Finding out about fruit: Fera team visits NIAB East Malling

This spring we were lucky enough to get additional funding from UKRI to enable some of our researchers to go on placements to different work environments to learn skills and build relationships. We’ll be sharing reports from all of the placements. Our third report is from three members of the Xanthomonas Threats project, Joana Vicente, Jenny Cole and Andy Aspin (all Fera), who visited NIAB’s East Malling site in Kent. Here they report on their visit.

We were hosted by Scott Raffle, NIAB Knowledge Exchange Manager, who has a vast experience in connecting research and industry having previously worked for ADAS and AHDB. Scott outlined the history of the site at East Malling, stressing the importance of the breeding work developed over the years, especially the world-famous apple rootstocks. NIAB now has a range of projects at East Malling in partnership with Greenwich University and many industrial partners. Part of the Pseudomonas-Prunus project is also based at East Malling.

Strawberry breeding has been a very successful activity on the site since the early 80s. We visited the glasshouses and talked with strawberry breeder Abigail Johnson. Their breeding plans have to be regularly reviewed and adapted to a fast-growing industry. This might require selecting plants adapted to tunnel production or different substrates, or plants that can extend the season or bridge gaps between existing varieties. The breeding programme always starts with a large number of unique plants. It can take at least 8 years and many rounds of selection and trials to develop a new variety. There are several successful varieties that have been developed at East Malling recently, including the very popular MallingTM Centenary, but also other MallingTM varieties like Ace, Allure, Champion, Supreme and others.

Disease resistance is also important for the breeding programmes. Some problems tend to be easier to control in plants grown on modern table-top systems rather than in soil. On the other hand, in some European countries, growing strawberries in soil is still common so breeding for those conditions is still relevant. Some European growers might also be slowly shifting to tunnels after some years of challenging hot and dry weather.

Despite an outbreak of angular leaf spot caused by Xanthomonas fragariae five years ago in the UK, this disease has not been a problem of late. The disease has been reported in many strawberry producing countries including several European countries like France, Belgium, Germany, Netherlands, Italy, Portugal and Switzerland. The status of angular leaf spot disease in the UK is uncertain. If it is not present in the UK, it could change from a Regulated Non-Quarantine Pest (RNQP) to a Quarantine pest. Some growers would like to see it completely deregulated. All these options would then have an impact on actions taken by Defra if the disease was ever detected on imported plants. On the other hand, if the UK was able to declare that it was free of angular leaf spot it might make exporting British strawberries easier.

Another species of Xanthomonas, X. arboricola pv. fragariae has been reported as causing bacterial leaf blight of strawberries in Italy and subsequently in Turkey, but this seems to only be in very particular hot and humid conditions and the virulence of the strains remain unclear. The work of the Xanthomonas Threats project includes screening popular varieties of strawberry, and the results could be interesting for selection of breeding lines that are more resistant or tolerant to angular leaf spot.

We then had a conversation with Felicidad Fernandez-Fernandez about raspberry and blackberry breeding. One common problem that has been highlighted recently by breeders and seed producers, is the difficulty of exchanging materials for field trials with international partners. The requirements for phytosanitary certificates are very complex and it can take over a year to obtain all the results necessary.

We visited the impressive new growth rooms and glasshouses where a range of projects linked to industry are being developed. Scott then took us to visit The Water Efficient Technologies (WET) Centre. This is important for the soft fruit sector as it demonstrates efficient technologies and best practice for strawberry and raspberry production in tunnels. The latest strawberry varieties are grown at the Centre so that growers and researchers can make comparisons of fruit yield and quality.

The UK fruit industry is struggling following some difficult years with rapidly increasing costs and declining returns to growers. However the vine and wine industry is flourishing in England, and NIAB has planted new research vineyards and has a brand-new winery building where their first wines will be produced from September this year. This increase in vineyards in the UK is a very important development. Xylella fastidiosa remains a big threat for a range of UK crops and this includes grapevines. The management of weeds and the insects that can transmit the disease might be needed if it was ever introduced. As with a range of other plants and trees, the main message is ‘Don’t risk it!’ and plants should be tested before being imported to avoid introducing Xylella.

Our visit to East Malling was extremely valuable as the links with the strawberry breeders and the fruit and wine industry are important for diagnostic and research projects that are run at Fera including the Xanthomonas Threats project. We thank everyone at East Malling and especially Scott Raffle, Abigail Johnson and Felicidad Fernández-Fernández for the insights into their work.