Effect of Provenance on Substrate pH Tolerance of Vaccinium arboreum
Type of DegreeMaster's Thesis
MetadataShow full item record
Around 400 species of blueberry, huckleberry, and cranberry make up the Vaccinium genus found throughout the world. Commercial production of blueberries in North America has developed from using different Vaccinium species native to regions where they are produced; wild lowbush blueberries (V. angustifolium) are grown in the northeastern U.S. and Canada, highbush blueberries (V.corymbosum L. and V. australe Small) are grown in the northern U.S. and in coastal regions, and rabbiteye (V. ashei Reade) and southern highbush (V. corymbosum x V. darrowii hybrids) are grown in the southern U.S. Like other members of the Ericaceae family, a major limiting factor for growing blueberries is the need for acidic soils with a pH around 4.5. Consumer demand for Vaccinium fruit crops has increased due to recent awareness of the health benefits they possess. As demand for blueberries grows, so does the necessity for innovative cultivation techniques to aid blueberry farmers in maintaining costs. Using a rootstock that is more tolerant of alkaline soil types and that could be mechanically harvested profitably would aid commercial cultivation of blueberries. To identify more tolerant rootstocks, two trials were set up using sparkleberry plants from FL, AL, MS, and TN that were arranged in 30L tubs containing a nutrient solution that had been buffered to one of four pH levels: 5.5, 6.0, 6.5, and 7.0. We observed that the provenances varied significantly in growth (percent change, final fresh weight, final dry weight). In the first study, plants from Green County Mississippi (GCMS) had ~3x higher fresh weight percent change than the other four provenances. On average, sparkleberry plants from the 5 provenances in the first study grown in a nutrient solution of pH=7.0 exhibited a 40-100% higher fresh weight percent change than those grown in more acidic solutions. In the second experiment, provenance and pH treatment significantly affected growth (percent change). Plants from Polk County Tennessee (PCTN) had ~2x higher fresh weight percent change than plants from Marion County Tennessee (MCTN) and ~200x greater than GCMS and Taylor County Florida (TCFL). In this 2nd experiment, plants grown in a pH=5.5 solution showed ~15x higher fresh weight percent change than plants grown in more basic nutrient solutions. Provenance showed an effect on sparkleberry performance, when substrate pH is varied. However, this was a small study with a limited number of provenance tested. More research should be conducted to find provenances that produce plants that excel in higher pH soils.