As reported in Grower in May, Belgium-based company Biobest made the insects commercially available to fruit growers for the first time this spring after successfully rearing the native British bumblebees (Bombus terrestris audax) in limited quantities.
The bees were bred following demands from soft fruit growers of outdoor crops who were unable to use the non-native species of bee used in glasshouses and polytunnels.
This non-native bee - a European subspecies of Bombus terrestris and mainland cousin of the British buff-tailed bumblebee - can only be used indoors due to concerns that it may harm native bumblebee populations when used in the open field.
The top fruit industry had also been unable to use these pollinators but, thanks to Biobest's efforts, Norman Collett technical director Nigel Jenner has now placed multi-hives of the commercially-bred British bumblebees in three commercial apple orchards.
Jenner said: "Commercially, very few growers are now installing bee hives in orchards for the pollination of their crops - instead relying on natural pollinators and wind pollination. But gains in synchronicity and pressure, although not massively significant on Gala, could be very significant in the storage and shelf life of a variety such as Cox."
The bees' performance is being monitored alongside managed solitary bees introduced into the orchards. The bee-management programme is being run by Jenner and the Red Beehive Company's Robin Dean - who are also looking at both the pollination needs of new apple varieties and how compact orchard layouts influence fruit development.
Research they completed last year showed that managing pollinator levels in an orchard has a significant impact on factors such as synchronicity, storage potential and consistency of colour and size.
Jenner said: "Many of the new varieties are easily capable of achieving class 1 grade-outs of 90 per cent plus, but hand thinning and picking over the crop remain an essential part of good management. Even slight reductions in these tasks could lead to massive savings."
Norman Collett's 2010 bee programme is looking at the effects of pollinator management in five trial orchards - each containing 25 trees planted in a predetermined pattern.
They include a Rubens planting on a compact post-and-wire system, a pair of Gala orchards on M9 root stock and a pair of traditional M9 Bramley orchards.
In the Rubens and Gala orchards, Collett is examining any potential yield losses from having no pollinators. In the Bramley orchard the company is also looking to see whether there is any change in calcium levels to well-pollinated fruit.
Further details of these trials are being revealed at this year's Fruit Focus event, taking place in East Malling, Kent on 21 July. Visit www.fruitfocus.co.uk