Influence of micronutrient and phoshorous levels and chelator to iron ratio on growth, chlorosis, and nutrition of Vaccinium ashei reade and V. elliottii chapman

Abstract

‘Tifblue’ (V. ashei Reade) and US 280 (V. elliotti Chapman) blueberry plants were exposed to 2×2×2 factorial treatments of high and low phosphate and micronutrients (Cu, Zn, Mn, and B) and excess or stoichiometric concentrations of a chelator (EDDHA) added to Fe(NO₃)₃ in pH 6.8 solution cultures. Phosphorous was applied at 20 (low) or 400 (high) μM levels, micronutrients at low or high levels and either a 1:1 or 10:1 ratio of chelator to Fe concentrations.

Excess chelator in the nutrient solution always increased the severity of chlorosis except for US 280 plants grown under low P and stoichiometric chelator where neither micronutrient level resulted in chlorosis. Increased P concentration usually resulted in more severe chlorosis except for ‘Tifblue’ plants grown under low micronutrients and stoichiometric chelator where chlorosis did not develop with either P level. ‘Tifblue’ and US 280 differed in there response to excess solution Cu levels.

Unlike highbush blueberries (V. corymbosum L.), these two species of blueberries responsed to excess chelator in a manner similar to that reported for monocots.