Studies on the mineral nutrition of passion-fruit plant: VI. effects of macronutrients on growth and mineral composition

Abstract

The experiments described in this contribution had the following goals: (1) to assess the effect of mineral deficiencies on early growth and mineral composition of the several plant organs; (2) to obtain analytical data which would permit to distinguish between healthy and deficient plants. The following conclusion seems to be valid: 1 - growth was affect primarily by the deficiences of N, S and Ca, whereas the lack of P, K and Mg had less efect. 2 - The following leaf values seem to indicate adequate levels: N - 4,44%; P - 0,16%; K - 2,07%; Ca - 1,22%; S - 1,10%; Mg - 0,58%. 3 - The nutritional status of the plants seems to be best revealed in the following organs: leaves of the mature stem: N, P, S, Mg; leaves of the developing stem: Ca; new vines: K.