By Robert Bergman, ILoveGrowingMarijuana.com
Diseases on marijuana plants and infections usually create the worst possible issues for your plants. They have a tendency to be much harder to treat than pests. Diseases in your plants will usually come in one of two major categories: fungal or bacterial.
Fungal diseases are often caused by environments that are too damp or humid, or places which lack airflow. Fungal spores float around in the air looking for a suitably damp place to root down and if the environment is right, that suitably damp place might be on your cannabis plant.
Bacterial infections are often sneakier and harder to notice. They are spread by a number of different possible vehicles, ranging from insects and humans to rain and unclean soil or substrate. Bacteria can sometimes get into a plant and then leave it mostly untouched unless the plant is weakened by external stresses, at which point they can quickly take down the whole plant.