J. Expt. Biosci. 4(2):35-38, July 2013 ISSN 2223-9626 (Online), ISSN 2077-3358 (Print) 35 PERFORMANCE OF HYBRID AND INBRED RICE GENOTYPES AT TWO DIFFERENT LOCATIONS OF BANGLADESH DURING DRY SEASON M. S. Islam 1* , M. M. Rashid 1 , M. A. Kabir 1 , M. R. Karim 1 , and J. Timsina 2 *For correspondence, E-mail: sirajul.i@brac.net Abstract Bangladesh is an extremely land scarce country. Any improvement of rice yield has significant impact on the overall food security of the country. Hybrid rice is one of the viable and proven technologies that have been considered as a new frontier to increase rice production. Performance of two new exotic hybrid rice genotypes from India BIO-404 and BIO-452 including two popular BRAC hybrid (Alloran and Sathi) and one inbred (BRRI dhan28) were evaluated at BRAC Agricultural Research and Development Centre of Gazipur and also in the farmer’s field of Rajshahi district during dry season (boro) of 2011. Both the exotic BIO genotypes showed a better cold tolerance at the seedling stage. The initial growth of BIO-404 and BIO-452 were better compared to other tested genotypes. But at the later stage they showed a higher plant height and lower panicle number resulting in lower grain yield than the check hybrids. The spikelet fertility of the two exotic hybrid rice genotypes was also low. Hybrid Alloran produced the highest grain yield in both the locations which was attributed to higher spikelet fertility and higher individual grain weight. Key words: Hybrid rice, Grain yield, and Spikelet fertility Introduction Agriculture is the mainstay of Bangladesh economy and about 43.6% of the labor force is employed in agriculture with about 57% being employed in the crop sector (BER, 2011). The principal crop and the dominant food staple is rice, which occupies nearly 76% of its total cropped area in the country (BER, 2005). Due to the inception of HYVs under irrigated condition in Bangladesh, the rice yield has increased to manifolds. But the ever increasing population demands further improvement in yield level as the cultivation area is either decreasing or remaining constant. One important innovation could be the development of hybrid rice varieties, which is expected to shift the yield potential of the rice plant by 15-20% or more with the application of almost same amount of agricultural inputs (Hossain et al., 2000). Nevertheless, hybrid rice is one of the viable and proven technologies that have been considered as a new frontier to increase rice production and it has greatly contributed to the growth of rice production in China (Lin, 1991; Lin, 1994; Virmani et al, 1998). The technology has attracted the attention of research leaders and policy-makers in many Asian countries who found it as an opportunity to overcome the yield ceiling reached by many enterprising farmers in the irrigated ecosystem (Hossain et, al., 2003). Hybrid rice is rice that has been created by crossing two different parental strains. Such crosses generally result in an F1 generation that is more robust than either of the parental strains. Good rice hybrids have the potential of yielding 15-20 percent more than the best inbred variety grown under similar conditions Farmers achieve 25-30% yield gains from hybrids as compared to best inbreds. So hybrid rice can play a vital role in future food security of Bangladesh. In 2010-11, country’s hybrid rice production was only 28 lakh tones from 6.53 lakh hectares of land, but now the hybrid rice production has increased significantly (www.bangladesh-economy.org). A recent report in the Philippine Star, a major Manila daily, said that Bangladesh was banking on the Philippine-produced hybrid rice seeds in its program to achieve rice self-sufficiency. Therefore, an in-depth study on prospect of hybrid rice cultivation at the farmers’ level is essential to evaluate yield performance and profitability, and farmers’ acceptance of hybrid rice varieties and their production technology. The main focus of the present study is to generate primary data from two different regions to study the performance of two new exotic hybrid rice genotypes BIO-404 and BIO-452. The study also focuses on the farmers' perception about the hybrid rice. Materials and Methods An experiment was conducted at BRAC Agricultural Research and Development Centre (BARDC) Gazipur and a field of Paba Upazila of Rajshahi district during the boro season 2011 to study the performance of two new exotic hybrid rice genotypes BIO-404 and BIO-452 including two hybrid (Alloran and Sathi) and one inbred (BRRI dhan28) checks. The 1 BRAC, 75 Mohakhali, Dhaka 1212, Bangladesh 2 International Rice Research Institute, Bangladesh Office, Banani, Dhaka, Bangladesh