Vol. 11, Special Issue 5 (2022)

Author(s):
Kabita Saikia, PC Dey and Lipika Talukdar

Abstract:
The present investigation entitled “Assessment of growth and heat susceptibility index of different rice genotypes subjected to heat stress” was carried out at Regional Agricultural Research Station, AAU, Titabar in split-plot design with treatments (control and high temperature stress) as main plot treatments and 33 genotypes as sub-plot treatments. The high temperature treatment was imposed by covering the one set of genotypes with polyethylene sheet to raise the temperature and allowed to grow inside the enclosure from panicle initiation until physiological maturity. Elevated temperature had no significant effect on mean days to flowering and days to maturity for all the genotypes. However, significant differences were observed between varieties. Less reduction in Leaf area index were observed in IET 26775, IET 26776, IET 26778, Gontra Bidhan-3, N22, S-458, 175-2K within the range of 4-10% compared to control. Dry matter heat susceptibility index (DMHSI) varied between a minimum of 6.76 (N22) to a maximum of 41.52 (IET 26777). The grain yield heat susceptibility index (GYHSI) was lowest 11.24 in 175-2K. Amongst the remaining varieties IET 26757, IET 26778, S-458 and N22 performed relatively better with < 15 grain yield heat susceptibility index (GYHSI).