Advances in hybrid rice technology
in the Philippines

S.R. Obien, E.D. Redoña and F.M. Malabanan

Philippine Rice Research Institute (PhilRice), Muñoz, Nueva Ecija 3119, the Philippines

INTRODUCTION

Along with many other rice-growing countries, the Philippines is affected by factors that exert tremendous pressure on the country's ability to produce enough rice for its population. These factors include unabated population growth (2.5 percent per annum), diminishing rice production area (1.8 percent per annum) and levelling-off of rice yields (5 to 6 tonnes/ha during the dry season). While the country was able to increase rice production from 7.6 million tonnes in 1980 to 11.3 million tonnes in 1996, rice production growth has mostly lagged behind population growth, except during the green revolution period from 1965 to 1980. By 2025, 40 to 50 percent more rice relative to current production levels will be needed to feed the Philippines' projected population of 100 million. Since the Government of the Philippines has adopted a food security policy based on rice self-sufficiency, this extra rice production will have to come from less land and use less water, labour and pesticides.

In preparation for the enormous task that lies ahead, the government is currently modernizing its agricultural research, development and extension delivery systems and infrastructure. For example, one of the major programmes being implemented by the Department of Agriculture is the Agrikulturang Makamasa (or Agriculture for the Masses) programme, a revitalized and expanded version of the former Gintong Ani (or Golden Harvest) programme. The major goal of this programme is to bridge the gap between the potential of currently available technologies and current levels of on-farm production. At the same time, the programme aims at developing existing, and/or adopting, foreign technologies that would enable the country to reach higher levels of rice productivity.

Increasing rice yields per unit area and unit time is an obvious strategy for increasing rice production. In the post-1980 period, however, yield growth accounted for only 34 percent of the 1.9 percent growth in rice production, compared with a 74 percent share of the 4.6 percent rice production growth during the green revolution period. Clearly, new technologies are needed to spur further yield growth and, hence, rice production increases.

As demonstrated in China, and recently in India and Viet Nam, rice hybrids can be used to increase rice production with such consequent positive benefits as generating rural employment, land savings and women's empowerment. Experts have predicted that demand for hybrid rice technology in the Philippines will increase as a result of the country's high labour-to-land ratio and the high proportion of irrigated rice land (Lin and Pingali, 1994). In January 1998, the Philippine Government launched a national hybrid rice programme that aims at utilizing hybrid rice technology as a new approach to increasing national rice production and the productivity and competitiveness of Philippine farmers over the short term, and for attaining national rice self-sufficiency and food security over the long term.

DEVELOPMENT OF HYBRID VARIETIES

In the Philippines, experimental hybrids must exhibit at least 15 percent higher yield relative to standard inbred check cultivars before they can be recommended by the National Seed Industry Council (NSIC) for commercial cultivation. So far, two hybrids have been released - PSB Rc26H, or Magat, in 1994 and PSB Rc72H, or Mestizo, in 1997 (Table 1). Both Magat (IR62829A/ IR29723-143-3-2-1R) and Mestizo (IR58025A/IR34686-179-1-2-1R) were bred at the International Rice Research Institute (IRRI). Magat is early-maturing (110 days) and recommended for the northern Philippines, while Mestizo is medium-maturing (123 days) and recommended for nation wide use. A third hybrid, CXRH 05 developed by Cargill Phils. Inc., was due for release during 1998 in specific regions of the country. This was to be the first private sector-developed rice variety released in the Philippines.

Hybrid rice breeding activities in the country are undertaken by both the public and private sectors. In the public sector, IRRI started hybrid rice research and development (R&D) activities in the late 1970s. Two commercially usable cytoplasmic male sterile lines, IR58025A and IR62829A, and numerous restorer lines, adapted to the tropics, were bred at IRRI during the 1980-1998 period. Eleven of the 16 hybrids currently waiting for release were bred at IRRI. In 1989, PhilRice, which is the sole agency mandated to establish and coordinate all national rice R&D activities, established a hybrid rice breeding project. Since then, some
experimental hybrids developed by PhilRice have entered the national yield trials. To strengthen its technology-generation capacity, PhilRice has forged technical collaborations on hybrid rice R&D with Chinese institutions such as: Yunnan Agricultural University, in 1989; Jiangxi Academy of Agricultural Sciences, in 1995; Guangxi Academy of Agricultural Sciences, in 1997; and Fujian Agricultural University and Yangzhou University, in 1998. These collaborations have proved effective in diversifying the germplasm base for breeding hybrids at PhilRice (Redoña et al., 1998) and in providing researchers in the Philippines with valuable exposure to technologies developed in China.

