USE OF DIVERSE GERMPLASM FOR GENETIC IMPROVEMENT OF RICE
Location: Dale Bumpers National Rice Research Center
Title: Effect of cultural management practices on the grain quality of two rice cultivars
Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 3, 2009
Publication Date: July 1, 2009
Citation: Bryant, R.J., Anders, M.M., McClung, A.M. 2009. Effect of cultural management practices on the grain quality of two rice cultivars. Cereal Chemistry. 86(4):405-409.
Interpretive Summary: In order to increase profits, farmers are trying new ways of growing rice two of which are crop rotation and increased fertilization. How the two interact to effect the cooking and processing quality of rice is not well understood. We looked at three crop rotation systems (continuous rice, rice/soybeans, rice/corn) and two nitrogen rates (recommended and 1.5 X recommended) and found that increasing nitrogen increased the protein content and changed the processing quality. However, crop rotation determined the magnitude of the change with continuous rice having the least affect and rice/soybeans having the greatest affect. This research will be beneficial to farmers, processors, and other scientists.
In order to reduce fuel and labor costs and increase profits, farmers are trying new ways of growing rice (Oryza sativa L.). This includes conservation tillage, crop rotations, and changing fertilization applications. There is little information on how these changes effect the cooking quality of rice. We, therefore, looked at the parameters associated with cooking and processing quality (apparent amylose, gelatinization temperature, lipid, protein, and pasting properties) of two rice cultivars, 'Cybonnet' and 'Wells' that were planted using conventional (no-till) tillage, a standard rate and high rate fertilization, and different crop rotations (continuous rice R/R, rice after soybeans R/SB, and rice after corn R/C). Rice grown in continuous rice rotation had the lowest protein content of brown and milled rice, 8.6 and 8.1%, respectively, as compared to the highest levels observed in the rice/soybean rotation, 9.3 and 8.6%, respectively. Rice grown in continuous rice rotation also had higher peak viscosity than other crop rotations. Increased fertility increased the protein content of brown rice and decreased the peak, trough and final viscosities. Apparent amylose content, gelatinization temperature, and lipid content were not affected by crop rotation or fertility, however, they were influenced by cultivar. Tillage method did not affect the cooking or processing quality of the rice tested. Using no-till farming may be beneficial in reducing the cost of rice production, however, crop rotation, cultivar selection, and application of nitrogen need to be evaluated carefully for impact on cooking and processing quality.