Strawberry Nematodes

(Aphelenchoides fragariae)

Description

Strawberry Nematodes are microscopic, unsegmented worms which actually feed within African Violets. They enter Violets through wounds or leaf pores (stomata). Damage is typically seen on the leaves and the flowers. In almost all cases, Strawberry Nematodes are fatal to African Violets. The best control for Strawberry Nematodes is, therefore, prevention.

Distinguishing Symptoms

• Leaves in the crown have almost no hairs growing from them. When Strawberry Nematodes are at work, this symptom will be most visible on the new growth, i.e., in the crown.
• Leaves have scarring on the upperside of them.

If your African Violet has both of these symptoms, there is a strong possibility that it has Strawberry Nematodes. (Note: In many ways, the symptoms of Strawberry Nematodes mimic those of Cyclamen Mites. However, whereas Cyclamen Mites will cause an excess of leaf hairs growing from the crown, Strawberry Nematodes will leave almost no leaf hairs growing from the crown. Also, when present, Cyclamen Mites should be visible with the use of a magnifying glass.)

Other Symptoms

• Leaves are deformed or twisted.
• Leaves pale. They appear yellow or grayish in color.
• Leaves wilt. They may appear translucent brown with a soft, jelly-like consistency.
• Flowers are damaged. They may have holes in them.
• Plant growth is slow.

Treatment

Unfortunately, the only effective treatment for Leaf Nematodes requires the use of Metasystox or Vydate, neither of which is available without a pesticide license. Unless you have one of these, your only remedy is to dispose of the affected plants. If the Nematodes are not too far advanced, you may be able to remove all the leaves and repot the crown. If you try this, however, be sure to isolate it in case the crown is infested.

Prevention

Always isolate new plants until you can positively determine that they are not infested.

Thoroughly wash hands before handling your plants.

Before repotting, pasteurize soil and disinfect pots with a 10 percent bleach solution, i.e., 1 part bleach to 9 parts water. Always isolate new African Violets until you can determine that they are not infested.

Begin New Diagnosis

Doctor Optimara Main Page | Glossary of Violet Terms | Contact Optimara

Pests, Pathogens and Cultural Problems (Complete List)

Copyright 1999 Optimara/Holtkamp Greenhouses, Inc. Nashville, Tennessee. Doctor Optimara is a trademark of Holtkamp Greenhouses, Inc. Optimara and the Optimara logo are trademarks of International Plant Breeding, A.G., Switzerland.