidas botânicos, climatizada a 27±1ºC e UR>80%. As larvas foram contidas em envelopes de papel filtro impregnados com as soluções (grupo teste) ou com água destilada (grupo-controle) e a mortalidade larval foi observada após 48h. S. saponaria demonstrou atividade larvicida satisfatória (CL50 e CL99 respectivamente de 1994 e 3922ppm) e os resultados demonstraram seu potencial como acaricida botânico e medida alternativa para o controle de R. sanguineus.

The larvicidal potential of the crude ethanolic extracts (CEE) of the stem peel of Sapindus saponaria was evaluated against Rhipicephalus sanguineus. Lethal concentrations (LC), were calculated by preparing CEE solutions at different concentrations in distilled water. Larvae fasted for 14-21 days were utilized in the bioassays, after incubation of engorged females collected from infested environments frequented by dogs in several neighborhoods of Goiânia, GO. Bioassays were performed in a specially constructed biological chamber for testing botanical acaricides, acclimatized to 27±1ºC, RH>80%. The larvae were counted on filter paper envelopes impregnated with the solutions or distilled water and larval mortality observed after 48h. S. saponaria showed good larvicidal activity (LC50 and LC99 of 1994 and 3922ppm, respectively) and the results demonstrated its potential as a botanical acaricide and an alternative control measure for R. sanguineus.

Estudaram-se os efeitos de cipermetrina, deltametrina e permetrina sobre larvas de uma cepa de campo de Goiânia, com o objetivo de monitorar a susceptibilidade de Boophilus microplus para esses acaricidas e fomentar medidas de controle. Larvas em jejum com 14 a 21 dias, imersas em soluções desses piretróides, foram mantidas a 27±1°C e UR% > ou = 80% e observadas por 24h ao estereoscópio, contidas em dispositivo desenvolvido originalmente para estudos da fase não parasitária do ciclo evolutivo. O material utilizado em sua confecção, placa de petri descartável, tecido organza e parafina, não foi tóxico para as larvas. Os seguintes efeitos toxicológicos foram observados: excitabilidade, movimentação repetitiva, diminuição da capacidade locomotora, desprendimento, paralisia, knock-down e proliferação cuticular de líquidos e gases. A mortalidade média na 24ªh foi de 76,3%, 87,5%, 77,6%, 91,2%, 86,20%, e 100,0%, respectivamente, para deltametrina 25ppm e 50ppm, cipermetrina 150ppm e 300ppm e permetrina 1250ppm e 2500ppm. O ixodídeo foi resistente às concentrações comerciais de deltametrina e cipermetrina. Apenas permetrina 2500ppm provocou índice de mortalidade superior ao valor recomendado pelo Ministério da Agricultura para acaricidas.

In order to monitor the susceptibility of Boophilus microplus to acaricides and improve control measures, the effects of cypermethrin, deltamethrin and permethrin on larvae obtained in the city of Goiânia in the Brazilian state of Goiás were studied. Although these pyrethroids are already sold as acaricides, their cost-benefit efficiency has been questioned. Fasting 14-21 day-old larvae were immersed in solutions of the acaricides under test, maintained at 27±1° C, and relative humidity over 80%, and observed under the stereoscope within an apparatus originally designed for studying the non-parasitic phase of the tick life cycle. The observed toxicological effects were: excitability, repetitive motion, decreased motor ability, detachment, paralysis, knock-down and cuticular proliferation of liquids and gases. The materials used in the manufacture of this apparatus consisted of disposable Petri dishes, "organza" cloth and paraffin, none of which are toxic to tick larvae. Mean death rates after 24h were 76.3%, 87.5%, 77.6%, 91.2%, 86.2% and 100% for 25 and 50ppm deltamethrin, 150 and 300ppm cypermethrin and 1250 and 2500ppm permethrin, respectively. The ticks were resistant to commercial concentrations of deltamethrin and cypermethrin. Only 2500ppm permethrin produced the mortality recommended by the Brazilian Ministry of Agriculture.

Investigaram-se os efeitos toxicológicos in vitro de três piretróides em diferentes concentrações, formulados para uso pecuário, domiciliar e em cães, sobre larvas de R. sanguineus, objetivando monitorar sua suscetibilidade e fomentar seu controle. Utilizaram-se 1.604 larvas em jejum, com 15 a 21 dias, obtidas por infestação artificial em cão, imersas nas soluções testadas, contidas em dispositivos constituídos por placa de Petri descartável, papel filtro e parafina, mantidas em incubadoras do tipo BOD e observadas ao estereoscópio por 24h. Observaram-se excitabilidade, movimentação repetitiva, diminuição da locomoção, desprendimento, paralisia, "knock-down" e proliferação cuticular de gases e líquidos. A mortalidade na 24ª hora foi de 86,9%, 100,0%, 80,3%, 86,0%, 68,2% e 78,0%, respectivamente, para permetrina 1250ppm e 2500ppm, cipermetrina 150ppm e 300ppm, e deltametrina 25ppm e 50ppm. Não houve mortalidade no grupo controle.

Aiming at monitoring the susceptibility, increasing the control and evaluating the toxicological effects, of different concentrations of three pyrethroids were investigated in vitro against Rhipicephalus sanguineus larvae using concentrations formulated for cattle, dogs and household use. A total of 1,604 15-21 day-old fasting larvae, obtained by artificial infestation in dogs, was immersed in the solutions. Larvae were then maintained in BOD incubators inside experimental devices, constituted by disposable Petridishes, filter paper and paraffin, and observed on the stereomicroscope during a 24-hour period. The larvae have shown excitability, repetitive movements, decrease of locomotion, detachment, paralysis, knock-down and production of gases and liquid in the cuticle. Mortality after 24 hours was 86.9% (1250ppm) and 100.0% (2500ppm) for permethrin; 80.3% (150ppm) and 86.0% (300ppm) for cipermethrin; and for deltamethrin 68.2% (25ppm) and 78.0% (50ppm). Mortality was not observed in the control group.