My strawberry plant has small brown spots on some of it’s leaves. What causes this and how do I stop it?
Question by methouten: My strawberry plant has small brown spots on some of it’s leaves. What causes this and how do I stop it?
Answer by MGM
It sounds as if you have common leaf spot. Check the photos and descriptions in the links below to make sure.
If your problem looks like it is common leaf spot, here is some info from Washington State University:
Common leaf spot is caused by a fungus that overwinters on old infected leaves. It produces abundant spores in lesions of infected leaves, and rain splashes them onto healthy tissue. Only young leaf tissue is susceptible to infecting, and long wet periods and warm temperatures encourage spread of the disease. Foliage symptoms start as dark purplish red spots, and eventually become grayish white. Developed spots are about a 1/10 inch in diameter, with a white center and reddish outline, and become scattered all over the leaf surface. Sometimes the whitish centers of spots fall out, leaving a hole in the leaf. Infections occur in moist weather and are most severe in spring and fall. “Olympus” and “Shuksan” cultivars are the most susceptible.
Non-chemical approaches to try first:
- After harvest, renovate by removing leaves of June-bearing plants 0.5 inch above the crown, but do not mow other types.
- Removing foliage after harvest reduces spore counts.
Chemical controls (last resort):
- Bonide Copper Spray or Dust RTU
- Bonide Liquid Copper Fungicide Conc
- Soap-Shield Flowable Liquid Copper Fungicide
** Read the fungicide label carefully and follow it exactly. Since you will be treating a food crop, pay special attention to instructions on when (or even if) your strawberries can be safely eaten after treatment.
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