Growth and Morphological Characteristics of Red Rice (Oryza sativa) Biotypes

Pot experiments were conducted in the field at Stuttgart, AR, during 1982 and 1983 to evaluate growth and morphological differences between strawhull and blackhull red rice (Oryza sativa L. ♯ ORYSA) biotypes collected from Arkansas, Louisiana, and Texas. All red rice biotypes were compared with rice (Oryza sativa L.) cultivars ‘Lebonnet’ and ‘Nortai’. Growth and morphological differences were greatest between cultivars and red rice biotypes, less between blackhull and strawhull types, and least among collections within blackhull or strawhull. Cultivars emerged slower, were shorter, tillered less, produced less straw and fewer panicles/plant, had a lower leaf area index, and had less grain shattering than most of the red rice biotypes. Blackhull red rice biotypes tillered 27% more, produced 18% more straw, and had later maturity than strawhull. Blackhull red rice from Arkansas emerged earlier, tillered 6 to 38% more, and produced 8 to 38% more panicles per plant than other red rice biotypes, whereas blackhull red rice from Texas was 11 to 26% taller at maturity than other biotypes.