Help rot?

A few of the branches on my plants are turning yellowy brown in spots and are verry weak. Im 4 weeks into flowering and am scarde! I dont want to loose it all.

pictures are the best way to diagnose
as far as your description its either the rest of the plant pulling nutrients from the leaves (yellow spots) or like you think... dreaded bud rot

its not on the leaves its on the actuall branch itself. my intake fan was blowing right on the spot where the problem is, maybee from the moisture in the air?? i cut the branch off below the problem, will this help?

anyone have any input?

I have the exact same problem, is there about a 1/2" -2" dead spot on the branch itself which looks like a powdery fungus of some sort. Mine is on about 3 plants which are also situated infront of my fan. I did some research and found out that is could be a "Stem Canker" I cant really find a cure for this but heard of a few people using "DEFENDER" fungicide to prevent it from spreading. Post some pics, I will do the same and we can compare and figure ou a way to get rid of this tear jerking occurance....GOD HELP OUR GIRLS.....LOL

do you ever see any extra moisture at the spot where the problem is?
if youre misting or watering on the leaves and the water is puddling up somewhere thats a perfect medium for a lot of stuff to grow

I dont have a camera rite now but ill go buy one today and put up some pics. i just hope they make it!!!

so i went to the hydro store today and asked wat they had for this problem. they gave me a bottle of NODAMP, they said it is a comon problem and the comercial guys they deal with swear by it. so ill give it a try and see how it works.