James B. Wills, Gary Honea, Allan Straw, Charles A. Mullins,

David Lockwood, Dennis Deyton

In the first year when the plants were getting established, mortality was greatest for plants grown on the bare ground and bare ground with mulch.

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 as 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.

Two varieties of blueberries were selected for the trial that were expected to do well in Tennessee. The Rabbiteye variety selected was Tiftblue and the Highbush variety was Bluecrop. The Bluecrop plants were obtained from a Michigan nursery and had a ball root system. Its selected pollinator was Centura. The Tiftblue were obtained from a nursery in North Carolina and were bare root. Its selected pollinator was Duke. The experimental design was randomized complete block with a split plot factorial arrangement of treatments. There were five treatments: raised bed with no mulch, raised bed with sawdust mulch, raised bed with black woven polyethylene ground cover, raised bed with black woven polyethylene ground cover and sawdust mulch over the black woven polyethylene ground cover, and raised bed with black woven polyethylene ground cover painted white. All treatments were on raised six inch beds four to five feet wide with trickle irrigation and the capability to fertigate through that irrigation system. The five treatments were replicated four times. Pollinators were placed in border rows on each side of the plots, at one end of each treatment row and approximately midway down the row of each treatment. Each treatment row consisted of five plants of each variety and two pollinators for a total of 12 plants. Research blueberry plots were placed at four UT experiment stations: Knoxville Experiment Station, Plateau Experiment Station, Highland Rim Experiment Station, and the Middle Tennessee Experiment Station. Plots at each station were basically the same with minor variations commensurate with the limits of the individual locations. At each location a total of 240 record plants were transplanted with additional plants in the borders and for replacement of mortalities. The plot at the Knoxville Experiment Station were instrumented to record temperature and moisture at 12-13 cm ( 5 in ). The goal was to evaluate survivability and

productivity of the two varieties under the five different treatment systems. The plants were transplanted in late February and early March of 2000 after sawdust mulch was worked into the soil and sulfur added to bring the pH into the desired 5.2 to 5.5 range.

Since production is not expected until after approximately three years only survivability, temperature and moisture will be addressed. The mortality at each of the four experiment stations is presented in Table 1 - 4.

Table 1. Mortality at HRES, Springfield, 2000

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Table 2. Mortality at KES, Knoxville, 2000

Table 3. Mortality at PES, Crossville, 2000

Table 4. Mortality at MTES, Spring Hill, 2000.

A statistical analysis was accomplished on the above mortality information using the Mixed Procedure. The mortality numbers were converted to percent for the statistical analysis and looked at in terms of treatment and location. The locations were three experiment stations for which appropriate information was available. The analysis by treatment is presented in Table 5 and the analysis by location is presented in Table 6.

Table 5. Statistical Analysis of Mortality by Treatment.

Table 6. Statistical Analysis of Mortality by Location.

From Table 5 the only statistically significant difference is that Bare and Bare + Mulch has greater mortality than Black where only one Duke pollinator was lost. The other two treatments are intermediate between these two groups. The date from the Plateau Experiment Station was not available be treatment and therefore was not included in the analysis. From Table 6 there was no statistically significant difference among any of the three experiment stations analyzed.