86 
BULLETIN 1260. U. S. DEPARTMENT OF AGRICULTURE. 
sorgo was cut each year at four different stages of maturity. These 
stages can not be closely defined, owing to the fact that the sorghum 
made a normal growth each season only until it reached approxi- 
mately the first head stage, after which it usually showed marked 
drought injury and gradually dried up without maturing many heads 
except around the margins of the plat. 
The first cutting was always made at a time when the crop was 
clearly too miniature for good hay or at least for maximum yields; 
at this stage the young plants were still making vigorous growth and 
had not begun to head. The second and third cuttings followed at 
2-week intervals, with drought injury gradually more marked, and 
the fourth cutting was made after the crop had definitely matured 
seed, dried up. or been frosted, so that no further growth was pos- 
sible. The seedings were accomplished under excellent soil condi- 
tions in most seasons, the date ranging from May 23 to June 7. with 
May 31 the average. The average date of the first cutting was 
August 2, and for the other cuttings August 15, August 31. and 
September 24, respectively. 
In only one case was there a second growth more than a foot tall; 
this was harvested from the plat used for the first cutting in 1920, 
and the product of the second growth was included in the yield of 
the first cutting for that year. As in all the other work reported 
from Hays, the hay yields were corrected by samples to an air-dry 
basis, and in the first three years, 1917 to 1919, samples of each 
cutting were sent to the Bureau of Chemistry, United States Depart- 
ment of Agriculture, for a determination of their composition. 
The annual and average yields of hay, the average number of 
days from seeding to cutting, and the average height of the plants ; 
are shown in Table 27. 
Table 27. — Agronomic data regarding close-drilled Red Amber sorgo when cut at 
different stages of maturity at Hays, Kans., in stated years. 
Stage of growth. 
Yields of air-dry hay per acre (tons). Average. 
Cutting. 
1917 
1918 
1919 1920 
1921 
1922 
Grow- 
Aver- ing Height 
age. season (inches). 
j (days). 
First 
Before heading 
Partially headed 
Bloom to dough 
Seed ripe 
1.57 
1.97 
1.93 
2.33 
1.61 
2.07 
2.54 
2. 16 j 5. 15 
2. 95 ! 4. 13 
3.10 4.17 
3.19 
3.34 
3.37 
3.99 
2.37 
3.13 
3.51 
4.04 
2. 68 62 41 
Second,. _ . 
Third 
2. 93 74 46 
3. 10 90 48 
Fourth 
2.84 3.39 1 5.61 
3.70 111 ' 50 
It will be noted in Table 27 that the yields ordinarily increase with 
the length of the growing season. Cutting as late as possible when 
the sorghum had completed its growth for the year produced Uton 
more hay per acre than cutting before the plants began to head. 
The quality of the hay from the second and third cuttings appeared 
to be the best, however, and all factors considered cutting at the 
third stage of maturity or a little later is probably the most practi- 
cable time for farm purposes. 
It is well known that the chemical composition of plants varies 
with the stage of maturity. A study was therefore made to deter- 
