Topics : Species and Forage Variety Trials : Species Fact Sheets : Sorghum & Sudangrass
Species: Sorghum & Sudangrass
Additional sorghum & sudangrass information via the Forage Information System (FIS)
Sorghum & Sudangrass Establishment
Summer annuals should be planted from two weeks after corn until the end of June. Soil temperatures should be at least 60 degrees F. Seedings may be made as late as July 15 in emergency situations, but yields will be reduced because of limited moisture in the summer and cool temperatures during the fall. When utilizing any of the summer annual crops in a planned rotational grazing situation, two seedings should be made about three weeks apart. This will stagger the maturities and make grazing management easier.
Forage and grain sorghum planted for forage should be planted in rows to facilitate harvest and minimize lodging. Avoid planting the sorghums too deeply as emergence problems may occur when planted deeper than one inch in most Pennsylvania soils. Also, avoid seeding rates above 10-12 pounds per acre since they can increase the risk of lodging, particularly with the tall forage sorghum types. Corn planters work well for planting sorghum provided the appropriate plates or feed cups are used to achieve the desired seeding rates. Sorghum can be planted using any tillage system provided adequate weed control can be achieved.
Fewer herbicides are labeled for grain and forage sorghum than corn so select fields where weeds can be controlled with labelled herbicides. When using Lasso or Dual, be sure to use seed that has been treated with the appropriate safener. When planting after a failed corn crop, be sure that the herbicides used on the corn are labelled for sorghum.
The other summer-annual species can be broadcast seeded and cultipacked or seeded with a grain drill into a well-prepared seed bed. A firm, well- prepared seedbed is best, however, acceptable stands may be established without tillage using no-till drills. Solid seedings result in finer and shorter plants which are desirable for silage and grazing. Wider row spacings (20 to 36 inches) allow for cultivation and results in better regrowth and more uniform production throughout the season. Narrow rows provide intense competition and herbicides are rarely necessary when seeded in this fashion. Only a few herbicides are labelled for these summer-annual crops so weed control should be considered carefully in selecting a row spacing. Row spacing itself, however, has relatively little effect on total forage production. Seeding rates vary depending on seeding method and anticipated moisture conditions.
Plant sudangrass, sorghum-sudangrass hybrids, and millets 1 inch deep in medium to heavy soils and 1 1/2 inches deep on sandy soils. If the soil is dry and rain is not anticipated before seedling emergence, cultipack the seedbed to maximize seed-to-soil contact and moisture conservation.