Photoperiod is dominant so first cross all F1 seeds will be photoperiod ,,,the auto is recessive.
Cross the F1 seeds and you will get F2 seeds that will be 25% auto ,,scrap the rest and only work with those autos,,which are now Auto dominant.
cross those seeds to get F3 seeds which will ALL be Autos..
Now you have autos but to get what you want quality wise you’ll need to continue with line breeding ,which can take many generations to fix the phenotypes you want.
you will need to work in numbers for the pheno hunts coz you can’t clone to backcross and you won’t know what the father brings to the table .
All above should be correct, and you will see that by using a Punnet Square,.
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EDIT,,,,ignore this bit, think I was too stoned.
this bit I’m not 100% sure but should work .
And can save time.
As a side line to follow ,start selfing the best pheno that suits you
to fix traits .then continue line breeding with the best of the S1 seeds