Chanpithya Shimphalee creator Peacock, Christabel P. Chairperson Gartner, Joseph A. Examination Committee Demaine, Harvey Examination Committee FAO/UNDP Scholarship Donor text series technical report th Bangkok Asian Institute of Technology 1988 continuing eng 84 p. A farm trial on rainfed rice cultivation was carried out in Village No.10, Khao Perm sub - district, Ban Na district, Nakhon Nayok province after the existing farming systems had been d escribed and the problems identified. Three de signs for rice improvement were continually adapted to match the changing environmental conditions. The first design concerned fertilizer trial for rice cultivation but it had to be adapted due to low and late rainfall. Th e second design was arranged to cope with the low and l ate rainfall by comparing field crops and dry seeded rice cultivation . However , heavy rain in September made it impossible to carry on the trial and the final design was made to test three rice varieties namely Khao Puang, RD27 and RD7. Two methods of establishment, direct seeding and trans planting, we re used for RD7. Despite severe aridity, the newly introduced RD27 was superior to the others in terms of grain yield ( 240 kg/rai). Khao Puang, RD7 ( transplanted) and RD7 (direct seeded) had yields of 2 16, 204, and 196 kg/rai respectively . Khao Puang produced the highest straw yield (40-0 kg/rai). RD27, RD7 (transplanted ) and RD7 (direct seed e d) contributed straw yields of 391, 365 and 330 kg/rai respectively . RD7 and RD27 after milling gave head rice of 61.3% a nd 60 . 1% which is higher than Khao Puang ( 5 4.6%). RD27 ha d a higher gross margin of 469 baht/rai and RD7 (direct seeded ) followed with 446 baht/rai . RD7 (transplanted) provide d 354 baht/rai and Khao Puang had 346 baht/rai. Most farmers were like l y to accept RD27 but further verification trials to test its suitability to the environment under a wide range of conditions must be carried out. In times o f .low and late rain, non-photosensitive rice varieties are not necessarily better than photosensitive varieties. Direct seeding was not the usual method of rice growing in the area and farmers agreed to utilize only in case of severe drought when trans planting could not take place. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development Thesis (M.Sc.) - Asian Institute of Technology, 1988 Rice Thailand Nakhon Nayok Planting Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B18941 http://203.159.5.9/ait-thesis/detail.php?q=B18941 110920 20260817163634.0