Preparing For Wheat Harvest
Good Day! Hope all is well for you!
Rainfall for last week ranged from a trace to 0.2 inch with an average of 0.07 inch. The rain fell early Sunday morning. Rainfall for the month of July, ranged from 0.98 inch to 2.16 inches with an average of 1.42 inches, which is 1.93 inches below normal of 3.35 inches! The high temperature for the past week ranged from 74 to 88 degrees Fahrenheit with an average of 79 degrees Fahrenheit, four degrees below the normal high temperature of 83 degrees. The high temperature for the month of July ranged from 71 to 93 degrees Fahrenheit with an average of 81 degrees. That is the normal high temperature for the month of July. The high temperature forecast for the coming week will be above normal.
We are nearing wheat harvest! We could start harvest in about 10 to 14 days.
Preparing the grain bin is critical to controlling insect problems since wheat is the most likely grain to have pest problems. Hopefully your bins have already been prepared for filling. It is best to prepare them at least two weeks in advance and preferably earlier. To prepare the bin, remove ALL grain from the inside and outside of the bin, including below the floor and vegetation from around the outside of the bin. If wheat will be stored for a long period of time consider spraying an insecticide on the walls and floor of the bin.
Setting up the combine is extremely critical to harvesting quality grain with minimal loss. It is recommended to set the cylinder/rotor and concave spacing to ¼ inch with a range of 1/8 to ½ inch. Set the cylinder/rotor speed to 1000 revolutions per minute (rpm) with a range of 750 to 1350 rpm. Set the fan speed or choke near the high end with a range of medium to high. The recommended sieve opening is ¼ inch with a range of 1/8 to 3/8 inch. The recommended chaffer opening is 5/8 inch with range of ¼ to ¾ inch.
Estimating yield loss during harvest is very important to properly adjusting the combine. To check for harvest loss, stop the combine. Once the header and combine have stopped operating back the combine up about 20 feet then turn off the engine. Take a one-foot square frame and place it three times in the standing wheat ahead of the header and count the number of wheat kernels in each square and take an average. This is the preharvest count. Repeat the three square count in the area between the standing wheat and the header. This is the header count. Now take the header count and subtract the preharvest count and divide by 20. This is the header loss per acre. Twenty is used in the calculation because this is considered the number of kernels in a square foot equal to one bushel per acre. Go behind the back of the combine and lay the counting frame down three times in the area between the tires counting the seeds in each square and obtain an average. This is the separator count. Take the separator count and subtract the header count and divide by 80 (number of kernels per square foot behind separator discharge to equal one bushel per acre with no spreading device). Eighty is replaced by 65 if a bat type spreader is used, by 50 if a straw chopper is used, and by 25 if a chopper and chaff spreader are used. The goal is to have harvest losses below 2% of total yield. To learn more read “Harvesting Wheat” from Kansas State University (https://www.bookstore.ksre.ksu.edu/pubs/MF2026.pdf).
Once the moisture of wheat reaches 20%, begin harvesting. Harvesting at 20% moisture and air drying will result in higher test weight and quality. Harvesting 20% moisture wheat will reduce the chance rain will reduce grain quality from sprouting. Harvest wheat before it reaches 14% moisture because kernel damage will occur below this moisture. Wheat can lose 2.5% moisture each day. Check with your local buyer to determine what their discount rate is for delivering wheat above 14%. Do not fill the bin beyond nine feet when air drying.
