For example, are you talking about:
* The potato blight? This fungal disease, *Phytophthora infestans*, primarily affects potato and tomato plants.
* The Dutch elm disease? This fungal disease, *Ophiostoma ulmi*, affects elm trees.
* The chestnut blight? This fungal disease, *Cryphonectria parasitica*, affects American chestnut trees.
* The soybean rust? This fungal disease, *Phakopsora pachyrhizi*, affects soybean plants.
Once you specify which blight you're interested in, I can tell you which organisms are affected.
