A field experiment was conducted at Kaha Farm of the Horticulture Research Institute, at Kalubia Governorate, Egypt during the two successive seasons of 2008and 2009. Seeds of basil were coated with cotongen (seed coating agent) was prepared by dissolving 800g of cotongen in 1liter water which containing iron, manganese and zinc as chelated compounds plus agricultural sulfur, potassin-P (a foliar plant nutrient containing potassium K₂O 30% and phosphorus P₂O₅ 8%) used with rates of 1.5, 3 and 4.5 ml/liter and the  feddan. the treatment with cotongen and the different levels of potassium sources gave a positive effect on growth characters (plant height), number of branches, fresh and dry weights plant ^-1 , fresh herb yield fed ^-1  and volatile oil percentage and its component in comparison with other treatments, the data also revealed that, treating plants with cotongen and potassin-p (4.5 ml/l.) showed a significant effect on growth and volatile oil.