Orchard pruning for cider apple production

Orchard pruning for cider apple production

Summary

Hard cider production has increased dramatically in the U.S. in recent years with an annualized growth rate of 50% between 2009 and 2014 and revenues totaling $292.5 million in 2014. In Vermont, orchards are being managed specifically to provide fruit to this expanding market, but prices paid for processing fruit remain below those for fresh market apples. In order to meet demands for fruit supply at lower price points, growers must adapt management to reduce inputs and labor without compromising crop yield or quality.

This project seeks to evaluate reduced-labor practices that may improve profitability of cider apple production in Vermont. In two Vermont orchards, mature ‘McIntosh’ or ‘Empire’ trees will receive four pruning treatments: (1) ‘commercial’ dormant pruning with no summer pruning; (2) commercial pruning followed by summer pruning; (3) ‘light’ dormant pruning with no summer pruning; and (4) light pruning followed by summer pruning. Standard measurements for labor hours, sunlight interception, crop yield, and juice quality will be collected and analyzed to determine potential profitability of each system.

The first season of field activities has been completed. UVM staff completed most activities except for dormant winter pruning and fruit harvest which were performed by the grower participant. Sample fruit were juiced at harvest, and chemical analysis of juice will be completed in January 2017. All activities will be repeated for a second season in 2017.

Objectives/Performance Targets

Project work was conducted in two orchards in Addison and Chittenden Counties, VT during the 2016 growing season. Treatments were applied to established ‘McIntosh’ trees on M.26 rootstock (New Haven) or ‘Empire’ trees on Mark rootstock (South Burlington) and trained to a freestanding central leader system. Treatments included: (1) ‘commercial’ dormant pruning (standard pruning intensity used in commercial production (Bound and Summers, 2001))with no summer pruning; (2) commercial pruning followed by summer pruning; (3) ‘light’ dormant pruning with no summer pruning; and (4) light pruning followed by summer pruning.

In the South Burlington orchard, the four pruning treatments were applied in a completely randomized design with six single-tree replications per treatment. The New Haven orchard was set up in a randomized complete blocks design, with six single-tree replications per treatment.

Dormant pruning was performed mid-March (March 19^th), and summer pruning in early-August (Aug-4) prior to harvest. All treatments will be applied to the same trees in the following season.

For each treatment-replicate, data was collected for: time to perform pruning, total crop yield (kg/tree) including dropped and harvested fruit, and photosynthetically active radiation (PAR) within the canopy following modified standard protocols (Hampson et al., 2002). Pruning time data for New Haven was collected by the grower participant’s workers, and was incomplete for 2017. Thus, pruning labor costs will be extrapolated from limited data collected in 2016 and additional data collected in 2017.

Modifications for measuring PAR included time of day and full light readings that were taken before each tree was measured. Light measurements within the canopy were taken at the north, south, east, and west sides of the tree. At each side of the tree measurements were taken at the trunk, 1 meter (m), 1.5m, and 2m from the trunk in the horizontal plane. Vertical light measurements were taken 1m, 2m, 3m, and 4m from the ground.  No light reading was made if no tree canopy was above the sensor.

At harvest, a randomly selected sample of 25 fruit per treatment-replicate (tree) was collected and assessed for fruit size, color, general defects, and USDA grade distribution (Bradshaw et al., 2016). In addition, a sub-sample of ten fruit was selected for grading will be analyzed for juice quality parameters including pH, titratable acidity, total phenolics, and soluble solids using standard protocols (Miles and King, 2014). Data will be subjected to analysis of variance (ANOVA) procedures by pruning treatment and orchard site (SAS Institute Inc., 2002-2010).

In addition, pruning time will be extrapolated to cost per acre and evaluated against potential orchard profitability per acre based on fruit grade distribution and annually published prices paid for fresh market and cider apples in Vermont (NASS, 2014).

Bound, S., and Summers, C. (2001). The Effect of Pruning Level and Timing on Fruit Quality in RedFuji’Apple. Acta Horticulturae 557, 295-302.

Bradshaw, T., Parsons, R., Berkett, L., Darby, H., Moran, R., Garcia, E., Kingsley-Richards, S., Griffith, M., Bosworth, S., and Gorres, J. (2016). Long-term economic evaluation of five cultivars in two organic apple orchard systems in Vermont, USA, 2006-2013. Acta Hort 1137, 315-322.

Hampson, C.R., Quamme, H.A., and Brownlee, R.T. (2002). Canopy growth, yield, and fruit quality of ‘Royal Gala’ apple trees grown for eight years in five tree training systems. HortScience 37, 627-631.

Miles, C.A., and King, J. (2014). Yield, Labor, and Fruit and Juice Quality Characteristics of Machine and Hand-harvested ‘Brown Snout’ Specialty Cider Apple. HortTechnology 24, 519-526.

NASS (2014). Annual Bulletin, New England Agricultural Statistics, 2013, G.R. Keough, ed. (Concord, NH: New England Agricultural Statistics ), pp. 61-64.

SAS Institute Inc. (2002-2010). SAS 9.3 (Cary, NC).

Accomplishments/Milestones

Because apples are a perennial plant on which fruit buds are formed in one year which determine the potential crop yield in the following year, the project will be conducted over two growing seasons in order to assess cumulative effects of pruning practices over multiple years. Project activities will occur according to the following timeline. All activities will be performed by the principal investigator unless referenced otherwise.

Winter 2015-2016:           Developed treatment randomization scheme in test orchards. Applied pruning treatments in March. Per-tree pruning time data was incomplete as collected by cooperator laborers, and final economic extrapolation

April-August 2016:            Applied standard orchard management practices (pest management, fertility, crop thinning) equally to all study trees.

August 2016:                     Summer pruned appropriate treatments. Collected PAR measurements after summer pruning.

September 2016:              Harvested fruit and collected yield data. Graded fruit to USDA standards, and extracted juice and froze for later assessment.

January 2017:                    Juice chemistry quality parameters will be evaluated. First year data analysis and summary will be completed.

February 2017:                  Present preliminary project results at national (U.S. Association of Cider Makers Annual Conference, Chicago, IL) and regional (UVM Apple Program & Vermont Tree Fruit Growers Association Annual Meeting, Middlebury, VT) stakeholder educational meetings.

2017:                                   Repeat 2016 protocols.

Winter 2017-2018:           Analyze and summarize data, present at stakeholder meetings, publish results in peer-reviewed journal. Survey growers at annual meeting of the Vermont Tree Fruit Growers Association to assess changes in management including pruning intensity to evaluate the impact of this research on changes in practice.

Impacts and Contributions/Outcomes

Project impacts will be evaluated following data analysis and collection of grower surveys.

Collaborators: