03115cas a2200241 a 450000500170000000800410001703500150005810000260007324501110009926000520021030000100026249000270027250001520029950200570045152020300050865000430253870000420258170000480262370000440267171000340271581000590274985600650280820260817163634.0110920s1988    th uu|m rtt   0|  a1eng d  a.b100992190 aChanpithya Shimphalee10aAssessment of rice varieties and methods of establishment under rainfed conditions in Ban Na, Nakhon Nayok  aBangkok :bAsian Institute of Technology,c1988  a84 p.1 aThesis ;vno. AE-88-38  aA thesis submitted in partial fulfillment of the requirements for the degree of Master of Science, School of Environment, Resources and Development  aThesis (M.Sc.) - Asian Institute of Technology, 1988  aA 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.  0aRicezThailandzNakhon NayokxPlanting1 aPeacock, Christabel P., eChairperson1 aGartner, Joseph A., eExamination Committee1 aDemaine, Harvey,eExamination Committee2 aFAO/UNDP, eScholarship Donor2 aAsian Institute of Technology.tThesis ;vno. AE-88-38  3Full-Textuhttp://203.159.5.9/ait-thesis/detail.php?q=B18941