how and y should i top a plant ?

Cut off the newest plant growth, on the 2nd or 3rd leaves at the bottom. Use a new razorblade. People do this to increase the yield.

Topping will give you a plant that looks kinda like this.

IMGP7511.jpg


Gives you multiple colas instead of 1.

'fraid I'm too buzed to tell you how to do it, lot of threads on the subject if you care to search