Selection of Culm Characteristics of Rice to Improve Lodging Resistance and Yield Components

Rice crop has reached its maximum potential yield due to greater photosynthetic efficiency. It is important to develop physiologically efficient plant architecture by increasing source capacity. The better option is to increase plant height up to realizable level but, lodging is a common problem in rice cultivation. Therefore, medium aged (100-109 days) rice parental lines and available accessions (78) were evaluated in 2020/21 Maha season at the Rice Research and Development Institute, Batalagoda (i) to determine variability of culm characters of selected varieties, (ii) to determine appropriate characteristics with high heritability and genotypic relation on lodging, yield and yield component, (iii) to explore maximum realizable culm length, diameter and strength that could be utilized to achieve lodging resistance, (iv) to find out suitable donor parents for future rice breeding programmes. Culm characters, lodging, yield of accessions and yield components were recorded. Length, width, thickness, diameter and lignified cells of culm are highly heritable characters. Alteration of culm length up to 90 cm with 2.8 N culm strength and increasing culm diameter up to 10.0 mm could hold greater source capacity for large panicle bearing varieties. Bg Acc 89 Sudu Heenati, NSICRC 182, Bg Acc 627 Dahanala, and Bg Acc 611 Batapolal are suitable traditional donor parents for greater culm characteristics.