Not all root and crown rots are the same. Whenever I see yellowing, wilting foliage, my first thought is that the problem is most likely due to Pythium or Phytophthora root rot. However, dieback on cyclamen could be Fusarium wilt.
Fusarium wilt of cyclamen occurs worldwide and is caused by the fungus, Fusarium oxysporum f. sp. cyclaminis. This species of Fusarium is specific to cyclamen and will not infect other plant species within the greenhouse. Fusarium wilt can be a devastating disease as the disease may go undetected in young, vegetative plants. Symptoms of Fusarium wilt are often not seen until the infected plant begins flowering or plant experience stress, such as drought stress.
Infection and symptom development may also be delayed in cooler greenhouses (60°F) and will develop more quickly under warmer temperatures (above 70°F). Once symptoms develop, infected plants need to be removed and discarded to reduce spreading Fusarium spores to adjacent plants.
One of the first symptoms seen with Fusarium wilt is yellowing of leaves followed by leaf wilting and death. Initial foliage symptoms may only be seen on a few leaves but eventually the whole plant may be killed. As infection progresses, roots will discolor and rot, which can be confused with other root diseases.
Read the complete article at www.e-gro.org.
