1. Iron (Fe) Deficiency Interveinal or uniform chlorosis
Leaflet tip necrosis
Dark green spots accompany chlorosis on some species
Affects youngest leaves only

2. Symptoms for Lady palms and Licuala sp.
On some species such as queen palms, Rhapis spp., or Licuala spp.the new leaves will have diffuse small green spots superimposed on the otherwise interveinally chlorotic leaflets. This is very diagnostic for Fe deficiency, since no other physiological disorder causes this type of symptom. Not all Fe-deficient palms of these species will show these spots, however.
Notice green small green spots and intervienal chlorosis

3. New leaves may emerge uniformly chlorotic
At other times, new Fe-deficient leaves will emerge uniformly chlorotic.

4. Severe Fe deficiency. Notice leaf tip necrosis.
Under severe Fe deficiency, new leaves may emerge almost white in color and may show leaf tip necrosis as well.

5. Causes of Deficiencies
Insufficient nutrients in the soil
Nutrients in unavailable form
pH too high or too low
Complexation with phosphates or organic matter
Nutrient imbalance
It is important to remember that too much of one element can affect the uptake or utilization of another element. There are numerous examples of “antagonism” among various nutrient elements.

6. Manganese deficiency is due to insufficient amount in soil
Manganese deficiency, or “frizzletop” is a common problem on queen palms. New leaves will emerge chlorotic with longitudinal necrotic streaking within the leaflets. Once this necrotic area expands sufficiently to affect the midvein of the leaflet, the portion of the leaflet distal to this necrosis will wither and curl, giving the leaves this frizzled appearance. Note that the older leaves on the palm are normal in length. Manganese deficiency affects only the youngest leaves. If leaves of all ages are reduced in size, chlorotic, and frizzled, this is probably late-stage K deficiency. Of course, it is not unusual to find both K and Mn deficiencies on the same palm, making diagnosis more difficult.

7. Potassium (K) Deficiency
Insufficient amounts in soil
Nutrient imbalance (due to wrong fertilizer)
These sabal palms are suffering form severe K deficiency. Only a few healthy new leaves remain within the canopy. It was induced by applying high N turf fertilizer to the turf below these palms. The high N forces new growth that was not supported by the amount of K in the soil or fertilizer. This caused the existing K within the palm to become diluted and resulted in a worsening of the K deficiency. Not shown in this photo were two other sabal palms that had died from induced K deficiency!

8. Nutrient antagonisms
Mg deficiencies caused by nutrient imbalances (except for P. canariensis).
K-deficiencies cannot be corrected by adding K alone.
Fe and Mn are also antogonists.
Adding K by itself to correct a K deficiency, as done here, upset the K:Mg balance. The end result was that these previously K-deficient palms are now Mg deficient instead. When you see Mg deficiency in any species of palm except for Phoenix canariensis, it was likely caused by a nutrient imbalance, and not by Mg insufficiency in the soil. Another common example of nutrient antagonisms is between Fe and Mn.

9. Causes of Deficiencies
Root problems
Root rot diseases
Poor soil aeration
Improper planting depth

10. The paurotis palm on the right was suffering from severe Fe deficiency, despite the fact that the grower was treating them with micronutrients.
The paurotis palm on the right was suffering from severe Fe deficiency, despite the fact that the grower was treating them with micronutrients.

11. Importance of Proper Fert. Rates
Too Low
Nutrient Deficiency
Too High
Soluble salts injury
In the case of macronutrients, too much fertilizer can cause soluble salts injury.

12. Prevention of Deficiencies
Proper fertilization
Good soil aeration
Proper planting depth
Proper soil pH
In landscape and field soils, excessively high or low pHs can be adjusted to keep most nutrients available to palms.

13. Components of a Fertilization Program
Appropriate fertilizer analysis:
Field production or landscape:
Mg plus micronutrients
Effective sources
Alkaline field or landscape soils:
N, K,& Mg – 100 controlled released
sulfate or chelated (Fe only) micronutrients
Balanced released characteristics for all nutrients

14. Recommended Nutrient Sources
N: S-coated urea, urea-formaldehyde, resin-coated urea or ammonium salts
K: S-coated potassium sulfate
Mg: Coated or uncoated prilled kieserite
Fe: Trachelene Fe, FeEDDHA (138), not suitable for blending in granular fertilizers
Mn: manganese sulfate (TechMangam)
B: Solubor, borax, boric acid

15. Fertilizer A Fertilizer B
How can one determine if a particular palm fertilizer will be an effective one? This slide shows two labels from actual palm special fertilizers, both of which have analyses of One of these labels represents an excellent palm fertilizer, while the other has some very serious problems and would not produce deficiency-free palms in south Florida. It is essential to understand what a fertilizer label can and cannot tell you about a product’s suitability.

16. Fertilizer A Fertilizer B
The only K-containing ingredient in the second product is polymer-coated sulfur-coated potash (=potassium sulfate), a slow release form, while the first product also contains sulfate of potash magnesia, a water-soluble source of K. We cannot determine from the label alone how much of each component is included in the first product, but ANY water-soluble K source is unacceptable for this element. The blender’s batch sheet would tell you exactly how much of each ingredient goes into their blend, but this information is not usually available to the consumer.

17. Fertilizer A Fertilizer B
The magnesium component of these fertilizers is just as important as N and K. Again, both labels claim 4.0% water soluble Mg, yet we recommend only 100% slow release Mg.

18. Fertilizer A Fertilizer B
Looking at micronutrients, we see that the first product contains primarily oxides of Mn, Fe, Zn, and Cu, all of which are largely unavailable to plants in neutral to alkaline soils. The second label, however, uses primarily sulfates plus FeEDTA, a water-soluble chelated form of Fe.
In summary, it is essential that you look beyond the analysis when evaluating any fertilizer product.

19. Fertilizer application methods
Field production or landscape:
Broadcasting – good
Banding – bad
Fertigation –maybe, but…
Soil injection - bad
Of the several methods of fertilizer application that can be used in the landscape, broadcasting using a calibrated rotary spreader is the simplest and most effective method. Banding fertilizers tends to concentrate it in a small area, where a limited percentage of the roots will be in contact with it. The roots directly below the fertilizer band may even be burned by the fertilizer. Fertigation, or injection of water soluble nutrients into the irrigation water works well in container production, where irrigation is applied every day, but in the landscape, irrigation is generally not applied during rainy periods, when plant nutrient requirements are high and nutrient leaching losses are also high. Soil injection, or deep root injection, is a method wherein water soluble nutrients are injected under pressure below the surface of the ground, ostensibly to provide nutrients to tree roots, while bypassing the turf roots. There are two problems with this concept. First, water soluble nutrients are used, and these will be much less ineffective than controlled release fertilizers due to their leachability. Secondly, any fertilizer injected into the soil deep enough to avoid the turf roots will bypass 90% or more of the tree roots as well. Primary palm and tree roots may be 6 to 18 inches deep, but the small feeder roots that actually take up nutrients grown upward and will be intermingled with turf roots. Thus, it is impossible to fertilize tree roots in a mixed landscape without affecting turf roots as well.
Banding of fertilizers, such as seen here used to be the normal method of applying fertilizers to palms. However, it is not a very efficient method of getting nutrients into the palm. In this planter, the roots of these two palms easily fill the entire planter area, yet only about 10% of the root area is located below the fertilizer band. Since nutrient movement is only downward, the other 90% of the root system will never be in contact with the applied nutrients. The 10% of the root system below the band may even be damaged by excess salts. It would be much more efficient to spread the same amount of fertilizer uniformly over the entire bed area.