04108nas|a2200385 a 4500 20260817173406.0 190701s2015 th uu m rtt 0| a1eng d .b12317068 AIT RSPR no. AS-15-05 Ullah, Hayat Comparative study of the root systems of drought tolerant (RD-6) and drought sensitive (RD-10) Thai rice varieties under different cultivation methods and moisture levels Pathum Thani, Thailand : Asian Institute of Technology, 2015 1 online resource (47 leaves) : ill. Research studies project report ; no. AS-15-05 A research submittedin partial fulfillment of the requirements for the degreeof Master of Science in Agricultural Systems and Engineering, School of Environment, Resources and Development Research report (M. Sc.) - Asian Institute of Technology, 2015 Root system of rice (Oryza sativa L.)has a crucial role in water and nutrients uptake from soil. A well-developed root system is the foundation of good growth and yield. To find the effect of different cultivation methods and water regimes on root growth,a study was conducted in a greenhouse at AIT by measuring root number (RN), root length (RL), root length density (RLD), root biomass (RB) and root to shoot ratio (RS ratio). Two varieties (RD6 with drought tolerance ability) and RD10 (normal one) were used. Two methods of cultivation 2direct seeding3(DS) and 2transplanting3(TP) were evaluatedfor above mentioned properties under two water regimes, field capacity (FC) and 50% of FC. Data were collected during two stages of life cycle,i.e.,tillering andflowering. At flowering stage the performance of DS was found better for all properties with statistical significance (p< 0.05) in most of the cases.The highest difference of 125% between means of DS and TPwas recorded for RL and RLD. During tilleringstage RL and RLD values were 31.5%, RB8.39% and RS 12% higher for TPthan DS with statistical significance. Two water regimes showeddifferentratioresults, 50% FC hadhigher average value during both stages of life cycle for RL and RLD (22% and 8.72% at tillering and flowering stage,respectively). For RN 50% of FCshowedhigher value at tillering stage and FC at flowering stage. For RB and RS ratio exactly opposite trend was observed than RL and RLD for both growth stages. Statistically significant varietal difference was also observed with higher value of RN, RL and RLD for RD10 at tillering and RD6 at flowering stage, while average higher value of RB was recorded for RD6 during both stages. For RS ratio average higher value was found for RD6 at tillering and RD10 at flowering stage. Overall the results showeda better performance of DS for both varieties. Deficiency of water hadan effect on root system development and two varieties responded differently during different growth stages. Rice Varieties Thailand, Central Datta, Avishek, Chairperson Anal, Anil Kumar, Examination Committee Shrestha, Rajendra Prasad, Examination Committee Higher Education Commission (HEC) Pakistan, Scholarship Donor AIT Fellowship, Scholarship Donor Asian Institute of Technology. Research studies project report ; no. AS-15-05 Full-Text http://203.159.5.9/ait-thesis/detail.php?q=B01276 .b12317068 mnait m 240422 0 190701 m a m 0 mnait mnait 20 Barcode : 30050120958995 CREATED : 2019-01-07 RECORD # : i13199766 LPATRON : 1029385 LCHKIN : 2021-08-03 # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 1 TOT RENEW : 0 Barcode : 30050120958961 CREATED : 2019-01-07 RECORD # : i13199778 LPATRON : 0 LCHKIN : - # RENEWALS : 0 # OVERDUE : 0 IUSE3 : 0 TOT CHKOUT : 0 TOT RENEW : 0 19771 19771 0 0 0 0 MAIN MAIN mnait 2026-08-17 50.00 0 AIT RSPR no. AS-15-05 30050120958995 2026-08-17 17:34:06 1 2026-08-17 20 0 0 0 0 MAIN MAIN mnait 2026-08-17 50.00 0 AIT RSPR no. AS-15-05 30050120958961 2026-08-17 17:34:06 2 2026-08-17 20