Carrageenan extracted from seaweeds and further degraded through irradiation may be the latest breakthrough in Philippine agriculture.

Carrageenan is an indigestible polysaccharide which, when subjected to modified irradiation technology, can be an effective growth regulator.

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 CPGR in addition to 3 and 6 bags of chemical fertilizer per hectare led to a 65.4% increase in grain weight. Panicle length increased from 3.5% to 12.5%.


A field in Pulilan, Bulacan shows standing rice treated with CPGR (left) while untreated side (right) shows lodged rice (Photo from UPLB)

Productive tillers and panicle length were also found to be significantly higher in the trials compared with those in the farmers’ field.

Using the CPGR also makes the rice stem stronger and improves resistance to lodging. It is also compatible with farmers’ practice, thus giving higher grain yield. It also promotes resistance to rice tungro virus and bacterial blight. Furthermore, it is environment friendly as it has no harmful effects on natural enemies or beneficial insects.

DOST upscale 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 in late 2015 to upscale verification testing in Regions 1, 2, 3, 4A, 6, 9, and 11. The purpose was to further allow end-users to test the efficacy of carrageenan based on established nutrient management practices for dry and wet cropping seasons.

Early in 2016, demonstration trials were 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, CPGRs were distributed for free to 650 farmers in Pulilan, Bulacan. These plant growth regulators will be field tested in 2,000 hectares of rice fields in Bulacan.

In Isabela, DOST’s Philippine Council for Agriculture, Aquatic and Natural Resources (PCAARRD) distributed CPGRs in turn-over ceremonies held at the Isabela State University Echague Campus. Almost 8 tons of CPGRs had been produced by DOST’s Philippine Nuclear Research Institute (DOST-PNRI) for this purpose.

“In response to the challenge, the government, as stewards of the nation’s S&T agenda, have continuously strengthened our S&T ecosystem, through funding support for R&D programs and facilities, enhanced S&T policies, and capacity building,” said DOST Secretary Mario G. Montejo in his message during the opening of PCAARRD’s ongoing SIPAG FIESTA event. “We shifted our focus from traditional academic and technical research to S&T in response to the need of society to benefit Aling Maria and Mang Juan,” he added.

Radiation-modified carrageenan is currently one of the technologies being showcased in SIPAG FIESTA from March 2-4, 2016 at the PCAARRD headquarters in Los Baños, Laguna.

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:

*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 PNRI in the aforementioned regions.

SIPAG FIESTA aims to ensure that the fruits of R&D activities for the agri-aqua sectors will be a blessing for every Juan.