Papaya Pythium Rot Info
What is papaya stem rot? Caused by the Pythium fungus, it mostly affects saplings. There are several species of pythium fungus that can attack papaya trees, all of which can lead to rot and either stunting or death. When it infects young saplings, especially soon after transplant, it manifests itself in the phenomenon called “damping off.” This means the stem near the soil line becomes water soaked and translucent, and then it dissolves. The plant will wilt, then fall over and die. Often, the fungus is visible as a white, cottony growth near the point of collapse. This usually results from too much moisture around the sapling, and it can usually be avoided by planting the trees in soil with good drainage and not building the soil up around the stem.
Pythium on Papaya Trees That are Mature
Pythium can also affect more mature trees, usually in the form of foot rot, caused by the fungus Pythium aphanidermatum. The symptoms are similar to those on young trees, manifesting in water-soaked patches near the soil line that spread and multiply, eventually converging and girdling the tree. The trunk becomes weakened, and the tree will fall over and die in strong winds. If the infection is not as intense, only half of the trunk may rot, but the tree’s growth will become stunted, the fruit will become malformed, and the tree will eventually die. The best defense against pythium rot of papaya trees is well-draining soil, as well as irrigation that does not touch the trunk. Applications of copper solution shortly after planting and during the time of fruit formation will also help.
