Manage the 2000 Soybean Crop
Despite current moisture deficits and some pessimistic forecasts, the 2000 growing season could be very similar to normal--or not.
That makes the coming season a lot like any other, and it's also why Purdue agronomists are cautioning corn and soybean producers against expecting, and planning for, bad weather.
"Trying to plan for a growing season quite different from normal is a major gamble," says Purdue Extension soybean specialist Ellsworth Christmas. "Each growing season could, and in most cases does, vary from normal. Since we do not have a clear view of the 2000 weather pattern, we should treat this year as any other normal year."
That means using the most efficient means to maximize yield.
Christmas says growers should plant a full-season variety for their area with good disease resistance and a high yield record.
"To change to an earlier or later maturing variety could spell disaster," he says. "An early maturing variety does not have the ability to fully compensate for late July and August rains while a full season variety can respond nicely to these late rains."
He adds that weather forecasting will have to become far more sophisticated before growers can pick anything but full-season varieties with confidence. "If you can guess correctly on the timing of a dry period," he says, "then you could change the maturity group to your advantage."
Between May 5 and May 20 is the best time to plant beans in a typical Indiana year, Christmas says.
"Planting earlier than April 25 or later than June 5 usually results in a significant yield reduction," he says. "Full-season varieties planted on or before May 20 will usually begin flowering on approximately the same day whether planted in April or May. The idea that planting early will result in significantly earlier reproductive development of the soybean plant is FALSE."
If the soil is unusually dry when it's time to plant, Christmas recommends planting anyway. This beats waiting to plant until rains come, and then waiting again until soils are dry enough for planting.
Don't change a seeding rate based on any weather expectation.
"A population of 165,000 plants per acre in drilled soybeans is considered a perfect stand and would require a seeding rate of 200,000 seeds per acre," he says. "With a 30 inch row spacing, a perfect stand would be 105,000 plants per acre with a seeding rate of 130,000 seeds per acre. A 15-inch row spacing will require a seeding rate of 165,000 seeds per acre to give a perfect stand of 130,000 plants per acre."
Because much of the 2000 soybean seed supply was produced in areas with rainfall deficits in 1999, Christmas says it has a higher seed count per pound than normal.
"It will pay to calibrate drills and planters with the seed that you will be planting this year, and to check the calibration as you move from one seed lot to the next," he says. "Over seeding by 5 pounds per acre on 100 acres is equal to 10 units of soybean seed. Proper calibration and seeding rates can result in input costs savings."
Christmas says that given the limitations of the forecast information that's available today, growers' best bet is to plan for a near-normal growing season and develop a production system based on normal expectations.