AVALIAÇÃO DA PRODUÇÃO DE FITOMASSA E SINTOMAS DE DEFICIÊNCIA NA CULTURA DO JAMBU [ Acmella oleracea  (l.) R. K. Jansen] CULTIVADO SOB OMISSÃO DE MACRONUTRIENTES E FERRO

Abstract

The jambu [Acmella oleracea (L.) R. K. Jansen] has northern Brazil as one of its centers of origin. This vegetable is widely consumed in regional cuisine, and has been gaining ground mainly for its medicinal properties. In spite of the big interest for its biological qualities, there are few studies that deal with its nutritional management as well as the possible disorders generated from the lack of a particular nutrient. The aim of this study was to evaluate the effects of macronutrient and iron omission on nutrient omission of jambu plants, characterizing the visual deficiency symptoms produced by the plants, evaluating air and root dry mass production data. The experiment was conducted in a greenhouse. The statistical design was completely randomized with eight treatments and five repetitions. The plants were grown in complete solution containing all the nutrients until the beginning of flowering, and from that moment, the treatments were applied: Complete Solution, Nitrogen Omission, Phosphorus Omission, Potassium Omission, Calcium Omission, Magnesium Omission, Sulfur omission and iron omission. Solutions were applied daily and plant evaluations were performed to characterize the deficiency symptoms. The plants were collected 35 days after the beginning of the treatments and the shoot and root dry matter were evaluated, as well as the description of the symptoms observed during the experiment. At the time of collection, the material was separated into aerial and root parts, the materials were identified, placed in a Kraft paper bag and sent to the IFPA soil laboratory. The material was oven dried at 65C for 72 hours until it reached a constant mass. When removing the material from the kiln, digital scale weighing was performed. After that the data were tabulated and the statistical software IBM SPSS was used to perform the statistical analyzes. The omission allowed the visualization of symptoms of deficiency. With this it was possible to verify the limitation to plant growth with the worsening of symptoms, especially in the treatment with potassium omission, which was the most limiting treatment to the growth of the crop. In decreasing order the treatments that most limited the growth of the culture were: Potassium> Nitrogen> Calcium> Phosphorus> Magnesium> Sulfur> Iron. Therefore, nutrient omission provides an important tool for visualizing nutritional deficiencies.