SUDAN GRASS AND RELATED PLANTS. 15 
A second natural cross between sorghum and Johnson grass was 
discovered on September 16, 1913, on the farm of J. W. Austin, Pilot 
Point, Tex. This was located in a field of Honey sorgo, and is quite 
surely a cross between Honey sorgo and Johnson grass. Mr. Austin 
has applied to this cross the name “Johnsorgo.”’ ‘This hybrid has 
abundant and very large rootstocks and will probably not become 
popular in the South except as a hay and pasture crop on fields already 
Fic. 11.—A row of ‘‘ Johnsorgo,’’ F.C. I. No. 8557, 8 feet tall, at the Arlington Experimental Farm, Va., 
October 11, 1915. 
infested with Johnson grass. Johnsorgo is remarkably like Sudan 
grass In appearance (fig. 11), but is much less subject to the attacks 
of the red-spot, or sorghum blight, a disease which is very destructive 
to Sudan grass in warm, moist climates. Johnsorgo is the most prom- 
ising of all the hybrids between sorghum and Johnson grass yet 
tested. 
In order to provide material for a more definite study of these 
hybrids several artificial crosses of sorghum and Johnson grass were 
made. The first of these, F. C. I. No. 6573, a cross between Black 
Amber sorgo and Johnson grass, was made at the Arlington Experi- 
mental Farm, Va., in September, 1912. The first-generation plant, 
which was grown in the greenhouse that winter from a hybrid seed 
which developed on the Black Amber sorgo, looked more like Johnson 
grass than sorgo, but had no rootstocks. Seed from this F, plant was 
