Let your plant grow till at least day 50, at that time flush out your grow nutrients, then if possible change the spectrum of your light to bloom only, i have a 600w 2 cycle light and run my autos under blue only till they stop growing vertical and are in full flower then turn off the blue and turn on the red and add bloom nutrients for the rest of the grow i usaley flip around day 50 strain dependent but that is average, if you cant flip your light to bloom flush out grow nutrients when your plant has topped ie stopped growing vertical flush out your grow nutrients and get hold of some Atami Bloombastic 2ml per US gal and just a little bit waterd down, Warning!!! If you do not go super super easy you will fry your plant for shure, i put 2ml in a milk jug and pour a little splash by eye into a 16oz cup of water stir and feed this will blow up your plant, i have been running autos for allmost 10 years and this is how i grow them i do not cut the light cycle but change the spectrum up till i flip i use. Botanacare pro grow after day 21 and again 2ml per USgal a small splash in a 16oz cup of water stir and feed if you give 2 much you will burn them, up till day 50 all i want to have happen is my plants to stop growing vertical and be in flower, after day 50 i enhance what flower there is do you understand? If you are useing a good medium i allways use fox farm ocean forest you dont have to feed much but if you do go lightly, autos luv just blue light when there in veg mode and red light in flower the only thing im doing is feeding lightly till they stop growing vertical and are in flower and it averages out to around 50 days or so, after that i change the spectrum of my light to bloom only flush out plants check ph and start giving Atami Bloombastic for the rest of my grow, i have been doing this so long i just do it buy eye but remember either in veg or flower just a small splash in a 16oz cup of water stir and feed got it? If you do use Atami to flower your plants look at your leaf tips i sometimes very slightly discolor the tips this tells me the plant is at maximum uptake and if i give mor i will burn them, yea i know autos flower with age but you want to enhance what flower you have after they have stopped growing vertical, you can train your branches by moving them up and down and back and forth but once they harden stop bc you dont want to snap them, my Skywalker plants i should have lollypoped ie got rid of the small crap at bottom of plant, this will let your plant concentrate on blowing up your main branches your at 35 days and if you have allot of small flower low on the plant prune it off, most but not all autos dont mind pruning if your unshure leaf tuck, finally dont blast your plants with wind you just want the leaves very gently flutering in a light breeze you can give them wind burn and they can dwarf out, finally you want your plants reaching for the light but not overley stretching, this all may sound odd but autos are not photoperid plants and you do not grow them the same way, i have perfected this over allmost 10 years and it works great for me.
If you pull now you’ll be losing a lot of weight. Trichomes are how you tell if your plant is ready so I always recommend getting a jewelers loupe or 60x magnifying lenses. 
