Potato is being sold at Rs 5 per kg as compared to the Rs 24 per kg before demonetisation while onion and tomato are being sold at half their earlier price of Rs 20 per kg.
Left with heavy stock of potatoes and less number of customers, some farmers are giving away sacks of potatoes to the needies for free.
"The group of farmers here have given nearly 400 sacks of potatoes for the prisoners," a personnel of Kanpur jail said.
The prices have declined for other vegetables also by nearly 50 to 60 per cent.
"People are buying less vegetable since they do not have cash with them and despite the low price they are only purchasing the amount of vegetables that they really need," said another vegetable vendor, Kamlesh Kumar from Ghatampur.
"And due to the lack of customers we are forced to sell the vegetables at low prices," he added.