Is four enough? Is six too many?

We’re not talking about prunes, here, but the math still makes sense. With cotton seed prices at historic highs and cotton yield goals equally optimistic, farmers can’t scrimp too much on seeding rates, but neither can they afford to put more money in the ground than is necessary to hit production targets.

Recent research indicates that farmers can not only get by with a few less seed per foot of row, but that returns on investment may be equal to or better than higher rates.

Peter McGuill, county Extension agent in Wharton County, Texas, says three years ago farmers were planting a lot of seed, up to 70,000 per acre, in his area. “From 52,000 to 54,000 is closer to where we need to be,” McGuill said during a cotton section presentation at the Texas Plant Protection Association annual conference in College Station last December.

“We started looking at a full rate versus a half rate and a grower agreed to plant different populations for several years to establish an acceptable population of cotton seedlings.”

He said the increased cost for enhanced technology cotton seed raises production costs. “We wanted to evaluate plant population, costs, yield, and quality and compare the dollar returns for various seeding levels.”

They worked with three seeding rates, 2, 4 and 6 seed per foot of row, all Phytogen 440 W, the grower’s choice. “We’ll look at other varieties in other tests to examine Bt Flex and to check different seed costs,” McGuill said.

He said actual plants per foot of row from those planting rates came in at 1.7, 3.2 and 4.6. “The more plants per foot of row the higher the seed cost and total production cost."

Higher populations also meant more days to cutout and fewer fruiting sites, but no difference in total number of bolls. He also noted no “statistical difference” in turnout, quality or loan value.

Returns for the three final plant populations were: 1.7 plants per foot of row, $318.70; 3.2 plants per foot of row, $320.83; and 4.6 plants per foot of row, $305.89. The lower return for the higher plant population resulted from higher seed cost, McGuill said.

“We saw no significant difference between seeding rates on growth factors,” he said. “The dollar return per acre above seed and technology costs was better with lower seeding rates.”

He said the optimum seeding rate probably will be 4 per foot of row. “At 2 seed per foot, we have very little security. But a 4 per foot of row rate is a good bet and gets us to 52,000 to 54,000 per acre, where we should be.

“We’re also collecting good data about replant decisions,” McGuill said.

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