Integration of soil solarization and potential native antagonist for the management of crown gall on cherry rootstock colt

Bacillus subtilis applied 24 h prior to inoculation of pathogenic Agrobacterium tumefaciens resulted in production of galls on three out of nine inoculated wounds on artificially inoculated tomato plants. In 2000 and 2001, solarization of sick nursery plots with 25 μm thick transparent polyethylene sheet for 90 days after irrigation to field capacity increased the soil temperature by 13-14, 4-5 and 2-3 °C at 8, 15 and 30 cm soil depth, respectively, as compared to temperature recorded in nonsolarized beds. In the next growing seasons, 2001 and 2002, cherry rootstock colt transplanted in 90 days solarized irrigated plots, had 14.83% and 17.58% compared to 44.72% and 58.25% incidence of crown gall in nonsolarized plots, respectively. Bacillus subtilis applied as soil drench in sick nursery beds resulted 2.40 and 3.13 compared to 11.04% and 11.93% incidence of crown gall in untreated nursery beds in 2001 and 2002, respectively. Integration of soil solarization for 90 days under irrigated soil conditions with B. subtilis soil drench significantly reduced incidence to 11.04 and 11.93 as compared to 70.52% and 73.78% in control in 2002 and 2003, respectively.