soil fungi
Vegetables grown in tropical areas are affected by several telluric parasitic fungi and Oomycetes, sometimes opportunistic, which find conditions of humidity and temperature particularly favorable to their development.
Among the most common and damaging are Sclerotium rolfsii , several Oomycetes ( Pythium and Phytophthora ), Rhizoctonia solani , etc. It should be noted that some of them, although they are soil fungi, are capable of attacking the aerial organs of vegetables if they are in contact with the ground, or following water splashes and soil particles, or even or through their mycelium traveling on plant tissues.