RCA trellis with covers

RCA trellis with rowcover, Piedmont Research Station, Salisbury, NC. Photo: K. Snider. 

Blackberry canes with emerged buds, under rowcovers. Photo: K. Snider. 

At the Piedmont Research Station in Salisbury, NC, we have a set of four RCA trellises oriented  North/South and East/West. The primary objective of this project is to evaluate attributes of fresh blackberry fruit. We are most interested in the level of sun scald based injury to fruit based on canopy orientation.

However, the RCA trellis is used in colder regions of the country as a way to grow varieties that are not cold hardy. In North Carolina, twice in the past decade, we have experienced low temperatures (8 April 2007 and 12 April 2012)  that have resulted in significant crop loss. Developing flower buds and therefore the blackberry crop were killed by late season frost/freeze events. So, we are looking at this trellis system as an option for protection from cold in NC.

Temperatures at the Piedmont Research Station in Salisbury, NC, for the have been cold, 20F on 21 March. We had emerged buds so we protected blackberry plants under rowcovers. Although the buds would likely have survived, we wanted to protect them, just in case. We have data loggers recording temperatures under the covers and will download them next time we get to the field and update this post to include those temperatures.

Rotating Cross Arm Trellis August update

Figure 1. Rotating cross arm trellis in August.

Earlier this spring, I posted a picture of a new trellis we are trialing at one of our research stations (http://teamrubus.blogspot.com/2012/05/rotating-cross-arm-trellis.html). Above is a picture taken on August 22, 2012.  We have 3 cultivars on each section of this trellis, Apache, Ouachita and Von (aka NC430).

Figure 2. Training of primocanes on wire. 

The second and third images show how we trained the primocanes to the bottom wire as they emerged from the crown. The canes were tied to the low horizontal wire. This encouraged buds that were on the horizontal wire to start growing. These secondary buds will produce canes that are very productive and are easier to train to the trellis because they are narrower. Fumi Takeda has done some very nice work describing the productivity of the buds in this paper. Here is a link to a summary of this work.
http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=281491

Image 3. Close-up of training of primocanes on the horizontal wire. Photo: Fumi Takeda. 

To get the entire article, you will need to become a member of NARBA. (http://www.raspberryblackberry.org/subtopics.cfm?topic=Membership)

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/).