Nitrogen–phosphorus–potassium Effects on Forms of Sulfur in Leaves and Fruits of Cucumber

The impact that nitrogen (N), phosphorus (P), and potassium (K) application rates on the sulfur (S) fractions in leaves and fruits of greenhouse-grown cucumbers plants (Cucumis sativus L. cv. Brunex) are presented. The treatments were as follows: N (N11⁄4 5 g NO3NH4=m, N21⁄4 10 g NO3NH4=m, N31⁄4 20 g NO3NH4=m , N41⁄4 40 g NO3NH4=m), two levels of P (P11⁄4 8 g H3PO4=m 2 and P21⁄4 16 g H3PO4=m), and two levels of K (K11⁄4 20 g K2SO4=m and K21⁄4 40 g K2SO4=m). The foliar and fruit contents were determined for total S, organic S and sulfate. The influence of the N treatments on the total S (St: organic S þ sulfate) concentration, proved significant, showing a progressive increase in the leaf and fruit concentrations. In the leaves, the P slightly diminished the St concentration but values in the fruits did not appreciably differ from control. The K dosage did 2151 JOURNAL OF PLANT NUTRITION Vol. 25, No. 10, pp. 2151–2159, 2002 DOI: 10.1081=PLN-120014067 0190-4167 (Print); 1532-4087 (Online) Copyright # 2002 by Marcel Dekker, Inc. www.dekker.com *Corresponding author. Fax: þ34 958 243254; E-mail: [email protected] ©2002 Marcel Dekker, Inc. All rights reserved. This material may not be used or reproduced in any form without the express written permission of Marcel Dekker, Inc. MARCEL DEKKER, INC. • 270 MADISON AVENUE • NEW YORK, NY 10016