Macronutrient deficiencies on Solanum topiro Humb.& Bonpl

Abstract

In order to obtain: a) a clear picture of the picture of the deficiency symptoms of N, P, K, Ca, Mg, and S; b) the effects of lack of the elements on the dry matter production, and; c) concentrations of the macro and micronutrients, excepted for Mo and CI, on the leaves, stems and roots; young cubiu plants (Solanum topiro Humb. & Bonpl.), 'INPA-P6-PL2-BLUU-Exp l', were cultivated in nutrient solutions, in which one of the following elements were omitted at once: N, P, K, Ca, Mg and S. Clear cut symptoms were obtained for N, K, Ca and Mg. The symptoms for P and S were uncleared. The growth rate of the cubiu plants was drastically affected by lack of N, P, K, followed by Ca and Mg. The omission of S from the nutrient solution did not affected the growth of the plants. The levels detected by chemical analysis of the leaves from "deficient" and "normal" plants were" N% = 2,02-3.53; P% = 0.12-0.20; K% = 0.84-3.44; Ca% = 0.22-2.64; Mg¾ = 0.07-0.48; 5¾ = 0.10-0.25.