In the private sector, Cargill Phils. Inc. has worked on hybrid rice R&D since 1988. Four Cargill hybrids have entered national yield trials and, in 1997, the company initiated marketing trials for CXRH 05 and a new hybrid, CXRH 24, in 30 locations in the southern Philippines. In 1996, another private company, Hyrice, also engaged itself in hybrid rice R&D. Using germplasm developed at IRRI, Hyrice is currently engaged in developing hybrid combinations for the northern Philippines. Other private companies, such
as Plantek Inc. and Allied Botanicals, and a non-governmental organization (NGO), Brigada Berde (or Green Corps Foundation), have also started hybrid rice operations, especially in the areas of seed production.

SEED PRODUCTION

A seed yield of at least 1 tonne/ha is considered to be the profitability threshold in Philippine hybrid seed production. Using the hybrid seed production technology developed at IRRI between 1986 and 1992, in 1993, PhilRice began to conduct and supervise small-scale (< 1 ha) on-farm seed production activities in the northern Philippines (Lara et al., 1996). The average top yield obtained by accredited seed growers over four seasons was 1.9 tonnes/ha (de Leon et al., 1998).

Large-scale seed production of rice hybrids in the Philippines has, however, mostly been undertaken by PhilRice, research stations of the Department of Agriculture and IRRI. F₁ seed yields have improved recently with the aid of technologies introduced through PhilRice's Chinese collaborations. Seed yields in large-scale A/R seed production plots of Mestizo, for example, increased from 1.7 tonnes/ha in the 1997 dry season to 2.3 tonnes/ha in the 1998 dry season. Yields in the A/B multiplication of the CMS line IR58025A also increased, from 3.3 tonnes/ha in the 1997 dry season to 3.5 tonnes/ha in the 1998 dry season. A record wet season seed yield of 1.3 tonnes/ha for Mestizo A/R large-scale seed production was also attained in 1998.

There is now nationwide interest in hybrid seed production among inbred seed growers. During the 1998 wet season, for example, about half of the country's more than 100 ha of hybrid seed production area was planted by seed growers from various regions of the country, notably, regions 2, 3, 5, 6, 11 and 13. About a third of these activities were conducted by Cargill Phils. Inc. and Brigada Berde. Based on projected hybrid rice cultivation targets, the seed production requirements for the next seven years have been determined (Table 2).

A technical working group from NSIC, responsible for seed certification and seed standards, is currently finalizing the guidelines for hybrid rice seed production, testing and certification. Eventually, commercial F₁ seed production in the Philippines will be handled by accredited seed growers (preferably belonging to organized groups with compact seed production areas) and private seed companies.

TRAINING THE HYBRID RICE WORKFORCE

The development of a critical mass for hybrid rice research and seed production was started in the Philippines in 1987 with IRRI assistance (Redoña et al., in press). To date, 29 PhilRice and Department of Agriculture researchers have been trained at or through IRRI on hybrid rice seed production and/or breeding technology. Most of these trained personnel are currently active players in the national hybrid rice programme. After the release of Magat and Mestizo hybrids, PhilRice began organizing various training courses for seed growers, seed inspectors, technical personnel, agricultural technicians, seed coordinators, private-sector R&D personnel and policy-makers from all over the country. Since 1997, for example, 449 potential key players in the national hybrid rice programme have participated in 12 training courses on hybrid rice seed production conducted by PhilRice at its headquarters in Nueva Ecija and at various branch stations in the northern and southern Philippines. More than half of the training participants were private seed growers (mostly members of seed-grower cooperatives) who were interested in hybrid rice seed production. To expedite the spread of technical expertise on hybrid rice, a four-month specialized training course on hybrid rice seed production was conducted during the 1998 wet season for 22 Department of Agriculture and NGO trainers from the regions that had been selected for hybrid rice cultivation and seed production. After their training, participants are expected to train seed growers and farmers in their respective regions on hybrid rice technology. For farmer participants in the various hybrid rice technology demonstration areas across the country, a 16-week Farmers' Field School is currently being conducted by the Department of Agriculture. The training curriculum encompasses all facets of rice production, with special emphasis on hybrid rice cultivation.

