Tomato (Solanum lycopersicum)-Double Streak


Cause A combination of Tobacco mosaic virus and Potato virus X. Workers or equipment mechanically transmit this disease. Virus strains, plant age, and day length influence symptom severity.

Symptoms Symptoms may appear suddenly. Small, brown leaf spots appear on young leaves. Leaves curl down, and leaves and stems die. Long, narrow, dark brown streaks on the stem and petiole extend beneath the epidermis into the pith. The whole plant may be killed. Fruit may be distorted and have small, superficial lesions, or fruit may not form.

Cultural control

  • Wash hands with soap and water, especially after smoking, before handling plants.
  • Do not smoke while handling tomato plants. About 80% of cigarettes contain virus-infected tobacco. Do not handle potatoes before working with tomatoes.
  • Remove and destroy infected plants.
  • Do not plant tomatoes where there is potato debris.
  • Disinfect tools after handling infected plants.
  • Use Tobacco mosaic virus-resistant varieties along with the above cultural practices.

Reference Gabor, B., and Wiebe, W. 1997. Tomato Diseases: A Practical Guide for Seedsmen, Growers and Agricultural Advisors. Saticoy, CA: Seminis Vegetable Seeds, Inc.