Blueberry rootstock: selection, evaluation, and field performance of grafted blueberry plants

Abstract

There is currently no rootstock available for blueberry production in nurseries. Vaccinium arboreum, a native species in the United States posesses several desirable traits for use as a blueberry rootstock. Such traits include a sturdy single trunk, and a root system which can thrive in a wide range of soils that differ in soil pH and organic matter. Seeds of V. arboreum from Florida (FL), Oklahoma (OK), and eastern Texas (TX) were germinated through various treatments in the greenhouse. The best germination rate (43%) was obtained from 90 days of cold stratification of seeds from dried V. arboreum fruits. Seedlings were then planted at the North Willamette Research and Extension Center (NWREC) in Aurora, OR. The plot had over 500, 200, and 50 V. arboreum selected seedlings from TX, OK, and FL seed sources, respectively. Foliar nutrient levels varied among the three seedling sources, with plants from TX and OK showing higher N, P, K, B, and Mn levels than plants from the FL source. Plants from TX and OK were more vigorous than those from FL. In another plot at the NWREC, three blueberry cultivars ('Draper', 'Liberty', and 'Aurora') were grafted onto V. arboreum seedlings. Grafted blueberry plants were compared to their own rooted plants under two soil treatments. Results demonstrated that fruit firmness, size, total soluble solids, and titratable acidity were not affected by grafting and soil treatments. Variations in foliar nutrient levels N, P, K, Ca, Mg and Mn observed in the grafted plants may be due to grafting because no cultivar and rootstock interactions were found. The potential for using V. arboreum as blueberry rootstock is promising.