Oil palm

{Elaeis guineensis}
Oil Palm: Weak and narrow leaflets

Spotting a Boron Deficiency

Weak and narrow leaflets on oil palm.

Oil Palm: Hook leaf of palm leaves

Spotting a Boron Deficiency

Hooked leaf in palm leaves occurs with severe boron deficiency. The young leaves become brownish and bend.

Oil palm: Weak and narrow leaflets with signs of hook leaf

Spotting a Boron Deficiency

Weak and narrow leaflets with signs of hook leaf.

Oil Palm: Crinkled pinnae

Spotting a Boron Deficiency

With crinkled pinnae, the leaf bone shrinks. This is a sign of severe boron deficiency.

Oil Palm: Blind frond

Spotting a Boron Deficiency

Broken leaf edges (otherwise known as blind frond).

Oil Palm: Frond shatter

Spotting a Boron Deficiency

With frond shatter, the leaf blade detaches from the bone and each leaf become two separate leaves. Frond shatter is a sign of severe boron deficiency.

Oil Palm: Fish bone leaf

Spotting a Boron Deficiency

With fish bone leaf, the leaflets are fused at the end while the tips of the leaves dangle on each side midrib to look like fish bones.

Oil Palm: Round front tip

Spotting a Boron Deficiency

Round front tip: The palm grows short as long as the tip circular midrib. This indicates mild boron deficiency.

Boron Deficiency in Oil Palm

Boron is the most often deficient micronutrient in oil palm cultivation. Boron’s primary role in oil palm is to act as a key component in a number vital process such as cell division, root development, cell wall formation, sugar transport, and calcium uptake.

Boron is necessary for:

  • Preventing “fishbone leaf” or “hooked leaf”
  • Elimination of white stripe occurrence in leaves
  • Preventing seedless fruitlet
  • Adequate fresh fruit bunch formation
  • Enhanced root growth

Several symptoms of various leaf malformation are associated with boron deficiency. “Hook leaf,” which consists of a single or double hook on the pinnae near the tip, and transverse corrugations on the pinnae are usually the first symptoms to appear.

Fasciation and the inability of pinnae to expand are associated with more severe deficiency. The leaf tissue is very fragile and the leaflets break easily, resulting in the condition known as leaflet shatter. Incomplete development of the pinnae, which develops as a tuft of bristles at the terminal end of the frond—“blind leaf”—is also a symptom of boron deficiency. The development of extremely small, thin pinnae—“fishbone leaf”—is a sign of very severe deficiency. The breakdown of the growing point resulting in a dry heart rot can be expected as a final characteristic symptom.

On young seedlings, the dark green lamina will be sprinkled with white dots and streaks, which are more pronounced on older leaves. There is a tendency for seedlings to show juvenile tendencies with the entire bifurcate leaf remaining unsplit.

How much boron is enough?


We recommend doing a spray test on several seeds to find out the appropriate dosage before application on all plants in the nursery. In general, 13.6 g of Solubor® (67.3% B2O3) in 100 L of water is the recommended concentration for spraying. Solubor can also be mixed with insecticides or fungicides commonly used in nurseries.

Divide into three to four applications during periods of spraying insecticides or fungicides. The application of boron for prevention can be carried out during the fourth, eighth, and tenth months after germination.


Oil palm removes significant amounts of boron from the soil each year. Dosage rates for young and mature oil palm depend on the soils and yield goals. In general, the standard application for young palms is 50 g per palm per year of Fertibor®, increasing to 100-200 g per palm per year up to four to six years. Always consult your local department of agriculture to check the proper dosage.

Your boron fertilizer options

  • Granubor® 2 is an ideal material for dry blends for soil application.
  • Fertibor works in isolated soil applications and supplemental auxiliary application.
  • Solubor allows you the most flexibility for applying boron in solution. It can be dissolved alone in water or in liquid fertilizer and/or pesticides, and then applied to the soil or directly onto the palms. Boric acid is not recommended for foliar applications.*

*Rajaratnam, J., A., Expl. Agric., 9, 129, 1973.

Soil Application (Suggested rates of application)

  Granubor 2 Fertibor
LBS./ACRE 13-35 13-35
KG/HA 14.63 - 39.38 14.63 - 39.38

Foliar Application (Suggested rates of application)

LBS./ACRE Not recommended
KG/HA - 0

Returning to refined boron: Central America

Customer Success Story Oil Palm

A U.S. Borax customer who decided to switch to nonrefined mineral borates sees a real difference in crop yield. Learn More

U.S. Borax, part of Rio Tinto, is a global leader in the supply and science of borates—naturally-occurring minerals containing boron and other elements. We are 1,000 people serving 500 customers with more than 1,700 delivery locations globally. We supply 30% of the world’s need for refined borates from our world-class mine in Boron, California, about 100 miles east of Los Angeles.  Learn more about Rio Tinto

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