Abstract The present study was based on the analysis of 10,467 trawls of the industrial piramutaba (Brachyplatystoma vaillantii) fishing fleet of the Brazilian state of Pará, which were mapped by onboard GPS loggers (between February 2008 and September 2011) and the PREPS data from 40 vessels which were tracked by this system between 2008 and 2011. The variation in the mean monthly CPUE, based on Lomb’s periodogram, revealed a well-defined and constant cycle with a duration of approximately one year. Three environmental factors influenced this cycle. The El Niño 3.4 index had a negative correlation with the CPUE of the piramutaba fishery, with a time lag of 15 months, while monthly rainfall and the mean discharge of the Amazon River correlated strongly (r=0.89 and 0.87, respectively; p<0.001) with the CPUE, with time lags of 12 and 11 months, respectively. The spatiotemporal analysis of the distribution of the activity of the piramutaba fishing fleet indicated that the most intense area of operation of the fleet lies between latitudes 00º N and 02° N, and longitudes 047º40’ W and 049º40’ W. This area was divided into four geographic quadrants, although fishery operations were concentrated in only three of these quadrants. The study proposed a quadrimester fishing cycle with zoning in three of the quadrants, where fishing would be permitted for four months (occupation period), followed by an 8-month rest period for the recuperation of stocks, aiming at the sustainability of this fishing exploration.

Teve-se o objetivo de, com a realização deste trabalho, obter a curva de neutralização do pH de amostras dos horizontes A e B de um Latossolo Vermelho-Amarelo distrófico, utilizando-se de farelo de conchas de vôngole (Anomalocardia brasiliana); além disso, avaliar a capacidade de adsorção de fósforo, obtendo-se a isoterma de adsorção de melhor ajuste aos dados obtidos. Verificou-se que o farelo de concha de vôngole apresenta potencial para uso como corretivo de acidez do solo e que a dose recomendada para correção do pH do horizonte A do Latossolo Vermelho Amarelo distrófico estudado foi de 2,92 t ha-1, enquanto, para correção do horizonte B, foi de 3,35 t ha-1. O farelo de conchas de vôngole também apresentou alta capacidade de adsorção de fósforo, o que indica possibilidades de sua utilização em sistemas que visem à remoção deste elemento químico de águas residuárias. Os modelos de Langmuir e Freundlich ajustaram-se bem aos dados e podem ser utilizados para representar a isoterma de adsorção de fósforo.

The objective of this study was to obtain the curve of pH neutralization for samples of the horizons A and B of a dystrophic Rhodic Haplustox soil using ground clam shells (Anomalocardia brasiliana), as well as assess the capacity of phosphorus adsorption to obtain the adsorption isotherm that best fit to the data obtained. It was found that the ground clam shells present potential to be used in soil acidity correction and that the recommended dose for pH correction of horizon A of the dystrophic Rhodic Haplustox studied was 2.92 t ha-1, while for correction of horizon B was 3.35 t ha-1. The ground clam shells also showed high adsorption capacity for phosphorus, which indicates possibilities of its use in systems targeting the removal of this chemical from wastewater. The Langmuir and Freundlich models fit well to the data and may be used to represent the adsorption isotherm.

Com o objetivo de avaliar a produção e distribuição de biomassa de algumas espécies arbóreas de múltiplo uso em condições de sequeiro do submédio do São Francisco, instalou-se um experimento no Campo Experimental da Caatinga da Embrapa Semi-Árido, Município de Petrolina, PE. Foram realizadas medições de altura e diâmetro à altura do peito (DAP) de 16 árvores centrais, em três parcelas de cada espécie: Leucaena diversifolia, Caesalpinia velutina, Caesalpinia coriaria, Mimosa tenuiflora e Ateleia herbert-smithii. A biomassa foi estimada com base na árvore de altura média de cada parcela, avaliando-se, separadamente, cada componente (folhas, galhos, cascas e lenho). A biomassa nos diferentes componentes arbóreos das espécies foi distribuída na seguinte ordem: folha<casca<galho<raiz<lenho, excetuando-se A. herbert-smithii, que produziu mais folha do que casca. A produção de biomassa total foi superior em C. velutina (51,6 kg ha-1), seguida por L. diversifolia (36,6 kg ha-1), A. herbert-smithii ( 26,4 kg ha-1), Caesalpinia coriaria (23,0 kg ha-1) e Mimosa tenuiflora (21,6 kg ha-1). Entretanto, a matéria seca foliar, que é o principal componente forrageiro das espécies, foi maior em C. velutina (3,7 kg ha-1), vindo em seguida A. herbert-smithii (2,8 kg ha-1) e C. coriaria (2,2 kg ha-1), L. diversifolia (2,0 kg ha-1) e M. tenuiflora (1,3 kg ha-1), representando, respectivamente, 7,2; 10,7; 9,5; 5,3; e 6,3% da biomassa total. C. velutina destacou-se por ser a mais produtiva, tanto como madeireira (lenho=30,8 t ha-1) quanto forrageira (folhas = 3,7 t ha-1), enquanto a M. tenuiflora foi a de menor potencial forrageiro.

