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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #317999

Title: Root production, distribution, and turnover in conventional and organic northern highbush blueberry systems

item VALENZUELA-ESTRADA, LUIS - Oregon State University
item VARGAS, OSCAR - Oregon State University
item Bryla, David

Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 6/1/2015
Publication Date: 8/4/2015
Citation: Valenzuela-Estrada, L.R., Vargas, O.L., Bryla, D.R. 2015. Root production, distribution, and turnover in conventional and organic northern highbush blueberry systems. HortScience. Abstract 70.

Interpretive Summary:

Technical Abstract: Northern highbush blueberry is a shallow-rooted crop with very fine, fibrous roots. Recently, we installed minirhizotrons (root observation tubes) in a conventional and an organic blueberry planting in western Oregon. We wanted to know exactly when and where new roots were being produced and determine whether different fertilizer and weed management practices were affecting root production and turnover. At both sites, root production peaked once in mid- to late May, about a month prior to harvest, and again in September, about a month before dormancy each year. Most roots were located < 30 cm deep and averaged only 20–75 micrometers in diameter. In general, plants produced more roots in raised beds than in flat ground, with sawdust mulch than with weed mat, with granular fertilizer than with fertigation, and with no or lower rates than with higher rates of fertilizer. Plants on raised beds and grown with no or low rates of fertilizer also produced deeper roots. The average median lifespan of the fine roots was 115–135 days, but roots survived an average of 60 days longer with fertigation than with granular fertilizer. Overall, timing of root production in blueberry appears to be highly dependent on temperature, shoot growth, and fruit development, while total root production and lifespan are mostly affected by availability of soil water and nutrients. Practices such as raised beds, sawdust mulch, and reduced fertilizer rates can be used to increase root production, while fertigation may reduce plant carbon costs associated with root turnover.