To confirm the mobility of boron in pineapple, twelve 'Pérola' pineapple seedlings were cultivated in a complete nutrient solution containing 1 mmol L-1 B in a completely randomized design. After 45 days, B was removed from the nutrient solution, and four plants were harvested (T0), and in the eight remaining plants 10 mmol L-1 H3BO3 solution were painted, for 3 consecutive days, on both faces of the basal leaf number seven (7). One day after the third foliar application, four plants were harvested (T1) and, sixty days later, the last four plants were harvested (T2). The plants were partitioned into different parts in which total B concentration was determined by azometina-H method. In T0 the largest B concentration was in the root; in T1, in the painted leaf and the root and, in T2, in the painted leaf. The content of B followed the variation of the dry weight of the portions of the plant, and in T2 the largest content of B and dry weight were observed in the new leaves formed between T1 and T2. Boron contained in those leaves (29, 8% of the total boron of the plant) came from the oldest leaves which content decreased significantly, confirming the mobility of Boron in pineapple plants.
Annanas comosus; B mobility; B content
