Effect of organic and biofertilizers as a partial substitute for inorganic nitrogen in superior grapevines [electronic resource].

Includes references.

During 2005, 2006 and 2007 seasons, the recommended rate of N for Superior grapevines namely 80 g I vine was added either, completely via mineral source or at various ratios from inorganic, organic and bioforms. The study focused on the effect of these treatments on the leaf area and its content of N, P and K, berry set % , yield as well as physical and chemical properties of the berries. Results showed that application of the recommended rate of N as inorganic at 50 to 75 % as well as organic plus bioforms at 25 to 50% resulted in an obvious promotion on the leaf area and its-content of N, P and K, berry set % , yield and qUl\lity of the berries rather than application of N completely via inorganic form. Reducing the percentage of inorganic N to 25% of the recommended rate of Nliad an adverse effects on all investigated characters. Using of N via the three sources (inorganic + organic + bioforms) was preferable than using N via inorganic and organic forms only.

Summary in Arabic.

1