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Topics : Species and Forage Variety Trials : Species Fact Sheets : Sorghum & Sudangrass

Species: Sorghum & Sudangrass

Additional sorghum & sudangrass information via the Forage Information System (FIS)

Characteristics & Adaptation of Sorghum & Sudangrass

Shortages of forage crops in Pennsylvania most often occur during the summer months when the productivity of pastures, hay crops, or silage corn fields have been reduced by dry conditions. Summer- annual grasses, which maintain relatively high levels of production during hot and dry conditions, can greatly reduce the risk of inadequate forage production during the summer. They can also be used as an emergency forage source when production from corn and hay crops is likely to be less than adequate.

Descriptions of Different Summer-Annual Grass Species

Summer-annual grasses differ in growth and production potential but have several similar characteristics. They grow best at relatively high temperatures (80 degrees F) and can produce under conditions of limited moisture.

Sorghum is an upright growing grass which has been bred for both grain and forage production. The grain sorghum types are relatively short growing (less than 6 feet) and provide moderate yields when harvested as a forage. Forage sorghum, on the other hand, grows tall (6 to 15 feet) and has the potential for high yields. Of the two types, forage sorghum is the preferred type for forage production. Like corn, sorghum hybrids are classified into maturity classes. Late-maturing sorghum types yield more than earlier- maturing types, but may not reach maturity before a killing frost. The forage sorghums are usually harvested only once and used for silage or green-chop production.

Sudangrass usually grows between 3 and 8 feet high and has stems about 1/4 inch in diameter. Solid stands of sudangrass grow shorter than when seeded in rows. Sudangrass develops only fibrous roots and does not have rhizomes. However, many stems may develop from a single seed if space is available. Sudangrass will regrow following each harvest until cool temperatures or lack of moisture inhibit growth.

Sorghum-Sudan Hybrids or Sudax resemble sudangrass but are taller, have larger stems and leaves, and give higher yields. Hybrids tend to be coarser than sudangrass and vary in seed color and size, yield and growth characteristics depending on their parents. Like sudangrass, sorghum-sudangrass hybrids will regrow after each harvest unless environmental conditions are restrictive.

Millet has smaller stems and is more leafy than the sorghum, sudangrass, or sorghum-sudangrass hybrids. Pearl millet will regrow after harvest but not as rapidly as either the sudangrass or sorghum- sudangrass hybrids. German or Foxtail millet, however, does not regrow after harvest. Millet yields are usually lower than sorghum-sudangrass hybrids.