Southern U.S. Long-Grain Rice Quality

Steven Linscombe  |  3/18/2013 8:22:37 PM

Rice grains - chalk

Over the past three years, there has been a great deal of discussion about quality aspects of the long-grain rice produced is the southern U.S. rice-growing region. U.S. long-grain rice has historically been considered the quality standard of the world. In recent years, however, a number of both domestic and international customers have complained about the quality. The complaints have focused primarily on the high levels of chalk in much of the long-grain rice produced in the region in recent years. Other negative comments concern milling, nonuniformity of grain size and problems with cooking characteristics. These concerns were pervasive enough that the USA Rice Federation in February 2011 formed the Rice Marketability and Competitiveness Task Force to address them. I serve on this committee along with several Louisiana producers and milling industry representatives.

This task force has taken on several projects since its formation. The most ambitious endeavor was the 2012 research study to evaluate differences in U.S. long-grain cultivars grown in similar environments for objective and subjective quality traits. In this project, 19 southern U.S. inbred varieties and hybrids were grown in 11 southern U.S. environments that included six locations and two planting dates (at five of the locations).The cultivars in these studies were planted at an optimum planting date and at a delayed planting date, approximately one month later. Locally recommended cultural management practices were used at each location. Samples were combine-harvested at approximately 18% moisture and dried to 12% moisture. The study was conducted in such a way to remove as much environmental influence as possible and focus on inherent genetic differences among the varieties on the quality parameters of interest.

All of the samples generated in these studies were shipped to Louisiana Rice Mill in Crowley, where samples were milled to a consistent degree using near-infrared spectroscopy technology. Head rice and total milled rice percentage were also determined for each sample. The study also included imported milled rice samples from Uruguay and Thailand. All samples were coded to be unidentifiable by the evaluator and then shipped to 10 commercial rice mills in the southern United States, where they were evaluated for five qualitative traits – bran streaks, chalk, kernel color, uniformity of grain length and overall appearance. In addition, several other quality parameters were measured on the samples by the USDA Rice Quality Lab in Stuttgart, Ark., and by the Rice Experiment Station in Biggs, Calif. The samples were also evaluated for commercial export standards by the Russell Marine Group in Metairie, La. The ultimate goal of this research was to determine how U.S. cultivars compared with each other as well as to high quality imported rice samples. The study also strived to learn more about the relationship between subjective and objective assessments of quality.

The study demonstrated a number of important points. These included the fact that the various rice mills that participated in the subjective ratings evaluated the samples quite differently. Also, environment, as expected, did have a major influence on quality of the samples. In most cases, the earlier planting dates at each location yielded the highest quality samples. Also, there where major differences in quality among the various testing locations.

Most importantly, however, the study did confirm that there are inherent differences among the major commercially available pure line varieties and hybrids in all of the rice grain quality traits that were evaluated. Some varieties consistently scored more favorably for the important quality traits than did others. In general, the highest quality varieties are not the highest yielding varieties/hybrids available for rice farmers to plant.

So what does this all mean? Basically, it means that to improve the overall quality of the southern U.S. long-grain rice crop, there must be an economic incentive for rice producers to plant those rice varieties that have higher quality but perhaps not the highest yield potential. Some of the rice mills in the region have begun recently to offer price premiums to producers for delivering identity-preserved varieties that typically display higher grain appearance quality. All indications are that this is having an impact – at least in Louisiana where in 2013, we will have a larger percentage of acreage planted to those varieties that fit into the higher quality category. However, it will take a similar price premium program across the entire southern U.S. rice-growing belt to have a major impact on improving the overall quality of the majority of the long-grain rice produced in the region.

Permission granted, March 15, 2013, by B. Leonards (LA Farm & Ranch) to republish article on www.lsuagcenter.com

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