Dragon Tree Fungus

Fusarium Leaf Spot

• Caused by Fusarium moniliforme, fusarium leaf spot primarily affects Dracaena marginata. The infection produces watery-looking spots on the margins of new leaves. As the disease progresses, the spots spread and turn tan or reddish brown with a yellow halo. Severe infection can spread to and kill buds. A study by the University of Florida revealed that D. marginata "Bicolor" and D. marginata "Tricolor" resist fusarium wilt better than other cultivars. Use a fungicide labeled to treat fusarium leaf spot and follow label directions for proper application and timing.

Erwinia Fungal Rot

• This fungus is bad news for dragon tree owners. Erwinia carotovora pv. carotovora attacks young, rooted dragon tree cuttings, turning the roots and lower stem soft. The area is discolored or brownish and the appearance of rot is obvious. This rot smells bad. Erwinia causes the dracaena's lower leaves to fail and collapse. Fungicides do not help; destroy or discard infected plants. If the plant is in a container, discard the contents of the pot and disinfect the pot before using it for a new plant.

Root Rots

• Rotting dragon tree roots often appear an unhealthy brown color and exhibit areas of necrosis, or death, that may turn black. Root rot can advance upward and infect individual canes, turning them soft. The cane may turn brown inside. Pythium fungus lives in the soil and can survive for years, waiting for a plant to infect. Pythium gramincola and Pythium splendens cause stunted growth and the dracaena's leaves may become chlorotic as the failing roots become less able to circulate nutrients to the aboveground portion of the plant. Fungicides are more effective in preventing pythium diseases than treating them.

Other Fungal Infections

• Over watering and overhead watering provide breeding grounds for fungus spores such as pythium phytophthora. Spores can travel through water accumulated atop leaves or in excess water around the base of the plant. Wounds caused by pruning and breakage can also become a doorway for fungal spores such as Thielaviopsis paradoxa to enter and infect dracaena plants. Get a specific diagnosis before attempting to treat any fungal infection of dragon trees.