The objective of this study was to evaluate the growth and accumulation of nutrients in accessions of organic jambu. The experiment was conducted in the didactic garden of the Federal Institute of Pará, Campus Castanhal, in the period May and June 2015. The experimental design was a randomized complete block design with a 2 x 5 factorial arrangement with four replicates. The treatments were a combination of two jambu accessions (Purple Flower and Yellow Flower) and five sampling times (10, 18, 26, 34 and 42 days after transplanting - DAT). The period of greatest growth and nutrient demand was for access to Purple Flower from 18 to 34 DAT and for the Yellow Flower from 26 to 42 DAT. Nutrient accumulation by the two accesses of jambu, in decreasing order, was: potassium, nitrogen, calcium, magnesium and phosphorus.

Na região semiárida do nordeste do Brasil, o reuso pode ser uma fonte alternativa de água, matéria orgânica e nutrientes com possibilidade de assegurar e incrementar a produção agrícola durante as estiagens prolongadas, em especial ao nível da agricultura familiar, contribuindo para a fixação do homem no campo. O presente trabalho teve como objetivos investigar a resposta de duas cultivares de alface (Babá de Verão e Scarlet) em sistema hidropônico utilizando água de esgoto doméstico em diferentes doses. O experimento foi conduzido em ambiente protegido na UFERSA-Mossoró, em delineamento inteiramente casualizado, sendo cinco doses de esgoto doméstico tratado e duas variedades, com cinco repetições. Os tratamentos constaram da mistura de duas fontes de água, sendo uma de abastecimento (AA) e outra residuária (AR), resultando em: T1-100% água de abastecimento (AA); T2-75%AA + 25%AR; T3-50%AA + 50%AR; T4-25%AA +75%AR; T5-100%AR. Para o parâmetro altura da planta observou-se diferença estatística entre os tratamentos, sendo que T1 (100% água de abastecimento) o tratamento que apresentou melhor resultado. De maneira geral, observou-se que a tolerância das culturas varia entre variedades de uma mesma espécie sendo que nas condições em que a pesquisa foi desenvolvida, as cultivares Babá foi mais tolerante com a utilização de água de esgoto tratado.

Maize plays an important role in the economy and the social and cultural development of several regions in Brazil. However, its productivity is considered low, since the management of nitrogen fertilization and the selection of efficient cultivars in using nitrogen are the main factors responsible for the low productivity of this crop. This study had the purpose to evaluate the efficiency of nitrogen usage in maize cultivars for the production of grains. The experiment was conducted at the vegetable garden at Universidade Federal Rural do Semi-Árido, in the municipality of Mossoró -Rio Grande do Norte state, Brazil. Treatments consisted in the combination of two nitrogen doses (0 and 90 kg N ha -1 ) and three maize cultivars (Cruzeta, Truck and AG 1051). A randomized complete block experimental design was used, in a 2 x 3 factorial arrangement, with five replications. The most productive performance was observed when the evaluated cultivars were fertilized with nitrogen. Based on the values from nutritional indices, cultivar AG 1051 was more efficient in using nitrogen to produce grains.