From the standpoint of azalea protection, the above mentioned method 
combines three safety features: mildness, liquid form, and soil applica- 
tion. By contrast, if dry chelated metal is applied to soil around azaleas, 
some heavy deposits may reach the shallow roots and burn them. 
If azaleas are seriously chlorotic, several mild soil treatments are 
better than one strong application. 
If seriously chlorotic azaleas need speedy help to survive, a spray 
treatment may be used. Directions for use ordinarily accompany com- 
mercial chelated metal products. A spray applied to azaleas should be 
kept within the lower range of recommended strength to avoid or minimize 
burning foliage, especially if plants are young or grown in greenhouse 
conditions. 
The most advantageous time to apply chelated iron to azaleas is in 
the active growing stage. An initial small treatment at the start of active 
spring growth may be followed by a second treatment, if it seems needed, 
perhaps a month later. Small plants are most likely to need this follow- 
up treatment. Applying the chelated metal to azaleas in autumn is helpful 
only to large woody plants. 
If azalea plants which have been normally green show some yellowed 
foliage in winter and early spring, there is no cause for immediate con- 
cern. Temporary yellowing limited to these seasons is not unusual in 
azaleas, and such plants are not deficient in iron. Their roots are taking 
up iron and the nutrient metal will reach the leaves in due time for active 
growth needs. 
MUCH RESEARCH WORK AHEAD 
Despite advances thus far, the controlled use of chelates in agricul- 
ture and the knowledge of how chelates work are still in early stages of 
development. 
Some of the chelates that have proved beneficial for certain chlorotic 
plants may have wider usefulness--which can be determined only by con- 
tinued tests in additional soil-plant situations. Also, the introduction of 
new types of chelates could re-open the possibility of using a chelated 
metal where those tried in the past were not promising. 
Even more basic help to plant growers in overcoming plant malnutri- 
tion may come through use of chelates in studies of plants' nutrition pro- 
cesses and problems. Major questions about chelates and plant chlorosis 
that are not yet clearly answered include: 
* How do chelates function in plants? 
* What is the metabolic fate of a chelate in plant tissue? 
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