Evaluation of acute toxicity of piperonylic acid
Acute toxicity of PA to M. incognita was evaluated by incubating 50 J2s in 300 µM PA or a corresponding mock solution and assessing motility after 48 h. PA’s acute toxicity to P. syringae DC3000 and B. cinerea R16 was tested by adding 300 µM PA to their media and monitoring growth (OD600 after 24 h for P. syringae and colony area after five days for B. cinerea). Acute toxicity to T. urticae, A. lycopersici and F. occidentaliswas tested as by Xue et al. (2020). Briefly, ±25 adults (T. urticae, A. lycopersici) or larvae (F. occidentalis) were placed on 1 cm2 leaf discs and sprayed with 300 µM PA or a mock solution in a spray tower; mortality was recorded after three days.