Análise da expansão da agricultura de grãos na região de Santarém e Belterra, Oeste do estado do Pará.

The images obtained from orbital platforms have been used for the analysis of many occupation processes of the Amazon region along the years. Nevertheless, analyses that have only one date of passage portray just a point in time and, for that, do not explain the occupation process of the region. The evolution of the mechanical agriculture in the towns of Belterra and Santarém, in the west side of Pará state, is causing a series of conflicts between the producers and the environmental movements because of the hypothesis of the expansion of the cultivated area in detriment of the areas of forest formation. Through a time series analysis that uses images from the sensors MSS and TM Landsat from 1975, 1986, 1997, 1999, 2004 and 2005, using digital classification and an intense field work, it was possible to observe the dynamic of the use and the discovery of the land. The results show that there was a reduction of 25% of the forest in the last 30 years. Although the main landscape is the forest formation, it was found that the use of the land with the most occupied area are the regions destinated to the agriculture and cattle activities and which are related to the producers of different levels of technology who try to combine a series of productive systems, aiming the diversity of the natural resources. In addition, it was possible to observe that, unlike other regions in the Amazon, the areas of secondary vegetation presented a high growth in the analyzed time period. Finally it is noticed that the culture of grains was implemented, mostly, in areas that were altered and used for pasture, secondary vegetation and agriculture and livestock activities (related to small and medium producers), having been converted a total of 435 km2 of forest from the year of 1999 to 2004, representing 8% of the total planted area in that year. Although we notice a smaller impact in the environmental context, the direct conversion of the agriculture and livestock class into the grain plantation seems to indicate a process of land concentration and migration of smallholder farmers to the urban areas and/ or new fronts of occupation. This social impact, already observed in Santarém suburbs, should be object of study for the government, mainly concerning the elaboration and implementation of a specific agricultural politics for the Amazon and should enable the smallholder farmer the maintenance of his land and food production

Produção de abelhas rainha européias (Apis mellifera), utilizando diferentes métodos de manejo em Captain Cook, Havai, EUA.

Objetivou-se verificar a influencia do uso de diferentes métodos de manejo nas colmeias recria, na aceitação de larvas para produção de abelhas rainha (Apis melífera ligustica). O trabalho foi conduzido durante o mês de agosto de 2008, na Hawaiian Queen CO, cidade de Captain Cook, estado do Havaí, EUA. Foi utilizado o método proposto por Doolittle (1899), utilizando-se cúpulas de acrílico. Os tratamentos foram: T1- colmeia recria com rainha composta por um ninho, tela excluidora e sobreninho (recria); T2- colmeia Recria com rainha composta por ninho, sobreninho 1, tela excluidora e sobreninho 2 (recria); T3- Introdução das larvas transferidas para ambiente com abelhas operárias órfãs e transferência para uma colmeia recria com rainha composta por um ninho, tela excluidora e sobreninho (recria); T4- Introdução das larvas transferidas para ambiente com abelhas operárias órfãs e transferência para uma colmeia recria com rainha composta por um ninho, sobreninho, tela excluidora e sobreninho (recria). Após execução do teste da normalidade de Shapiro-Wilk, foi executado o teste t para amostras independentes e Mann-Whitney. Verificou-se significância ao nível de 5% de probabilidade entre os tratamentos, ou seja, os tratamentos 1, 3 e 4 mostraram-se mais eficientes para aceitação das larvas e produção de rainhas

Avaliação do potencial germinativo de sementes de café em estádio precoce do desenvolvimento.

Pesquisas recentes identificaram estádios precoces do desenvolvimento das plântulas de café, após a protrusão da radícula, em que todas as partes essenciais da plântula podem ser avaliadas, e assim atesta o potencial das sementes em gerar plantas normais. Desta forma, o objetivo nesta pesquisa foi desenvolver estudos para reduzir o período do teste de germinação de sementes de café. Dez lotes de sementes de café foram avaliados por meio do teste de germinação, a cada dois dias, a partir do décimo dia da semeadura, segundo os critérios morfológicos das plântulas. Os dados foram comparados aos do teste padrão de germinação e analisados por meio de análises de regressão não linear segmentada e modelo de resposta em platô. Concluiu-se que a avaliação de plântulas de café aos 16 dias, no estádio S1, proporciona resultados similares ao teste padrão, permitindo redução significativa do período para atestar a germinação de um lote de sementes; a avaliação das plântulas de no estádio S2 não permite redução do período de avaliação da germinação de sementes de café, em relação ao teste padrão

Minimum period to assess the potential of germination of coffee seeds.

In recent research, early stages of coffee seedling development were identified, after radicle protrusion, in which all the essential parts of the seedling can be assessed to demonstrate the potential of seed germination to generate normal plants. Thus, the objective of this research was to develop studies to reduce the time on the germination test. Ten seed lots of coffee were assessed through the germination test, every two days, from the tenth day of sowing, according to the morphological criteria of the seedlings. The data were compared to the standard germination test and analyzed by means of regression analysis and segmented nonlinear regression and planteau response model. It was concluded that the assessment of coffee seedlings at 16 days, in stage S1, provides the similar result of the pattern germination test, allowing a significant reduction of time in order to demonstrate the germination of the seed lots; the seedling assessment coffee in stage S2 does not have reduction of the time for assessing the coffee germination, in relation to the pattern

Water use efficiency in bananas pome type cropsusing empirical coefficient based on leaf area.

The aim of this work was to evaluate the yield and water use efficiency (WUE) of banana ?Prata-Anã? (AAB) and ?BRS Platina? (AAAB) during two cycles of production in a semi-arid climate of Brazil (classified as Aw according Köppen)

Physiological and biochemical responses of sugarcane varieties to salt stress.

Salt stress is one of the most limiting environmental factors for agricultural yields in the Semiarid region of Brazil. Considering the expansion of areas with sugarcane crops in this region, the selection of more adapted plant varieties to this environment is an essential tool for the sustainability of this activity. Thus, the objective of the present work was to evaluate the physiological and biochemical responses of plants of ten sugarcane varieties to salt stress. The experiment was conducted in a greenhouse using a randomized block design, in a 6×10 factorial arrangement consisting of six salinity levels in the irrigation water (0, 1.0, 2.0, 4.0, 6.0, and 8.0 dS m-1) and ten sugarcane varieties (VAT 90212, RB 72454, RB 867515, Q 124, RB 961003, RB 957508, SP 791011, RB 835089, RB 92579, and SP 943206), with three replications. Salt waters were applied every two days to increase the soil moisture to field capacity and promote leaching. The gas exchange, chlorophyll content, and total soluble and reducing sugars of leaves were evaluated at 90 days after planting. The highest chlorophyll contents were found in plants of the varieties Q 124, RB 96103, RB 835089, and SP 943206. The effect of salinity on the sugarcane plants affected their leaf gas exchanges and total soluble and reducing sugar contents, denoting the adaptability of plants to the stress conditions evaluated. The decrease of stomatal conductance resulted in decreases in photosynthetic rates in plants of all sugarcane varieties evaluated, except for RB 86751