leaf discoloration with pics

A friend of mine has an outdoor plant that has been in the ground for three months. a few days ago he noticed these leafs. Any advice? Thanks in advance.

Looks like severe nute burn.

he says that he has not used any nutes

ok your plant is suffering from lack of phosporus and potassium. this is what happens when your plant doesnt have the nutrients to survive. you cannot grow marijuana with just water. you need nutrients to make nice crystaly buds. your best bet right now is to go to your local hydroponics store and get some seabird guano cause its stronger than bat guano and remember you want the hydroponic solution type. that way its immediatly available to your plants as soon as you mix and water. it also might not be a bad idea to mix som sort of super bloom in there as well to really give it what it needs with a punch.

severe lack of nutrients!