The present study was carried out at the Experimental Farm of El-Quassassin Hort. Res. Station, Ismailia Governorate, Hort. Res. Institute, Agric. Res. Center, Ministry of Agric., Egypt. during the two successive seasons (2010/2011) and (2011/2012) to investigate the effect of water requirements (1150, 2300 and 3450 m 3 / fed.) and fertilization treatments (mineral fertilizers NPK (control) at the rate of 300 kg / fed ammonium sulphat, 300 kg / fed super phosphate and 200 kg / fed potassium sulphate), (three sources of organic manure, i.e., poultry manure (PM), compost (C) and cattle manure (CM) at 10,15 and 20 m 3 / fed) respectively and their interactions between them on growth, dry ray flowers yield and active ingredient of marigold (Calendula officinales L.) plant using drip irrigation system under sandy soil condition.Irrigated marigold plants by 3450 m 3 / fed water recorded maximum values of plant growth parameters ,i.e., plant height, number of branches / plant, plant fresh and dry weights, yield of dry ray flowers / fed, carotenoides and olenolic acid in flowers of marigold plant as compared to other irrigation treatments. While, the lowest values of these parameters were obtained with 1150 m 3 /fed water. On the other side, water use efficiency (WUE) was the highest with 1150 m 3 /fed irrigated water in both seasons. Plant growth parameters and the yield of dry ray flowers/ fed, WUE, carotenoides and olenolic acid content in flowers were increased significantly with plant fertilization with poultry manure (PM) at 10 m 3 / fed. Interaction treatment between water quantity at 3450 m 3 / fed and poultry manure (PM) at 10 m 3 / fed or the same rate of irrigation combined with mineral fertilizers was the superior treatments for enhancing plant growth, yield of dry ray flowers and chemical constituents in flowers of marigold plants in both seasons. While the interaction between 1150 m 3 / fed water and poultry manure (PM) at 10 m 3 / fed was the best treatment for increasing water use efficiency (WUE) in both seasons.It could be concluded that irrigated marigold plants by 3450m 3 water/ fed combined with 10m 3 /fed poultry manure (PM) was the best treatment for enhancing plant growth parameters, yield of dry ray flowers, carotenoides and olenolic acid in flowers. On the other side, water use efficiency (WUE) was the higher when irrigated plants with 1150 m 3 water / fed combined with 10 m 3 /fed poultry manure.