Sorghums are classified into four groups – grass sorghums, grain sorghums, broomcorn, and sorgos. The grain sorghums are typically planted for deer and other wildlife because of their ability to produce grain. It is this grain, produced in a seed head at the top of the stalk (seen in the photo above), that deer eat.
Grain sorghum (Sorghum bicolor) was introduced into the United States from Africa and Asia and can be classified into seven groups – hegari, kafir, milo, shallu, durra, kaoliang, and feterita. Most of the grain sorghum varieties grown today are hybrids created by crossing milo and kafir.
Grain sorghum is a warm-season annual grain/grass and is widely adapted throughout the whitetail’s range. Grain sorghum comes in many shapes and sizes, depending on the variety. Some varieties reach 3- to 4-feet tall, while others may reach 10 feet. Most have thick, juicy stalks that support a large seed head. The color of the seed ranges from white to red to pink, depending on the variety. It is very drought tolerant, which makes it a great substitute for corn in drought-prone areas. Grain sorghum is also cheaper to establish and manage than corn, which is another reason food plotters are attracted to it. However, it is not as attractive to deer as corn. Under normal conditions one could expect to produce 50 to 60 bushels per acre of grain with proper management.
As always, collect soil samples to determine nutrient availability and soil pH to develop a lime and fertilizer recipe for your plots. Grain sorghum does not do well in acidic soils, so the pH should be maintained above 6.0 with the appropriate amount of lime.
If broadcasting seed or using a conventional seed drill, be sure to prepare a firm, smooth seedbed to ensure optimum seed-to-soil contact and germination. If using a no-till planter, be sure to kill the existing vegetation with glyphosate to eliminate weed competition a couple weeks prior to planting.
Grain sorghum has moderate phosphorus and potassium requirements, but like corn, it is a heavy nitrogen user, so be sure to apply the amounts recommended from the soil test to ensure nutrient levels are in the high range. It is important to remember that deer prefer to eat the seed heads of grain sorghum and not the leaves. Thus, maximizing grain production through proper fertilization and management increases food availability.
Grain sorghum needs about four months to mature, so be sure to time your planting accordingly. In the South it can be planted anytime from April to June. It should be planted in June in the North. If broadcasting seed in a pure stand, plant 8 to 10 lbs./acre. If using a seed drill, back off the rate to about 5 to 6 lbs/acre.
Regardless of planting method, be sure to cover or drill seed about an inch deep. Also, it’s important to plant when there is good soil moisture or when a good chance of rain is in the forecast. I can’t emphasize this enough. Far too often, food plotters schedule their planting dates weeks or even months in advance!
Although deer readily eat grain sorghum, I do not plant it in a pure stand when managing specifically for deer. Instead I prefer to plant forage legumes, such as soybeans, cowpeas, lablab, alyceclover, and jointvetch during the summer months and rely on cool-season forages in the fall through winter. However, I sometimes use grain sorghum in summer mixtures to provide more structure in the plot for the legumes to climb on for increased production and cover.
Using grain sorghum in this fashion is an excellent strategy as long as the plot doesn’t have a problem with grass weeds – and very few summer plots do not have a problem with grass weeds. Thus, as I have mentioned in previous profiles, it is more important to select a planting mixture to accommodate weed management options. If your plots are like mine, grass weeds such as johnsongrass, crabgrass and broadleaf signalgrass will take over if not controlled with herbicides. Thankfully there are several good herbicide options for grain sorghum that will be discussed later.
A good blend that includes grain sorghum is provided below. Rates are for broadcasting with drilled rates in parentheses. The grain sorghum will provide ladder structure for the cowpeas and lablab to climb upon for increased production, and deer will consume the seed heads in the fall after the forage legumes play out.
Cowpeas 40 lbs./acre (25 drilled)
Lablab 10 lbs./acre (6 drilled)
Grain Sorghum 3 lbs./acre (2 drilled)
The variety of grain sorghum used should also be considered prior to planting. Bird-resistant varieties have been developed to reduce depredation from birds, which is obviously important when managing for deer. These varieties contain more tannin, which makes the seeds less attractive to birds and other wildlife. After a frost, tannin levels drop and palatability increases. Personally I like using the WGF sorghum variety because of its height (3- to 4-feet tall) and hardiness.
Several herbicide options exist for controlling weed competition in grain sorghum, particularly if it is planted alone. Knowledge of the weeds you may encounter in your plots is invaluable for developing an effective strategy.
If broadleaf weeds are a problem, they can be easily controlled with a forb-selective herbicide, such as 2,4-D, Banvel, or Clarity. However, the fact that some of the worst summer weeds are grasses creates a dilemma when planting grain sorghum because it is a grass. If grass competition is a problem, your options are basically limited to several herbicides that can only be applied preplant incorporated with grain sorghum, such as atrazine (restricted use) or Dual Magnum. This technique is where you spray the soil with the herbicide and disk it in prior to planting. It is important to know that if using Dual Magnum, the grain sorghum seed must be treated with Concep seed safener.
Unfortunately, weed control for mixtures that contain grain sorghum and broadleaf species like cowpeas is limited since a grass is being mixed with forbs. In fact, I’m not aware of any current herbicide options that will accommodate this for grain sorghum (there are options here when using corn, however). Thus, it is important to address this on the front end and develop a planting strategy accordingly.