Evaluation of Growth and Yield Parameters of Exotic and Local Rice Hybrid Varietiesin Low Country Intermediate Zone

Abstract

Exotic hybrid rice varieties were evaluated to identify the adaptable rice hybrids for local environment. An experiment was conducted adopting Randomized Complete Block Design with 03 replicates in Yala2016 and Maha2016/17 at Rice Research and Development Institute. Eleven treatments were included six exotic rice hybrids, two local rice hybrid and three inbred standard check varieties. Yield and yield components were recorded and data analysis was done using SAS software package. Standard heterosis (SH) of all hybrids was calculated compared with standard check varieties which come under the same age group. In Yala season three months aged two exotic and local hybrids (CH3, CHS HRIO) showed SH of-39.08%, -34.07%, 22.66% respectively. Three and a half (3 1/2) months four exotic hybrids CH4, CH6, CH7, CH8 showed SH of-11.19%, -11.22%, -0.86% and 14.44% and 4-month local hybrid showed standard heterosis of 1.90%. Exotic hybrid CH8 showed positive standard heterosis (14.44%) but did not show potential level of SH (>15%). HRIO local rice hybrid variety is having positive SH of 22.6% when compared to the exotic rice hybrid varieties. In Maha season grain yield of six exotic hybrids were 4.88, 4.86, 4.33, 4.28, 4.82, 4.82 t hal and grain yield of two local hybrids were 4.27, 5.67 t hãl. Three months two exotic and local hybrids (CH3, CH5, HRIO) showedSH0f7.62%, -4.14%, 33.81%. 3 1/2 months four exotic hybrids CH4, CH6, CH7, CH8 showed SH of6.93%, -6.25%, 5.86%, 5.28% and 4month local hybrid 407H showed SH of 0.75%. In Yala season exotic hybrid rice varieties (CH3, CH4, CHS CH6.CH7 and CH8) not performed potential level of SH. But in the Maha season hybrid varieties such as CH3, CH4, CH7 and CH8 showed the positive SH and but not exceed the potential level SH Result concluded that exotic rice hybrid varieties did not perform better in the low country intermediate conditions compared to the local rice hybrid varieties