Effect of Irrigation Intervals, Nitrogen Sources and Nitrogen Levels on Some Characters of Parsley (Petroselinum crispum Mill )

Two field experiments were carried out at the Agricultural Research Experiment Station, King Abdulaziz University, Hada Alsham, Saudi Arabia, during 2007 and 2008 seasons. The aim of this investigation was to study the effects of four irrigation intervals (2, 4, 6 and 8 days), two nitrogen sources (urea and ammonium sulphate), three nitrogen levels (0, 100 and 200 kg N ha^-1), and their combination treatments on some vegetative growth and yield characters of parsley. The obtained results revealed significant effects of the three studied factors on vegetative growth and yield characters during the two seasons. Application of 2 days as irrigation interval, urea form as source of nitrogen and 200 kg N ha^-1, produced the highest mean values of plant height (32.0 cm), number of branches/ plant (7.14), number of leaflets/ plant (18.41), fresh weight of plants/ m^2 (2.852 kg) and fresh weight of 5 plants (53.74g).