（Plant Protection Institute，Hebei Academy of Agricultural and Forestry Sciences，IPM Center of Hebei Province，Key
Laboratory of Integrated Pest Management on Crops in Northern Region of North China，Ministry of Agriculture and Rural
Affairs，Baoding 071000，Hebei，China）
The joint toxicity of mixing fluopyram with pyrisoxazole at different matching ratios against B. cinerea XSZH1 was determined by measuring mycelial growth rate test．The inhibitory activity of the mixture
with the other 4 isolates of B. cinerea was also determined by the same method．The efficacy in controlling tomato
gray mould was tested through field trials．The results showed that synergia effect against B. cinerea of mixing
fluopyram with pyrisoxazolewere found at the ratios of 2∶1 and 1∶4，while the ratio of 2∶1 exhibited the most
obvious synergia effects，the synergistic coefficient was 1.69．The mixture of fluopyram with pyrisoxazole，at the
ratio of 2∶1，also showed synergistic inhibition to the other 4 isolates．The control effect of this mixture（2∶1）
against tomato gray mould was 80.50%-90.13%，under the dose of 150-250 g·hm-2．The mixture of fluopyram
and pyrisoxazole（2∶1）could effectively control tomato gray mould．It is suitable to use this mixture in field
application and extension．
