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Wheat will dry quickly at maturity but can rewet just as quickly even during small rains. The highest quality wheat is harvested during moderate weather without repeated rains at maturity. When rains continually threaten a wheat crop, consider harvesting when wheat is still somewhat above the market moisture content of 13.5 percent. The extra handling required to temporarily bin the wheat to dry it can outweigh the cost of delays and poor quality. Wheat dries easily, and can become overly dry very quickly, but by watching the temperature and humidity and using shallow layers, high quality wheat can be dried to near perfect final moisture content quickly. The first key is to understand the drying quality of the air and operate fans accordingly. The second key is to ensure plenty of airflow so that drying is not delayed. Using the equilibrium moisture content chart below and following daily cycles for temperature and humidity, fans can be run intermittently to utilize the best drying air. Wheat on the bottom will routinely become overly dry, but can pick up some moisture during the nighttime hours when humidity may be as high as 80 to 90 percent. The most important management decision is how full to fill the bin to get wheat dry quickly without allowing wheat on the top to spoil. As the drying front moves through the wheat, it becomes saturated so that wheat at the top will not dry until wheat below has dried. The small kernel size of wheat restricts airflow more than corn or soybean seed, so shallow depths of wheat less than about 8 feet might be appropriate for drying wheat. If necessary use more than one bin to get the wheat appropriately dry in a short period of time of just a few days and do not attempt to dry wheat much wetter than about 18 percent. Harvesting throughout the day, binning wheat harvested in the morning and delivering wheat harvested in the afternoon, can accomplish the harvest more quickly and help achieve nearly perfect market moisture contents with a minimum of delays and a minimum need for artificial drying. Avoid the temptation to use heat to dry wheat since even small amounts of heat can shift moisture contents quickly to the lower left hand corner of the equilibrium moisture content chart and severely over-dry the wheat and even cause heat damage. If you plan to hold wheat beyond immediate delivery, you will need to dry the wheat by another point or two for safe storage, but keep in mind that cooling is nearly impossible during the summer and insect prevention will be very important to keeping the wheat in good condition.

Equilibrium Moisture Content for Soft Red Winter Wheat
Relative Humidity Percent

Bill Casady
573 882-4370