Photostabilization of Azadirachtin-A. Part-II: Stability Enhancement

Studies were conducted to find the effect stabilizers during storage under laboratory conditions and on the leaf surface under simulated field conditions. A 1000 ppm solution of Aza-A (65%) was mixed with the stabilizers viz.p-aminobenzoic acid (PABA), butylated hydroxy anisole (BHA) and bis-phenol (BP) to get 2:1, 4:1 and 9:1 composition of aza A and stabilizers. Maximum stability was achieved when aza A was mixed with BHA in 9:1 ratio; half-life of aza A (T_½) was found to be 44 days compared to 23.7 days when aza A was kept alone during storage. Whereas, maximum stability on leaf surface was achieved (T_½ 1.65 days) when aza A was mixed with BHA and neem oil in 1:1:1 ratio (T_½ of aza A alone was 0.56 day).