As you consider soybean production inputs for this coming year, you should reevaluate the 2000 season. I had the opportunity to see many fields in Mississippi, particularly those fields enrolled in our SMART program. We had fields all the way from Ripley, Miss., to Vicksburg, Miss., and we were in these fields once if not twice a week all season. Because the fields represent a good cross section geographically, I believe we were exposed to the majority of problems most producers had to deal with.
Most were ready to put the 2000 crop in the ground early, but the large amount of rain we received in late April kept most from getting started planting until about the last five days of April — late for dryland production.
A large percentage of that acreage was planted in Group IVs. Was that the wrong thing to do? Last year it hurt, but Group Vs planted the same time or later were hit even harder. So, the answer is, “No.” If I had to do it over again, I would still plant Group IVs into early May.
Early-maturing varieties offer some excellent opportunities to increase yields. The majority of the early-maturing varieties we plant are late IVs. When they are planted into May, their maturity may shift enough that they act like a maturity Group V. That happened last year when planting was shifted to mid-May.
At Stoneville, Miss., an April 21 dryland planting of a maturity Group IV yield 50 percent less than an April 28 planting. Although April 28 usually is not late, it was last year.
Don't base your upcoming decisions on last year. 2000, an extreme year, should not be the basis for deciding what does and does not work.
‘Pythium is a problem under cool, wet conditions. The uncertainty of spring rains makes me feel seed treatments for pythium are needed on all early soybean plantings.’
Regarding variety selections for the coming year, we are encouraging our SMART participants to plant Group IVs on dryland fields. Year-in and year-out they offer us the best hedge against nature. Growers tell me that Group IVs get in the way of corn or rice. If you will plant them earlier, they could mature earlier. Regardless, if you can be assured of higher yields, I think the harvesting conflict can be handled.
Early planting is an integral part of nonirrigated production; it is essential.
I still see problems arising from the use of seed treatments for pythium, which is going to be a concern under cool, wet conditions. Pythium has the potential to be worse on heavy, poorly drained soils. Not everyone needs a seed treatment on every field every year, but the uncertainty of spring rains makes me feel it is needed on all early plantings.
Will seed treatments give a yield increase? They will for certain if you lose a stand and have to plant over. If a problem occurs, you will see yield differences. This is a basic decision that does not require volumes of research data to see. With so few days for field work in April, you have to get a stand the first time. You cannot afford to re-purchase seed because of the expense and because odds are that you will have to replant with less-desirable variety. Even if someone gives you the seed, you can't compensate for the decrease in yield from the later planting date.
As I mentioned earlier you do not need to use a seed treatment every year on every acre. Possible exceptions are fields planted on raised beds, if you are following corn or sorghum or if you plant in an optimum timeframe, a time when rapid, vigorous emergence is expected.
The big question mark in all this is knowing when it is going to rain. I looked at about 300 acres in the north Delta in early June. It had rained the night after planting and pythium had taken out the entire stand. You expect rapid, uniform emergence in June, but that unpredictable shower caused the entire stand to be wiped out by pythium.
A base program is built around a material that controls pythium. You might broaden the spectrum by adding materials that control rhizoctonia and even consider adding a seed protectant. At planting, time is valuable and a seed treatment is a form of insurance.
Comparing the Cadillac seed treatment program (approx $3) to the cost of Roundup Ready soybeans ($24), if you can avoid replanting one year out of eight you will have paid for eight years of seed treatment, not to mention the equipment trips across the field, labor, lost yield and additional seed costs.
Alan Blaine is the Mississippi Extension soybean specialist.
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