Authors: Iput Pradiko, Dhaffa Agung Thirafi, Eka Tarwaca Susila Putra, Sumaryanto, Muhdan Syarovy, et al. | Year: 2026 | DOI: 10.17503/agrivita.v48i1.4713
Water is the lifeblood of oil palm (Elaeis guineensis) plantations. An oil palm tree is an extremely heavy drinker: on a hot day, a single mature tree can evaporate tens of liters of water through its leaves via the process of transpiration. Without understanding how much and when it happens, irrigation management is just a guess. This study aims to answer that question quantitatively: what weather and soil factors most determine the rate of transpirasi in oil palm varieties?
The research team installed sensors directly in the field to monitor the transpiration rate of the plants in real-time, recording plant conditions every hour without stopping. The data was then matched with daily weather conditions: solar radiation, air temperature, relative humidity, wind speed, and soil moisture at various depths. Several commercial varieties widely planted in Sumatra were included to see if their responses to the weather differed from one another.
The results are clear. Solar radiation proved to be the main driver of daily transpiration rates: the hotter it is, the more water the tree evaporates. Next, it’s the turn of vapor pressure deficit (VPD) to take a role, where hot and dry air pulls more water out of the leaves. What’s interesting: each variety responds to weather stress differently. This means that choosing a variety is not just about yield potential, but also about how efficiently the tree uses water during the dry season.
| Factor | Role in Transpiration | Most Active Condition | Dominance | Notes |
|---|---|---|---|---|
| Solar Radiation | The main driver of daily transpiration rate. The stronger the sunlight, the more water is evaporated through the leaves. | Daytime, dry season | Highest | Active every day without depending on the season, like a pump that never stops. |
| Vapor Pressure Deficit (VPD) | Dry air pulls more water vapor out of the leaf pores. | When it’s hot and the air is dry | High | The higher the VPD, the greater the air’s pull on the leaves and the more direct the effect on the transpiration rate. |
| Soil Moisture (0–30 cm) | The availability of water in the root layer determines how much can be absorbed and evaporated by the plant. | Dry season | Medium–High | Only becomes a limiting factor when soil water is depleted. The tree cannot transpire much if there is no water to absorb. |
| Air Temperature & Wind | Accelerates evaporation from the leaf surface directly. | Throughout the day | Medium | Plays a role, but its influence is smaller compared to radiation and VPD, which work more directly. |
| Varietal Differences | Each superior variety responds to the weather differently due to genetic variations in water use efficiency. | Clearly visible during the dry season | Real | There are varieties that are more water-efficient during the dry season, but the biological mechanisms still need to be studied further. |
The impact is directly felt in the field. If we know when and how much transpiration occurs per variety, the irrigation schedule can be adjusted to the actual weather conditions, not just a weekly routine. Water is not wasted when the rain has just fallen, and plants are not thirsty when VPD is at its highest. In an era of increasingly unpredictable weather, this ability can be the difference between an efficient and a wasteful plantation.
In the future, variety-specific transpiration data can be used to map water needs per plantation block, even integrated into data-based agricultural management systems. For the Indonesian oil palm industry, which produces more than half of the world’s palm oil, findings like this are not just academic knowledge, but a real tool for survival amidst climate pressure and global competition.
What is your experience in managing irrigation in the field during the dry season? Or do you have questions about transpiration and oil palm water needs? Write in the comments column, we’re happy to discuss.
Glossary
- Transpiration
- The process of trees releasing water vapor through small pores on the surface of leaves, similar to sweating in humans, but occurring on the entire leaf surface throughout the day.
- Vapor Pressure Deficit (VPD)
- A measure of how “thirsty” the air is for water vapor. High VPD means the air is hot and dry, encouraging trees to evaporate more water from their leaves.
- Solar Radiation
- The light energy received by the earth’s surface from the sun. The higher the radiation, the more energy drives the transpiration process in plants.
- Superior Variety
- A type of plant resulting from selection that has certain desired traits, such as high yields, disease resistance, or efficient water use.
- Soil Moisture
- The water content stored in the soil. The 0-30 cm layer is the active root zone of oil palms, where trees absorb most of the water that is then evaporated through the leaves.
Source
Pradiko, I., Thirafi, D. A., Putra, E. T. S., Sumaryanto, S., Syarovy, M., Darlan, N. H., Sujadi, S., Hutagalung, N. A., Farrasati, R., & Syarif, A. N. (2026). The quantitative analysis of weather and soil moisture role on daily transpiration dynamics of oil palm varieties (Elaeis guineensis Jacq.). Agrivita, 48(1). https://doi.org/10.17503/agrivita.v48i1.4713