Answers
The symptoms on your green bean leaves are due to sun burn (commonly called sunscald). The appearance of brown patches (i.e., scorching of leaf tissue) are due to intense sun light.
Remove the affected leaves and provide shade to plants during afternoon intense sunlight. Also water the plants regularly.
Remove the affected leaves and provide shade to plants during afternoon intense sunlight. Also water the plants regularly.
Bean sunscald 1
Common blight
Alternaria leaf spot
Bean Sunscald 2
Halo blight
Anthracnose disease
Ascochyta leaf spot
Posted
by: Dr. Ravishankar Narayana
(15 points)
Posted: May 3, 2016
Dr. Ravishankar Narayana commented,
I won't thing it is blight. The common diseases on beans are 1. Common blight caused by Xanthomonas campestris pv. phaseoli (bacteria) where the leaves exhibit brown and necrotic spots with yellow margins. 2. Halo Blight caused by Pseudomonas syringae pv. phaseolica (bacteria) where the leaves shows small angular water soaked spots initially. As disease progress the size of the spots increases and characteristically surrounded by yellow halo. 3. Alternaria leaf spot caused by Alternaria alternata (fungus) show appearance of small irregular brown lesions on leaves which expand and turn gray-brown or dark brown with concentric zones. 4. Anthracnose disease caused by Colletotrichum lindemuthianum (fungus) shows brick red to dark brown lesions on leaves, stem and pods. 5. Ascochyta leaf spot caused by Ascochyta boltshauseri (fungus) where the leaves exhibit large light/dark brown lesions with a series of conspicuous concentric rings (donate appearance). Also see the attached images of each diseases. Hope this will clarify your doubt. over 8 years ago.
I won't thing it is blight. The common diseases on beans are 1. Common blight caused by Xanthomonas campestris pv. phaseoli (bacteria) where the leaves exhibit brown and necrotic spots with yellow margins. 2. Halo Blight caused by Pseudomonas syringae pv. phaseolica (bacteria) where the leaves shows small angular water soaked spots initially. As disease progress the size of the spots increases and characteristically surrounded by yellow halo. 3. Alternaria leaf spot caused by Alternaria alternata (fungus) show appearance of small irregular brown lesions on leaves which expand and turn gray-brown or dark brown with concentric zones. 4. Anthracnose disease caused by Colletotrichum lindemuthianum (fungus) shows brick red to dark brown lesions on leaves, stem and pods. 5. Ascochyta leaf spot caused by Ascochyta boltshauseri (fungus) where the leaves exhibit large light/dark brown lesions with a series of conspicuous concentric rings (donate appearance). Also see the attached images of each diseases. Hope this will clarify your doubt. over 8 years ago.
JOSIAS CORREA DE FARIA commented,
i DO AGREE with the answer. It frequently appears if the plants get water drops followed by a scalding sun: therefore the name. The water functions like a lens amplifying the power of the sun and burning the leaves. over 8 years ago.
i DO AGREE with the answer. It frequently appears if the plants get water drops followed by a scalding sun: therefore the name. The water functions like a lens amplifying the power of the sun and burning the leaves. over 8 years ago.
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Image is not clear. Can you please upload clear photos? Images of both surface of leaf will be helpful. over 8 years ago.
I updated more photos over 8 years ago.