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.