STUDIES ON SOME CACTI AND SUCCULENTS, AND THEIR USE IN EGYPTIAN BOTANIC GARDENS. 1. EFFECT OF SALINITY LEVELS AND FERTILIZATION ON VEGETATIVE GROWTH AND LEAF ANATOMICAL Structure OF Agave sisalana PERRINE PLANTS.

Abstract

A pot experiment was conducted in the two successive seasons2004/2005 and 2005/2006 at the Experimental Nursery of the OrnamentalHorticulture Department, Faculty of Agriculture, Cairo University, Giza,Egypt., with the aim of investigating the tolerance of sisal plant (Agavesisalana) to different levels of irrigation water salinity (0, 1000, 2000, 3000,4000, 5000, 6000 and 7000 ppm) as NaCl & CaC12 (1:1 by weight). Inaddition the effect of different fertilization treatments [unfertilized (control),organic fertilization (50 g compost / pot), chemical fertilizer (NPK) (2 g / pot),and compost plus NPK fertilizer], on reducing the unfavorable effects ofsalinity on vegetative growth and anatomical structure. The recorded resultsindicated that increasing salinity levels decreased most of the studiedparameters (plant height, number of leaves /plant, leaf area, leaf thickness,and dry weights of foliage and fibrous roots /plant). The anatomical studysupported and explained the recorded reduction of morphological traits underinvestigation due to salinity treatments. In general, it was noted that raisingthe level of salinity of irrigation water caused gradual decreases in means ofall the studied characteristics in both seasons, and these decreases wereremarkable at a salinity level of 7000 ppm. On the other hand, the fertilizationtreatments reduced, to some extent, the negative effect of salinity.