UK onion production has been "severely affected" by weather conditions during 2018, with yields 40% down compared with a normal season.
Higher levels of imports from elsewhere in the world will be required to make up the shortfall in 2019, according to the British Onion Producers Association (BOPA).
Tim Elcombe, chairman of the group, said British consumers can also expect onions to be smaller.
He said the poor yields are down to the ‘Beast from the East’, which caused havoc with plantings and drillings in the spring resulting in many crops being planted up to six weeks late.
The prolonged hot and dry period over the summer then put onion crops under extreme stress and adversely impacted the growing potential.
Speaking after a BOPA meeting, Mr Elcombe said: “UK onion production has been severely affected by the adverse weather conditions in 2018.
“Despite British growers’ best efforts to minimise the impact through round the clock irrigation, the onion crop has been severely affected,” he said.
The most important months for crop growth in the United Kingdom are May to August as temperatures, day length and weather are normally optimal for plant growth.
But water has been scarce this summer, leading to slow growth rates for crop coupled with reduced productivity levels.
According to a leading agronomist from the Royal Agricultural University, the impact of the summer heatwave on livestock and growers will be felt “for months to come”.
UK potato plantings have decreased amid the extreme conditions, making it the third-lowest planted area on record.
And British carrot growers advise that this year's conditions will lead to the lowest yields for decades and the highest levels of imports.
