Research Progress Report 285 Project 1332 March, 1967
1966 Forage Sorghum, Sudangrass and Grain Sorghum Variety Test Results on the Forage Farm
A.R. Campbell and R.C. Pickett, Agronomy Department

Grain Sorghum
The grain sorghum yield trials were not harvested in 1966. Because of the severe drought early in the season and through pollination, the plants grew to only half the normal height. The heads were only a tenth the normal size. The hot, dry weather affected the pollination resulting in much sterility on all of the sorghum heads.

These trials were planted in 14-inch rows spacings, as was the forage sorghum trial. The grain sorghum trial will also be planted in wider rows spacings in 1967 to try to a maximize use of available water.

A trial will be planted in 1967 to compare wide and narrow row spacings.

Forage Sorghum and Sudangrass
The results of the forage sorghum and sudangrass yield trials are shown in Tables 1 and 2. Two - and three-year averages are shown in Tables 3 and 4 for those entries tested in 1964, 1965, and 1966.

The yields from the sudangrass and sudangrass-sorghum crosses were higher in
1966 than in 1965. Drought early in the growing season caused a low yield for the first cut. Nitrogen was applied at the rate of 50 pounds per acre after the first cut followed by rain. Thus, regrowth conditions were favorable and the yields were almost two-fold for the second cut over the first cut.

The forage sorghums did not yield as well in 1966 as they did in 1965. Drought cut the stand appreciably and moisture limited growth. In 1967 the forage sorghum trial will be planted in 38-inch instead of 14-inch row spacings to try to improve moisture availability.

The proportions of leaf, stem, and head should be considered when evaluating a forage sorghum. Higher yielding varieties tend to have a higher proportion stalk and may have lower digestibility and nutritive value than some of the lower yielding types.

The ability of the sudangrasses and sorghum-sudangrass hybrids to utilize the late season rainfall and produce an excellent second cut suggests a good potential for this forage in this area. Many entries seemed very succulent and would probably make a highly palatable and digestible feed.

PURDUE UNIVERSITY • Agricultural Experiment Station • Lafayette, Indiana