With a potential seed shortage for some varieties and rising seed costs, rice farmers may want to consider reducing seeding rates this year. And they may be able to do that without sacrificing yield potential, say rice specialists from across the Belt.
“We've reduced seeding rates almost 25 percent and maintained yield in Arkansas,” said Chuck Wilson, University of Arkansas rice specialist.
Wilson and counterparts from other rice-producing states exchanged production ideas and updates recently at a Valent-sponsored rice seminar in San Antonio.
Wilson said Arkansas changed its seeding recommendation last year, dropping recommended rates from 90 pounds per acre on silt loam soils to 70 pounds per acre. “We need to adjust upward for clay soils,” he said. “We've recommended 120 pounds per acre in the past and we're now down to 90 to 95 pounds.”
He said early-season insect damage may concern some growers. “They can lose stands. Seed treatments could be an advantage with reduced seeding rates.”
He said growers in northeast Arkansas are still looking at seeding rates. “We're evaluating varieties and looking at row spacings.”
Narrow row planting may offer some advantage. “We saw a significant yield advantage the first year in narrow row. Last year we did not see much difference.”
Tim Walker, Mississippi State University, said lodging problems were not as bad with lower seeding rates. He looked at two varieties, Wells and Francis. “Wells at 40 pounds per acre was one of our best yielding treatments,” he said. “Lower seeding rates could be a benefit with the seed situation this year.”
He said growers should consider “how much risk they are willing to take” with lower seeding rates. “With a full gamut of seed treatments, growers might be more willing to cut rates.”
Lee Tarpley, Texas A&M, said reduced rates, 40 pounds per acre, with CL 171 showed yields on the main crop to be about the same. “The ratoon crop was significantly better.”
Walker said seeding rates that optimize main crop yields appear to optimize ratoon yields as well.
Seeding method also affects rate. If growers water seed, they use about 30 percent more seed than in drill seeding.
Texas studies showed Cypress variety at 40 pounds per acre as the best yield in one year's test.
Studies also show that a 20-pound per acre seeding rate results in 100 percent of seed producing seedlings. At 120 pounds per acre, that percentage drops to 50.
Karen Arthur, a Valent product development manager, said ongoing development of seed treatments should produce options that combine insect, disease, and nematode controls with growth regulators, herbicide safeners and fertilizer polymer coatings. “For now, we're screening a lot of fungicides.”
She said commercial products will not be available for “several years,” but that several products look promising. Rice water weevil and stem borers are primary insect targets.
Specialists said seed treatments for water weevils would provide benefits for growers. They said early tests show excellent results and good yield responses.
M.O. Way, Texas entomologist, said improved seed treatments for rice would be a welcome addition to growers' pest management programs. “We want to test efficacy of new products on stem borers and we hope something is available in a year or two.”