Interest in grain sorghum in the Midsouth is based mainly on its ability to withstand drought better than corn. Thus, it would appear to be a suitable rotation crop for dryland soybean production systems in the Midsouth. However, grain sorghum is not widely grown in Mississippi, usually occupying well below 100,000 acres per year in the state.

According to the Mississippi NASS office, the average yield of grain sorghum in Mississippi over the last 5 years (2009-2013) is 82.4 bu/acre harvested from an average of 35,800 acres per year. The forecast yield for 2014 is 90 bu/acre to be harvested from an estimated 110,000 acres.

Unlike corn, soybeans, and cotton, there are no grain sorghum hybrids that are herbicide-resistant (HR). There is no apparent effort to produce sorghum hybrids that are tolerant to glyphosate, a mainstay in the HR toolbox for the other crops. Thus, weed control in grain sorghum is dependent on growing conventional hybrids and using conventional herbicides and in-season tillage, which is not an option when sorghum is grown no-till. This limits weed management in the crop.

Grain sorghum production in the region is now hampered by the recent incursion of the white sugarcane aphid into Midsouth sorghum fields. If left untreated, severe infestations will result in a total loss of yield. On the other hand, insecticidal control of this insect will average $25/acre according to the 2015 planning budgets for Mississippi. Also, the estimated $309/acre total for direct costs for growing grain sorghum in Mississippi in 2015 does not include a cost for insecticidal control of sorghum midge, which in all likelihood will be present in damaging numbers every year. The cost for two applications of insecticide to control midge will be about $20/acre. Thus, direct costs for grain sorghum production in Mississippi will more likely be about $354/acre.

Using the above $354 direct cost per acre to grow grain sorghum in Mississippi and the 5-year average yield of 82.4 bu/acre (46.14 cwt), a commodity price of about $7.67/cwt will be required to cover estimated direct costs. The 2013 seasonal average price for grain sorghum in Mississippi was $8.75/cwt. Thus, according to these numbers, there is only a small chance for making a profit when growing grain sorghum in Mississippi, especially since the $354/acre projected cost represents only direct costs.

A possible rotation for Mississippi producers to consider is grain sorghum/wheat/soybeans. However, according to information cited here (p. 6), wheat following grain sorghum often grows poorly and may require the addition of fall-applied nitrogen (Kansas State MF 2641, General Recommendations) to overcome this effect. If a soybeans/wheat/grain sorghum rotation is considered to overcome this negative, the general date of wheat harvest, which is early to mid-June, will necessarily postpone grain sorghum planting (usually about 75% planted by late May) beyond the time that is generally recommended. This will limit grain sorghum yield potential and most likely will increase costs for late-season insect control.

The above presentation appears to disparage grain sorghum as a rotation crop with soybeans in Mississippi. However, that is not the intent; rather, the points presented here are meant to provide producers a list of important production issues they should be aware of when considering sorghum as a rotational component in a dryland soybean production system.

Composed by Larry G. Heatherly, Nov. 2014, larryheatherly@bellsouth.net