Salvadora persica is the most used medicinal shrub in the Arab world. This experiment was conducted to evaluate seedling performance at different rates of NPK. Seedlings were treated with N:P:K at 4:2:2 (N:P:K 2:2:2 g + 2 g of nitrogen supplemented as ammonium sulfate), 6:3:3 (N:P:K 3:3:3 g + 3 g of nitrogen supplemented as ammonium sulfate), 2:1:1S (N:P:K 1:1:1 g + 1 g of nitrogen supplemented as ammonium sulfate), 2:1:1U (N:P:K 1:1:1 g + 1 g of nitrogen supplemented as urea), 4:1:1S (N:P:K 1:1:1 g + 3 g of nitrogen supplemented as ammonium sulfate), 4:1:1U (N:P:K 1:1:1 g + 3 g of nitrogen supplemented as urea), 6:1:1S (N:P:K 1:1:1 g + 5 g of nitrogen supplemented as ammonium sulfate), 6:1:1U (N:P:K 1:1:1 g + 5 g of nitrogen supplemented as urea) in addition to the control. The results indicated that NPK application significantly affected the vegetative and root growth parameters and the chemical contents. Among the various treatments of NPK, the application of 6:3:3 rates showed the highest values for aboveground parts, root parameters, and greenness level. Therefore, the present study demonstrates the optimum NPK levels that can enhance seedling growth throughout the nursery period.

ABSTRACT:The diffusion of sodium sulphate in dilute solutions of carboxymethylcellulose sodium salt (CMC) was studied using the porous frit technique. It was found that at relatively low CMC concentrations, the diffusivity of sodium sulphate (D) is higher than that in water (D0); with increasing CMC concentration, the diffusivity of sodium sulphate decreases gradually and reaches a value lower than that in water. The relation between salt diffusivity ratio (D/D 0 ) and CMC concentration (C) is represented by the equation: D/D0 =a-bC. The effect of temperature on the diffusivity of sodium sulphate in CMC solutions was found to obey the Arrhenius equation with an activation energy of 2600 cal mo1-1 .

The diffusion coefficients of potassium aluminium sulphate, ferric ammonium sulphate, chromium potassium sulphate and chromium sulphate were determined using the porous disc technique. For all salts studied linear relations were found between the diffusion coefficient and the square root of the salt concentration: The effect of temperature on the diffusion coefficient of the salts was studied. The data were found to fit the Arrhenius equation. The activation energies for the diffusion of potash alum, ferric alum, chrome alum and chromium sulphate were found to be 1.8, 7.4, 2.8 and 3.4 kcal/mol respectively.

synopsisThe diffusion of sodium chloride in dilute solutions of carboxymethylceilulose (CMC) was studied using the porous frit technique. It was found that at relatively low CMC concentrations the diffusivity of sodium chloride (D) i s higher than that in water (Do); with increasing CMC concentration, the diffusivity decreases gradually and reaches a value lower than that in water. The relation between the diffusivity (D) and CMC concentration (C,) was represented by the equation D = a -bC,. The effect of temperature on the diffusivity of sodium chloride in CMC solutions was found to obey the Arrhenius equation with an activation energy of 2230 cal/mol.

The diffusion of sodium phosphate in dilute solutions of sodium carboxymethyl cellulose (CMC) is studied. At relative low CMC concentration the diffusivity of sodium phosphate is higher than in solution without CMC. With increasing CMC concentration the diffusivity of sodium phosphate decreases gradually and reaches a value lower than that in water. The effect of temperature on the diffusivity of sodium phosphate in CMC solutions obeys the Arrhenius equation.