Abstract

Phomopsis azadirachtae causes die-back of neem and this disease is presently a major devastating disease of neem in India, resulting in the reduction of life expectancy and flower production. Development of effective, eco-friendly management strategies against this disease is most important. Two systemic fungicides carbendazim and thiophanate- methyl were combined with ethyl acetate extract of antagonistic bacteria Pseudomonas aeruginosa culture filtrate at different concentrations,namely 100F: 0E, 80F: 20E, 60F: 40E, 50F: 50E, 40F: 60E, 20F: 80E, 0F:100E and evaluated against P. azadirachtae under in vitro conditions. The parameters studied were colony diameter, mycelial dry weight, pycnidial formation and the germ tube growth of the pathogen. The effect of these combinations on neem seed germination and seed-borne pathogen was also tested. The results indicated that the combinations tested were effective in inhibiting the growth of the pathogen in vitro. The combinations also inhibited the growth of P. azadirachtae from die-back infected neem seeds and had no significant negative effect on neem seed germination. These combinations could be utilized for the integrated control of die-back of neem.

Key words: Die-back of neem, Phomopsis azadirachtae, integrated management,Pseudomonas aeruginosa, carbendazim, thiophanate-methyl.