The Philippines is one of the developing countries that are actively looking for alternative source of fuel to reduce foreign oil import cost; to mitigate pollution and global warming. One crop that is being considered for propagation is sweet sorghum (Sorghum bicolor (L.) Moench.). These sweet variety store large quantities of energy as sugar in the stalk while producing reasonable grain yields.

How to Produce Sorghum

Sorghum is propagated by seeds. It matures in 100-115 days after planting. Farmers can harvest the crop three times a year through ratooning. Sorghum ratoon matures 85-95 days after cutting. If the farmer opted to plant other crops sorghum can be used as a component crop in multi-cropping system. It can be planted after rainfed lowland rice, upland rice, corn or legumes. Sorghum is drought tolerant crop. It only requires about 175 m3 of water. Sorghum grows best in well-drained soil. It is best to plow the field once and harrow it twice.
A hectare of sorghum would require 5-8 kilograms of seeds or a plant density of 130,000-150,000 plants per hectare. Seeds could be planted manually by hand or by using a planter. The distance of planting varies during June-July planting the distance of planting is 100 cm. apart 10 cm. deep while during September –October planting the distance of planting is 75 cm apart and 15-20 cm. deep.
Just like any crop sorghum requires fertilizer for vigorous growth and for higher yield. The general fertilizer recommendation for clay loam soil is 80-30-30. It is important to practice thinning before hilling up or side-dressing application of fertilizer.

It has been reported that the common pest of sorghum are shoot fly and stem borer. Shoot fly attack the plant after germination until 30 days after planting Stem borer can be prevented by using granular insecticide applied on leaf whorls 2-3 granules per plant.

Harvesting sorghum is similar to sugarcane. The panicles are first cut and separated from the stalks. Stalks must be cut close to the ground leaving about one node. Then the ratoon will sprout in the node.

Sorghum as source of ethanol
Reports showed that sorghum like sugarcane and corn, also exhibits C4 metabolism – the reason why it is more efficient in converting atmospheric carbon dioxide into sugar than most plants. The juice squeezed out of sweet sorghum stalks contains about 15-20% sugar that can be fermented into ethanol. It was also found out that the ethanol produced is cheaper than sugarcane and corn. The ethanol produced from sorghum can be used to blend petrol and diesel. It minimizes carbon and monoxide emission in motor vehicles. It is also known to be a ‘clean burning fuel” with high octane rating. The procedures involved in the production of ethanol include fermentation using yeast then, distillation. Ethanol is used in the production of gasohol, a sulfur and lead free fuel containing a certain percentage of ethanol in gasoline, which has lower carbon monoxide and nitrogen oxides compared to pure gasoline. A hectare of sorghum could produce about 3,000 liters of ethanol.

Other Benefits from Sorghum
For 150 years sorghum has been known as source of distinctive type of syrup. The grain and stem of sorghum is also a source of alcohol, sugar, fodder, fuel bedding, roofing, fencing, and paper. But the important product now of sweet sorghum is ethanol. Sorghum is also used in the preparation of silage. The silage produced from sorghum has higher biological value compared with the bagasse from sugarcane when used as feed for animals. It was also learned that it is rich in micronutrients and minerals.

Evaluation and commercialization project
In the Bicol region, the Bicol Integrated Agricultural Research Center conducted a varietal screening for sweet sorghum. The study focused on the yield of sweet sorghum for ethanol and grain. Five varieties were tested in Bicol conditions during the dry season cropping of 2006-2007 namely: ICSR, ICSV93048, SPV 422, ICSV 700, NTS 2. From among the varieties tested ICSV 700 is the tallest with 334.95 cm.height. But considering the grain yield SPV 422 obtained the highest yield with 9.55 metric tons while for percentage sugar expressed in brix SPV 422 again obtained the highest with 18.6 brix (measure for sugar content in liquids).


According to Romulo Cambaya, Agriculture Center Chief II and at the same time researcher of BIARC, the seeds produced during the first cropping were distributed to Cararayan in Naga City, Goa, Canaman, Oas, and Pili. Knowing the potentials of sorghum the center will undertake commercialization of sorghum. In order to realize this project, a proposal was submitted for ACEF funding.

Current Initiatives -
With the approval of bio-fuel act the government is bent on looking for sources of bio-fuels that can be developed and sustained. Ethanol from sorghum will not only save foreign exchange but also reduce pollution and provide cleaner air. One of the constraints seen in ethanol production is the supply of raw materials. Agencies concerned must identify suitable varieties in every region that can store large quantities of energy as sugar in the stalks and at the same time produces reasonable amount of grains. Aside from providing suitable varieties, technology must be provided to the farmers in order to obtain the expected yield both for the grains and for the ethanol. Linkages must be forged between implementing agencies and the farmers so that resource complementation is easy.
With the many potentials of sweet sorghum, project implementers and the farmers alike must be aware that in the initial stage there will be more constraints than benefits. Their rewards will be obtained later from the ethanol they produced.
Moreover, current technologies on ethanol production and sorghum production need fine-tuning. The different varieties need further testing before going into massive production. Once the production technology is made available the ethanol plant has been set up at the village level more farmers would be encouraged to venture into sorghum production. In every production endeavor farmers always look for a ready market for their produce. Hence it is necessary that before commercializing the crop a thorough study on the establishment of village level ethanol plant must be given priority.