An agricultural treatment method involves applying alkali metal bisulfate to modify surface pH on growing plants, or on seeds before planting, in an agricultural area. In certain aspects, the method involves applying an aqueous composition including the alkali metal bisulfate to the plants or seeds. The alkali metal bisulfate may be sodium bisulfate. An aqueous composition includes an alkali metal bisulfate in an amount from 0.1% to 5% by weight. The composition also includes a second material selected from stickers, antimicrobial agents, chelating agents, surfactants, or combinations thereof. Water makes up the final composition.
