Variables: pH Keywords: monitoring Substances: Acibenzolar-S-methyl (UELITFHSCLAHKR-UHFFFAOYSA-N) 1-Methyl-Benzotriazole (HXQHRUJXQJEGER-UHFFFAOYSA-N) 3-5-Diamino-2-4-6-triiodobenzoic acid (GOQCZMZLABPEME-UHFFFAOYSA-N)