Ornamental plants most likely to be killed by iron deficiency and some control measures

Abstract

A list of over fifty plant species that are commonly used as ornamentals and which are susceptible to iron deficiency, especially in calcareous soils, is given. Although many susceptible plants die of iron deficiency, there are now control measures that will increase survival. Susceptible plants should perhaps be avoided, if possible, on calcareous soils, and the more resistant cultivars may be planted. The next most important control is avoidance of excess soil moisture. Two ways to achieve this are to improve water permeability with polymer soil conditioners and with regulation of irrigation. Soil acidification is helpful, and only part of the soil need be acidified. Elemental sulfur has limited value because it is not readily oxidized by microorganisms in high pH calcareous soils. Iron can be applied to plants by foliar, tree trunk, or root applications, all with varied success. Root application can be preventative and/or corrective. Iron can best be added to roots in zone applications and could include iron salts, iron chelates, natural iron pyrites, waste iron products, or organic matter‐iron mixtures. Avoidance of nutrient imbalances is extremely important in preventing iron deficiency in plants. Proper choice of nitrogen and potassium fertilizer sources can help control iron deficiency.

Key words:

• Iron efficiency
• comparative mineral nutrition
• polymer soil conditioner

Notes

The Laboratory of Biomedical and Environmental Sciences is operated for the U.S. Department of Energy by the University of California under Contract No. DE‐ACO3–76‐SF00012.