Minnesotans See Dividends In Higher-Moisture Harvest
Tuesday, August 1, 1995
filed under: Harvest/Storage
Many Northern Plains sunflower producers end up harvesting their crop when seed moisture levels are in the upper ’teens. For most, that’s probably out of necessity, given their hectic fall workload and/or a delayed crop maturity in a year like 1995 with its late, wet spring.
Other growers believe they’re better off waiting for Mother Nature to dry down the seeds into the low ’teens or below, thereby saving on both drying costs and drying time.
For John Swanson and Russ Wilson, however, harvesting high-moisture sun-flower is a matter of deliberate choice — a choice which they say consistently puts additional money in their pockets.
For more than 15 years, these Mentor, Minn., producers have harvested their sunflower crops in September — or, at the latest, the first week of October — while seed moisture is in the upper ’teens. They then pull down the moisture in their high-temperature continuous-flow dryers and usually store the crop through the winter.
The northwestern Minnesota neighbors say their early harvest routine has several advantages — the first being an obvious one: By taking the ’flowers off the field as soon as possible, they’re cutting short the crop’s exposure to potentially damaging wind, rain, late-season head-rot problems, birds — and deer (a significant threat in their wooded area of Polk County).
Also, seed shatter loss at the header is minimized when harvesting at higher moistures, they point out. Wilson, who has conducted side-by-side comparisons with 10- to 11-percent moisture ’flowers versus seeds in the upper ’teens, says the differ-ences are dramatic. For his part, Swanson contends the cost of drying the high-moisture seeds is more than offset by the decrease in field shatter loss alone. (Con’t)
By drying in September or early Octo-ber, while ambient daytime temperatures in northern Minnesota typically are hovering around 70 to 75 degrees, they’re also reducing the time and extra heat required for drying in their high-temperature units. “We’ve seen years where you could have taken the seeds off in the high ’teens and at 70 degrees, or waited for the seed moisture to get down to 10 percent — which it never did,” Swanson notes. “So those who waited probably ended up harvesting their seeds at 17, 18 percent or higher — but with snow or freezing temperatures.”
Even when drying in warm weather, Swanson prefers not to harvest at more than 18 or 19 percent moisture, however. “Anything below 19 usually harvests easily and moves well through the dryer,” he remarks. “But when you get over 20, it takes longer in the dryer and your chances of fire increase due to the ‘fuzz and fines.’ ”
Swanson, who is sunflower product manager for Cenex/Land O’ Lakes in addi-tion to operating his farm, runs all his seeds through a rotary screener prior to placing them in his high-temp dryer. “When you take a 19-percent sunflower, you’re going to have some florets — and they’re pretty wet,” he points out. The screener removes the florets, along with most weed seeds and other trash. Screening the foreign materials out of the field-run ’flowers can, in itself, reduce moisture levels by a percent or more, Swanson estimates — while reducing the risk of fires inside the dryer as well.
(Swanson also recommends running the combine cylinder speed as slowly as possi-ble, resulting in an intact head after thresh-ing. That translates into minimal head pith material entering the screener and/or dryer.)
In some years, there’s one last advantage to the early harvest, Wilson and Swanson add. Depending upon sunflower stocks levels and/or other market factors, early autumn market prices may be quite attrac-tive. By being among the first producers in the region to harvest their crop, the Polk County neighbors sometimes are able to take advantage of such price levels and sell ’flowers immediately, prior to the standard harvesttime price dip.