Macronutrients and boron deficiencies on rubber-tree (Hevea brasiliensis L.)

Abstract

In order to obtain: a) a clear picture of the deficiencies symptoms of N, P, K, Ca, Mg, S and B; b) the lack of the elements on the dry matter production; c) concentration of the macro and micronutrients on the leaves, stems and roots. Young rubber plants (Hevea brasiliensis L.), were cultivated in nutrients solutions, in which one the following elements were omitted at once: N, P, K, Ca, Mg, S and B. Clear out symptoms were obtained for all macronutrients and boron. The growth rate of the rubber plants were drastically affected by lack of N, K followed by other nutrients. The omission of P from the nutrient solution did not affected the growth of the plants. The levels detected by chemical analysis of the leaves from with symptoms of deficiency and without symptoms of deficiency plants were: N% = 1.94 and 3.40: P% =0.14 and 0.25; K% = 0.79 and 2.22; Ca% = 0.59 and 1.28; Mg% = 0.26 and 0.50; S% = 0.10 and 0.10; B ppm = 31-3 and 171.8.