Sorghum Life Cycle

The History of Sorghum


The origin and early domestication of sorghum took place in northeastern Africa. The earliest known record of sorghum comes from an archeological dig at Nabta Playa, near the Egyptian-Sudanese border, dated 8,000 B.C.

Sorghum adapted to a wide range of environments throughout Africa, spreading from the highlands of Ethiopia to the semi-arid Sahel. The crop then spread to India and China and eventually worked its way into Australia.

In the U.S., the first known record of sorghum comes from Ben Franklin who wrote about its application in producing brooms in 1757. Over the centuries, sorghum has planted its roots in many U.S. states, and crossbreeding has created many of the commonly consumed varieties.

Today, thanks to American farmers, sorghum can be enjoyed in your favorite foods.

Life Cycle

Planting

Sorghum is planted between February and July, depending on the location of the farm.

Growing

Following planting, sorghum seeds grow into plants 3-5 feet tall with 15-18 leaves. The flag leaf is the last to form and once its leaf tip becomes visible the sorghum head will emerge in 7-10 days.

Flowering

Once the sorghum head has formed, it begins flowering at the top of the head downward in a 3-7 day period. After flowering, the grain begins to form.

Maturing

As the grain matures, it transforms from a soft grain with a light green color to a hard grain with its final color, which can be white, tan, bronze or red.

Harvesting

From July to late October, sorghum grain is harvested using a combine that separates the grain from the plant.

Sweet Sorghum

Sweet sorghum is grown similarly to grain sorghum with the main differences being that it grows 7-10 feet tall and is harvested mostly for syrup. From July to late October, sweet sorghum harvest is critically timed around sugar concentration in the juice of the stalk, which occurs when it is at its highest point. Sugar concentration is measured in Brix. One-degree Brix is equal to 1 gram of sugar in 100 grams of juice. Sweet sorghum is generally harvested either by a cane harvester or by hand. Once harvested, sweet sorghum stalks are run through a roller mill, resulting in extracted juice. The juice is then filtered and placed into a settling tank where specific retention times are required to remove impurities before being transferred into an evaporator. Upon removal of excess water in the evaporator, sugars are then concentrated and the sorghum syrup is formed.