Organic production systems in Northern highbush blueberries

The production of highbush blueberries is increasing worldwide. Organic production of blueberries in Sweden is presently very limited but is expected to have a great potential to expand as the berries are popular and have a good shelf life. The fact that blueberries require acid soils raises several questions concerning suitable substrates in combination with mycorrhizal inoculation and fertilization in organic production systems. Field and pot experiments have been established during 2011 and 2012 with the aim of developing a sustainable production system for high quality organic blueberries. After the second experimental year, total fruit yields were similar for plants grown in a plastic tunnel and in the open field. Yields were not affected by the addition of 10% forest soil to the peat-based substrate. Inoculation with ericoid mycorrhizal fungi had little effect on shoot length in a greenhouse pot experiment. Blueberries may be particularly suitable for organic production as the need for fertilizers is low combined with a relatively low disease pressure on the blueberry crop in the Nordic countries. The Swedish blueberry production might be expected to expand in the near future. The development of a successful and resource-efficient growing system for organic blueberries may encourage new blueberry growers to chose organic production.