The 2022 growing season was a season of firsts for rice research in Missouri’s Bootheel, from leading the nation in rice seeding-rate trials for furrow-irrigated systems to evaluating rice cultivars.

But Justin Chlapecka and his research team are not resting on their laurels. Instead, they are already busy in 2023 looking for opportunities to boost rice yield.

The University of Missouri Extension rice specialist at the Fisher Delta Research, Extension and Education Center had the chance to share research results from two rice projects last year and provide updates on the future of rice research in the Bootheel.

“We conduct these trials in flood-irrigated as well as furrow-irrigated systems,” Chlapecka says, “which is unique because I do not know of any other research in the U.S. that has looked as extensively at seeding rate in furrow-irrigated rice.”

In a furrow-irrigated rice field, the top third is never underwater. The middle third has a little standing water but is mostly muddy. And the bottom third is in standing water like a conventionally flooded rice field.

The point of the trials on furrow-irrigated rice is to try to move the needle on yields closer to flooded rice, Chlapecka says, because furrow-irrigated rice growers generally see a 10% decrease in yield compared to flood-irrigated rice.

Planting study results

While decreased yields with furrow-irrigated rice do not always occur, there is a need for research to help mitigate the risk.

MU Extension conducted a seeding rate trial at two research farms — the Missouri Rice Research Farm and the MU Lee Farm.

Preliminary results from 2022 showed the need for a higher seeding rate in the top and, usually, the middle thirds of the field, Chlapecka says. “However, a seeding rate near or slightly lower than the typical recommended seeding rate was able to maximize yield potential at the bottom of the field, where conditions more like a flood-irrigated field are present.”

UP AND GROWING: A rice field is planted March 16 for cultivar and seeding rate trials at Lee Farm at the MU Fisher Delta Research, Extension and Education Center in Portageville, Mo.

While there is not a one-step cure-all aside from pulling levees and putting a flood back on the field, Chlapecka says that altering the seeding rate “has the potential to be one of many pieces in the puzzle of making up for the yield drag in furrow-irrigated rice.

But rice yield also depends on hybrid or inbred variety.

A look at cultivar research

MU Extension wrapped its first year of rice cultivar trials on both flood-irrigated and furrow-irrigated production systems in the Bootheel region of the state.

Chlapecka says these trials evaluate not only grain yield, but also milling yield, which is a quality measure that helps determine the final payment a rice farmer receives.

“The goal here is to evaluate how each cultivar performs across the moisture gradient of a non-flooded field as plant behavior and the subsequent yield on the upper end of the field, where there’s no standing water, will be much different than toward the bottom, where flooded conditions are usually present,” he says. “Although 2022 results are preliminary, based on the first year of the trial, data showed a stark difference between hybrids and inbred varieties.”

One of the greatest variations came in the area of the planting dates’ effect on yield.

The yield potential of inbred varieties declined by nearly 5 bushels per acre per week when planted after the first planting date in mid-March, Chlapecka says, while hybrids maintained yield potential when planted into the first of May.

More rice research to come

Chlapecka is continuing both rice research projects in 2023.

With funds from the Missouri Rice Research and Merchandising Council, he is expanding the seeding rate research to three furrow-irrigated sites.

Plans for the cultivar study include four on-farm locations (one furrow-irrigated and three flood-irrigated) and two research stations with both flood-irrigated and furrow-irrigated trials.

He is also including two sites for planting date studies, with five planting dates planned per site. The first planting dates were March 15-16 near Malden and Portageville.

“This would allow us to evaluate each cultivar in 22 unique environments,” Chlapecka adds.

Visit the MU Rice Extension website for more on the 2022 research reports.

The University of Missouri Extension contributed to this article.