Septoria leaf spot is caused by the fungus Septoria lycopersici. Septoria leaf spot is one of the most destructive diseases of tomato foliage.  |
Symptoms: Symptoms appear around the time of fruit set. Small, circular lesions with dark brown margins and tan to grayish centers. Photo by Plant Disease Clinic |
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Symptoms: The disease spreads up the plant, from oldest to newest growth. Fruit infection is rare. Photo by Chad J. Behrendt |
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Sign: Black pycnidia with cylindrical spores. Photo by Plant Disease Clinic |
| Causal organism: | Septoria lycopersici |
| Over wintering: | In infected plant material and debris, and solanaceous weeds such as deadly nightshade |
| Months of infection: | June-September? |
| Method of dispersal: | Infected seed, wind and rain |
| Infection point: | Leaf tissue through stomates |
| Control: | Cultural rotation every 1-2 years, removal of infected material, spacing to allow plants to dry between waterings. Several fungicides, including Chlorothalonil, are labeled for control of Septoria leaf spot. |
| Labeled fungicides | Several fungicides, including Chlorothalonil and Kocide(Copper Hydroxide), are labeled for control of Septoria leaf spot. As always, follow manufacturers' instruction. |
| Comments: | There are no Septoria-resistant varieties. |
| For Additional Information | Back to Tomato Diseases |
