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 several vital processes such as cell division, root development, cell wall formation, sugar transport, and calcium uptake.
Adequate 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 malformations 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, a flattened fan-like growth pattern, and the inability of pinnae to expand are associated with more severe boron deficiency. The leaf tissue is fragile and the leaflets break easily, resulting in the condition known as leaflet shatter. With “blind leaf,” another symptom of boron deficiency, the pinnae develop incompletely as a tuft of bristles at the terminal end of the frond. A very severe boron deficiency results in “fishbone leaf,” identified by extremely small, thin pinnae. The breakdown of the growing point results in a dry heart rot as a final characteristic symptom.
On young seedlings, there are a few signs of boron deficiency. The dark green lamina is sprinkled with white dots and streaks, which become more pronounced on older leaves. There is a tendency for seedlings to show juvenile tendencies with the entire bifurcate leaf remaining undeveloped.