Today I would like to let you know about a relatively new introduction in the blackberry world. According to an April 2004 news release, The University of Arkansas Division of Agriculture has released the world’s first commercial primocane-fruiting blackberries. These will be the equivalent of Heritage, currently the most popular fall-fruiting red raspberry.

"Prime-Jim™" and "Prime-Jan™" are the names given to these primocane-fruiting blackberries. All other blackberries grow one year and fruit the next. These new blackberries produce berries on both types of fruiting wood. Harvest is usually in early June in Arkansas and then the primocanes start producing fruit beginning in mid-July. Fruit production will then continue until frost.

These two new varieties may allow more blackberry production in Michigan. The reason being that with primocane-fruiting, they avoid our cold winter climate. You can just mow them off after the winter and not worry about winter injury. However, these two have not been fully tested in Southwest Michigan.

Prime-Jim™ and Prime-Jan™ are named after Dr. James N. Moore, who founded the University of Arkansas fruit breeding program, and his wife, Janita.

They produce good quality fruit up to 5 times larger than wild blackberries. Size is about an inch in length and about one-half inch in diameter. Cooler regions have been found to produce bigger berries.

The two drawbacks to Prime-Jim™ and Prime-Jan™ are thorns and poor shipping ability. This might limit the commercial appeal; however, this could be a plus for pick-your-own establishments or home gardens.

Prime-Jim™ and Prime-Jan™ have been made available to licensed propagators and should be available from nurseries now.

Repeating, the University of Arkansas has developed two new fall-bearing blackberry varieties. These would be ideal for the homeowner and pick-your-own farm. Look in the nursery catalogs for Prime-Jim™ and Prime-Jan™.

That is all for today. This has been Al Gaus for Michigan State University Extension in Berrien County.