Abstract

                                Field investigation on the influence of soil moisture stress (MS) on leaftemperature of rice at 0600 hours was made in Tamil Nadu AgriculturalUniversity, Coimbatore during Kuruvai (July-November) 2019 and Navarai(December-March) 2019-20 seasons. The treatments are T1: MS for 10days from PI, T2: MS for 15 days from PI, T3: MS for 20 days from PI, T4: MSfor 25 days from PI, T5: MS for 10 days from flowering, T6: MS for 15 daysfrom flowering, T7: MS for 20 days from flowering, T8: MS for 25 days fromflowering and T9: Control (Maintaining 2cm of water throughout the cropperiod). The experiment was laid-out in Randomized Completely Block Designwith three replications. Leaf temperature was measured using an infraredthermometer at 0600 hours. Moisture stress had a significant influence onthe leaf temperature of rice in the early morning hours. In Kuruvai season,an increase in leaf temperature was to the tune of 0.13oC to 2.20oC duringPanicle Initiation (PI) stage (T1, T2, T3 and T4) and 0.16oC to 2.27oC duringflowering stage (T5, T6, T7 and T8) over control due to MS. Similarly, increasedleaf temperature to the tune of (0.13oC to 2.97oC and 0.07oC to 2.96oCduring PI stage and flowering stage, respectively) was observed due to MStreatments than MS relieved treatments and control during Navarai season.The results confirmed that the direct influence on leaf temperature of rice wasdue to MS irrespective of the stages and seasons. The correlation betweengrain yield and leaf temperature due to the MS was found to be negative.

Key words : Rice, moisture stress, panicle initiation stage, flowering stage, leaf temperature