EFFECTS OF CYCOCEL AND NITROGEN FORM ON TOMATO WATER RELATIONS, ION COMPOSITION, AND YIELD

Abstract

Fertilizing tomatoes (Lycopersicon esculentum Mill.) Missouri breeding line 76-1-60-8 with NH4-N, as compared to NO3-N sources, in pot culture with unequal anion species and concentration and constant substrate moisture supply increased leaf diffusive resistance and water stress; reduced total transpiration and transpiration rate, leaf area, and mean fruit weight; and increased fruit and leaf Ca concentration and fruit Mg, K, and P concentration. Cycocel applied both foliarly and as a substrate drench to plants under NH4 nutrition increased leaf diffusive resistance; and reduced water stress, total transpiration, plant height, and total and mean fruit weights. Cycocel treatment under both N forms, with the exception of reduced leaf Ca concentration, either had no effect or increased leaf and fruit ion concentration. Under NH4-N nutrition, Cycocel treatment gave a 54% increase in fruit Ca concentration.