Most oil palm growers know and appreciate the importance of potassium (K) in ensuring good fresh fruit bunch (FFB) yields. Without sufficient K, oil palm yields suffer and bunch size is reduced. In fact, mature oil palms generally require between 1.8 – 2.4 kg K₂O fertilizers per palm per year (equivalent to 3 – 4 kg MOP per palm per year), depending on the palm age, nutrient status and soil type. What are the roles of K nutrition in oil palm?

Higher FFB yields: This is the most well-known role of K in oil palms, and yields are even better when balanced with sufficient N nutrition. K and N also both contribute to higher oil yields in the bunches.

Vegetative growth: K regulates the opening and closing of stomata, microscopic pores on the leaves that allow plants to ‘breathe’ and exchanges gases during photosynthesis. Additionally, K has a synergistic effect with nitrogen (N) to promote overall plant growth.

Tolerance to drought and diseases: K is responsible for many enzymatic functions and protein synthesis in the cells. These roles make K an important nutrient in drought tolerance and resistance to diseases such as Fusarium oxysporum.

Here are some common symptoms of K deficiency in oil palm:

Orange spotting: Also known as confluent orange spotting or orange blotch, the leaf pinnae develop yellowish spots that gradually turn orange. The orange spots may then dry up and die (necrosis) due to secondary disease infection.

Mid-crown yellowing: This is more commonly seen on acidic or sandy soils. Mid-crown fronds turn yellow without the usual orange spots associated with K deficiency. In severe cases, older fronds may suddenly wilt and die.

White stripe: Pale whitish bands appear on both sides of the pinnae midrib which reduces the ability of the palm leaves to carry out photosynthesis and eventually affects the yield. White stripe occurs to due to a nutrient imbalance of low K and very high N supply. Consult your agronomist before adjusting your fertilizer programme to overcome this problem.

Fig: Common symptoms of K deficiency in oil palm include (left) Confluent Orange Spotting (COS) and (right) white stripe. The latter is associated with a nutrient imbalance of very high N paired with K deficiency.

 

While K fertilization is vital and beneficial for high oil palm yields, planters should take care not to over-fertilize because excessive K inputs can suppress the uptake of other essential nutrients such as magnesium and boron which are also both important for oil palm yields. K fertilizers like MOP and SOP are also highly soluble and easily leached, so the improper application can lead to high losses for planters. Therefore, balanced plant nutrition is the best way forward.

To ensure adequate K absorption by the palms, we recommend to split your K application to at least 2 rounds per year, and allow a minimum of 4 weeks’ time gap between applying K and Mg/B fertilizers when using straight fertilizers. Also take note of your estate’s rainfall and avoid applying K fertilizers on very wet months (more than 250 mm rainfall/month) to minimize runoff and leaching losses.

Alternatively, you can use Plantsafe sachets which contain a balanced mixture of all the essential plant nutrients for oil palm in one easy-to-use package. Our patented sachet technology also ensures that nutrients are gradually released for efficient uptake by your palms with minimal losses to the environment.