This study was conducted at the Department 01 Ornamental Horticulture. Faculty
01 Agriculture, Cairo Unillersity, Giza, and the Farm of Medicinal and Aromatic Plants,
Faculty of Pharmacy. Cairo Unillersity, Giza, during the two successjvs seasons of 1997
and 1998, with the aim of inllestigating the effect of Irrigation intervals and chemical NPK
fertlJJzaUon on the lIegetatilie growth and production of pods in senna (Cassia acuU(olia,
Delile) plants. Cassia acutifolia plants were irrigated ellery 1, 2 or 3 weeks, and were supplied
with chemical NPK fertilization using combinations of N at the rates of 0, 25, 50 or 75
kg/fed. (No, N" Nz and N), respectively), P₂0_S at 0,25 or 50 kg feddan (Po, P, and P_a,
respectively) and K20 at 25 kglfed. (K,). In acoitton, plants receilling no chemical
fertilizaUon (NoPoKo) were used as the control; Irrigation ellery 3 weeks galle the highest mean values for plant height, number
of branches/plant. fresh and dry weights of lsaves and stems/plant, whereas irrigation
ellery 2 weeks galle the highest mean values for pods production (number 01 pods/plant,
and the fresh and dry weights of pods/pian!)' All fertilization treatments promoted
lIegetatilie growth and pod production, with N₂P,K, gilling the tallest ptants. Fertilization
with N3P2K, galle the highest mean values for fresh and dry weights of leaves/plant,
while the highest fresh and dry weights of stems/plant were obtained from plants
fertilized with N3P,K, Of N3P2K,. On the other hand, HZP2K, gelle the best pods
production. Moreoller, combining this treatment (N2P2K,) with irrigation ellery 2 weeks
galle a better production of pods, compared to any other combination of irrigation
Intervals and fertilization treatments, whereas the highest fresh and dry weights of
lealleslpJent were obtained with weekly irrigation + N3P~K,. The highest fJ:esh weight of
stems/plant was obtained when irrigation ellery 3 weeks was combined with fertilization
u5ing NJP,K" while lhe highest dry weight of stems/plant was obtained when irrigation
at 3 weeks was combined with fertifization using N3PoK" N3P,K, or N3P2K,.