For the first time in 2023, we are growing the new everbearer strawberry MallingTM Ace. The WET Centre has allowed NIAB to experiment with, and demonstrate, the performance of its newly released varieties, and the work at the Centre has included the Junebearer MallingTM Centenary, and more recently the everbearer MallingTM Champion.
MallingTM Ace offers a higher yield and quality compared to MallingTM Champion, with the added advantage of larger berries and crown rot resistance. However, it is susceptible to powdery mildew, so growing it at the WET Centre will allow us to reassure growers that if powdery mildew can be controlled satisfactorily with optimal husbandry and agronomy, its potential is enormous.
MallingTM Ace is being grown at a lower density than MallingTM Champion, and has been planted at six plants per linear metre, with increased spacing, to allow for improved air circulation to reduce the risk of mildew infection. There will also be a comparison of five versus seven drippers per bag this year, which will allow us to compare the water distribution in the bag and assess the effect of higher numbers of drippers on water use efficiency and cropping potential. In theory, more points of application should give more even application, but the variation in bag moisture content will guide us on the merits of this.
In our raspberry tunnels, we are working with Netafim to compare the use of their new ‘Netbow’ irrigation delivery system in MallingTM Bella raspberry, compared to two standard drippers per pot.
In 2022, we employed a raspberry nitrogen demand model that had been developed by NIAB to compare the use of a standard grower feed recipe with a reduced nitrogen recipe which followed the nitrogen demand model. This led to a reduction of more than 50% of the nitrogen used in the standard recipe, although by the end of the season, there was a slight reduction in marketable yield.
The original model had been developed using different glasshouse-grown crops overseas and the generic crop coefficients embedded in the model were not found to be accurate enough for raspberry production in the UK, so NIAB are developing specific crop coefficients for raspberry and are repeating the exercise in 2023 for MallingTM Bella.