Iron nutrition of the broadleaf evergreen shrub, Euonymus japonica thunb

Abstract

The decline in pH of a complete nutrient solution, during flushes of shoot growth for the evergreen shrub, Euonymus japonica, was suspected of being caused by Fe deficiency. Experiments with plants grown in buffered and unbuffered solutions and in solutions with and without Fe, coupled with analyses for Fe in Euonymus tissue and for reductant in the nutrient solution indicated that these pH changes were not a response to Fe deficiency. When Euonymus became Fe‐deficient, however, it did lower the pH of an all NO₃‐nitrogen nutrient solution as so‐called “Fe‐efficient”; plants do and released reductant into solution. If Fe was not added to solution, plants became severely Fe‐chlorotic and lowered the solution pH but did not release substantial amounts of reductant until Fe was added.

Key words:

• Iron deficiency
• episodic growth
• solution culture
• reductant
• FeEDDHA