Indices of competition and bio-agroeconomic efficiency of lettuce and tomato intercrops in greenhouses

Intercropping is a cropping system for the production of greenhouse vegetables. It uses space more efficiently, thus reducing the cost of production. Intercropping tomato and lettuce has not been studied, but knowledge of the competitive and agroeconomic indices of these vegetables can help in the management of the intercropping system. The objectives of this study were to assess, through biological and agroeconomic indices, the competition between species and the profitability of intercropping tomato and lettuce at different times of transplantation over two growing seasons (autumn-winter and summer-winter) in greenhouse conditions. In autumn-winter, two experiments were conducted with a randomised complete-block design and five replicates. Tomato and lettuce were the main crops in the individual experiments. Treatments were arranged in a factorial of two cropping systems (intercropping and individual crops) with four transplants of the secondary crop (0, 10, 20 and 30 days after) plus an additional treatment (individual main crop). These two experiments were repeated in summer-winter. Tomato was the dominant crop regardless of transplant order. Intercropping systems established with transplants of both species on the same day had higher values of indices of competition and bio-agroeconomic efficiency than systems with longer periods of transplants between main and secondary crops. The intercropping of lettuce and tomato in greenhouses, regardless of transplant time or order, had bio-agroeconomic advantages over individual crops. The transplantation of tomato after lettuce is recommended for greater profitability.

Globalization and tax competition: implications for developing countries

Includes bibliography

International competition and globalization challenging the Brazilian automotive industry

Includes bibliography

Competition and complementarity between road and rail transport in the carriage of freight

A seminar on competition and complementarity between road and rail transport in the carriage of freight was conducted at ECLAC Headquarters on 6-7 November 2001. The seminar was attended by experts on transport matters from a range of countries, and their presentations covered the current state of integration of transport in countries like Argentina, Brazil, Chile and Mexico. Also in attendance was an expert from Central America, who spoke about modal integration of freight transport in that region. Three round-table discussions were held with the participation of representatives of the trucking and rail sectors, drawn from both the private and public spheres.

Competition Policy and Trade Agreements in the Region: Exploring Forums for Cooperation and Convergence

The similarities of competition provisions in integration and other intraregional agreements and the dissemination of this information could serve as a basis for progress in cooperation and convergence on this issue in the region. The negotiation processes that have taken place for these agreements have also enhanced communication between the national agencies concerned, leading to processes of learning and harmonization; these processes could be strengthened as part of the current efforts of administrating and implementing trade agreements. This edition of the FAL Bulletin reviews the information available in order to see how progress can be made on this issue on the basis of the analysis and bibliography of Álvarez and others (2006), and Silva and Álvarez (2006).

Interações intraguilda e toxicidade a agrotóxicos a Neoseiulus californicus (McGregor) e Agistemus brasiliensis Matioli, Ueckermann & Oliveira no controle de Brevipalpus phoenicis (Geijskes) em citros

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Nonlinear dynamics of within-host parasite competition

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

An Additional Baurusuchid from the Cretaceous of Brazil with Evidence of Interspecific Predation among Crocodyliformes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Decay of interspecific avian flock networks along a disturbance gradient in Amazonia

Our understanding of how anthropogenic habitat change shapes species interactions is in its infancy. This is in large part because analytical approaches such as network theory have only recently been applied to characterize complex community dynamics. Network models are a powerful tool for quantifying how ecological interactions are affected by habitat modification because they provide metrics that quantify community structure and function. Here, we examine how large-scale habitat alteration has affected ecological interactions among mixed-species flocking birds in Amazonian rainforest. These flocks provide a model system for investigating how habitat heterogeneity influences non-trophic interactions and the subsequent social structure of forest-dependent mixed-species bird flocks. We analyse 21 flock interaction networks throughout a mosaic of primary forest, fragments of varying sizes and secondary forest (SF) at the Biological Dynamics of Forest Fragments Project in central Amazonian Brazil. Habitat type had a strong effect on network structure at the levels of both species and flock. Frequency of associations among species, as summarized by weighted degree, declined with increasing levels of forest fragmentation and SF. At the flock level, clustering coefficients and overall attendance positively correlated with mean vegetation height, indicating a strong effect of habitat structure on flock cohesion and stability. Prior research has shown that trophic interactions are often resilient to large-scale changes in habitat structure because species are ecologically redundant. By contrast, our results suggest that behavioural interactions and the structure of non-trophic networks are highly sensitive to environmental change. Thus, a more nuanced, system-by-system approach may be needed when thinking about the resiliency of ecological networks.

Ecological competition and the incidence of Acinetobacter baumannii bloodstream infections in a teaching hospital in Southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Early selection in open-pollinated Eucalyptus families based on competition covariates

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of Temperature on Intraspecific Competition in Ectotherms

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)