A DC electromagnet is simply a coil of wire connected to a DC voltage source. It can have an air core or an iron core.
Northern Highbush Varieties. High Chill Varieties. Northern Highbush varieties are the most widely planted blueberries in the world. They grow best in temperate climates where total winter chilling is 1,000 hours or more.Except where listed, most Northern Highbush varieties are relatively self-fertile.orthland is the one of the most cold-hardy Highbush varieties. It is vigorous, easy to grow and adaptable to different soil types and conditions. Northland yields are heavy and the berries are sweet with high sugar content.
The bushes can grow up to 12 feet tall, but most peak at about 6 feet. In the spring, clusters of beautiful white blossoms pop up all over the bushes and are pollinated by bees. Each blossom eventually becomes one blueberry â first hard and green, then reddish-purple, and finally blue, sweet and ready to eat!or the fresh market, blueberries are mainly picked by hand, but some are gathered with large harvesting machines that move slowly along the rows of blueberry plants and gently shake each one so ripe berries fall into a catching frame. (Most machine-harvested berries are washed, frozen and sold in stores year-round.).