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BULLETIN 1155, U. S. DEPARTMENT OF AGRICULTURE. 
On the broadcast plats the highest average yields, 5,112 pounds 
per acre in the period from 1913 to 1917 and 3,315 pounds in the period 
from 1918 to 1921, were obtained from the heaviest rate of seeding. 
The average yields from the medium rates of seeding in these two 
periods were 4,821 pounds and 3,017 pounds per acre, and the average 
yields from the lowest rates were 4,340 and 3,273 pounds per acre in 
the two periods. 
On the broadcast plats there was a marked increase in yield during 
the first period from increased rates of seeding up to 100 pounds per 
acre, but from the 110, 130, and 150 pound rates there was but little 
difference in the average yields per acre. 
In comparing the average yields obtained from the drilled and 
broadcast plats, there was a marked increase in favor of drilling dur- 
ing the earlier period for each rate up to 100 pounds per acre, but dur- 
ing the second period there appeared to be no advantage in drilling 
over broadcasting on a well-prepared seed bed. The rate-of-seeding 
experiment has been conducted on new or fallow land, on which a 
good seed bed has been prepared each year. 
EXPERIMENTS IN 1921. 
The yields obtained in rate-of-seeding experiments with three 
varieties of rice in 1921 are shown in Table 9. The preparation of 
the land, date, depth, and manner of seeding were the same on all 
plats, but the rate of seeding varied from 85 to 175 pounds per acre. 
The lowest yield of each variety was obtained from the 85-pound 
rate of seeding. The yields of Selection No. 175 increased with each 
increase in the rate of seeding up to 150 pounds per acre, but the 175- 
pound rate of seeding produced a lower yield than the 100, 115, or 
130 pound rates. The yields of Caloro varied, but did not give con- 
sistent increases with the increased rates of seeding, though the 
highest yield was obtained from the 175-pound rate. The yields of 
Wataribune show a gradual increase, except for the 130-pound rate, 
with each increasing rate up to 150 pounds per acre. 
Table 9. — Yields obtained from three varieties of rice in the rate-of-seeding experiments 
at the Biggs Rice Field Station, Biggs, Calif, in 1921. 
Rate of seeding. 
85 pounds . 
lOOJpounds 
115"pounds. 
130 pounds. 
150 pounds . 
175 pounds. 
Yield per acre (pounds). 1 
Selection 
No. 175. 
1,880 
2,660 
2,710 
2,740 
3,030 
2,450 
Caloro. 
2,380 
2,630 
2,460 
2,510 
2,860 
3,080 
Average. 
2.578 
2,653 
Watari- 
bune 
(CI. 1561). 
2,150 
2,800 
3,210 
3,160 
3,640 
3,290 
3,042 
Average. 
2,137 
2,697 
2,793 
2,803 
3,177 
2,940 
1 Yields from single tenth-acre plats. 
The average yields of the three varieties at each rate show in- 
creases in yields with each increase in the rate of seeding up to 150 
pounds per acre. The average yield of the three varieties sown at 
