The Breeding Project, under the direction of senior rice breeder Dr. Steve Linscombe, has the responsibility of developing both conventional and herbicide-resistant long grain varieties. Although the primary objective is variety development, the Breeding Project also conducts other research that may have direct and/or indirect contributions on work to develop new varieties.

In one year, this project evaluates approximately 60,000 experimental or progeny rows, 400 F₁ transplants and 350 space-planted F₂ populations. About 400 new crosses are made each year. In addition to this, the project plants, maintains, collects data on and harvests about 5,000 yield plots each year. These plots are located on the Rice Research Station as well as on up to seven off-station locations.

The date-of-planting study is the first test planted each year, normally around March 1. A planting date is then seeded at approximately 2 week intervals until early June. The eighth and final planting is put in around July 4. The purpose of this study is to analyze the effects that planting date has on yield and milling quality as well as other agronomic variables of released varieties, hybrids and advanced experimental lines. Another test includes a two-rep preliminary yield evaluation which includes mainly F₅ and F₆ generation lines that are being evaluated for the first time. A single rep test also evaluates first-time entries. The Uniform Regional Rice Nursery (URRN) is a cooperative test among six states, including Arkansas, Louisiana, Mississippi, Texas, California and Missouri. The nurseries are used to test the adaptation of entries in the diverse rice-growing environments of the United States.

The Commercial /Advanced Trial includes released varieties, hybrids and advanced experimental lines from this and other Southern breeding programs. This trial is conducted at the Rice Research Station as well as at a number of off-station locations each year.

In all of these tests, the lines are evaluated for yield, seedling vigor, milling characteristics, other quality parameters and numerous other agronomic characteristics. Hand-cut milling samples are taken on approximately two-thirds of the 5,000 plots planted. From this sample, a sub sample is taken, and milling quality is evaluated. All yield plots are harvested using a small-plot combine which measures yield and harvest moisture. Many of the yield trials are also evaluated for ratoon production.