Early harvest reports of low test weights are coming in from producers in south central and south western South Dakota. If producers suspect low test weights they should contact their crop insurance agent to evaluate their options before the fields reach maturity or cut them for hay, suggested Bob Fanning, Plant Pathology Field Specialist.
"Although many wheat fields appear to be a week to 10 days or more away from harvest maturity, those in particularly dry areas are progressing quickly and a few fields in south central South Dakota have already reached maturity. As they began to harvest the crop, some producers have quickly learned that the test weight was very low," Fanning said.
One such field produced wheat that weighed 47 pounds per bushel.
"As test weights drop below 60 pounds per bushel discounts begin to mount," Fanning said. "The lowest test weight that wheat can be marketed at grain elevators is 50 pounds per bushel, with discounts in the neighborhood of 70 cents per bushel at that level."
Fanning said there are several potential reasons for wheat being low in test weight, including drought, root and crown rots, viral diseases, fungal or bacterial foliar diseases, scab, aphid feeding, etc.
"It is difficult to determine the test weight of a wheat crop until it is mature and harvested, but the presence of a substantial percentage of shriveled and/or small kernels should raise a red flag," he said.
If wheat is low in test weight, one strategy Fanning suggested may be to open the sieves on the combine and turn up the wind in hopes of blowing some of the lighter, shriveled kernels out the back.
"Harvested wheat that is light might also be cleaned aggressively in an attempt to gain test weight," he said. "If the majority of the kernels are lighter and shriveled, the potential of gaining much test weight by is likely to be limited."
If using either of these strategies, Fanning said producers would need to compare the benefit of gaining test weight against the yield loss due to blowing the light seeds out the back of the combine or aggressive cleaning.
The remaining options available are to harvest the wheat and sell it as feed wheat at a significant discount or harvest as hay.
"Unfortunately, crop insurance may not offer substantial coverage for wheat that is low in test weight. The adjustment for light wheat doesn't reach significant levels until the bushel weight drops into the low 40 pounds per bushel range," he said.
If considering harvesting the crop as hay, Fanning reminds growers to check herbicide, fungicide or insecticide labels of any products that have been applied for the pre-harvest interval or if the label allows harvesting as hay.
Source : SDSU