Reddish Spots on Bean Leaves - Ask Extension
Hello,
I noticed this reddish coloring on my lima beans and purple hull peas that I sowed on May 26 from seed. I've cut most of the damaged leaves of...
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Reddish Spots on Bean Leaves #873623
Asked June 18, 2024, 1:51 PM EDT
Hello,
I noticed this reddish coloring on my lima beans and purple hull peas that I sowed on May 26 from seed. I've cut most of the damaged leaves off. But I don't know what the discoloration is and if it will spread or come back. Thank you for any insight you can provide.
Regards,
Rochelle
Frederick County Maryland
Expert Response
Hi- we think that the reddish brown leaf discoloration in photo 3007 may be a response to high heat or another plant stressor. High ozone levels can produce similar symptoms in beans but we haven't had extended poor air quality days.
Some fungal and bacterial diseases cause leaf spots, but the symptoms in photos 3008 and 3106 aren't entirely consistent with those diseases. The spotting could also be a function of environmental stressors. Leaf burn occurs commonly in bean plants during hot, sunny weather, although the symptom is usually light tan blotches. Seedlings are generally more
vulnerable to stress injury than older, well-established plants.
Check your drip system to ensure that the root zone is thoroughly moistened. Compared to hand watering, drip irrigation will help reduce leaf wetting and the risk of disease. If you haven't fertilized your bean plants, you may want to consider using a complete fertilizer (containing nitrogen, phosphorous, and potassium).
Please send photos if the symptoms change or worsen.
Jon
Some fungal and bacterial diseases cause leaf spots, but the symptoms in photos 3008 and 3106 aren't entirely consistent with those diseases. The spotting could also be a function of environmental stressors. Leaf burn occurs commonly in bean plants during hot, sunny weather, although the symptom is usually light tan blotches. Seedlings are generally more
vulnerable to stress injury than older, well-established plants.
Check your drip system to ensure that the root zone is thoroughly moistened. Compared to hand watering, drip irrigation will help reduce leaf wetting and the risk of disease. If you haven't fertilized your bean plants, you may want to consider using a complete fertilizer (containing nitrogen, phosphorous, and potassium).
Please send photos if the symptoms change or worsen.
Jon
