What is with Mamba Negra (Blimburn seeds, last pho...

Looks like it’s from rain bro mine went like that after a bad storm trim Off the dry bits and leafs you’ll be good ...also if your transplanting try some great white dry powder

It may possibly be some type of Blight. https://www.zamnesia.com/cannabis-grow-guide/68-cannabis-diseases It looks like your day time temperatures are cool so your night time temperatures are getting cold. This is leaving a heavy coating of dew on your buds setting up a perfect scenario for mold/rot issues. Don't panic yet another possibility is the wet leaves exposed to strong sunlight may have caused a bit of burn on the tender leaves. With out more information about your grow like watering,nutrients do you spray feed her it's the best educated guess I can make as to a what's going on with your plant. I feel it's odd that your other plants aren't showing the same issues.👍

first its outdoor so protect them from nature then change nutriment if using any (try sea weed extract) it will continue spreading if not care for right away you can also use growdiaries.com/nutrients/green-planet-nutrients/zyme this will help your root to recuperate you also want organic only like brew your own tea worm casting/seaweed extract/voodoo juice/peat most/crab meal/alfa alffa /molasses

I was thinking you have applied to much fert in foliar spray (or spilt potent ferts on leaves when watering) but then I noticed the cling wrap ( humidity dome covering your pot! That could be your issue... Almost looks like your cooking your roots! Hope this helps... I love a good Guerilla grow 👍👏👐🙌💪

What makes me days that it isn't a roots system issue is the fact that only the extremities are hurts ( tops buds of the stems ). It appeared burn like if it was spread with something just before the Sun goes up and it has been burn by that , or just the Sun if it's still a Hot one. My last thought is that you are maybe dealing with a fungus because they are generally starting on a specific spot of the plant before spreading . Whatever's your case is I would advise you to cut the affected part and to monitor your plant. And as you are growing outdoor I would have put that one one quarantine to avoid any spreading on the others plants