"Many strawberry plant seedlings are unfortunately lost before they reach the planting out stage, this will help fruit growers reduce waste in the very early stages of plant growth," says Lily Manzoni, Head of R&D at LettUs Grow.
A large portion of LettUs Grow's work is dedicated to exploring the potential of controlled environment agriculture beyond growing herbs, salads, and leafy greens. Using aeroponic technology at key stages of plant development, particularly during propagation phases, can potentially increase the productivity, efficiency, and sustainability of the growth cycles for many different plants. During this set of trials, they explored propagating strawberries in an aeroponic indoor farm.
Problems with growing the UK's favorite fruit
Approximately 85% of UK-grown strawberries are grown from imported plants. The UK imports ~£180 million of strawberries every year, which accounts for 32% of the market. The overall quality and consistency of propagated plant material is not always high - and plant health or stability results in a large amount of plant waste and money lost. Therefore, propagating in the UK could reduce food miles and produce better quality plants for growers more sustainably by using aeroponics.
"We would recommend using aeroponic irrigation in vertical farming for the initial stages of growth, from germination to seedling. At this point in the life cycle, you will be able to develop tissue culture, plant tips, and healthy root structures much faster as they are exposed to a higher volume of oxygen. Once the crops mature to the plant stage, they can either remain in the vertical farm set-up for pollination or be planted out into greenhouse, polytunnel, or outdoor environments," says Andrew Worrall, Head Grower at LettUs Grow.
Why aeroponics and strawberries?
At LettUs Grow, the team always adopts aeroponics, as they believe it boosts plant yields and growth rates by allowing plant roots to access high oxygen levels, which helps them to grow healthier and faster. Using aeroponics at key stages within the strawberry growth cycle, they look to demonstrate that this method could reduce waste and increase profit margins for strawberry growers.
There are different developmental stages when it comes to growing strawberries. You begin with a tissue culture mother plant, which grows until it produces runners. These then produce daughters, also known as tips. These tips then go on to become plants that will grow the fruit.
It usually takes 4-6 weeks for tissue culture to produce tips, so the first aim of the trial was to reduce this time. The second aim was to reduce plant loss, which can be as high as 20-30% when using traditional methods. Using aeroponics, plant loss was reduced to 5%, and the growing period was reduced to 2 weeks.
During the second stage, a tip will traditionally take between 5-6 months to become an established strawberry plant. Using aeroponics, this growing period was reduced to 5 weeks. The strawberry plants in their aeroponic system also remained free from rust and white fly - diseases typical in strawberry plants - and the nutritional value of the plant was high.
Choosing the right tech for the right stage
It's at this stage we would recommend the strawberry plant be transferred, whether that be outside or to a polytunnel or greenhouse, to operate at maximum efficiency, both energy and cost-wise. This is because controlled environment agriculture is not always appropriate throughout the entire growth cycle - it makes the most sense to utilize it at specific stages.
Commenting on the results, Nick Green, Head of Commercial at LettUs Grow, shared that it's an exciting time at LettUs Grow, where the team has proven that aeroponic irrigation can be harnessed to have a profoundly positive impact in the growth cycle of fruiting crops. "The next stage for us is to expand our research with grower partnerships, who also face similar challenges with crops beyond leafy greens and herbs. We aim to continue to support growers from across the industry in their quest to respond to the ever-increasing challenges they face in growing food. This is about rising to the real challenge that growers face today. We're working on several projects at the moment, so keep an eye out."