White (grey or tan) drupelets

In the last few days I have had several calls and emails from growers concerned about white drupelets. Here are a few points that I have gleaned from experience and other articles (see links at the end of the post).

• It is thought that this condition is caused by UV radiation and appears when there has been an sudden increase in temperatures.
• Rainfall appears to make the problem worse, with sunlight on wet berries plus high temperatures. (We have had quite a bit rain in parts of NC lately).
• This was thought to be a result of stinkbug damage many years ago. BUT not now.
• Apache shows more of this problem than any other variety, but white drupelets have been seen on most of the Arkansas varieties. 
• Tolerance for white drupelet varies to some extent by grower. Growers that ship berries have no tolerance, while pick-your-own growers can tolerate a few white drupelets (see last point, educate your clientele).
• White drupelet disorder is usually a problem early in the season and then disappears.
• The berries are still edible, they make delicious pies, juice, ice cream...

For more information see

http://plantpathology.uark.edu/Number_15-2010.pdf

and

http://www.raspberryblackberry.com/Webdocs/nabga08-06news.pdf

Rotating Cross Arm Trellis

RCA trellis with young untrained canes at Piedmont Research Station, 2011.

At our Piedmont Research Station, in Salisbury NC, we (Gina Fernandez and Penny Perkins-Veazie) have started evaluating the Rotating Cross Arm Trellis system. This project is in cooperation with Dr. Fumi Takeda, USDA-ARS. Dr. Takeda has been working on this system for many years and is helping us train and manage the canes on this trellis.

This year we are determining if row orientation will impact blackberry fruit quality. Row are orientated N-S and E-W. The set in the foreground is running  E-W while the second set of trellises in the background of this image runs N-S. We will be collecting yield data and post harvest attributes. We think that this type of trellis may improve fruit quality and yield.

This trellis system also has potential to enable growers to cover the plants in the winter or during spring frosts like the one we had this year. The trellis arms rotate, so the canes can be layed down and row covers could be placed over the trellis to protect the plants, similar to what is done in strawberries. Here is a picture of a field with the RCA in Ohio in the summer and winter.

The trellis was donated by Trellis Growing Systems (http://trellisgrowingsystems.com/).