• By Vicky Boyd,
Since acquiring Bayer’s rice breeding program in 2015, Nutrien Ag Solutions has mostly flown under the radar developing new rice cultivars for the U.S. market.
That will change in 2021 with the launch of DGL-263X, a high-yielding, high-quality, long-grain inbred variety in final development and the first commercial rice cultivar under the DynaGro brand, says Randy Ouzts, Nutrien U.S. rice manager.
“It looks really, really good,” he says. “We have several inbred lines in development, this is the first one and looks to be very promising.”
The breeding program, led by Dr. Qiming Shao at Nutrien’s research facility near El Campo, Texas, has continued with hybrid development. The company anticipates launching it’s first hybrid product in the 2023-24 timeframe.
Zach Tanner, a Bernie, Missouri, seed producer, this season planted DGL-263(X) at 12-15 pounds per acre for seed increase. Ouzts says Nutrien expects to have seed available for the 2021 season with a target launch of 25,000 commercial acres. This will give growers and mills an opportunity to evaluate it in a commercial setting across the rice belt.
If all goes according to plans, Ouzts says the company could have two additional inbreds for the 2022-2023 season, including a high quality medium-grain variety.
The low-down on DGL-263X
DGL-263X reaches 50% heading in 82 days in University of Arkansas trials. With a height of 34 inches, it has good straw strength, which was noted in testing under hurricane conditions seen at Nutrien’s Texas facility in 2018 and 2019.
“Post hurricane, we saw yields of 9,000-plus pounds and limited lodging in trials, and that’s when we knew we had something,” Ouzts says.
The variety has a diverse genetic background, with germplasm from China, India and Brazil as well as japonica lines from the United States, Shao says.
“We continue to focus on three-line hybrid breeding in our program,” Shao says. “As with most breeding programs, we use restorer lines to create hybrids for commercial evaluations. DGL-263X has been developed from this part of our program.”
Strong trial performances
DGL-263X has been in the Arkansas Rice Performance Trials for a number of years. When he first saw the variety’s yield potential, University of Arkansas Extension rice agronomist Jarrod Hardke says he was excited because it was similar to those of hybrids. At the same time, the candidate variety had good milling quality.
In the 2019 ARPT, for example, DGL-263X yielded an average of 239 bushels per acre across four locations, with a high of 255 at the North East Rice Research Center near Harrisburg. The Rice Research and Extension Center near Stuttgart was close behind with 253 bushels per acre. Milling yield across all four locations averaged 58/68.
In the same ARPT trials across four locations, Diamond averaged 204 bushels per acre with milling yields of 58/70; RT XP753 averaged 242 bushels per acre with milling yields of 56/71; and RT Gemini 214 CL averaged 239 bushels per acre with milling yields of 57/70.
“Certainly, there are going to be some limitations,” Hardke says. “But under really good, well-managed conditions, (DGL-263X) has some extremely high yield potentials.”
The variety has shown to have a better fit in Arkansas and the Missouri Bootheel than to South Texas and Southwest Louisiana, Ouzts says. Trial work continues in all southern rice growing states with results from 2020 to be released this fall.
In Louisiana State University AgCenter trials conducted at Crowley in 2019, DGL-263X yielded 9,116 pounds (202.5 bushels) per acre in the main crop and 1,724 pounds (38.3 bushels) per acre in the second crop for a total of 10,840 pounds (240.8 bushels) per acre. Milling yield was about 59/69.
“First-crop yield is high enough for some growers, the need to ratoon may not be necessary,” Ouzts says. “Growers in some areas are looking for this type yield potential and a ‘one-and-done’ variety they can rely on.”
Based on what he’s seen, Hardke says the DynaGro variety appears to have a disease package similar to many other newer inbreds. The 2019 season did not produce high disease pressure, so he says researchers weren’t able to see how new varieties and hybrids performed under severe conditions.
As with many other inbreds, DGL-263X may require a sheath blight fungicide under conducive conditions, Ouzts says.
In addition to Pi-ta genes, which have become the standard ways to convey natural blast resistance, Shao is looking at other blast germplasm sources in the program. .Nutrien’s laboratory in Saskatoon, Canada, as well as university plant pathologists and U.S. Department of Agriculture personnel are assisting with this work, and to date the findings have been positive.
Good grain quality
In tests conducted on behalf of USA Rice’s Rice Marketability and Competitive Task Force, DGL-263X had amylose content of 25% or better, making it attractive for par boiling, Ouzts says. Amylose, a type of starch, influences rice stickiness. The higher the amylose content, the more apt the rice is to cook fluffy with separate kernels.
The high amylose content, along with the variety’s low chalk values, also make it attractive for the packaged rice market, Ouzts says.
“It should fit anybody’s expectations anywhere because of the low chalk,” he says. “We set stringent limitations on chalk content for releases, and this variety is the first of several to meet our standards.”
The task force initially screened 33 elite rice lines from universities and private breeding programs. Participating mills narrowed the candidates to 10 lines, on which additional cooking tests will be performed. Of the six DynaGro lines in the initial screening, five advanced, says Shao, who was involved in the task force meetings.