Variation in Nutrient Requirements of Blueberries and Other Calcifuges

Calcifuges, represented by the blueberry and cranberry ( Vaccinium spp.) and rhododendrons and azaleas ( Rhododendron spp.), are an economically important segment of the horticultural industry. They share the common requirement of an acid soil, about pH 5.5 or below, and minimal nutrition. Indeed, overfertilization, particularly when plants are young, can cause foliar injury. Much nutritional research has been performed on these acid-loving plants from the aspects of fertilizer recommendations and soil management practices. It is not the purpose of this paper to review the nutritional requirements or recommendations of blueberries and other calcifuges. Such information can be found elsewhere (Eck, 1966; Joiner et al., 1983; Kenworthy, 1973; Kofranek and Lunt, 1975; Korcak, 1988; Trevett, 1962). Instead, the two-fold purpose of this paper is to first examine the role of selected elements (Mn, Al, Fe, Ca, and N) on blueberry growth in atypical soil/site environments and, second, to explore the potential variation within Vaccinium that may be beneficial in genetic selection for growth under these new situations.