Carrageenan extracted from seaweeds and further degraded through irradiation may be the latest breakthrough in Philippine agriculture.
In multi-location trials conducted in Bulacan, Nueva Ecija, Laguna, and Iloilo, the carrageenan plant growth regulator (CPGR) applied at low concentrations in rice has been found to enhance the yield by 15–30%.
In Bulacan, the application of 20 ml/li of the plant growth promoter in addition to three and six bags of fertilizer per hectare led to an increase grain weight yield of 450 grams and 455 grams, respectively, compared with the 275 grams of grain weight yield produced through traditional farmers’ practice.
Productive tillers and panicle length were also found to be significantly higher in the trials compared with those in the farmers’ field.
DOST upscales testing
Due to encouraging results, Department of Agriculture (DA) Secretary Proceso J. Alcala and Department of Science and Technology (DOST) Secretary Mario G. Montejo signed a memorandum of agreement late in 2015 to upscale verification testing in Regions 1, 2, 3, 4A, 6, 9, and 11 to further allow the end-users to test the efficacy of carrageenan based on established nutrient management practices for dry and wet cropping seasons.
Early this year, demonstration trials have been initiated in Regions 2 and 3. In a turnover ceremony led by Secretary Montejo and DA Assistant Secretary for Field Operations Edilberto M. De Luna, carrageenan plant growth regulators were distributed for free to 650 farmers in Pulilan, Bulacan. These plant growth regulators will be field tested in 2,000 hectares of rice field in Bulacan.
In Isabela, DOST’s Philippine Council for Agriculture, Aquatic and Natural Resources (DOST-PCAARRD) distributed carrageenan plant growth regulators in turn-over ceremonies held at the Isabela State University Echague Campus. The activity was coordinated by the Cagayan Valley Agricultural and Aquatic Resources Research and Development (CVAARRD) and DOST Region 2. Almost 8 tons of CPGR had been produced by DOST-Philippine Nuclear Research Institute (DOST-PNRI) for this purpose.
CPGR is being applied at 3 li/ha per scheduled application every 12–15 days after transplanting (DAT), 30–35 DAT, and 45–50 DAT, which can be translated using the table below:
| DAT | Rate of application | No. of Tank Loads/ha (TL/ha)* |
| 12-15 | 300 ml/TL | 10 TL/ha |
| 30-35 | 300 ml/TL | 10 TL/ha |
| 45-50 | 300 ml/TL | 10 TL/ha |
*TL – 16L knapsack sprayer
*A farmer needs 3L of CPGR per hectare per application for three periods of application; thus 9L of CPGR/ha is needed for the whole lifecycle of rice.
DOST also approved a counterpart project under semi-commercial testing of the carrageenan plant growth promoter by the DOST-PNRI in the aforementioned regions.
Carrageenan is an indigestible polysaccharide extracted from edible seaweeds. When subjected to modified irradiation technology, it can elucidate growth promotion of plants. Studies show that it can strengthen rice stem, improve rice resistance to lodging, and develops rice resistant to rice tungro virus and bacterial leaf blight.
DOST-PCAARRD will showcase radiation-modified carrageenan including other science and technology (S&T) agri-aqua research and development (R&D) outputs on March 2-4, 2016 during the SIPAG FIESTA at its headquarters in Los Baños, Laguna.
SIPAG, a technology transfer strategy, embodies the Council’s commitment to DOST’s Outcome One in a bid to ensure that the fruits of R&D activities for the agri-aqua sectors will be a blessing for every Juan.