Phythopthora blight causes black large lesions on the stem of pepper which leads to its collapse. The affected plants show wilting symptoms. White sporangia can be seen on infected sections.
The pathogen can also cause symptoms on leaves which are circular in shape, garnish-brown in color, white in center during early stages and water-soaking.
Ovoid-shaped sporangia on infected tissue releases zoospores, the asexual reproductive structure, which can easily move in water spreading the disease. Sporangia can also be spread through air.
The pathogen survives as oospores, the sexual reproductive structure in infected tissue inside the spherical oogonium shown in the picture. Oospores is thought to serve as the primary inoculum for the disease.