Articles
RECENT PROGRESS IN RASPBERRY BREEDING AT EAST MALLING
Further East Malling primocane selections are on trial and younger material under selection.
Some of the most promising material is derived from Rubus spectabilis.
Earlier cropping primocane types now overlap in August with late ripening summer fruiting types. ‘Malling’ Leo and ‘Malling’ Joy have extended the raspberry season well into August and selections a week later than Leo are on trial.
Selections derived from R. crataegifolius start ripening 4–5 days earlier than Glen Clova and finish over a week earlier.
Derivatives of R. spectabilis are earlier still and while fruit colour is good, fruit size is only moderate.
Several approaches are being followed to improve yield, including selecting for large fruit mainly in Malling Delight derivatives, selecting for floriferous laterals in R. cockburnianus derivatives, selecting for short internodes and the ability to produce two laterals/node.
Since 1980 a New Zealand Agricultural Engineering Institute horizontal harvester has been used at East Malling to select types which are suitable for machine harvesting.
The criteria for harvestability are high yield, high proportion of good fruit compared to damaged, overripe or fruit picked with plugs, good quality fruit and low susceptibility to post harvest fruit rots.
Three clones, two of which were bred for mechanical harvesting, have been selected for trial.
All three performed better than commercially available varieties bred for hand picking.