The International Rice Research Institute (IRRI) was established in 1960 by the Ford and Rockefeller Foundations with the help and approval of the Govern- ment of the Philippines. Today IRRI is one of 16 nonprofit international re- search centers supported by the Consultative Group on International Agricul- tural Research (CGIAR). The CGIAR membership comprises Organisation for Economic Cooperation and Development donors, international and regional organizations, and private foundations. IRRI receives support from several CGIAR members, including the World Bank, European Union, Asian Development Bank, International Fund for Ag- ricultural Development, Rockefeller Foundation, and the international aid agen- cies of the following governments: Australia, Belgium, Brazil, Canada, People’s Republic of China, Denmark, France, Germany, India, Islamic Republic of Iran, Japan, Republic of Korea, The Netherlands, Norway, Philippines, Portugal, Spain, Sweden, Switzerland, Thailand, United Kingdom, and United States. The responsibility for this publication rests with the International Rice Research Institute. Copyright International Rice Research Institute 2002 Mailing address: DAPO Box 7777, Metro Manila, Philippines Phone: (63-2) 845-0563, 844-3351 to 53 Fax: (63-2) 891-1292, 845-0606 Email: [email protected] Home page: www.irri.org Riceweb: www.riceweb.org Riceworld: www.riceworld.org Courier address: Suite 1009, Pacific Bank Building 6776 Ayala Avenue, Makati City, Philippines Tel. (63-2) 891-1236, 891-1174, 891-1258, 891-1303 Suggested citation: Pandey S, Mortimer M, Wade L, Tuong TP, Lopez K, Hardy B, editors. 2002. Direct seeding: research issues and opportunities. Proceedings of the International Workshop on Direct Seeding in Asian Rice Systems: Strategic Research Issues and Opportunities, 25-28 January 2000, Bangkok, Thai- land. Los Baños (Philippines): International Rice Research Institute. 383 p. LAYOUT AND DESIGN: George R. Reyes FIGURES AND ILLUSTRATIONS: Emmanuel Panisales and George R. Reyes COVER DESIGN: Juan Lazaro IV ISBN 971-22-0173-2 Contents FOREWORD vii ACKNOWLEDGMENTS viii The needs for and challenges of direct seeding Economics of direct seeding in Asia: patterns of adoption 3 and research priorities S. Pandey and L. Velasco Direct seeding of rice in Asia: emerging issues and strategic 15 research needs for the 21st century V. Balasubramanian and J.E. Hill Patterns and processes in direct seeding Gogorancah rice in Indonesia: a traditional method 43 in the modern era A.M. Fagi and S. Kartaatmadja The beushening system of rice crop establishment 53 in eastern India V.S. Tomar Environmental conditions as determinants of direct seeding 75 techniques in different ecosystems in the Mekong Delta of Vietnam Nguyen Duy Can and Vo-Tong Xuan Impact of direct seeding on rice cultivation: lessons from the 87 Muda area of Malaysia Nai-Kin Ho and Z. Romli iii Farmers’ direct-sowing practices in rainfed lowland rice in southern 99 Thailand: improving a traditional system G. Trébuil and S. Thungwa Development trends and farmers’ benefits in the adoption 115 of wet-seeded rice in Thailand S. Isvilanonda Changes in crop establishment methods and constraints to 125 adoption of wet seeding in the Chao Phraya delta, Thailand F. Molle and C. Chompadist Economics of direct seeding in northeast Thailand 139 S. Pandey, L. Velasco, and N. Suphanchaimat Status of dry-seeding technologies for rice in Korea 161 M.-H. Lee, J.K. Kim, S.S. Kim, and S.T. Park Seedling broadcasting in China: an overview 177 Tang Sheng-xiang Dry-seeded rice for enhancing productivity of rainfed 185 drought-prone lands: lessons from Bangladesh and the Philippines M.A. Mazid, S.I. Bhuiyan, M.A. Mannan, and L.J. Wade Direct-seeding and reduced-tillage options in the rice-wheat 201 system of the Indo-Gangetic Plains of South Asia P.R. Hobbs, Y. Singh, G.S. Giri, J.G. Lauren, and J.M. Duxbury Overcoming constraints in direct-seeded rice Mechanization issues in tillage and crop establishment for dry 219 direct-seeded rice R.R. Bakker, M.A. Bell, and J.F. Rickman On-farm seed priming to improve crop establishment and yield 231 in dry direct-seeded rice D. Harris, R.S. Tripathi, and A. Joshi Enhancing the performance of dry-seeded rice: effects 241 of seed priming, seeding rate, and time of seeding L.V. Du and T.P. Tuong iv Contents Rice cultivar requirements for direct seeding 257 in rainfed lowlands S. Fukai Manipulation of seed and seedling vigor and their implications 271 for the performance of wet-seeded rainfed lowland rice H. Kyu, S.T. Amarante, A.A. Gomez, H.P. Samonte, R.P. Robles, and L.J. Wade The dry-seeding technique for saving water in irrigated 281 rice production systems D.F. Tabbal, S.I. Bhuiyan, and E.B. Sibayan Increasing water productivity