TECHNOLOGY DEMONSTRATION

Demonstrations of hybrid rice technology were initiated using Magat hybrid at PhilRice in 1995 (Lara et al., 1996) and in selected Gintong Ani programme demonstration sites in 1996 (de Leon et al., 1998). In these demonstration trials, the Magat hybrid exhibited a yield potential of up to 11.8 tonnes/ha using a 180-60-60 nitrogen-phosphorus-potassium (NPK) fertilizer level applied in three splits. In 1997, larger technology demonstration plots (500 m²), which included the Mestizo hybrid, were set up in selected farms in three northern Philippine provinces. The results of these trials demonstrated the superiority of hybrids over modern inbred cultivars. Based on the average from five locations, for example, the Magat and Mestizo hybrids had yields of 7.1 and 8.2 tonnes/ha, respectively - more than the most popular inbred varieties in their localities by 22 and 37 percent, respectively.

In the national hybrid rice production programme launched in 1998, 11 provinces were chosen as targets for hybrid rice cultivation: Cagayan, Isabela, Nueva Ecija and Camarines Sur in the northern Philippines; Bohol and Iloilo in the central Philippines; and Davao del Norte, Davao del Sur, Davao Oriental, Maguindanao and Lanao del Norte in the southern Philippines. These provinces were selected because they were of strategic significance and already had high rice yields and productivity, favourable and irrigated rice-growing environments, and locally available trained labour.

Using Magat and Mestizo hybrids, large-scale technology demonstration trials (5 to 20 ha) were set up by PhilRice and the Department of Agriculture during the 1998 dry season in five of the 11 provinces targeted for hybrid rice cultivation. In these trials, the Mestizo hybrid yielded up to 10.2 tonnes/ha (with a mean of 7.45 tonnes/ha) - more than the best inbred varieties used as checks which, on average, yielded up to
6.7 tonnes/ha (with a mean of 6 tonnes/ha, see Figure). Mestizo was also reported to have good eating quality, comparable to that of the high-eating-quality modern inbred variety IR64.

The hybrid rice cultivation practices promoted under the national hybrid rice programme included: use of
20 kg F₁ seeds/ha; use of a 400 m² seed bed; incorporation of ten bags of organic fertilizer in the seed bed; sowing of 50 g of seed per square metre of seed bed; and use of one seedling per hill during transplanting. The other cultivation practices promoted were similar to those used for modern inbred varieties.

Through earlier studies conducted by both PhilRice and IRRI, it was determined that the hybrid would have to have a yield advantage of at least 1 tonne/ha over existing inbreds if hybrid rice cultivation was to be attractive and profitable for farmers.

INFORMATION DISSEMINATION

The public awareness campaign on hybrid rice technology in the Philippines was started in the early 1990s, when PhilRice began to feature the potential of this technology in its quarterly PhilRice Newsletter. More recently, efforts have been intensified on both the technical and popular fronts.

For example, the launching of the hybrid rice programme was accompanied by a massive information campaign that utilized the triple-media of television, radio and print. PhilRice published and distributed various information booklets such as Hybrid rice questions and answers, Hybrid rice production technology (which was translated into five Philippine dialects) and the Hybrid Rice Programme Document. In addition, articles, news features and/or press releases were generated for the PhilRice Newsletter and for major newspapers with national and regional circulation. Spots were acquired on television and radio for discussion of hybrid rice technology. At the technology demonstration sites, posters, calendars and other information materials on hybrid rice were displayed and/or distributed during planting demonstrations, field days and training activities.

Yield of Magat, Mestizo and check inbred varieties in large-scale technology demonstration trials, 1998 DS

FUTURE OUTLOOK

To unify and coordinate the country's R&D and extension efforts on hybrid rice technology, a hybrid rice programme was established at PhilRice in 1998. The major goal of the programme is to develop and use hybrid rice technology to increase national rice production and farmers' productivity and competitiveness, and to attain rice self-sufficiency over the long term. Multidisciplinary in character, the programme will plan, implement and coordinate breeding, seed production, agronomy, crop protection, socio-economics, policy, engineering, chemistry and food science technology activities on hybrid rice in the country. It will also link up with seed production and technology promotion groups of PhilRice, the government and the private sector and with the R&D programmes of other countries. The PhilRice branch station in Isabela is scheduled to become the National Hybrid Rice R&D Center and the seat of the programme.

