Shoppers who value their 5-a-day are smiling this month. First there was the £1 pineapple. Then the news that prices are falling overall. Richard Ford reports

This month's basket of fruit and vegetables, drawn from The Grocer 33 price database, shows eight out of the 12 items have gone down in price since last month - taking the overall price down 5.6%

Exotic fruits and vegetables, as well as produce typically grown in the UK, have experienced price falls as a result of seasonal fluctuations in supply. The price of avocados, for example, has dropped 2.8% month-on-month, and the decrease in price year-on-year is more dramatic, at 14.8%. Prices had been high for some time, following a difficult period of supply caused by crop shortages in Spain and Israel, which kept wholesale prices up.

However, the wholesale price is now beginning to fall, as supply becomes less tight. And the forecasts for volumes coming in from Peru and South Africa look healthy.

Another reason the price of so many exotics is coming down could, of course, be the high level of promotional activity. With sales of tropical fruit - perceived as expensive luxury items - struggling in the recession, supermarkets have been looking for ways to give sales a boost.

Pineapples have been heavily promoted, which has driven down the month-on-month price by 14.4%. Asda, Morrisons and Tesco have been promoting pineapples at £1 in recent weeks. Promotions were also far more important in the winter just gone than ever before, as retailers fought hard to maintain consumers' interest in fresh produce and stop them defecting to the frozen aisle.

Red seedless grapes, which have fallen in price 8.1% month-on-month, have been the main driver of growth in the grape category over the past five to eight years, and now account for 35% of it. The remainder comprises white seedless grapes, which make up approximately 55% of the category, and mixed and black grapes. However, the black seedless grape is gaining ground, with one grape supplier proclaiming "black seedless is the new red".

Although the price of lemons has gone down since last month, by 0.8%, it has increased 6.3% year-on-year, a rise likely to have been caused, in part, by the fluctuation in exchange rates.

There was also likely to be an element of "supermarkets holding the prices up for margin purposes", said a source. "I would expect the price of lemons to rise slightly going forward," he said.

As supply switched to the northern hemisphere from the southern hemisphere, it would result in higher logistics costs which would, in turn, place upward pressure on price, he added.

There have also been some price rises month-on-month. Celery shows the biggest increase in price, up 9.7% month-on-month and 15.8% year-on-year.

The past eight weeks have seen inflation caused by a rise in import costs (at this time of year, most celery is imported from Spain). However, the price is expected to gradually fall as the home-grown celery season starts in the next few weeks.

Runner beans, which are down in price by 6.2% month-on-month, will also be a vegetable to watch as the British pea and bean season begins soon.