in rice cultivation: impact 299 of the large-scale adoption of direct seeding in the Muda irrigation system R.J. Cabangon, T.P. Tuong, E.B. Tiak, and N. bin Abdullah Nutrient management of direct-seeded rice in different 315 ecosystems of eastern India H.C. Bhattacharyya, V.P. Singh, and K. Borkakati Developing a direct-seeding technology package for rainfed 331 lowland rice in Lao PDR Sipaseuth, P. Sihavong, V. Sihathep, P. Inthapanya, M. Chanphengsay, and S. Fukai Influences of changing from transplanting to direct seeding 341 on the status of some pest species T. Wada Weed management in direct-seeded rice in South Vietnam 349 D.V. Chin and M. Mortimer Weed species shifts in response to serial herbicide application 357 in wet-seeded rice in Malaysia Azmi Man and M. Mortimer Managing direct seeding for rainfed lowland rice with particular 369 attention to weed control P. Romyen, S. Khunthasuvon, and S. Fukai RESEARCH ISSUES IDENTIFIED DURING THE DISCUSSION SESSIONS 381 Contents v Foreword Asian rice systems are undergoing various types of change in response to economic factors and technological opportunities in farming. One such change has been a shift from transplanting to direct-seeding methods for rice establishment. While the rising cost of labor has provided economic incentives for direct seeding, the availability of short-duration rice varieties and chemical weed control methods has made such a shift economically profitable. Direct-seeding methods have also played a critical role in the intensification of Asian rice systems. In the future, in addition to the rising cost of labor, rice farmers of Asia will have to deal with an anticipated increasing scarcity of irrigation water as the demand for water from the urban and industrial sectors expands. Direct-seeding methods, especially dry seeding, may help in achiev- ing higher water-use efficiency. Despite the underlying trend toward direct seeding, the relative importance of direct seeding and transplanting varies among regions and ecosystems. Traditional direct-seeding systems with low productivity dominate in some areas, whereas suc- cessful transformations to high-productivity systems have occurred in others. Trans- planting culture may also continue to dominate under certain environmental and socioeconomic conditions. IRRI, together with the Rice Research Institute, Thailand, organized an interna- tional workshop on Direct Seeding in Asian Rice Systems: Strategic Issues and Oppor- tunities, held on 25-28 January 2000 in Bangkok, Thailand. The objectives of this workshop were to review past patterns of changes in crop establishment and factors explaining such patterns, assess the likely future patterns of change in crop establish- ment in various ecosystems and regions, and identify strategic research issues for im- proving rice productivity by manipulating crop establishment methods and related factors. IRRI and national agricultural research and extension system partners are al- ready making considerable efforts to develop more productive and sustainable direct- seeding systems. Although two previous workshops sponsored by IRRI (in 1990 and 1995) focused on the wet-seeding method, this workshop emphasized dry seeding. A cross-ecosystems perspective was taken so that the output of the workshop would be relevant to all rice production environments. The workshop helped identify strategic research issues on crop establishment methods covering aspects such as land prepara- tion; weed, water, and crop management; and crop improvement. This publication contains the papers presented at the workshop and the major research issues identified during the group discussions. We hope that this will be a useful source of information as we move forward in this important theme of research. RONALD P. CANTRELL Director General vii Acknowledgments Many people contributed to the success of the international workshop upon which this publication is based. The workshop was co-hosted by the Rice Research Insti- tute, Thailand. Boriboon Somrith, IRRI Liaison Scientist in Bangkok, provided the necessary logistical support to the workshop. The overall organizing and technical review committee consisted of S. Pandey (Chair), M. Mortimer, L. Wade, and T.P. Tuong. Ludy Velasco supported the organizing committee from the very beginning and assisted in the editing of this volume while L. Damian and Aranya Sapprasert provided the necessary secretarial services during the workshop. We thank T. George, K.L. Heong, V. Balasubramanian, J. Hill, D. Dawe, V.P. Singh, and M.H. Lee for reviewing some of the papers in this book. viii The needs for and challenges of direct seeding Economics of direct seeding in Asia: patterns of adoption and research priorities S. Pandey and L. Velasco Direct seeding