Leaf Wilt in My Orchid

Orchids are susceptible to fusarium wilt.

Orchids are grown by home gardeners for their great beauty and exotic blooms. While orchids are generally healthy, they are susceptible to fusarium wilt. This fungal disease causes serious effects in orchids and is most common in orchids under stress. If severe, fusarium wilt can cause orchids to die.

Identification

Fusarium wilt is caused by the Fusarium spp. fungus and is often seen in annuals and perennials.This fungus is soil borne and attacks plants under stress. Orchids and asters are commonly infected with fusarium wilt, as well as vegetable plants such as pumpkin and tomato. This fungal disease attacks plants underneath the soil at the roots. Orchids infected with fusarium wilt typically decline in appearance over a period of several months. Fusarium wilt is often known as "the yellows" because plants infected with this fungi often develop yellow leaves.

Effects

Fusarium wilt attacks the roots of orchids, especially those that have been divided. Orchids infected with this fungus develop yellow colored leaves that appear thin and shrivel over time. The overall health and appearance of the infected orchid gradually declines and root rot sets in. Along with rotted roots, orchids infected with fusarium wilt develop purple colored areas in the rhizome. Orchids with fusarium wilt usually decline over several months, but some orchids can die suddenly from infection.

Prevention

Fusarium wilt lives in the soil and typically helps break down plant tissues. However, orchids that are under stress from drought or injury may become infected with this disease. Keeping your orchids healthy and stress-free are important in preventing fusarium wilt. Always provide your orchids with adequate amounts of water, early in the day. This ensures your plants dry out completely before nightfall and helps prevent fungal disease development.

Considerations

Choosing plants resistant to fusarium wilt is the best way to avoid its development. There are fungicides that may help reduce the symptoms associated with fusarium wilt, but none ensures the plant's survival. Fusarium wilt fungi remains active in the soil for many years. If your orchids die from this disease, it is important to avoid replanting orchids in the same area for several years to avoid recurring infection.

References

• MOBOT: Kemper Center Factsheet; Orchids Problems
• University of Illinois: Fusarium Wilt Annuals And Perennials