The objective of the study was to quantify the production and biomass distribution of some potential arboreal species of multiple uses, under dry land conditions, in the Brazilian Semi-arid. The study was developed in the Experimental Station of Caatinga, of Embrapa Semi-Árido, Petrolina-PE, Brazil. Plant height and diameter at breast height (DBH) of 16 central trees of each plot, from three replicates, were measured. The following species were studied: Leucaena diversifolia, Caesalpinia velutina, Caesalpinia coriaria, Mimosa tenuiflora and Ateleia herbert-smithii. Biomass was estimated based on the medium height tree in each plot, evaluating each component separately: leaf, bark, branch, root and log, except for A. herbert-smithii that produced more leaf than bark. Total biomass production was superior for C. velutina (51.6 kg ha-1), followed by L. diversifolia (36.6 kg ha-1), A. herbert-smithii (26.4 kg ha-1), Caesalpinia coriaria (23.0 kg ha-1) and Mimosa tenuiflora (21.6 kg ha-1 However, leaf dry matter, the main potential component of forage species, was higher for C. velutina y A. herbert-smithii (2.8 kg ha-1) and C. coriaria (2.2 kg ha-1), L. diversifolia (2.0 kg ha-1) and M. tenuiflora (1.3 kg ha-1) representing, respectively, 7.2, 10.7, 9.5, 5.3 and 6.3% of total biomass. C. velutina stands out as the most productive, as well as wood (log = 30.8 t ha-1) as forage (leaves = 3.7 t ha-1), while M. tenuiflora showed the lowest forage potential.

O presente trabalho foi desenvolvido visando à obtenção de linhagens de Crotalaria juncea autocompatíveis e resistentes à murcha de Ceratocystis fimbriata. Plantios sucessivos de crotalária comum foram efetuados em área altamente infestada pelo patógeno. Em cada ciclo foram selecionadas plantas que chegaram a produzir sementes, sendo estas plantadas no ano seguinte. Após quatro anos, o material resultante foi cruzado com linhagens autocompatíveis, visando reunir o caráter resistência à condição de autocompatibilidade. A geração F1 desse cruzamento foi retrocruzada com pais resistentes e com pais autocompatíveis. As populações assim obtidas foram levadas até a geração F4, sendo que em cada geração eram feitas inoculações e seleção de plantas resistentes e autocompatíveis. A geração F5, com 1.030 plantas, foi selecionada para produção e qualidade de sementes, resultando em 111 plantas com as características desejadas. As linhagens dessas plantas, após inoculação com isolados do fungo, mostraram alta porcentagem de plantas autocompatíveis, com resistência à murcha.

This paper describes the methods used in obtaining lines of Crotalaria juncea to self compatibility and resistance to wilt (Ceratocystis fimbriata). Successive plantings of Crotalaria juncea were made in areas highly infected with wilt. In each cycle, plants which produced seeds were selected and the seeds were replanted. After four years this material was crossed with lines with self compatibility with the common goal of reuniting resistance to wilt and self compatibility. In f1 generation of this cross was backcrossed with the parents resistant to wilt and self compatibility respectively. The population obtained was multiplied up to F4 having been inoculated at each generation with wilt pathogen and selections made of plants resistant to the disease and self compatibility. In the F5 generation 1,030 plants were selected for seed production and seed quality, and of these only 111 plants showed the desired characteristics. The lines of these plants after inoculation with the wilt pathogen showed high percentage of resistance to disease and self compatibility.