Two field experiments were conducted at Sakha Agric. Res.. Station farm at Kafr El-Sheikh Governorate, Egypt during consecutive seasons of 2013/2014 and 2014/2015 to study some morphological and chemical characters inducing from salinity from irrigation by water have salinity (0, 7500 and 10000 ppm) in addition, nitrogen levels (20 and 30 kg N/fed) and potassium levels (24 and 48 kg N/fed.). All mentioned factors were collected in complete randomized block design in three replications.
Final results were pointed out that significant increase in all characters under study were observed resulted from decreasing salinity lowing less than (10000ppm) and increased nitrogen rate up to 30 kg/fed. and increased potassium dose up to 48 kg K2O/fad in both seasons. On the opposite direction, the same trend was found when salinity rate decreased than 10000 to control (without salinity and without nitrogen or potassium fertilization). This was true in both seasons. All values of all traits were increased with the 1st and 2nd cuts and decreased in 3rd, 4th and 5th cuts. These results due to bad effect of high salinity on absorption of elements and osmotic effect on absorption of water which affected on plant growth and stevioside content of leaves. Whereas, decreased of characters values in cut 3, 4 and 5 due to decreased in temperature degree in these periods.
Finally ,we concluded that the highest values for the mentioned characters under study were optained resulted from treatments 7500ppm salinity, 30 kgN/cut and 48 kg k2o/fad .for stevia plants.