Fungicide smoke generated by electrical heating effectively controls gray mold of Chinese chives and reduces residue risk through adequate environmental sterilization

BACKGROUNDLabor-saving pesticide application technology is eagerly pursued in the planting system of Chinese chives. In this study, we developed a set of application approaches by turning fungicides into smoke to achieve this goal. RESULTSThe fungicides fludioxonil, fluopyram, boscalid, procymidone, and prochloraz could be vaporized into smoke at temperatures below 300 degrees C. The SFR (smoke formation rate) decreased with the increasing temperature. At 300 degrees C, the SFR of fludioxonil, fluopyram, boscalid and procymidone were all higher than 80%. At 300 degrees C and 600 degrees C, there were no significant differences in the smoke particle state of these five fungicides. However, the inhibition rate of these five fungicides against the growth of Botrytis squamosa generally decreased with the temperature. At 600 degrees C, only fludioxonil and boscalid had inhibition rates higher than 80%. The deposition uniformity of fungicide smoke increased with the increasing amounts of NH4Cl. When the amount of NH4Cl reached 80% of the total content, the smoke of fungicide was uniformly deposited throughout each glass slide. In the greenhouse experiment, the control efficacy of fungicide application by smoke was significantly better than that of spraying application, whereas its residue was much lower. CONCLUSIONIt is feasible to control air-borne disease through the vaporization of fungicides into smoke by electrical heating. Smoke application would effectively inhibit the spores in the air and would not increase the humidity of the environment. These findings indicate that smoke application is a labor-saving pesticide application technology viable in production. (c) 2022 Society of Chemical Industry.

Automated summary

In this study, a set of application approaches were developed by vaporizing fungicides into smoke at temperatures below 300 degrees C. The smoke application effectively controlled air-borne disease and showed better control efficacy and lower residue compared to spray application in greenhouse experiments.