| Summary: | Palm tree production strongly depends on environmental factors such as
climate condition, fertilizer, water availability and the implementation of agronomic
techniques and internal factors such genotype potential. The process of oil synthesis
requires a highenergyprocess compared toproduction of the vegetative organ, so each
factor may restrict this process and in particular the environmental condition would
potentially reducethe oil yield production.There are two main sources of carbohydrates
for palm growth: carbohydrates that are moved from the stem as the reserve organ or
directly from leaves where the photosynthesis processoccurs. The combination between
those carbohydrate sources also might be occurring in certain periodswhen there is a lag
of photo-assimilate suppliedto the developed bunch.
A comparison between the conventional and simplified fruit sampling method
was conducted for a more simple and proper procedure to get palm fruit samples. A more
detailed experiment which applied in Nested design with 3 replications was constructed
for this study which consisted of 3 factors such as the site, genotype, and series of
experiment. Two different rainfall distributions between Riau and South of Kalimantan
were chosenfor representingthe two different sites. Two contrastinggenotypesbetween
high and low productions were selected on each site. Six series of consecutive
experimentswith a six-month duration and two-month intervalsbetween each series was
implemented toaccommodateforthe variation of rainfall distribution within a year. The
genotype factor, the series factor, the combination factor between the genotype and the
series were madewithin the site. Some variables in termsof oil yield were observed,such
as oil concentration, dry-biomass and oil content in mesocarp. Dynamic carbohydrates
from all aspects such as carbon assimilation, carbon reserve, and carbon utilization for
bunch development were analyzed torepresent the correlation between sourcesand sink
relationships. Climate variables were recorded and computed on a daily basis using
automatic weather stationsthat were installed at eachsite of the experiment.
A simplified sampling method was properly used to observe the oil
concentration of the mesocarp which begins from the top part of bunch and then goes
downward to the basal site. The period of severe dry season of more than 3 consecutive
months such as in South of Kalimantan resulted in a more negative impact to the oil yield
production. The genotype with high production performance ateach site wassignificantly
higher than the low genotype productivity related tothe production of oil yield per bunch.
The mobilization of NSC
total
on thephythomer scale was evidencedin the stem and petiole
organ and was greater compared to the leaves and mesocarp. Starch was the most
mobilizing sugar in stem, while glucose is in petiole during the oil synthesis. Sugar
mobilization depends on the balance between its reserve and demand during the oil
synthesis, as it may be mobilized from the stem as a reserve organ or directly from the
leaves or even a combination from both mechanisms.Declining photosynthesis activity at
maturation stages of a developed bunchis related to the declining oil accumulation and
carbohydrate demand for oil synthesis activity at the same period.
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