Yield improvement in zucchini under salt stress: determining micronutrientbalance

Zucchini plants (Cucurbita pepo L. var. Moschata) grown in pots under green house conditions were supplied with differing amounts of NaCl (0, 20, 40, a nd 80 mM). The foliar concentrations of Cl, Fe, Mn and Zn increased in resp onse to rising NaCl levels. The Cu concentrations in leaves were highest in the 0 mM NaCl treatment. In fruits, concentrations of Cl, total Fe and ext ractable Mn increased with higher levels of NaCl. Fruit yield was increased only by NaCl at 80 mM. Length and fresh weight of fruit tended to increase with increasing NaCl rate, and fruit dry weight proved greatest at 80 mM. The activities of catalase and ascorbic acid oxidase assayed in fruits show ed an inverse relationship with the salt concentrations applied. In this co ntext, it is useful to determine the effect of NaCl on the micronutrient co ncentration, given that the improvement of crop watered with saline water e nhances the micronutrient profile. Thus, at 80 mM NaCl treatment improved t he micronutrient levels in the shoot, and significantly increased the micro nutrient density in the edible part of this crop. (C) 2000 Elsevier Science B.V. All rights reserved.