The price of onions has gone up from ₹60 a kilo almost 10 days back to ₹75, with retailers warning that a kilo of the bulb could cost ₹80 later this week.

On Monday, onions sold for ₹75 a kilo at most of Calcutta’s markets.

Bengal requires around 10 lakh tonnes of onions annually. Around this time of the year, when local produce is unavailable, the state depends on supplies from Nashik in Maharashtra and parts of Karnataka, Andhra Pradesh, Rajasthan and Bihar.

Traders in Calcutta’s wholesale onion markets said heavy rain in Nashik in October had hit the supply from Maharashtra. Officials in the food processing industries and horticulture department said the rain had damaged around 21,000 hectares of onion.

With fresh supplies hit, the stored onion from last year disappeared faster than before at the wholesale market in Nashik, the officials said.

The Bangladesh government’s decision to waive import duty on onions till mid-January has compounded the problem as onion traders in India are now more keen on exporting the produce than feeding the domestic market.

“With stocks drying up, the supply of onions from Nashik to the wholesale markets in Calcutta has been dwindling for some time. The supplies are likely to be hit further as Maharashtra is going to the polls later this month,” said Kamal Dey, a member of the state task force on vegetables and the president of the West Bengal Vegetable Vendors’ Association.

At Koley Market, the biggest wholesale vegetable hub in the city, traders said the number of trucks carrying onions has dropped from around five a day a week ago to about three two days ago.

“Each truck carries 400 packets of onions from Nashik. Each packet contains close to 40kg of onions,” said Sekhar Das, an onion dealer. “We are forced to ration supplies to our retailers because of inadequate supplies from Nashik.”

The impact is being felt in most markets.

“The price has gone up by ₹15 a kilo within a fortnight,” said Prosenjit Ghosh, a vegetable seller at the Gariahat market.

Homemakers and market regulars said they had been feeling the pinch for some time and the situation has only worsened.

“I have cut down on onion purchases. Earlier, I would buy around 500g a week. Now it has been halved,” said Anumita Ghosh, a homemaker in Kasba.

Senior state government officials said farmers in Hooghly, Murshidabad, Nadia and Bankura have begun readying farmland for sowing onions. The first lot of homegrown variety is not expected before February.

“The land has to be elevated and must have enough moisture to become suitable for growing onions. The most common Bengal variety — Sukhsagar — is whitish,” said a senior state government official.