Honoring the Trinity River

New Texas long-grain release offers stronger yield potential than Presidio

presidio and trinity rice varieties

Close-up of selected whole milled grains of Presidio (left) and Trinity (right) rice varieties — photo by Peyton Croaker

• By Vicky Boyd,
Editor •

Texas A&M AgriLife Research is releasing Trinity, a new conventional long-grain rice variety with better first- and second-crop yield potential than Presidio — a previous Texas release that’s the most widely grown inbred in the state.

Formerly known as RU1603178, Trinity was developed by Drs. Rodante Tabien, Omar Samonte and Ted Wilson; research associate Chersty Harper; and Dr. Xin-Gen “Shane” Zhou, with funding from the Texas Rice Research Foundation, the Lower Colorado River Authority and Texas A&M AgriLife Research. The variety’s name pays homage to the Trinity River in Texas.

It is expected to be available for seed production in 2021 and for commercial planting in 2022, said Wilson, director of the AgriLife Beaumont Research Center.

“Overall with the main and the ratoon, it averages about 13% more yield potential, so it’s a good variety compared to Presidio,” Samonte said. “It doesn’t lodge. It heads four days later (than Presidio), is a bit taller, and the quality is good.”

In the pipeline are at least three additional elite rice lines with comparable grain quality to Presidio but even higher yield potentials, Wilson said.

Strong parentage

Trinity has parentage from Cocodrie, a Louisiana State University AgCenter semi-dwarf release; Saber, a Texas semi-dwarf variety; and Presidio. The initial cross was made in 2006.

Yield data has shown Trinity has a 12% main crop yield advantage and a 13% combined main and ratoon crop yield advantage over Presidio, which is known for good ratoon yield potential.

In trials, Trinity averaged 12,062 pounds combined main and second crop per acre compared to 10,692 pounds combined per acre for Presidio.

Trinity stands about 37.4 inches, or about 2 inches taller than Presidio. Nevertheless, the new release has good standability, and Samonte said it typically doesn’t lodge.

Trinity reaches 50% heading four days later than Presidio and matures about seven days later than the established variety.

Both head and total milled rice are comparable to Presidio, as is grain quality.

Kernels of Trinity average 6.6 millimeters, only minimally shorter than Presidio but still well within the acceptable range for Southern long-grain varieties. It has intermediate amylose content.

Trinity samples from a 2019 large-plot trial grown by the Texas Rice Improvement Association averaged 0.7% chalky grain, a highly desirable level. The result is a transparent kernel that makes for an attractive packaged product.

Production recommendations in the works

If Trinity has a downside, it’s the lack of blast-resistance genes, Samonte said. But AgriLife breeders are working on that for future releases.

All of the current varieties in development are grown under standardized fertility and fungicide programs. Samonte will be working with Zhou and Dr. Fugen Dou in 2021 to fine-tune those and develop commercial production recommendations for disease and nitrogen management.

“That’s what the farmers will be asking,” Samonte said. “What’s the disease package? What’s the fertility package? And what are your recommendations?”