Just this year, most of my habaneros have a black tip, like the one pictured. My cayennes and jalapenos in the same raised bed are doing fine, but the habs... not so much. The black flesh of the pepper is pretty tough... I am not exactly sure what is causing this, but I am having to cut off a significant portion of each pepper before using it. I talked to my dad [local growing expert], and he thought it may be due to the heat, and lack of moisture. We have been having 100+ days for several weeks now, and no rain at all. I have been watering every 2-3 days, and the foliage generally looks pretty good. Usually there is some wilting before I water, but not enough to cause me any concern for the over-all plant health. Could this be due to hot weather, or am I looking at a different problem?