Agriculture Reference
In-Depth Information
Phosphoric Acid (75-85% Phosphoric Acid)
Food-grade 75-85% phosphoric acid is useful in a foliar program. This is the stuff they
put in soft drinks, and in my opinion, we should not be ingesting it at all. Spraying two to
four teaspoons, however, with some fish and kelp and two quarts of water per 1,000 square
feet every couple of weeks during the growing season can be very helpful in keeping the
phosphorus, and therefore the brix, at appropriate levels. If you're in the dry season and the
humidity is low, keep it at two teaspoons maximum in order to not burn the leaves.
Phosphoric acid isn't a quick fix, but gradually helps throughout the season. It should
cost less than $20 for a quart. It's corrosive, so be extremely careful with it. Don't use it un-
less you have some knowledge and comfort working with this kind of thing. Don't mix it
with liquid calcium or you may get a jelly consistency in your sprayer.
