How to optimize page permalinks ?
 

Hello
I am using WP mainly as a CMS : let's saythe content is "vegetables"
Therefore my content is organized in the following way.

- HOME

-- Potato
--- Red potato
--- Sweet potato
--- yellow potato

-- Eggplant
--- Round eggplant
--- L-shaped eggplant


My permalinks are :"/pagetitle/" so the search engine list my page as :
www. veggies . com / Potato / Red potato

BUT
red potato market is very hot, and I would rather have an URL like the following:

www. veggies . com / Red potato

(no level 1 menu displayed).

How can I do that ? I've checked plenty of websites, but they all give advices on how to modify post titles, and not page titles.

Thanks