Sorghum Production Tips

Paul Hay, UNL Extension Educator, Gage County

Hybrid Selection and Seeding Population:

Select a top performing hybrid from one of the seed companies who are proud to sell milo seed. Don't be afraid of taller hybrids.  Many times these are top performers and height is not a real issue with today's combines and is not closely related to stalk rot or standability. Plant 80,000 plants per acre on dryland in any row spacing in Gage County and drop the population 5000 plants per acre for every county west across southern Nebraska.

Crop Rotation Considerations:

Please click here for a crop rotation study conducted by Paul Hay from 1994-2005. 

Fertilize for Top Yields:

Milo needs 1.1 pounds of nitrogen per bushel for top economic production. Soil test levels and past yield goals will tell you the nitrogen fertilizer addition you will need and the response you might expect from phosphorus and zinc. Check out the sorghum soil management page for current University of Nebraska-Lincoln Extension recommendations for nitrogen, phosphorus, potassium, zinc, iron, and sulfur. If the phosphorus level in the field is low, starter fertilizer is an excellent way to get the phosphorus efficiently placed for top response. Because of the great reliance on postemergent herbicides for weed control, starter fertilizer usually helps produce a larger plant sooner and aids in the weed control.

Please click here for information on a no-till sorghum starter fertilizer study.

Limit Tillage:

Milo yields have been excellent under no-till systems. If you feel you have to part the residue, do so without moving soil. This helps to take the E (evaporation) out of ET (evaporation & transpiration), which are the water use components. Crop residue does this in two ways. It eliminates the moisture lost from every tillage operation which amounts to one-fourth inch to one inch depending on timing and depth. Residue also shades the soil and reduces evaporation loss from the soil surface. Residue cover keeps the soil temperature a bit cooler and reduces stalk rot problems. This is particularly true as you move west in Nebraska to dryer and warmer summertime soil temperatures.

Weed Control:

The keys to weed control in milo are Early Preplant (EPP) and Days Before Planting (DBP) listed in the University of Nebraska-Lincoln Extension Guide for Weed Managemen (See the Sorghum Weed Management section). There are few options for post emergence grass control until Clearfield hybrids become available. So a solid before planting program is the best.

What about a burndown with glyphosate at planting or pre-emerge treatment? It can work, but there is a dangerous gap. Grass killers for sorghum are shoot absorbed. If there is no rain to activate the herbicide, escapes can occur where there is a bit of moisture in the soil to germinate grasses which come through the non-active barrier. When the herbicide is in place for the later planted crop, it saves moisture and gives the producer added options for both grass and broadleaf control. Spraying the last part of the herbicide behind the planter and/or using glyphosate behind the planter extends the weed control program and ensures a clean field at planting without using tillage to dry the soil and plant more weed seed. There are limited options for post grass control so scout heavy early and respond aggressively to escapes while they are small.

Insect Considerations:

July is greenbug month.  You have to scout fields carefully during July and make a decision on greenbug control. Treatments in August most often kill the greenbugs after the damage has been done.

Trifold Chinch Bug Plan:  Chinch bugs are a threat to sorghum at three stages. One, in the seedling stage when chinch bugs are present because of poor control or too late control of grasses like volunteer wheat. Two, when wheat or oats ripen and the chinch bugs march across to the milo field next door. Three, after heading when the second generation flies into the milo field and sets up housekeeping. Stay alert and do the best you can to choose treatment options for this troublesome pest. Seed treatment insecticides can help in the seedling stage and to a lessor extent after the wheat ripens. Kansas trials are often more promising than Nebraska experience because Nebraska milo producers have a longer time between milo planting and wheat ripening, which challenges the endurance of the insecticides.

Timely Harvest:

Part of treating milo as a second choice is to let it stand to dry while getting the corn harvested before the itching starts. This is not the way those choices should be made. In all management decisions including harvest, the milo producer who treats it a first class crop is going to be more successful. Milo packs denser in bins so it must be drier than corn for safe moisture levels for aeration only. With good aeration you can keep the fans running and handle corn at 19-20%, but milo at 17-18% is about as high as you should go. It is very important in either case to take a load out of the bin after filling to take the cone down (level the bin) and remove fines from the grain spreader out of the center of the bin.