To support the intensified R&D efforts on hybrid rice in the Philippines, funding has been obtained from both the government and external donor agencies. For example, the country has obtained a Technical Cooperation Programme (TCP) grant from FAO to strengthen its national capacity for hybrid rice development and use. Support has also been obtained from the Asian Development Bank through IRRI, and the Rockefeller Foundation for hybrid rice-related activities.

The continued support of both government and external donor agencies will be needed for the full development of hybrid rice technology in the country. The major issues that still need to be addressed include: the absence of a strong private rice seed industry; limited hybrid rice R&D infrastructure; inadequate trained labour for R&D and extension activities; problems with genetic purity and flowering synchronization in hybrid seed production; the limited number and experience of seed growers; inadequate equipment for research and seed production; and the limited awareness of the general public and key leaders, in both government and the private sector, of the potential of hybrid rice technology.

With continued support from both the government and external donor agencies, the country plans to plant between 50 000 and 100 000 ha with hybrid rice over the next five years. If productivity is increased by 1 tonne/ha, this would result in 50 000 to100 000 tonnes more rice, worth somewhere between US$10 million and $20 million. If the Philippines' total of 0.8 million ha of irrigated rice area were planted with rice hybrids, the resulting extra rice production could reduce, if not totally eliminate, the country's annual rice importation. Hence, hybrid rice technology is a major key for attaining rice self-sufficiency in the country.

REFERENCES

de Leon, J.C., Redoña, E.D., dela Cruz, I.A., Ablaza, M.S., Malabanan, F.M., Lara, R.J. & Obien, S.R. 1998. Hybrid rice in the Philippines: progress and prospects. In S.S. Virmani, E.A Siddiq & K. Muralidharan, eds. Advances in Hybrid Rice Technology: Proceedings of the Third International Symposium on Hybrid Rice, 14-16 November 1996, Hyderabad, India. Manila, IRRI.

Lara, R.J., Miranda, R.B., Javier, L.C., dela Cruz, I.A., Ablaza, M.S. & de Leon, J.C. 1996. Development of hybrid rice technology for the Philippines. Phil. J. Crop Sci. (Supplement l) 21: 4.

Lin, Y.L. & Pingali, P.L. 1994. Economic assessment of the potential for hybrid rice in tropical Asia: lessons from the Chinese experience. In S.S. Virmani, ed. Hybrid rice technology: new developments and future prospects: selected papers from the International Rice Research Conference. Manila, IRRI.

Redoña, E.D., Ocampo, T.D., Hipolito, L.R. & Sebastian, L.S. 1998. Classification of cytoplasmic male sterile rice lines based on RAPDs, SSRs and AFLPs. In P.J. Larkin, ed. Agricultural Biotechnology: Laboratory Field and Market. Proceedings of the Fourth Asia-Pacific Conference on Agricultural Biotechnology,
p. 87-89. Canberra, UTC Publishing.

Redoña, E.D., Virmani, S.S., Malabanan, F.M., Toledo, R.S., Javier, L.J., Casal, C.L., Rebuelta, P.I., Barroga, R.F. & Obien, S.R. Hybrid rice technology in the Philippines: from laboratory to farmers' fields. Phil.
J. Crop. Sci. (in press).

Progrès des technologies du riz hybride aux Philippines

En janvier 1998, le Gouvernement philippin a lancé un programme national sur le riz hybride visant à utiliser les technologies du riz hybride pour accroître la production nationale du riz. Les activités de sélection de riz hybride sont entre les mains du secteur public, notamment l'Institut philippin de recherche sur le riz (PhilRice), et du secteur privé. Deux hybrides ont été obtenus à ce jour par le Conseil national de l'industrie semencière pour les cultures commerciales, à savoir PSB Rc26H ou Magat en 1994 et PSB Rc72H ou Mestizo en 1997. En se fondant sur la moyenne pour cinq emplacements, on constate que les hybrides Magat et Mestizo ont permis des rendements de 7,1 et 8,2 tonnes à l'hectare, respectivement, dépassant les rendements des variétés les plus populaires dans ces mêmes localités de 22 et 37 pour cent, respectivement. Quatre hybrides de Cargill font depuis l'objet d'essais de rendements nationaux et, en 1997, la société a lancé des essais de commercialisation pour CXRH 05 et un nouvel hybride CXRH 24, sur 30 sites dans le sud des Philippines. En 1996, une autre entreprise privée, Hyrice, a également entrepris des activités de recherche- développement sur le riz hybride.

