Abstract
Leaf extract of Datura alba, seed oil of neem (Azadirachta indica), neemseed bitter and nimbokil 60 EC were evaluated at 1. 2 and 3% concentrations on the growth of Xanthomonas campestris pv. malvacearum. in vitro and on the greenho.use grown cotton varieties/lines. At 3% concentration Datura alba significantly retarded the growth of bacterium followed by nimbokil, neemseed bitter and neemseed oil respectively. None of the plant extracts showed effectiveness at I% concentration. There was significantly less number of leaf shedding, less number of bare nodes and more number. of boils, increased boil weight and yield of seed cotton of varieties sprayed with standard concentrations of Datura alba and nimbokil 60 EC as compared to untreated control. Disease severity was less in treated varieties as compared to untreated varieties. Key words: bacterial blight, biological control, plant extracts, Xanthomonas campestris pv. malvaccarum