Sorghum Production in Mississippi
When should I irrigate grain sorghum?
Grain sorghum is the most drought-tolerant grain crop planted in Mississippi. However, it will respond positively to supplemental irrigation during droughty conditions. These characteristics make grain sorghum well suited for limited irrigation.
Grain sorghum is most dependent upon moisture around the boot stage. The boot stage is characterized by the head swelling inside the flag leaf sheath, immediately prior to heading. Grain sorghum water use is maximized from rapid vegetative growth stages through the soft dough stage. Water use during this time typically peaks at about 1.5 inches per week. Water use rapidly declines after the soft dough stage.
A furrow-irrigation application just prior to the boot stage, followed by another at bloom (if needed) should provide nearly the entire yield potential of full irrigation. Center-pivot irrigation systems typically require several applications since total water application is limited (compared to furrow irrigation) by runoff potential.