Pffff... Phytium fungus... searches info
Always disinfect or clean all the growing material, from scissors and blades, to pots and stakes that you have already used before.
The use of beneficial fungi such as Trichodermas or Mycorrhizae has been shown to be very effective against Phytium in marijuana crops, increasing the resistance of the roots throughout the crop, in addition to ensuring greater assimilation of nutrients and protection against droughts. The use of hydrogen peroxide in irrigation will also help its prevention