How to Control Bud Rot:
Keep humidity under 50-55% and give plants plenty of air movement in a moderate environment.

How to Prevent Bud Rot:
Keep humidity under 50-55% RH
Good air movement
Keep plants from big temperature swings between day and night
Avoid letting buds get exposed to wetness
Remove all affected buds immediately
Avoid plant wounds
Keep some space between buds
Defoliate leafy plants
NOTE: Watch out for symptoms of bud rot. Watch plants closely for signs of bud rot in the late flowering stage, especially on large or dense buds, and especially after humid or wet weather. If you notice leaves dying in patches on your plants, don’t wait. Investigate immediately.