Integrated effect of inorganic and organic nitrogen sources on growth and yield of roselle (Hibiscus sabdariffa l. )‎

الملخص EN

The pot experiment was conducted in summer season of 2017 at Assiut Governorate, Egypt, to study the influence of compost and different rates of inorganic nitrogen on growth and chemical composition roselle as well as yield.

The studied treatments include the application of recommended dose of N as T1= urea, T2= compost, T3= 75% urea + 25 % compost and T4 = 50% urea +50% compost.

Plants treated with the combination of mineral nitrogen and organic fertilization gave the highest significant values of growth parameters, i.e., plant height, as well as fresh and dry weight of leaves, chlorophyll, carotenoids, N, P and K contents in leaves tissues.

While the application of full dose in the inorganic form gave the moderate values compared to the untreated plant.

The maximum sepals yield was obtained from the 100% of N from compost treatment which increased the fresh and dry weight of sepals by 228.75 and 138.96% above the un-treated soil.

Generally it is concluded that roselle sepals yield and quality can be improved through the treatment of 100% composted and application of 50 % urea + 50 % compost improved the growth and yield of roselle also increased the available N nutrients in the soil as well as the macronutrients concentrations.

Therefore, this treatment could be recommended to obtain economical yield with satisfactory quality and to improve the soil fertility under the conditions of the studied area