A stady on the effect of phosphorus fertilizer levels and Gibberellic acid (GA3) concentration, on seed and oil yield of Cheiranthus cheiri was conducted. Four levels of P 0.20, 30 or 50 g/ l and three concentrations of GA3 0.50 or 100 mg/ l were applied.
Results showed that the highest level of P (50 g/ l) was significantly increased 1000 seeds weight, % of linolic acid and % of olic acid (1.71 g, 17.80%, 9.17%) respectively. While 30 g/ l of P elevated % of olic acid in leaves and seeds weight (4% and 5.74 g) respectively. Gibberellic acid at 100 mg/ l was superior in increasing 1000 seeds weight, % of lenolic acid, % of linolinic acid, % of olic acid and % of total fatty acids (10.07%, 18.49%, 9.33% , 37.92%) respectively. The interaction between P levels and GA3 concentrations was highly effective on % of oil studied.