Submitted to: Arkansas Agricultural Experiment Station Research Series
Publication Type: Experiment Station
Publication Acceptance Date: 6/27/2006
Publication Date: 8/8/2006
Citation: Eizenga, G.C., Mcclung, A.M., Rutger, J.N., Bastos, C.R., Tillman, B. 2006. Yield comparison of indica and U.S. cultivars grown in the southern United States and Brazil. In: Norman, R.J., Meullenet, J.-F, and Moldenhauer, K.A.K., editors. B.R. Wells Rice Research Studies 2005.Arkansas Agricultural Experiment Station Research Series 540. p. 62-70. Available: http//www.uark.edu/depts/agripub/Publications/researchseries/.
Technical Abstract: Two subspecies of cultivated rice (Oryza sativa L.) are indica, grown in tropical areas like southern China, and japonica, grown in temperate areas. Tropical japonicas are the japonica subgroup grown in the southern US. When indica rices are grown in the southern US and compared to tropical japonicas there is a significant increase in grain yield and lodging, and decrease in grain quality. This study compared indica and US tropical japonica rices grown in the US, Stuttgart, AR and Beaumont, TX, and Mococa, Sao Paulo, Brazil. Seven US tropical japonica and seven indica cultivars were grown in four replications over two years. Characteristics measured were days to 50% flowering, days to harvest, plant height, lodging, tillering, grain yield, milling yield and grain quality. Averaged over all locations, the yields of the indicas was higher than the US japonicas but head rice yield was lower. Indica cultivars Zhe 733, Te Qing and Zhongyouzao 3 had the highest grain yield (7253-7965 kg ha -1) whereas IRGA 409 (4728 kg ha-1) and IR72 (4705 kg ha-1) had the lowest yield. By comparison, the US japonica yields ranged from 5285 to 6688 kg ha-1. Grain quality of the indicas, measured by apparent amylase content, was not acceptable for US markets, thus the challenge for US rice breeders is to capture the yield potential of the indica rice without sacrificing head rice yield and grain quality.