BUKU ABSTRAK - Universiti Putra Malaysia

Agriculture
Increasing Phosphate use Efficiency of Oil Palm through the Use of Appropriate
Promoters from Selected Oil Palm Genotypes
Prof. Dr. Zaharah A. Rahman
Siti Nor Akmar Abdullah
Faculty of Agriculture, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 6932; zaharah@agri.upm.edu.my
Increasing the yield of oil palm in Malaysia depends much on the application of fertilisers due to oil palm
high nutrient demand, uptake and removal. Malaysian soils are highly weathered, acidic and inherently low in
phosphate (P) and have high P fixing capacities, making P unavailable for plant uptake. P fertiliser is the third
most applied to oil palm to optimise and sustain high yields. Over the years, this has resulted in substantial P
accumulation in the oil palm soils. This could lead to eutrophication effects to ground water and other water
source. In light of this, a concept of “tailoring the plant to fit the soil” should be implemented in plant and soil
research. Instead of altering the fertility status of the soil to accommodate the plant nutrient demand, plants with
better P uptake should be used. Adopting plants with better nutrient uptake efficiency means more environmentally
friendly and ecologically feasible strategy to improve the growth of plant in low phosphorus soil. Our study has
shown differences in P uptake (12-46%) among oil palm genotypes by means of P-32 radioisotope study. The
significant difference of oil palm in P uptake implies that good planting materials with high P uptake ability could
optimise the usage of P fertiliser input. The presence of high affinity phosphate transporters was successfully
detected. We used a protein probe to locate the phosphate transporters in oil palm roots. By measuring the probe
activity in the root, we are able to measure the uptake ability of P by oil palm genotypes. The outcome of the
study will help in breeding superior oil palm genotypes for efficient P uptake ability. Our research aligns with the
concept of “tailoring the plant to fit the soil” in improving crop production in a more environmentally friendly
manner to benefit mankind.
Keywords: Oil palm genotypes, P use efficiency, high affinity phosphate transporters
Nitrogen Uptake by Some Upland Rice Landraces and Their Relationships to Root
Characteristics
Prof. Dr. Zaharah A. Rahman
Mohamed Hanafi Musa
Faculty of Agriculture, University Putra Malaysia,
43400 UPM Serdang, Selangor, Malaysia.
+603-8946 6932; zaharah@agri.upm.edu.my
Nitrogen is the most limiting plant nutrient that controls the growth and yield of rice and most other plants.
Currently, farmers in Asia typically apply 86 to 136 kg N ha-1, while in Malaysia, up to 170 kg N ha-1 has been
proposed. Increased N application is not advocated due to high cost of N fertilisers and from environmental
perspective, excess N fertiliser use has been associated to eutrophication of surface and ground water resulting
from leaching of excess nitrates. The size and architecture of the root system is an important variable ensuring
adequate access to soil N. The architecture of the root is determined by the pattern of root branching and the size
of the root relative to the rest of the plant. It has been predicted that in the next 30 years, increase of up to 60%
of the current rice yield must be targeted to sustain the population consumption of rice. Most of the crop varieties
grown in the developed world have been bred under conditions of high fertiliser input, while the indigenous
upland rice grown by most small farmers have not been tested for their N uptake efficiencies, since they have
been normally grown with minimal fertiliser input. This experiment was carried out where eight local upland
rice landraces and two genotypes obtained from Africa Rice Center (WARDA) were screened for their root
architectural characteristics and to relate to N uptake efficiency using N-15 labelled ammonium sulpahte. Our
study showed that total N uptake from fertilizer ranges from 60.98 kg/ha to 120.98 kg/ha and N use efficiency
ranges from 40.65 to 80.65. Variety Merah showed the most efficient N uptake, with 120.98 kg/ha, corresponding
to 80.65% N fertiliser use efficiency. Total N uptake g/plot showed positive correlation with root surface area
(r=0.37751) and root volume (r=0.41346).
Keywords: Upland rice, root characteristics, nitrogen fertiliser, nitrogen use efficiency
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