Curling and mottling of potato leaves

Dear network members,

During our visit to Ghoragacha (a village near Kalyani, West Bengal, India) last week we noticed the symptom of curling and mottling of potato leaves. This is not caused by potato leaf roll virus. The symptom is uniformly spread over the whole field (and in several fields of the village). Aphid infestation was found on few plants and boat like curling of leaves were also restricted to the plants showing black tips in it (due to aphid sucking). The tubers were procured from different sources. Hence, faulty tubers might not be a conclusion. There were sharp changes in temperature here within the last two weeks. Then, what is the problem exactly? More imortant is the way to combat it. Otherwise it is going to be a disaster. Please advise.

Regards.

CI Team, West Bengal, India