Researchers at East Malling have successfully produced the highest yields ever recorded from one of their everbearer strawberry varieties. In an experiment that began in May 2021 and has been running until recently, a single MallingTMChampion plant has produced more than 3kg of fruit, more than double the yield that is expected from typical everbearer plants.
Under normal autumn conditions, with decreasing daylength and temperature, flower and fruit production in everbearer strawberry varieties slows down rapidly in UK commercial production systems. The East Malling Strawberry breeders have long wondered just how much fruit their new varieties might produce if optimum light and temperature conditions could be maintained beyond the autumn, to allow for ongoing flower and fruit production.
In May 2021, Dr Mark Else and his Crop Science Team set up an experiment to investigate just that. They planted cold-stored mini-tray plants of the new everbearer MallingTM Champion into pots and held them in a ‘Total Controlled Environment Agriculture’ (TCEA) system for 12 months. This system is set up in a controlled growth room at East Malling and allows the team to maintain both optimal and constant light, temperature, and humidity conditions throughout this period. The precision irrigation system developed at East Malling was also used to match water and fertiliser demand with supply. The plants began cropping in August 2021 and have continued to crop through to May 2022 when they had reached their sixth fruiting flush.
Fruit size, yields and quality were recorded, and the two highest yielding plants have produced over 3kg/plant. The overall Class 1 yield per plant over the 50 plants in the experiment was recorded at 2.4kg, with the lowest yielding plant attaining 1.6kg. This variation in yield under optimal growing conditions is interesting the team and they are considering the reasons for the discrepancy and how they might ensure that plant quality is uniformly high enough in future to achieve the 3kg total yield from all plants.
Commenting on the results, Mark Else said, “We have for some time wanted to understand whether we could maintain growth and fruit production through the autumn, winter and spring months to increase total picked yields. This experiment has confirmed that we can do that by providing the optimum phytoclimate, leading to fantastic results in terms of yield and fruit quality. It demonstrates the huge yield potential and possible returns that can be achieved by commercial growers if the optimum conditions can be provided to the plants beyond the traditional growth period. We are now in discussion with companies interested in vertical farming systems who would like to work with us to utilise these approaches and harness new ways of achieving high and consistent berry production in commercial practice”
Mark is also interested in optimising the phytoclimate during the propagation phase of the plant’s production cycle. Optimising conditions during this phase is key to achieving the full yield potential of any variety, and TCEA systems offer the perfect opportunity to do this. Each aspect of the aerial and rhizosphere environments can be manipulated and optimised to achieve high-quality propagated plant material, which, in turn, will help to ensure that the full cropping potential of each variety is realised, be that in vertical farming, glasshouse or polytunnel production systems.
Senior breeder at The East Malling Strawberry Breeding Club (EMSBC), Adam Whitehouse, is also pleasantly surprised by these results. “The ability to produce high yielding everbearer lines has been a major aim of the EMSBC programme. Malling™ Champion, which was released from the EMSBC programme in 2019, has always shown strong generative characteristics, so it is especially pleasing to see this high yield potential being realised in a controlled environment production system at East Malling. Everbearing strawberries, such as Malling™ Champion, that have an extended production profile, combined with high yield and compact growth habit, appear to be well-suited to this type of production. The work carried out by Dr Mark Else and his team will help us to understand how the environment can influence the genetics we are producing at East Malling and aid us in identifying the type of traits that will be optimal for developing varieties for growing systems of the future”.