The microlepidoptera, Bedellia somnulentella (Zeller), is an important pest of sweetpotato, Ipomoea batatas (L.) Lam. Damage by B. somnulentella occurs in the larval stage and when consuming the foliar mesophyll of I. batatas make the leaves brown, wrinkled, and reducing the photosynthetic area and the yield. The detection and management of this pest depends on knowing its biological cycle and identifying its natural enemies. The objectives of this study were to determine the life history of B. somnulentella feeding on I. batatas leaves and to survey parasitoids of this pest in the field. The duration and viability of B. somnulentella egg, larva, prepupa, pupa, and adult stages were evaluated under laboratory conditions. Cephalic capsule width was measured to determine the number of B. somnulentella instars, based on the Dyar rule and analyzed by the Akaike statistical model (AIC). The developmental period of B. somnulentella was 32.5 ± 0. 21 d with a viability of 75, 84, 100, and 84% for the egg, larva, prepupa, and pupa stages, respectively. The identification of this pest on the plants is possible from the third instar and in the pupal and adult stages. The parasitoid Conura sp. (Hymenoptera: Chalcididae) was identified parasitizing pupae of B. somnulentella and could be considered a potential natural enemy for the integrated management of this pest.

Weeds and microorganisms interacting with their rhizosphere may influence nutrient absorption, which is an important factor for plant competition. The purpose of this study was to evaluate the microbiological activity, inorganic phosphorus solubilization (Pi) and acid phosphatase in the cultivated soil, in a combination of soybean (Glycine max) plants and weeds. Soybeans were cultivated in monoculture and in competition with Bidens pilosa, Brachiaria decumbens (Syn. Urochloa decumbens) and Eleusine indica, under two conditions: a) plants competing without contact between the roots b) plants competing with contact between the roots. A nylon screen with a 50 µm mesh was added to prevent contact between the roots of the species in competition so that the substratum could be separated in the vase. The experiment was conducted in randomized blocks, with four replications. The soybeans in competition with weeds led to lower oxidation of organic matter per unit of microbial biomass, resulting in a lower metabolic quotient, compared with the soybean monoculture. The contact between soybean roots and B. pilosa, B. decumbens and E. indica maintained a strong influence, raising the solubilization of Pi, respectively valued at 51, 39 and 31% in relation to the cultivation of each species with a nylon screen. Microbiological activity, inorganic phosphorus solubilization and acid phosphatase were altered by plant species, combinations of weeds and soybean plants in competition; by root contact in some cases. Thus, the microbiological activity of the soil can influence competition strategies and plant development.

Climatic changes have induced the spread of aridity in many parts of the globe. Eucalyptus plantations show wide variations in productivity due to several factors, including climatic changes. Therefore, Eucalyptus genotypes that can adapt to such conditions is very welcome. Thus, an evaluation was done by comparing the physiological responses of two Eucalyptus genotypes, tolerant and drought-sensitive. They were assessed in different stages of experimental period and the rate of chlorophyll and chlorophyll fluorescence (minimal fluorescence and maximal fluorescence) were recorded. The potential photosystem II (PSII) quantum efficiency was then calculated. A decline in the rate of total chlorophyll (values below 25) and in the minimal fluorescence (values below 190) in clone sensitive due to the water stress was observed, while an increase was noted in clone tolerant to aridity. A reduction in the maximal fluorescence and photochemical efficiency was recorded in the genotype not being irrigated, with an earlier and more severe effect being verified for the sensitive genotype with values below 300 and 0.40, respectively. The variables studied confirm that clone tolerant exhibits greater drought tolerance, thus indicating that the photochemical efficiency of photosystem II is a reliable tool that enables the nondestructive choice of genotypes naturally tolerant to water scarcity conditions. Key words: Abiotic stress, arid land plants, chlorophyll, ecophysiology, photochemical efficiency, tree drought tolerance, water deficit, water potential.

Terceiro maior país em produção de frutas frescas no mundo, o Brasil destaca-se por apresentar ampla capacidade de adaptação produtiva de fruteiras exóticas devido, principalmente, às suas condições edafoclimáticas que somados a práticas culturais já estabelecidas, permitem alcançar altas produções. Além disso, o país é detentor de uma das maiores agrobiodiversidades mundiais, possuindo espécies nativas frutíferas com alto potencial de exploração do consumo. Porém, muitas vezes essas frutas não recebem o devido valor, sendo negligenciadas pelo desconhecimento popular, e, consequentemente, apresentam baixa participação no comércio de frutas do Brasil. Diante deste cenário, o presente trabalho teve por objetivo identificar o padrão de consumo de frutas, analisar o conhecimento popular sobre fruteiras exóticas e nativas e verificar a potencialidade de inserção de espécies nativas do Brasil no mercado de frutas. Observou-se que, o consumo de frutas é inferior ao recomendado pela Organização Mundial da Saúde (OMS), sendo composto em sua maioria de fruteiras exóticas adquiridas em supermercados. Apesar da falta de entendimento dos termos de classificação de frutas quanto ao centro de origem, os participantes da pesquisa, compreendidos majoritariamente por pessoas que possuem ensino superior, conhecem quais espécies são pertencentes à flora brasileira e quais foram introduzidas no território nacional. Além disso os entrevistados demonstram consciência da importância das espécies nativas e dos entraves que impedem a inserção no mercado em maiores quantidades, afirmando que gostariam de consumir mais frutas nativas, o que demonstra a potencialidade da fruticultura nacional.