الفهرس 
Title: Effect of irrigation water salinity and zinc fertilization on growth of some mahogany species
AbstractOnly 14 pages are availabe for public view
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Abstract
This study was conducted to evaluate the effect of zinc application at different levels (10, 20 and 40 mg/kg soil) as ZnSo4 .7 H2O on growth and chemical composition of Swietenia mahagoni under salinity stress at three concentrations (4000, 6000 and 8000 ppm) NaCl and concentrations of (2000, 4000 and 6000 ppm.) NaCl for S. macrophylla. Tap water was used as a control. The results revealed that, seedlings of Swietenia macrophylla died under salinity stress of 6000 ppm. NaCl alone. while Swietenia mahagoni tolerate salinity stress till 4000 ppm. Salinity levels significantly decreased survival percentage and growth parameters (stem length, stem diameter, leaf area, leaf number, root length and fresh and dry weight for plant parts) for each species. Also, salinity decreased N, P, K, Ca, Mg, Zn, Chlorophyll and total carbohydrates in plant parts. However, salinity increased Na, Cl and proline content when compared to control. Zn application increased survival percentage and growth parameters (stem length, stem diameter, leaf area, leaf number, root length and fresh and dry weight for plant parts under salinity stress when compared to salinity treatments without Zn. Also, Zn application increased NPK, Ca, Mg, Zn, chlorophyll and total carbohydrates in plant parts. While, Zn decreased Na, Cl and proline content. In this study 20 mg Zn /kg soil recorded the best result with three salt concentrations