Feasibility of Shift Trellis Use for Northeastern Blackberry Production

2012 Annual Report for FNE11-706

Project Type: Farmer
Funds awarded in 2011: $3,318.00
Projected End Date: 12/31/2014
Region: Northeast
State: Pennsylvania
Project Leader:
Roy Brubaker
Village Acres

Feasibility of Shift Trellis Use for Northeastern Blackberry Production


In our project we are testing the feasibility of shift-trellis systems for blackberry production against conventional trellises by measuring fruit yield, quality, and harvesting efficiency over the first three years of production of a new blackberry planting.

In 2012, our Blackberry trellising project started by pruning back all four rows of blackberries and shifting the shift trellises back into the horizontal position in January of 2012, immediately after applying compost and mulch (Figures 1-5). Throughout the spring and early summer, time was spent training new canes to the trellis, and heading back canes to encourage branching of blackberries in both trellising systems. In late May, we shifted the shift trellis into the vertical position, after blossom but before the berries were set.

Throughout the harvest season, records of yields and harvest times were kept for each type of trellis system. This data will be summarized later in this report and will also be incorporated with subsequent years’ data to show a multi-year comparison of these trellising systems.


Our 2012 blackberry harvest showed a marked increase in production from 2011 and a first year to get real data to compare a shift-trellis system to a conventional vee trellis system of blackberry production. Between June 28th and August 10th we harvested 126.8 flats (1714 half pints) of blackberries from our 4 rows of Kiowa Blackberries. Sixty-three percent of these blackberries (1084.5 half pints) were harvested from the 2 rows that are shift trellised compared with the 37% (629.50 half pints) that were harvested from the 2 rows trellised with a standard vee trellis system (see Charts 1 and 2).

In addition to comparing yields from the two types of trellises, we kept record of berry quality from each type of trellis system. Of the berries harvested from the shift trellis 11% were considered 2nd quality and from the standard vee trellis, 14% were considered 2nd quality. (Chart 3)

The third parameter we measured was harvest time for each type of trellis system. Chart 4 shows a graph plotting the Number of Minutes per half pint unit throughout the harvest season for both trellis system. The shift trellis shows a harvest time advantage with an average of 2.07 minutes needed to fill a half pint container versus the 2.95 minutes required when picking from berries trellised in a standard vee trellis.

While the data collected this season points towards shift trellising as having some advantage over conventional vee trellising for increased yield, and decreased harvest time, we know that more extensive data is needed. Given the varying degree of experience and speed of our pickers, there is a great margin of error surrounding the harvest time and yield (if a picker is not being thorough).

Also one of our concerns regarding shift trellising is the large number of thick (apparently healthy) canes that break in the process of shifting the trellis from the horizontal to vertical position (see Figure 5). We are curious to find ways to minimize cane loss in this process as it seems yields from the shift trellis could be even higher if we could minimize damage in the shifting process. We also have been recording our time for triming/pruning blackberries in each trellising system. Chart 5 shows time comparison for non-harvest time inputs in this past year.

While a majority of the cooperators in this project remain the same, this year Debra Brubaker, daughter of Roy Brubaker and new business partner has stepped in to help with this Blackberry trellising project. Debra has taken over the responsibilities of Dave Ruggiero, who is no longer working at the farm, helping with record keeping and report writing. Roy Brubaker and Steve Freed continue to be involved with much of the maintenance of the blackberries and also help to lead the harvest. Kathy Demchak of Penn State Extension continues to serve as a technical advisor on this project.


Debra Brubaker

[email protected]
Village Acres
229 Cuba Mills Road
Mifflintown, PA 17059
Office Phone: 7173484916
Kathy Demchak

[email protected]
Senior Extension Associate
Penn State University
107A Tyson Building
University Park, PA 16802
Office Phone: 8148632303