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Oil palm is the main palm tree cultivated in the tropics, but little is understood about copper (cu) management in this crop. The objective of this study was to evaluate the nutritional status of copper in oil palms plants in the Eastern Amazon. The experiment was carried out in Tailândia, in the state of Pará (Brazil), using a completely randomized experimental design, with four replications and seven treatments (ages of oil palm plants: 2, 3, 4, 5, 6, 7, and 8 years). The concentration, accumulation, cycling, immobilization, export, and efficiency of copper use in the different organs of the plants were evaluated. The highest copper concentrations occurred in the palm heart in the second year, and copper accumulation (481 g ha−1) and export were highest in the eighth year of growth. Among the plant organs, the highest copper exports occurred in the bunches (69.38 g ha1). The highest proportion of copper was immobilized (326 g ha−1), while the lowest proportion of the nutrient accumulated in the export organs. Copper use efficiency increased with plant age, and efficiency was greater in the petiole and lower in the palm heart. The copper requirement increased with the age of oil palms grown in the Eastern Amazon. [ABSTRACT FROM AUTHOR]

In crop plants, various environmental stresses affect the balance of carbon, nitrogen, and phosphorus (C:N:P), leading to biochemical and physiological alterations and reductions in yield. Silicon (Si) is a beneficial element that alleviates plant stress. Most studies involving silicon have focused on physiological responses, such as improvements in photosynthetic processes, water use efficiency, and antioxidant defense systems. But recent research suggests that stressed plants facing either limited or excessive resources (water, light, nutrients, and toxic elements), strategically employ Si to maintain C:N:P homeostasis, thereby minimizing biomass losses. Understanding the role of Si in mitigating the impact of abiotic stresses on plants by regulating C:N:P homeostasis holds great potential for advancing sustainable agricultural practices in crop production. This review presents recent advances in characterizing the influence of environmental stresses on C:N:P homeostasis, as well as the role of Si in preserving C:N:P equilibrium and attenuating biological damage associated with abiotic stress. It underscores the beneficial effects of Si in sustaining C:N:P homeostasis and increasing yield via improved nutritional efficiency and stress mitigation. [ABSTRACT FROM AUTHOR]

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 FROM AUTHOR]

The concentrations of nutrients in the leaves allow a better understanding of the nutritional status of oil palm plants, making it a tool for diagnosing the origins of nutritional problems and assisting in fertilizer recommendations. In this sense, the objective of the current research was to evaluate the leaf concentrations of N, P, K, Ca, Mg and S in the oil palm under fertilization with phosphate, potassium and magnesium in edaphoclimatic conditions of Eastern Amazon. The experiment was conducted at the AGROPALMA® Company in the municipality of Tailândia, state of Pará, Brazil. The experimental design used was randomized blocks in a factorial scheme 4 x 2 x 3 x 2, with four levels of phosphorus, two sources of phosphorus (natural phosphate and triple superphosphate), three levels of potassium and two levels of magnesium. Phosphorus fertilization increased the leaf concentrations of N, P, Ca and Mg, providing higher levels when triple superphosphate was applied. However, in adult oil palm plants (12 years old), there was different on leaf concentrations of N, P, K and S between phosphorus sources aphid. Potassium and magnesium fertilization only increased the leaf concentrations of K and Mg, respectively. Fertilization with P, K and Mg promotes adequate leaf concentrations of K, Ca, Mg e S in oil palm plants grown in the Eastern Amazon. [ABSTRACT FROM AUTHOR]

In the northeastern of Pará, cowpea is one of the main protein sources of the population. This study aimed to evaluate the effects of liming, the P and K mineral fertilization, and the combination of seed inoculation with Rhizobium associated with mineral N supplementation in the growth and production of cowpea cultivars. Two experiments were carried out in two consecutive years at the Federal Rural University of Amazonia (Capitão Poço-PA). A randomized block experimental design with subdivided plots was used with four replications, two cowpea cultivars (BRS Tapaihum and BRS Marataoã) and six fertilization and liming treatments: i) without fertilization and without liming; ii) P and K mineral fertilization, liming and seed inoculation with Rhizobium; iii) P and K mineral fertilization and seed inoculation with Rhizobium; iv) N, P and K mineral fertilization and liming; v) P and K mineral fertilization and liming; and vi) N, P and K mineral fertilization, liming and seed inoculation with Rhizobium. Cowpea responded to liming and P and K mineral fertilization, but not N fertilization. There was no difference between the supply of N through seed inoculation or mineral fertilization. Thus, it is suggested to inoculate seeds with Rhizobium in order to maintain the soil N reserve. [ABSTRACT FROM AUTHOR]

The biological collections are evidence of the biodiversity and requisit instrument for several studies and, in this context, the Herbarium of Embrapa Amazônia Oriental appears, indexed by the Index Herbariorum under the acronym IAN, because at the time of its creation (1945) the company was called Instituto Agronômico do Norte. The IAN contains a wide diversity of gender Mimosa L., which shows notable economical potential by having a lot of applications in folk medicine, recovery of degraded areas, environmental services, animal food, timber and other utilities. This present study aims to realize the database collection, informatization and availability of Mimosa L. genus, in the herbarium IAN collection of Embrapa Oriental Amazon, highlighting the relevance of the collection and the diversity of existent samples. The data which contains the genus were extracted from the Herbarium IAN database with the software BRAHMS (Botanical Research And Management System) and compared with the data contained in the exsiccates, were it was possible to repair, add data and images that are not found in the database. After the verification and correction of the data and images, the Mimosa collection was made available via internet. So, there were obtained 683 gender Mimosa samples, with presence of 176 species collected in several places, and the estate of Pará being the most representative, emphasizing that the amount of species found corresponds to 34.5% of all the Mimosa species in the world. About computerization, it was found that around 93% of Mimosa from Herbarium IAN is computerized and with its respective scanned images, 86% of the entire Mimosa collection is available in the IAN virtual herbarium. The present study also points out the importance of the process of computerization and availability of collections, as they provide agility and accessibility for the scientific community and society in general. [ABSTRACT FROM AUTHOR]

AbstractIron (Fe) plays a fundamental role in the nutrition of plants, yet its role in oil palm remains understudied. This study aims to unlock the role of Fe by analyzing its cycling and export different stages of oil palm tree growth. The experiment was conducted in Thailand, Pará State (Brazil), in a dystrophic Yellow Ferralsol, in a split-block, with four replications and seven treatments (plant age; 2, 3, 4, 5, 6, 7, and 8). The concentration, accumulation, recycling, immobilization, and export of Fe were evaluated, in addition to Fe use efficiency, in all plant organs. Analysis of variance (p < 0.05) was carried out on the results and regression model adjustments. The concentration and accumulation of Fe in the stem was greatest at the eighth year of the plants, and the fruit had higher Fe export values in the eighth year of the oil palm as well. As plants aged, the Fe concentration, accumulation, export, and use efficiency increased. Oil palm accumulates and immobilizes more Fe in its organs than it exports, a fact that contributes to the cycling and nutrition of the Fe in the plant. This research paves the way for future studies to explore how Fe can be optimized in oil palm trees to unlock their full potential. [ABSTRACT FROM AUTHOR]