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Sweet
sorghum, a cane-like plant with sugar-rich stalk, is seen
as a promising bioethanol source for its 15 percent to 20
percent sugar that can be fermented faster and more
cheaply than the starch from sugar cane molasses and corn.
An ongoing
research at the Mariano Marcos State University (MMSU) in
Ilocos Norte shows that sweet sorghum (Sorghum bicolor
[L.] Moench) can yield up to 9,075 liters of ethanol a
hectare a year with one seed crop and two ratoon crops in
nine months.
Dr.
Artemio Salazar of the
Institute of
Plant Breeding-University
of the Philippines Los Baños (IPB-UPLB) considers MMSU
results particularly impressive because of the high grain
yields obtained.
With an
uptick in fossil-fuel prices, interest in biofuel research
has grown worldwide. In the
Philippines,
research agencies of the government, state universities
and colleges (SUCs) and the private sector have
collaborated in support of the National Bioethanol
Program.
One such
project is “Integrated R&D program on biofuels: Subprogram
on utilization of sweet sorghum and cassava as feedstock
for ethanol production.”
The
Philippine Council for Agriculture, Forestry and Natural
Resources Research and Development (Pcarrd), Department of
Energy, UPLB, MMSU, Central Luzon State University (CLSU)
in Nueva Ecija, among other organizations, have partnered
with the International Crops Research Institute for the
Semi-Arid Tropics (Icrisat) in
India
in implementing this project, which started in May 2007.
Sweet
sorghum for bioethanol production in the
Philippines
Researchers say sweet sorghum is the best alternative to
supplement sugar cane as source of bioethanol.
In MMSU
and CLSU, researchers evaluated initially the adaptability
of the varieties from Icrisat under local condition. A
number of varieties/lines are currently part of the
germplasm collection of the SUCs, according to Salazar.
Additional varieties are expected to come, and these will
be subjected to adaptability trials for industrial use as
source of biofuel.
Sweet
sorghum production area in Ilocos is estimated at 17
hectares, which is part of the adaptability trial being
conducted by MMSU, according to Dr. Jocelyn Eusebio of
Pcarrd.
In his
report, Salazar noted that there is no recommended variety
of sweet sorghum at present. In fact, support for sorghum
research ceased in the early 1980s. Salazar emphasized the
need to prepare for the long haul by continuous genetic
improvement of the crop if sweet sorghum commercialization
will happen in the country.
The
project aims to develop improved sweet sorghum lines from
genetic materials available locally and internationally,
develop/adapt appropriate cultural management systems for
sweet sorghum production in selected areas, develop
site-specific integrated nutrient and water-management
technologies for optimum production of biomass for maximum
production of ethanol, optimize the fermentation of
ethanol from sweet sorghum through biotechnology and
determine the most cost-effective treatment of distillery
slops from distillation of ethanol from sweet sorghum,
among other things.
Eusebio
shared that the country has given little attention to this
crop because of its minor economic importance, although
many promising varieties have been introduced to the
Philippines
more than 30 years ago.
She added
the sorghum research in the Philippines then was focused
on developing appropriate technologies needed to produce
and become self-sufficient in feed grains that can
complement corn, and not intended for ethanol production.
As a
feeding material, sweet sorghum is comparable with corn
and has relatively higher protein content than corn.
Sweet pick
to dwindling fuel resources
Studies
conducted by Icrisat scientists prove that bioethanol
production from sweet sorghum has even greater energy
savings compared with that from corn grain, which has to
be hydrated and converted from starch to sugar before it
can be fermented, as well as that from sugar cane, which
requires at least a year to grow and large amounts of
irrigation water.
Icrisat
reported that sweet sorghum grows in about four months and
uses only 8,000 cubic meters of water over two crops. This
is four times lower than the 14-month growing period and
36,000 cubic meters of water requirement per sugar cane
crop.
Icrisat
considers sweet sorghum as one of the most efficient
dry-land crops for converting atmospheric carbon dioxide
into sugar, making this crop a promising feedstock for
ethanol production.
Furthermore, the studies claim that the food value of
sweet sorghum grain need not be compromised for the sake
of ethanol production, unlike when corn is used for this
purpose.
Bioethanol,
along with biodiesel, is cited as a promising fuel
alternative because its source is sustainable, reliable,
indigenous, renewable and biodegradable. Dr. Kiran Shiram,
a principal scientist at Icrisat, agreed on this claim
during his lecture on transgenic technology held at Pcarrd,
Los Baños, Laguna, on April 25.
Besides
the Philippines, Icrisat has also supplied seed samples of
sweet sorghum to Thailand, Kenya, Ethiopia, Malawi, Egypt,
Japan, Colombia, Mexico, Uruguay and Azherbaijan. | 
