Ivo de Sá Motta

Análise econômica da produção do Maracujazeiro amarelo em sistemas orgânico e convencional

Este trabalho foi realizado no municipio de Maringa, localizado na regiao noroeste do Parana, com o objetivo de analisar e comparar economicamente sistemas de producao orgânico e convencional de maracujazeiro-amarelo (Passiflora edulis Sims. f. flavicarpa Deg.). Para se montar a matriz de coeficientes tecnicos, os custos de implantacao e producao e os indicadores de lucratividade da cultura, os dados foram obtidos com extensionistas da regiao e baseados em trabalho de pesquisa, realizado na Fazenda Experimental de Iguatemi da Universidade Estadual de Maringa, no periodo de junho de 2002 a julho de 2004. O custo total de producao da cultura em dois anos agricolas alcancou um valor 12,94% maior para o sistema convencional, e referente ao mesmo periodo, o indice medio de lucratividade foi 21,39% maior para o sistema orgânico. O sistema orgânico de producao se mostrou viavel economicamente, proporcionando maior lucratividade.

Infestation of weed species in monocrop coffee or intercropped with banana, under agroecological system

We aimed with this study to compare weed infestation in coffee under two different cropping managements: conventional coffee grown alone, or intercropped with banana plantation in a year-round basis (late spring, late summer, late fall and late winter). The experiment was installed in 2009 under field conditions at the Escola Municipal Rural Benedita Figueiro de Oliveira, in the city of Ivinhema in the state of Mato Grosso do Sul, Brazil. Assessments of weed occurrence were made three years after employment, on both cropping systems, and density, frequency, dominance and the importance value for each plant species in each system and season were quantified. Plant diversity within each system was estimated by Simpson and Shannon-Weiner indexes. Similarity between cropping systems were also assessed by the binary asymmetric similarity coefficient of Jaccard. Absolute infestation and spontaneous species differed between the two cropping systems in all seasons. Overall species diversity is higher in the monocrop compared with the intercrop, and it is associated in this study with the higher incidence of troublesome species. Areas were similar in terms of weed composition only in the Fall. Shading provided by the banana trees shows to be an efficient culture management aiming to suppress weeds in agro-ecological planting systems.