Last week I checked six wheat fields across Butler County, Ohio for head scab as part of a long-term study conducted by Dr. Pierce Paul, OSU Extension Plant Pathology.

He and several other researchers from across the nation have developed a Wheat Head Scab Prediction Model based on rain and humidity at flowering.

Visit www.wheatscab.psu.edu to evaluate the risk of head scab in your wheat. This is a site you may want to bookmark. If next year, the model predicts a high risk of scab, you could apply a fungicide at flowering, not before or after.

The model predicted, if the wheat flowered between May 16-23, that the risk for head scab was low this year. That is what I found.
The highest incidence of scab in any of the fields was only 3 percent.

Four of the six fields had one percent or less of the heads infected with scab. It was interesting to see the variety of “problems” encountered.

Wet soils in one field had infested the roots of a small number of plants with a pathogen that had destroyed the roots. Another field had low numbers of armyworms and the wet field had several disease infested dead armyworms attached to the heads.
Cereal leaf beetle was found in three of the fields, but below economic thresholds.

Cereal leaf beetle has not been a problem since the USDA released a predator wasp in the 1970s. Hopefully, the population of the predators can continue to stay ahead of this insect pest.

Start scouting wheat fields next year at boot stage to prevent any of these problems from costing you money.

Straw: A valuable byproduct

What is straw worth if you sell it out of the field? The answer is more than you might think. I had a call this week where the buyer wanted to bale the straw and pay 30 cents a bale. When pricing anything, a safe answer is a fair price is any amount the buyer and seller can agree.

From a pure fertilizer value, wheat straw contains little in the way of phosphorus (P2O5) but moderate amounts of nitrogen (N) and potassium (K2O). The actual amounts of N, P2O5, and K2O contained in a ton of wheat straw are 11, 3, and 15 pounds, respectively.

A 60-bushel wheat crop might produce upwards of 2.7 tons of straw per acre, removing 30 pounds of N, 9 pounds of P2O5, and 41 pounds of K2O. Depending what price you will need to pay to replace these nutrients, you have about $60 per acre going off with the straw.

Wheat straw residue also contains organic matter that, when returned to the soil, does have value, but it is difficult to put a dollar value on it. Continued removal of the above-ground biomass may have negative repercussions in the long run in the form of decreased organic matter, especially if some organic residue is not returned to the soil.

For hay growers, nutrient removal is a little different, since most of the plant material is removed as the crop.

As it was described in last week’s C.O.R.N. newsletter article on hay economics, grass hay will remove 40 pounds of nitrogen, 13 pounds of phosphate (P2O5) and 50 pounds of potash (K2O) per ton harvested.

The views and opinions expressed in this column are those of the author and not necessarily those of Farm World.