ABSTRACT A comprehensive knowledge about micronutrient dynamics in leaves and bunches of black pepper is needed in order to proper diagnose nutrient needs, and thus facilitate fertilization management. This study aimed to evaluate micronutrient concentration and accumulation in leaves and bunches of black pepper bunches to understand the crop nutritional demand. The experiment was carried out on in a commercial field of Piper nigrum ‘Bragantina’ located in São Mateus, Espírito Santo, Brazil. Composite samples of leaves and bunches were taken periodically during two crop cycles and the concentration of Fe, Zn, Mn, Cu, and B were assessed. The micronutrient accumulation curves behaved linearly and quadratically, reaching the maximum accumulation point during the time of harvesting. Fe, Mn and B were the micronutrients with highest concentration in both bunches and leaves of black pepper. The nutrient concentration in leaf tissues varied seasonally. These results may contribute to a more sustainable agriculture, in which fertilization rates should consider different needs through the crop stage.

RESUMO: O acúmulo de nutrients em plantas/frutos variam de acordo com o estádio de desenvolvimento das culturas, sendo que sua quantificação é importante na determinação da exportação de nutrientes para o planejamento da adubação e para o balanceamento de nutrientes. Esse estudo objetivou determinar o acúmulo de nutrientes em diferentes partes dos cachos de Piper nigrum ‘Bragantina’ colhidos em dois estágios de maturação (coloração da casca verde e coloração da casca vermelha). As avaliações foram feitas separadamente nos cachos de Piper nigrum com coloração verde (fruto e pedúnculo) e vermelha (grão, casca e pedúnculo), em que os cachos foram colhidos, secos e as partes foram separadas para análises químicas. N e Mn foram os macro e micronutrientes mais acumulados nos frutos dos cachos com coloração da casca verde e nos grãos dos cachos com coloração da casca vermelha, enquanto K e B foram mais acumulados em outras partes da planta, independente do estágio de maturação. O processo de removação da casca para produção de pimenta branca levou a uma diferença na concentração e no acúmulo de nutrientes nos frutos de pimenta preta e nos grãos de pimenta branca. Uma contribuição significativa para entrada de nutrientes pode ser obtida se as cascas e pedúnculos forem mantidos na área de cultivo, o que diminui a dependência de fertilização, contribuindo para uma agricultura mais sustentável.

ABSTRACT: Nutrients accumulation in plants/fruits varies according to the crop development stage and its quantification is important to determine nutrients exportation for fertilization planning and nutrient balancing. This study determined the accumulation of nutrients in different parts of Piper nigrum ‘Bragantina’ spikes harvested at two ripening stages (still-green and red-colored spikes). Assessments in separate parts of still-green spikes (fruits and peduncles) as well as in red-colored spikes (grains, flesh and peduncles) were performed. Piper nigrum spikes were harvested, dried, and the parts were thereafter separated for chemical analysis. N and Mn were the macro and micronutrient most accumulated in the fruits of still-green spikes and in the grains of red-colored spikes, while K and B were most accumulated in the other parts of black pepper assessed, regardless of the ripening stage. The process of removing the flesh from the fruits for white pepper production led to a difference in nutrient concentration and accumulation between the fruits of still-green spikes and the grains of red-colored spikes. A significant contribution of nutrient input can be achieved by maintained flesh and peduncles in the crop area, decreasing the dependence of external fertilizers and thus contributing to a more sustainable agriculture.

Resumo: O objetivo deste trabalho foi determinar a dinâmica de macronutrientes em folhas e cachos de pimenta-do-reino (Piper nigrum), ao longo dos ciclos reprodutivos da planta. O experimento foi realizado em uma lavoura comercial de pimenta-do-reino 'Bragantina'. Folhas e cachos foram amostrados a cada 21 dias, por um ano, durante dois ciclos de cultivo. Os cachos foram amostrados desde o vigésimo oitavo dia após o lançamento das inflorescências até a maturação completa dos frutos. As amostras de folhas e cachos foram secas, e os conteúdos de N, P, K, Ca, Mg e S foram determinados. N, K e Ca foram os macronutrientes mais comuns nos cachos e nas folhas de pimenta-do-reino. O acúmulo de matéria seca nos cachos de pimenta-do-reino foi similar nos dois ciclos e foi ajustado aos modelos linear e quadrático. O acúmulo e o conteúdo de macronutrientes seguiram a tendência de comportamento da matéria seca. O conteúdo de macronutrientes nas folhas oscila durante o ano, e K e Mg variam mais do que N, P, Ca e S. O conteúdo de macronutrientes em folhas e cachos de pimenta-do-reino depende do estádio vegetativo da planta, e essa variação deve ser considerada no planejamento do manejo de adubação.

Abstract: The objective of this work was to determine the macronutrient dynamics in leaves and bunches of black pepper (Piper nigrum) throughout the plant reproductive cycles. The experiment was carried out in a commercial field of 'Bragantina' black pepper. Leaves and bunches were sampled every 21 days for one year, during two crop cycles. The bunches were sampled from the twenty eighth day after the appearance of inflorescences until the complete fruit maturation. Samples of leaves and bunches were dried, and the contents of N, P, K, Ca, Mg, and S were determined. N, K, and Ca were the most common macronutrients found in the bunches and leaves of black pepper. The accumulation of dry matter in the bunches was similar for both cycles and it was adjusted to the linear and quadratic models. The accumulation and content of macronutrients followed the dry matter behavior trend. Macronutrient contents in leaves oscillate during the year, and K and Mg vary more than N, P, Ca, and S. The macronutrient contents in black pepper leaves and bunches depends on the plant vegetative stage, and this variation should be considered in the planning of the fertilization management.