Field trials were conducted at Jalandhar, during 1990–91 to 1993–94 autumn, to find out efficacy of boric acid seed tuber treatment against black scurf of potato; its mode and time of application: influence on soil inoculum and rhizosphere microflora. In all the trials poteptials of boric acid were compared with Emisan-6 and Carbendazim 50 WP to check black scurf development from seed and soil inoculum. Though all three chemicals were effective in checking the disease, the maximum reduction was achieved with 3% boric acid. It was found more effective in pre-cold storage treatment and equally effective in dip and atomized applications. Three per cent concentration of boric acid was found optimum in atomized application. It was found to reduce-spectacularly seed and soil inoculum as well as significantly increase population of actinomycetes and bacterta in the rhizosphere, species of which are well known for their antagonistic activity in soil against
