May a, 1921 
Cotton Rootrot in the San Antonio Rotations 
119 
It is not necessary for the present purposes to describe all the rotations 
in the San Antonio series, so that only those including cotton are given 
in the following list, and only the principal features of the tillage methods 
preceding the cotton crop are indicated. These cotton rotations may 
be grouped into four categories, as follows: 
1. Cotton continuously: 
A-4-19. Cotton following field peas plowed tinder in March. 
A-6-3. Cotton on land plowed in November. 
B-5-3. Cotton on land plowed in November. 
B-5-4. Cotton on land plowed in November and manured each year at the rate of 16 
tons per acre. 
2. Cotton on the same land alternate years: 
A-4a. Cotton on land plowed in December and fallowed for 16 months. 
A~4d. Cotton following com on land plowed in July and fallowed 8 months. 
A-5C1. Cotton following oats on land plowed in June and fallowed 9 months. 
A-5C2. Cotton following grain sorghum on land plowed in July and fallowed 8 months. 
A~5di. Cotton following cowpeas plowed under in November after an oat crop maturing 
in June. 
A~5d2. Cotton following grain sorghum on land manured and plowed in July and 
fallowed 8 months. 
A~5ei. Cotton following cowpeas plowed under and the land subsoiled after an oat 
crop maturing in June. 
A~5e2. Cotton following grain sorghum on land manured, plowed, and subsoiled in 
July, and fallowed 8 months. 
B~5a. Cotton on land plowed in November following forage sorghum. 
B~5b. Cotton on land plowed in November following forage sorghum. 
B~5e. Cotton on land plowed in July following grain sorghum. 
B-6a. Cotton on land plowed in July following com. 
B-6b. Cotton on land plowed and subsoiled in July following com. 
B-6c. Cotton on land manured and plowed in July following com. 
B-6d. Cotton on land following com, manured, planted to field peas, and plowed in 
March. 
B-6e. Cotton following com, manured, planted to field peas, plowed under in March, 
and subsoiled after the cotton crop. 
B-6f. Cotton following com on land disked in July after the com crop but not 
plowed until after the cotton crop. 
B-6g. Cotton on land plowed in February after com. 
B-6h. Cotton on land plowed and subsoiled in February after com. 
B-6i. Cotton following com with rye disked in after the com and plowed under in 
February. 
3. Cotton on the same land every third year: 
A~5a. Cotton on land plowed in June, fallowed 9 months following oats for hay, which 
had followed grain sorghum. 
A~5b. Same as A-5a, except that the land was manured following the cotton crop. 
B~4a. Cotton on land plowed in November following Sudan grass, which in turn fol¬ 
lowed grain sorghum. 
B~4b. Cotton following field peas plowed under in March after oats for hay which 
followed grain sorghum. 
4. Cotton on the same land every fourth year: 
A-4f. A rotation of oats for grain, land plowed in June; grain sorghum followed by 
field peas plowed under in March; forage sorghum, land plowed in November; cotton 
planted the following April. 
A-4g. A rotation that differs from the above only in that the field peas are cut for hay 
instead of being plowed under. 
