Whether they’re being used as a welcome addition to a soporific muffin or a healthy topping for a warm bowl of porridge, winter sees UK consumers swipe blueberries and raspberries off the shelves just as eagerly as in summer. To safeguard their UK production, a handful of Innovate UK-sponsored and fresh produce industry-backed projects are underway at The James Hutton Institute (JHI) in Dundee to better understand how these crops grow. Produce Business UK finds out more from Dr Julie Graham, a soft fruit geneticist at the Scottish institute
Blueberry biochemistry
Fresh produce buyers are fully aware of the need to provide modern day consumers with a continuous supply of nutritious berries. Just this month Waitrose has experienced a 33% rise in weekly raspberry sales and 22% hike for blueberries as healthy eating resumed during the first week of the new year.
What buyers may not realise, however, is there’s still a great deal about these popular crops that growers do not fully comprehend. Blueberry yields in the UK, for instance, mysteriously vary greatly from season to season, while some raspberry varieties seemingly stand up better to disease and drought than others.
Although berry crops are understandably best known as “summer fruits”, the bushy plants grown in the UK must also endure erratic British winters. One Innovate UK project, whose consortium members include the upmarket retailer Marks & Spencer (M&S) and soft growers S&A Produce, Castleton Farm and Thomas Thomson, is therefore examining how these plants behave during all seasons, including the chillier time of year.
The JHI team hopes that by gaining a better understanding of plant behaviour it can start solving the mystery of yield instability in blueberries. Dr Graham explains: “Yield is probably determined before you get the crop – it could just be that the plant doesn’t get what it needs before the winter.
“At the moment, every couple of weeks, we go outside and we cut down the blueberry canes of a whole host of varieties. We want to understand what happens to their biochemistry during winter when the temperature drops. We are cutting the canes and analysing substances like sugar and carbon. We are seeing this change over winter so that we can get a handle on how the biochemistry of the plant behaves.”
Genotyping blueberries
Another Innovate UK project, whose consortium members include S&A Produce and Total Worldfresh, is seeking to gain a better understanding of blueberry DNA by developing a genotyping-by-sequencing map.
This “map” will help the JHI team to identify the genetic markers responsible for desirable traits in the plants, such as early or late ripening and the ability to adapt to certain climates. The information can then be used in marker-assisted breeding programmes. Already, the researchers are establishing pre-breeding populations that will be used to produce new blueberry cultivars.
“We traditionally use [fruit] populations that come in from Michigan State [in the US] but as time has gone on we have realised that these are not suitable for the UK climate,” notes Dr Graham. “We need to develop a new population from parents that are suited to the UK. Once we know what’s happening with yields we will apply that [data] to the mapping tool. We will make the new map and tie in the data we’ve developed.”
Dr Graham claims she is “very hopeful” this research on blueberry crops will make a big difference to the UK industry. “Because of climate change this is really important,” she notes. “We are already seeing the effects of this on blackcurrants’ bud break.”
An early warning system
Visitors to JHI this spring may also spot an unusual looking machine amongst its fields of blueberry and raspberry plants. This is because a unique, portable, sensing system is due to be trialled outdoors for the first time this year.
The system combines data from several types of cameras – including a thermal camera, a short wave infrared (SWIR) camera, plus a visible and near infrared (VNIR) camera. It is helping to detect different kinds of stresses in raspberry and blueberry plants.
If the team can get it right, it’s hoped this type of technology could be used as an early warning system to alert soft fruit growers to initial signs of trouble in their crops.
Dr Graham says: “We want to see under very controlled conditions if we can pick up all of the individual stresses, as well as combined stresses. So, in the glasshouse we have three water treatments [including a “drought” and an “over-watered” treatment], as well as a vine weevil and root rot (phytophthora) treatment.
“We are using a mounted platform to run the cameras alongside the plants. It’s a completely non-disruptive way of imaging the plant. It’s a really good project but a lot of work. We have actually employed a physicist who used to work on imaging eyes as no one knew how to combine the different types of data coming off the different imaging platforms.”
According to Dr Graham, the system could help shed some light on the relationship between water use efficiency and fruit yield and quality. Another aim is to explore the relationship between water usage and pest and disease susceptibility.
“Can we find ways of really seeing which plants are more resilient to stress?,” she asks. “We can then come to the genetics behind it. But, from a grower’s point of view, if we have an early warning system that can help them as well. When we have a handle on it from the glasshouse it will be easier to know what we are looking at in the field.”
Consortium members for this particular Innovate UK project include Thomas Thomson, Total Worldfresh and M&S. The fact that leading representatives from different areas of UK’s fresh produce supply chain are coming together to support these initiatives illustrates just how important it is to ensure a stable supply of our favourite berries. Thanks to the ingenuity of researchers at JHI, the UK’s soft fruit industry looks set to enjoy a stable future.
