Abstract
To understand the growth habit of rice plants under direct seedling cultivation on well-drained paddy fields, physiological and ecological characteristics were compared among directly seeded and transplanted rice cultivar "Whasungbyeo". Photosynthesis and respiration were lower in direct seeding cultivation (DSC) than in mechanical transplanting cultivation (MTC). Chlorophyll content and root activity were lower in DSC than in MTC from the tillering to heading stages, while they were higher 15 days after heading in DSC. The stomatal resistance of the upper leaves was higher in DSC than in MTC from the tillering to heading stages, however, it was higher in MTC than in DSC 15days after heading. The specific leaf area was higher in MTC than in DSC from the tillering stage to 15 days before heading, and was lower in MTC from the heading stage to 15 days after heading. The length of leaf blade and internode were longer in DSC than in MTC except the flag leaf and first internode. Partial dry weight was high in the upper part in MTC and lower part in DSC. CGR, RGR, NAF and LAI were higher in DSC than in MTC from the tillering to heading stages. The number of spikelets, yield and ripened grain ratio were higher in DSC than in MTC, while the number of panicles was higher in MTC.
