I recall learning that geotropism exerts the stronger influence that phototropism.
I’d put my money on geotropism first.
Assuming you meant, learned it in school, in your younger years, let me ask you this:
Were they correct? You were also told that the Universe was infinite (I assume), then you were told it was Finite (after discovery of the big bang wave). Which is true?
We are arguing that scientists of the past may have been misinformed ( like, say, Darwin) and yet you stick to a teaching that may be just as untrue.
Matter of fact, if you look at nature around you, you will see that the Sun is the main force of growth, and that gravity more likely plays only a tiny little part in a plant 'figuring' out which way to grow.
What I'm saying is that if one wants to imply that plants 'understand' and 'use' gravity, (pretty intelligent thing, I'd say), then OK. But, they also know if they don't follow, or grow towards the Sun, they will die.