Characterization of deficiency symptoms and mineral nutrient content in Acmella oleracea cultivated under macronutrient and boron omissions.

Acmella oleracea occurs in the Amazon forest and is widely consumed in regional cuisine and folk medicine. Many studies concerning its active principles are available, but few studies have been carried out regarding mineral nutrition. The aim of this study was to characterize deficiencies symptoms and nutritional content in Acmella oleracea. The experimental design applied was a randomized block with four replications. After blooming, following treatments were applied: complete solution, absence of Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Sulfur, and Boron. After harvesting, growth and nutrient content of inflorescences, new leaves, old leaves, and stems were assessed. The absence of aforementioned nutrients allowed for characterization of visual deficiency symptoms. The first observed symptom was absence of Nitrogen. The accumulation of macronutrients in inflorescences followed the order N > K > Ca > P > S > Mg, in new leaves, N > K > Ca > S>Mg > P, in old leaves, K > N > Ca > Mg > S > P, and in stems K > N > Ca > Mg > P > S. The greatest growth restrictions were observed in nitrogen and calcium absence treatments. [ABSTRACT FROM AUTHOR]