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RICE

Adoption and Spatial Diversity of Later Generation Modern Rice Varieties in the Philippines

^a Graduate School of Kuroshio Science, Kochi Univ., Monobe Otsu 200 Nankoku city, Kochi, 783-0093 Japan
^b Philippine Rice Res. Inst., Maligaya, Science City of Muñoz, 3119 Nueva Ecija, the Philippines

^* Corresponding author (ccasiwan{at}yahoo.com).

Not much information has been publicly available on the diffusion of modern varieties (MVs) from the 1990s and on current diversity of rice (Oryza sativa L.) varieties in farmer fields. Using national household surveys of Philippine growers conducted in 1993, 1997, and 2002, this study describes the adoption of specific MVs and variety groups in farmer fields; measures the adoption rates of newly released varieties; and analyzes the spatial diversity of varieties planted in farmer fields. Data showed that IR64, IR74, IR42, and Burdagol are enduring varieties from 1970s and 1980s, and PSB Rc18, PSB Rc10, PSB Rc28, Masipag, PSB Rc14, and PSB Rc82 are the most commonly planted new varieties. The MV3 varieties (released mid-1980s to mid-1990s) were popularly planted with an observed decrease in the use of MV2s (released mid-1970s to mid-1980s) and increase in the use of MV4s (released after 1995). Around 30 to 40% of the total rice area is planted to new rice varieties and the aggregate replacement period of rice varieties is around 8 to 11 yr, with faster adoption rates during dry season (DS) in irrigated areas. On average, only 10 varieties occupy around 70% of the rice area in major rice-producing provinces in one season. Indices of spatial diversity show wide variability across provinces in terms of the richness of diversity, dominance of specific varieties, and the equality of abundance, but no clear trend across periods. Policymakers are thus encouraged to continually support and strengthen the current efforts of public rice breeding research and extension, even as research beyond analysis of on-farm morphological diversity is recommended.

Abbreviations: DS, dry season • FS, foundation seeds • IRR, irrigated • IRRI, International Rice Research Institute • MVs, modern varieties • NSIC, National Seed Industry Council • PhilRice, Philippine Rice Research Institute • RBFHS, rice-based farm household survey • RF, rainfed • TFP, total factor productivity • TV, traditional varieties • WS, wet season

¹ Beginning in 1990, the NSIC adopted a variety nomenclature using a code prefix of PSB Rc plus a number for all rice varieties released. Each variety also is assigned a local name corresponding to names of popular river or lake for irrigated and rainfed-lowland varieties, and mountains for upland varieties.

² For the paper, an analysis of the 1997 data set showed 10% of the rainfed rice farmers adopting certified, registered, and foundation seeds, while 21% adopted in irrigated areas. In 2002, 28% of the farmer-respondents in irrigated areas adopted certified seeds or better compared with only 17% in the rainfed areas.

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Received for publication September 4, 2007.