Raspberries: A impressive century of breeding

NIAB’s Scott Raffle and Feli Fernández outline how the history of East Malling has shaped the raspberry breeding that continues at the site today

The growth of fruit production in Kent and the South East led to the founding of East Malling Research Station in 1913; an establishment which developed into the world-renowned centre of excellence that we know today under the NIAB name.

Much of NIAB’s success at East Malling has been built on the employment of enthusiastic scientists from a wide range of disciplines who have become experts in their eld. Together, they have engaged directly with fruit growers to develop solutions to their problems and help to increase yields and fruit quality, allowing local growers to remain pro table and compete on the world stage. NIAB’s famous series of apple rootstocks at East Malling, its pioneering work on apple storage technology and development of modern high-yielding strawberry varieties, has been achieved by multidisciplinary teams collaborating closely with the industry.

Although nowadays it has a slightly lower pro le than its modern strawberry counterpart, raspberry breeding began at East Malling over 100 years ago and has released 32 varieties to UK and overseas growers, as well as the amateur market. The e orts of the rst 20 years of the programme led to the release of multiple virus tolerant varieties including Malling Jewel, Malling Promise and Malling Exploit in the 1940s.

Desirable traits

During the 1950s and 1960s, the principal objective was to introduce desirable traits from closely related Rubus species. Expertly championed by the late Dr Elizabeth Keep, this approach bene ted the East Malling programme along with other private and international public programmes, through Dr Keep’s generous exchange of germplasm and expertise. Released in the 1970s, Malling Admiral, Malling Delight and Malling Leo, all pest and disease resistant varieties with improved cane and fruit characters, were the key results of that strategy. Indeed, Leo set a new standard for (sweet) avour and signi cantly extended the summer fruiting season.

The release of Autumn Bliss in 1984 was a major breakthrough for the programme and the UK industry. As the rst primocane raspberry to be bred for UK conditions, it allowed growers to extend their production season from the summer fruiting cultivars through August, September and into October. An added bonus was its exceptionally early-ripening character, which is notoriously di cult to breed for in raspberry.

In the post-war years, the programme was funded primarily by government and from the late 1980s until 2009, was part-funded by the Horticultural Development Council and a small industry consortium, and led by Vicky Knight. A notable release during that period was the widely grown variety Octavia; a very late season summer-fruiting raspberry that extended oricane cropping into late July and August, bridging a gap in the English production season between the summer-fruiting and autumn primocane varieties that had previously been di cult to ll.

Private funding

Since 2009, the programme has been funded by private companies, many of whom have rst refusal on selections and named varieties that are released to the industry. Since 2012, Lubera Edibles has been our partner for the amateur market and with them we have bred varieties such as the purple-fruited Malling Passion. In 2015, the East Malling Rubus Breeding Consortium was set up to capitalise globally on NIAB’s long-term raspberry breeding on the site as well as work funded by East Malling Research and Lubera. The consortium is led by NIAB fruit breeder Feli Fernández and currently funded by Onubafruit (based in Huelva, Spain); Chambers, Berry Gardens Growers, Blaise Plants and NIAB (all UK-based), Lubera and Tobi (CH), Perfection Fresh (Australia) and The Greenery (NL).

The programme’s e orts are split between raspberry (65–70%) and blackberry (30–35%), although blackberry breeding, initiated only in 2018, is still in its infancy at East Malling. Key breeding objectives for raspberry include high fruit quality and shelf-life, high yield and fruit size, simple cane architecture with ease of picking, pest and disease resistance and environmental adaptation. A quarter of the programme is dedicated to oricane and primocane fruiting cultivars each and the remaining half to double cropping cultivars, including purple hybrids.

The most recent and successful primocane cultivars to be released include Malling Charm and Malling Bella.

Malling Charm

An early primocane-fruiting variety, but suited to cool climates and is not suitable for double cropping.

The berries are attractive, bright and pale red in colour, with excellent sweet, juicy avour. Berries are large with average weight of 6.7g. Growth habit is upright with well displayed fruit, allowing fast picking. No disease resistance has been tested to date, but no problems have been reported from trial sites so far.

Malling Bella

A mid-season primocane variety, which is well adapted to UK and southern European conditions. It is suited for double cropping and long-cane production. Berries are attractive, mid-red in colour with excellent avour and shelf-life. Mean berry weight is 7g and the fruit maintains good size throughout the season. Growth habit is upright, with well displayed fruits, allowing for rapid picking. Like Malling Charm, no problems with disease have been identi ed so far.

Malling Bella is proving very popular with Spanish growers and is also being grown in the UK by WB Chambers, a member of the funding consortium. It is increasingly being employed for long-cane production.