ABSTRACT. Curves of crop growth and nutrient extraction and export are essential to develop fertilization strategies and management plans to maximize yield and reduce environmental impacts. Our study aimed to evaluate dry matter production and both extraction and export of macronutrients by arrowroots (Maranta arundinacea L.) to be used in further crop fertilization plans. To this purpose, two experiments were carried out in field conditions using the varieties Viçosa and Seta. The experimental design was randomized with four replications and nine periods of analysis, which were defined as days after planting (105, 135, 165, 195, 225, 255, 285, 315, and 345 DAP). Dry matter, extraction, and export of macronutrients by arrowroot seed-rhizomes, aerial parts, roots, and storage roots (rhizomes) were determined. The exports of N, P, K, Ca, Mg, and S of storage rhizomes of the variety Viçosa were 104.6, 51.83, 412.24, 15.85, 36.14, and 64.36 kg ha-1, while those of the seta variety were 160.6, 71.62, 521.31, 17.57, 60.09, and 160.41 kg ha-1, respectively. Both varieties proved to be efficient soil macronutrient extractors, mainly for K. The variety Seta had higher shoot, root, seed-rhizome dry matter contents, as well as greater macronutrient extractions and exports.

RESUMEN El umbú (Spondias tuberosa Arruda) es un árbol frutal adaptado a la región semiárida brasileña y constituye una fuente de ingresos importante para muchas familias en Brasil. Debido a esto, se deben estudiar métodos sostenibles de conservación de la fruta después de la cosecha. El objetivo de este estudio fue analizar la influencia de la biopelícula de almidón de yuca para la conservación poscosecha del umbú. El diseño experimental fue completamente al azar en un arreglo factorial 2x5 con seis repeticiones. Los dos tratamientos, recubrimiento de almidón de yuca al 1% y sin recubrimiento, se evaluaron durante cinco períodos (0, 3, 6, 9 y 12 d de almacenamiento). Se midieron la pérdida de peso fresco (PPF), la firmeza de la fruta (FIR), el pH, los sólidos solubles totales (SST), la acidez total titulable (AT), la relación SST/AT, el color: la luminosidad (L*), el ángulo de tonalidad (T*) y la cromaticidad (C*). El recubrimiento de los frutos con la biopelícula a base de almidón de yuca mejoró el PPF, el pH y los SST. La AT, la relación SST/AT y la L* no fueron influenciadas por el uso o ausencia del recubrimiento. El uso de almidón de yuca al 1% asegura una mejor calidad poscosecha del umbú y prolonga su vida poscosecha.

ABSTRACT The umbu (Spondias tuberosa Arruda) is a fruit tree adapted to the Brazilian semiarid region and constitutes an important source of income for many families in Brazil. Due to this, sustainable methods of fruit postharvest conservation should be studied. The objective of this study was to analyze the influence of cassava starch-based biofilm coatings for the postharvest conservation of umbu. The experimental design was completely randomized in a 2x5 factorial arrangement with six replicates. The two treatments, 1% cassava starch coating and no coating, were evaluated during five periods (0, 3, 6, 9, and 12 d of storage). Fresh weight loss (WL), fruit firmness (FIR), pH, total soluble solids (TSS), total titratable acidity (TA), TSS/ TA ratio, external color: luminosity (L*), hue angle (H*), and chromaticity (C*) were measured. The coating of fruits with cassava starch-based biofilm improved WL, pH, and TSS. The variables TA, TSS/TA ratio, and L* were not influenced by the use or absence of the cassava starch biofilm coating. The use of 1% cassava starch to coat the fruits ensures better postharvest quality of the umbu and extends its postharvest life.

Objetivou-se avaliar efeitos de doses de potássio aplicadas via fertirrigação no acúmulo de biomassa e desempenho produtivo de cultivares de morangueiro no litoral cearense. O experimento foi conduzido a pleno sol, no período de abril a agosto de 2012, em Fortaleza, Ceará. Os tratamentos foram distribuídos em blocos ao acaso, em esquema fatorial 5×2, referente a cinco doses de potássio (0,65 g; 0,97 g; 1,29 g; 1,61 g e 1,93 g por planta, semanalmente) aplicadas via fertirrigação e duas cultivares de morangueiro (Oso grande e Verão), em cinco repetições. Aos 40 dias após o transplantio iniciou-se a colheita dos frutos, que foram avaliados semanalmente quanto ao seu número por planta, ao diâmetro, ao comprimento, ao peso médio e à produtividade. A adubação potássica estimula a produção de matéria seca da parte aérea e da raiz para as cultivares de morango Oso grande e Verão. A dose de potássio 0,65 g por planta foi a mais eficiente para o número de frutos por planta para a cultivar Oso grande e para o peso médio de fruto com a Verão. O aumento da concentração de potássio reduz a produtividade das cultivares de morango Oso grande e Verão. A cultivar Oso grande apresenta maior adaptabilidade às condições climáticas do litoral cearense do que a Verão.

This study was aimed at evaluating the effects of potassium doses applied by fertigation on biomass accumulation and yield performance of strawberry cultivars in the Ceará coast. The experiment was conducted in full sunlight, in the interval from April to August 2012, in Fortaleza, Ceará. Treatments were disposed in a randomized blocks design, in a 2×5 factorial arrangement, consisting of five potassium doses (0.65, 0.97, 1.29, 1.61 and 1.93 g plant per week) and two strawberry cultivars (Oso Grande and Verão), with five replicates. At the 40th day after transplanting, the fruit harvesting started. The fruits were evaluated weekly, relatively to the the number of fruits per plant, fruit diameter, fruit length, average fruit weight and, at the end of the harvest period, the total yield. Potassium fertilization stimulates the production of dry matter of shoot and root for strawberry cultivars Oso grande and Verão. A potassium dose of 0.65 g plant-1 was the most efficient potassium dose (for fruit number per plant) for the Oso Grande cultivar and (for the average fruit weight) for the Verão cultivar. Increased potassium concentration reduces the yield of strawberry cultivars Oso grande and Verão. The Oso grande cultivar has higher adaptability to climatic conditions of Ceará than Verão.