Considering Grain Sorghum In 2015?
DR. ANTHONY OHNMES
JACKSON, MO.
I have had a few calls regarding grain sorghum this fall. Some of the reasoning behind an interest in milo is introducing a summer grass grain crop into continuous soybean fields in order to rotate herbicide modes of action for pigweed management. If it has been a few years or this is your first season planting milo, I will outline some management considerations.
Variety selection and identifying what varieties are available is the first component in making a decision to plant milo. Utilize variety testing data from MU and surrounding states and then speak with your seed supplier for variety availability. In general, full season varieties offer higher yield potential. After a few years’ hiatus, MU variety testing had grain sorghum trials throughout the state. The data is posted on the variety testing website: http://varietytesting.missouri.edu/sorghum/results.htm. Note: The Barton and Mississippi County trials were not included in harvest data.
The second is planting. Milo can be planted at various row widths. From a weed management perspective, 15 inch row spacing can help speed canopy closure while offering some flexibility with in-season management. Know your kernel weight since seed size will influence seeding rate. Target final plant stands between 50,000 to 70,000 plants on dry land. Plant when soil temperatures are approaching 65 degrees. Increase planting rate by 15 percent to compensate for any emergence losses. Planting depth is ½ inch to 1 inch but do not exceed 1.5 inches deep.
Third is fertility and pest management. Nitrogen recommendations are based on the formula: 60 + [(lbs of Milo/A)*(0.014)] - 10 = Units of N. So 125 bushels per acre (7000 lbs/A) would need 148 units of N. Phosphorus removal for 7000 lbs/A is 65 lbs P2O5/A. Potassium removal would be 42 lb K2O/A. Pest management considerations include preemergence and post emergence weed control. Grass control is limited to residual preemerge grass products. Insect management includes midge and corn earworm. Midge is critical to scout during the entire span of flowering. Flowering begins at the tip and moves down the head over 5 or more days. For more information on pest management options check the M171 Pest Management Guide: http://extension.missouri.edu/p/M171.
Other considerations are harvest and budgets. Harvest should begin when milo is between 20 percent and 17 percent moisture. Waiting past this point increases risks of lodging, bird feeding, sprouting or other yield loss factors. University of Arkansas has a guide on harvesting milo: http://www.uaex.edu/publications/pdf/FSA-1017.pdf. Another consideration is looking over the MU Crop Budgets that David Reinbott puts together each year: http://extension.missouri.edu/scott/crop-budgets.aspx. ∆
DR. ANTHONY OHMES: Agronomy Specialist, University of Missouri