Variables: pH Keywords: monitoring Substances: Acibenzolar-S-methyl (UELITFHSCLAHKR-UHFFFAOYSA-N) 2-4-dimethylphenylformamide (JOFDPSBOUCXJCC-UHFFFAOYSA-N) 2-Methyl-4-isothiazolin-3-one (BEGLCMHJXHIJLR-UHFFFAOYSA-N)