Climate-adapted raspberries and blackberries

The growing season started off very warm and sunny. Then it suddenly shifted to much colder temperatures and less sun. Such changes require rapid adaptation of growing conditions, as well as berry cultivars that are resilient to changing weather.

Now, researchers are collaborating with producers to find solutions for a more climate-adapted production of raspberries and blackberries, without compromising on berry taste. The aim is to extend the season by using plants ready to be harvested (‘long canes’) from June to October. This could increase the share of Norwegian-produced berries in the stores.

Dr Anita Sønsteby has 16 different varieties of raspberries and blackberries for testing at NIBIO Apelsvoll.

Climate change makes it timely to consider the possibility to grow the berry plants in pots and move them into plastic tunnels to gain better control over precipitation and temperature, thus achieving better control over yield and berry quality.

Researchers are testing various berry cultivars for taste and shelf life. They are also looking at how hot water vapor works as an alternative to pesticides and are testing alternative growing media that could eventually replace peat. However, there is one fundamental cultivation factor that Sønsteby emphasises as particularly important: the balance between water and nitrogen.

When it is hot and sunny, water frequently and reduce the amount of fertiliser dissolved in the water. If the weather turns cooler, water less often and increase the amount of fertiliser. It sounds simple, but it can be difficult to find the perfect balance that ensures good berry shelf life and taste throughout the entire season.

"The goal of the project is to find resilient berry cultivars that taste so good that you just have to buy another basket," says Sønsteby.