Phosphorous in earth tainers?

[Dewayne mater]

A fellow tomato grower tells me that phosphorous helps a plant flower as well as helps flowers set. Is that true?

If this is true, can I soak granular phosphorous in water and put that in the earth tainer fill tube? Are there better ways to get quick results with flowering and fruit set in what is likely to be very short season left to set fruit before the big heat takes over.

My plants are mostly looking great, growing great. Some are setting great. A few aren't setting at all yet (brandywine from croatia, goose creek, earl's faux) though the plants look great. G.C. and E.F. have always been later to set fruit for me, and BWC may fall into that category as well. Yes, I shake all my plants regularly to provide the assist. We've also had plenty of wind which should help, and has on other plants. Thanks for your input.

Dewayne mater