Abstract:The control efficacy and area under the disease progress curves (AUDPC) of alternate application of biofungicides with synthesized fungicides were detected in the trials conducted in tomato greenhouses to elucidate the effects of alternate application of synthesized fungicides with biocontrol agents and plant-derived fungicides on development of tomato diseases. The results showed that 7 alternate applications of Bacillus subtilis BAB-1 AS with synthesized fungicides had control efficacy of 86.9%, 61.0%, 72.3% and 77.2% for gray mould, leaf mould, late blight and early blight on tomato, respectively. Nine alternate applications of the plant-derived fungicide 1-O-acetylbritannilactone (ABL) EC with synthesized fungicides and the biocontrol agent B.subtilis BAB-1 AS, showed control efficacy of 88.6%, 87.4%, 85.4% and 83.2% for the four air-borne fungal diseases as mentioned above, respectively. Moreover, the development of the four diseases were obviously delayed and applications of synthesized fungicides were cut down through alternate applications of synthesized fungicides with BAB-1 AS and ABL EC.