L'intérêt pour la production de semences hybrides s'est généralisé parmi les cultivateurs de lignées consanguines dans tout le pays. Les rendements maximaux moyens obtenus par les cultivateurs de semences agréés pendant quatre campagnes ont été de 1,9 tonne à l'hectare. Un rendement record de saison humide de 1,3 tonne à l'hectare a été obtenu par PhilRice en 1998 pour la production à grande échelle de semences de Mestizo A/R. Quelques questions capitales doivent être résolues pour que les technologies du riz hybride se développent et soient utilisées avec succès aux Philippines. Ces questions incluent: a) l'absence d'une industrie semencière privée solide; b) les limites de l'infrastructure de recherche-développement sur le riz hybride; c) le manque de formation aux activités de recherche-développement et de vulgarisation; d) la pureté génétique et la synchronisation de la floraison dans la production de semences hybrides; e) le nombre et l'expériences limités des cultivateurs de semences; f) le manque de matériel pour la recherche et la production de semences; et g) la sensibilisation limitée des responsables des secteurs public et privé et du public en général au potentiel des technologies du riz hybride.

Adelantos en la tecnología del arroz híbrido en Filipinas

El Gobierno filipino puso en marcha en enero de 1998 un programa nacional de arroz híbrido con el que se pretende utilizar la tecnología de este arroz como nueva solución para aumentar la producción arrocera nacional. Estas actividades genéticas sobre el arroz híbrido en el país corren a cargo de los sectores público, especialmente el Instituto Filipino de Investigaciones sobre el Arroz (PhilRice), y privado. Hasta ahora son dos los híbridos que ha distribuido el Consejo Nacional de la Industria de las Semillas para su cultivo comercial, el PSB Rc26H, también llamado Magat, en 1994 y el PSB Rc72H, o Mestizo, en 1997. Partiendo del promedio obtenido en cinco lugares, los híbridos Magat y Mestizo registraron rendimientos de 7,1 y 8,2 t/ha, respectivamente, superando en rendimiento a las variedades endógamas más conocidas en sus localidades correspondientes en un 22 y un 37 por ciento, respectivamente. Luego se ha comenzado a ensayar el rendimiento de cuatro híbridos de Cargill y, en 1997, la compañía inició ensayos de comercialización para el CXRH 05 y un nuevo híbrido, el CXRH 24, en 30 lugares del sur de Filipinas. En 1996, otra compañía privada, Hyrice, también participó en I+D sobre el arroz híbrido.

A nivel nacional, entre los cultivadores de semillas endógamas se ha despertado interés por la producción de semillas híbridas. El rendimiento máximo medio obtenido por cultivadores habilitados de semillas en cuatro centros fue de 1,9 t/ha. En 1998 PhilRice consiguió un rendimiento sin precedentes de semillas de la temporada húmeda de 1,3 t/ha para el arroz Mestizo en gran escala. Hay que afrontar algunos de los principales problemas existentes para poder perfeccionar y utilizar satisfactoriamente la tecnología del arroz híbrido en Filipinas. Entre otros cabe enumerar: a) la falta de una industria privada fuerte de semillas de arroz; b) una infraestructura limitada de I+D sobre arroz híbrido; c) escasez de personal especializado para las actividades de I+D y extensión; d) la pureza genética y la sincronización de la floración en la producción de semillas híbridas; e) el limitado número y la poca experiencia de los cultivadores de semillas; f) la insuficiencia de equipo para la investigación y la producción de semillas, y g) la limitada sensibilización de los principales dirigentes del sector, tanto público como privado, y del público en general sobre el potencial que encierra la tecnología del arroz híbrido.