In 2004, the fifth year of this blueberry project, two aspects of the blueberry trials were considered; yield and temperature/moisture beneath the row covering. The plot at HRES had the highest yield which was 19.6 lbs per plant from Tiftblue on black row covering. The warmest temperatures at MTES occurred under the bare and white treatments and at both HRES and PES the warmest temperatures occurred under the black treatment. The highest soil moisture at MTES was for the bare treatment, at HRES it was the bare plus mulch treatment and at PES it occurred under the black teatment.

There is growing interest in producing blueberries across the state of Tennessee. Blueberry consumption has not been as high in Tennessee as in some northern states. However, with the influx of people from northern areas into Tennessee who bring with them a taste for blueberries as well Tennessee natives who are finding out about the many good qualitites of the blueberry that relate to health, the potential for increasing blueberry production is very good. Two of the basic types of blueberries are the Highbush and the Rabbiteye. Research was needed to evaluate at least one variety of each type and to evaluate various production systems for a period of five to ten years.

Blueberry plots have been placed at three different experiment stations representing different geographical regions of the state; Plateau Experiment Station (PES) in Crossville, the Highland Rim Experiment Station (HRES) in Springfield, and the Middle Tennessee Experiment Station (MTES) in Spring Hill. At each location there were four replications of five treatments (row coverings); bare, bare plus mulch, black, black plus mulch, and white. Two varieties were grown in each treatment; Bluecrop (highbush)and Tiftblue (rabbiteye) plus individual variety pollinators. Temperature and moisture were measured beneath the plastic at each location. Yield was determined by picking berries from two representative plants of each variety in each treatment in each of the replications.

YieldHRES - An average production from an established plant would be about 12 to 15 lbs per plant. These yield figures are for the second year of production. Due to problems with birds the are no yield for the Bluecrop variety at both HRES and at MTES. See Table 1 for yield by treatment at each location. Tiftblue had the following yields by treatment: bare - 5.2, bare plus mulch - 6.3, black - 15.9, black plus mulch - 14.3, and white - 7.3. Black and black plus mulch had the highest yields and were statistically the same while the remaining three had the lower yields and were all statistically the same.

MTES - Tiftblue had the following yields by treatment: bare - 7.7, bare plus mulch - 13.2, black - 19.6, black plus mulch - 19.1, and white - 11.1. Black and black plus mulch had the highest yields and were statistically the same. Bare had the lowest yield.

Table 1. Yield differences by treatment, variety and location - 2004

Note: Each column is a separate analysis, so letters cannot be compared between columns. Only within a column can letters be compared. Means within a column followed by the same letter are not significantly different at the 0.05 lever of probability, Duncan’s multiple range tests.

Temperature and Moisture

HRES - Averages temperature and moisture measurements took into consideration the primary growing season portion of the year (April through September). See Table 2 for temperature beneath row covering by treatment and location and Table 3 for moisture beneath row covering by treatment and location. The temperature results in Centigrade are as follows; bare - 23.4, bare plus mulch - 23.0, black - 24.0, black plus mulch - 23.1, and white - 23.2. All were statistically the same except black which was warmer than the rest. Soil moisture was measured in centibars or kilopascals of matric potential. The results were: bare - minus 144.7, bare plus mulch - minus134.4, black - minus 287.8, black plus mulch - minus 181.7, and white - minus 182.0. Black was the driest (the more negative the value the drier the soil).

MTES - The temperature results in Centigrade are as follows; bare - 23.9, bare plus mulch - 23.6, black - 23.0, black plus mulch - 23.1, and white - 23.9. All were statistically the same. The moisture results were: bare - minus 14.5, bare plus mulch - minus 24.3, black - minus 25.0, black plus mulch - minus 28.3, and white - minus 44.4. Bare was the most moist and black plus mulch was the driest.

PES - The temperature results in Centigrade are as follows; bare - 20.8, bare plus mulch - 20.8, black - 21.7, black plus mulch - 21.3, and white - 20.5. Black was slightly warmer than the rest. The results of soil moisture were: bare - minus 43.3, bare plus mulch - minus 19.6, black - minus 12.6, black plus mulch - minus 17.2, and white - minus 24.8. Bare was the driest. Black and black plus mulch were slightly wetter.

Table 2. Soil temperature beneath row covering in degrees C by treatment and location - 2004.

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Copyright © 1999 by The University of Tennessee. All rights reserved.

This research represents one season's data and does not constitute recommendations.  After sufficient data is collected over the appropriate number of seasons, final recommendations will be made through research and extension publications.