ABSTRACT Little is understood about the nutritional status of manganese (Mn) in oil palm (Elaeis guineensis Jacq.), further research is needed to provide technological support for greater productivity, especially on the dynamics of accumulation, recycling, immobilization and export. Thus, the objective of this work was to evaluate the dynamics of accumulation, immobilization, recycling, exportation and the efficiency of Mn use in oil palm plants at different ages. The experiment was carried out in a completely randomized design, with seven treatments (plant age: 2, 3, 4, 5, 6, 7, and 8 years of planting) and four replicates. The leaflets and male inflorescence were, the vegetative and reproductive organs with the highest Mn concentration, respectively. The accumulation of this nutrient in the tree crown predominated in the stipe through all years. The bunch exported the highest amount of Mn, especially in older plants. The oil palm immobilizes and recycles, more than exports, a large amount of Mn. The Mn use efficiency is increased as a function of the age of the crops in all the oil palm organs. In conclusion, the nutritional demand of oil palm is altered as a function of age, altering the dynamics of immobilization, recycling and exportation of Mn.

ABSTRACT Cultivation and commercialization of Capsicum pepper have great importance in Brazil. This work assessed the influence of omission of macro and micronutrients on the growth and mineral nutrition of sweet pepper plants (Capsicum chinense Jacquin). The research was carried out in a greenhouse with washed sand as substrate. The experimental design was completely randomized with five replications and eight treatments: complete (control), omission of N, P, K, Ca, Mg, S, and micronutrients (B, Cu, Fe, Mn and Zn). The plants were submitted to the treatments when they reached an average height of 20 cm and the nutrient solution was supplied by percolation in plastic pots and renewed every 15 days. Nutrients omission affected negatively plant growth as a whole. The omission of N, Ca, and micronutrients greatly reduced sweet pepper yield. The C. chinense plants presented the sequence by dry matter production of shoots and roots in descending order: COMP > OP > OS > OK > Omg > ON > Oca > OMicro.

ABSTRACT Oil palm production is strategic in the Amazon with high productive potential, but information on its fertilization is still relatively scarce for the region. The objective of this work was to evaluate the effects of phosphorus, potassium and magnesium fertilizations on oil palm production in different years in the state of Pará, Brazil. The study was conducted in Tailândia, Northeastern of Pará, Eastern Amazon, Brazil. A randomized block design was used in a 4 x 2 x 3 x 2 factorial scheme, with four levels of phosphorus, two sources of phosphorus, three levels of potassium and two levels of magnesium. Oil palm production responded positively to the increase in phosphorus levels, and until the eighth year of age of the plants, there was greater production when triple superphosphate was applied. From the ninth year onwards, fertilization with phosphine provided a production equal to the supply of phosphorus with triple superphosphate. The application of potassium chloride increased the number, weight and production of the bunches from the sixth year. The supply of magnesium sulfate increased the average weight of the bunches. Thus, phosphorus, potassium and magnesium fertilizations become essential to increase oil palm production in the Northeast of Pará.