Sorghum Benefits to South Texas Cropping Systems

By Brent Bean, Ph.D., Sorghum Checkoff Agronomist

With summer crops harvested and wheat planted, growers’ thoughts turn to the selection of different crops they should plant for the 2019 growing season. Growers should consider adding grain sorghum to the mix – and for good reasons.

Inexpensive to Grow

Grain sorghum is a drought-tolerant crop that is inexpensive to grow compared to other crops. Based on 2018 Texas AgriLife Dryland Crop Enterprise Budgets for the Texas Coastal Bend, the variable operating costs for sorghum are $74 less than GMO corn and $189 less than cotton.

The invasion of the sugarcane aphid a few years ago caused many growers to move away from grain sorghum. However, sugarcane aphid was only a minor problem in 2017 and 2018. Our best estimate is no more than 10 to 15 percent of the grain sorghum acres in South Texas and the Coastal Bend area needed to be treated for sugarcane aphid in 2018. Nature also has its unique way of dealing with new pests over time as beneficial insects adjust to a new food source. The planting of more sugarcane aphid tolerant hybrids has also helped keep the overall sugarcane aphid number down.

Yield Advantages When Grown in Rotation

Grain sorghum can produce yield advantages for cotton and  corn when used in rotation. Research consistently has shown yield advantages for cotton when following sorghum, and recent research with corn revealed positive results.

In rotation with cotton, sorghum breaks up soil disease cycles such as verticillium wilt, and the crop residue increases soil moisture storage and protects emerging cotton from wind damage. In a 2017 trial conducted by researchers at Texas A&M University, cotton following sorghum produced a 26 percent higher yield than continuous cotton.

A surprise to most growers, grain sorghum also appears to benefit corn yield when following sorghum. A five-year trial from Kansas State University recently demonstrated an 8.4 percent increase in corn yield following sorghum compared to continuous corn.

Herbicide Considerations

When used in a rotation with cotton, growers should consider the herbicides used and read the herbicide labels to determine if they pose any risk to sorghum. Always carefully read and follow all label instructions. Staple LX/Pyrimax and Envoke are the two most often used herbicides in cotton that can cause injury to sorghum the following year.