Jatropha curcas L. was cultivated in Abou Rawash, 6 th October Governorate, Egypt. The plants were irrigated at three different intervals (7, 14 and 21 day) using sewage water receiving primary treatment from Abou Rawash Station and were fertilized with calcium superphosphate (15% P 2 O 5 ) and potassium sulphate (50% K 2 O) every 2 months at rates of 0:0, 50:25, 75:37.5 and 100:50 g/plant.The obtained results indicated that 7-day irrigation intervals gave the best vegetative growth, fruit yield and oil percentage in seeds, followed by 14-day intervals but 21 days intervals gave the lowest value.Plants fertilized by 100:50 and 75:37.5 g/plant P 2 O 5 :K 2 O gave the highest values for vegetative growth, fruit yield and oil percentage as compared to other fertilizer treatments.The fertilization treatment of 100:50 g P:K/ plant combined with 7-day irrigation intervals increased vegetative growth, fruit yield and oil percentage as compared to other treatment combinations.

This study was conducted to evaluate the effect of zinc application at different levels (10, 20 and 40 mg/kg soil) as ZnSo 4 .7 H 2 O on growth and chemical composition of Swietenia macrophylla under salinity stress at three concentrations (2000, 4000 and 6000 ppm) NaCl. Tap water was used as control. The results revealed that, salinity at 6000 ppm caused death of seedlings. Salinity levels (2000 and 4000 ppmNaCl alone) significantly decreased survival percentage and growth parameters (stem length, stem diameter, leaf area, leaves number, root length and fresh and dry weight for plant parts. Also, salinity decreased N,P,K, Ca, Mg, Zn, Chlorophyll and total carbohydrates in plant parts. While, 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, leaves 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.