Vegetable plots are being left empty in Oxford because of vandalism and a lack of interest, an allotment association treasurer has claimed.

Mervyn Allmond, field secretary and acting treasurer for the Rose Hill and Thompson Terrace Allotment Association, has watched a set of prize winning allotments become almost half empty over the past few years.

Mr Allmond said only 52 of 80 allotment plots were currently occupied at the grounds near the Eastern Bypass in Rose Hill.

He said the allotments had been judged the best kept plots in England in the 1980s and he was disheartened by the decline.

He said: "A few years ago, we had a waiting list. But the older people who had allotments have died off and the youngsters think it is easier to go to Sainsbury's.

"The other trouble is with vandals. We have had sheds broken into and half the time there is nothing taken.

"We had sheds broken into only two weeks ago.

"It is a regular thing. It is kids with motorbikes - they break in to see if there is any petrol. People get their sheds broken into and they say they have had enough of it."

Allotments elsewhere in Oxfordshire are thriving, with 3,000 people attending the annual Elder Stubbs Festival in Cowley each year and demand for plots exceeding supply in Carterton.

Mr Allmond appealed for more people to take on a plot and added: "I would like to see them all occupied, but you can't make people do it."

Mr Allmond said a five pole plot, 27.5 yards square, was available for £7.50 a year.

He said: "You can grow fresh veg - I don't buy any veg and it's good exercise.

"Digging is the best exercise - you use your legs, your arms, your back - and you use your brain as well if you are going to do it properly."

Zoe Millington, project development coordinator for Oxford Healthy Living Partnership, said: "I would thoroughly recommend taking on an allotment.

"Not only do you get the benefits of physical activity, but you also get to grow your own fruit and veg.

"Some people club together with a friend to take half an allotment each, and there are often people around in allotments that can share their expertise."