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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Production and Genetic Improvement Research Unit » Research » Research Project #444958

Research Project: Impact of Primocane Management and Plant Spacing on Planting Performance and Economic Returns of 'Columbia Star' Blackberry

Location: Horticultural Crops Production and Genetic Improvement Research Unit

Project Number: 2072-21000-060-009-G
Project Type: Grant

Start Date: May 1, 2023
End Date: Oct 31, 2024

Determine the impact of plant spacing, primocane management and pruning/training treatments on growth, yield, fruit quality, and labor costs for machine-harvested 'Columbia Star'.

The goal of this project is to continue the work we started in our previous NCSFR funded study from 2019-2021. Prior funding was used to establish the trial and collect preliminary data on plant growth and yield components. The planting design is a split-split plot with in-row spacing (5 ft vs 2.5 ft) as the main plot effect (whole rows), pruning/training treatment (Aug-trained vs. new-over-old) as sub- plots (half rows) and primocane suppression (with or without) as sub-sub plots. There are four replicates of each treatment (32 plots). Each experimental plot is 20 ft long with plots separated by 10 ft of un-planted row space, to allow for clearing of fruit from the machine harvester before moving to the next plot. Rows are spaced 10 ft apart. Aisles are being maintained with bare soil using tillage and herbicides as necessary. The planting is flanked by guard rows. Irrigation and fertilization are by drip irrigation. Five additional rows (which include plots with weighing lysimeters) are located in the middle of this planting to study deficit irrigation practices. The planting is a total of 0.38 acres. Data will be collected on: length of primocanes when suppressed and at the end of the season during training time; machine-harvested yield, losses on ground (fruit drop collected and weighed per 3 ft in middle of plot), fruiting season, cull weight, and average berry weight; biomass of floricanes at caning out, floricane length, percent bud break, lateral length, and fruit/lateral (Aug-trained only); harvest contaminants (collect any contaminants present after the machine’s blower fan, per standard commercial harvest); assess and rate incidence of cold injury, cane disease, and insect presence in the field; and record labor hours required for all primocane management and suppression treatments. Data will be analyzed per split-split-plot design and will be presented to research colleagues and to industry in articles, oral presentations and journal papers.