Variation in rice root traits assessed by phenotyping under drip irrigation [version 1; peer review: 1 not approved]

Background: Roots are the key elements in water saving rice cultivation. So, the response of rice roots are to be phenotyped under varied drip irrigation treatments. Methods: This study describes an investigation on rice root phenotyping under drip irrigation treatments in split-split plot design. Two lateral spacing levels (0.8 and 1.2m), two depths of irrigation (5-10 and 15-20 cm) by solar powered and well operated irrigation were tested using TNRH 180, JKRH 3333 and ADT(R)45 rice genotypes during the summer season (2013 & 2014) in Coimbatore, India. Conventional aerobic irrigation was considered as control. Results and Discussion: An increased root length, root density (length and weight), root Adinosine Tri Phosphotase enzyme activity, root volume and filled grain percentage were favored in aerobic rice under the conditions of 0.8m lateral distance with 5-10cm depth of sub surface drip irrigation (SDI). Improved root characteristics were observed in JKRH 3333 rice hybrid, and root density and thickness favored the filled grains and yield increment in rice by drip irrigation. The 0.8m lateral distance laid out at 5-10cm depth SDI proliferated more roots at subsurface soil layer with significant yield increment in rice.