14 
BULLETIN 1155, U. S. DEPARTMENT OF AGRICULTURE. 
DATE OF SEEDING. 
The yields obtained in date-of-seeding experiments on duplicate 
tenth-acre plats during the 9-year period from 1913 to 1921, inclusive, 
are presented in Table 10. The preparation of the land and the 
rate, depth, and manner of seeding were the same for all plats, but 
the dates of seeding varied. The first seeding was made as early 
in the spring as possible, the date ranging from March 15 to April 23; 
the second seeding was two weeks later; the third seeding was two 
weeks after the second; and the fourth seeding two weeks after the 
third. These dates of seeding ranged from March 15 to June 1. 
Because of weather conditions it was not possible to sow at the same 
time each year. 
Table 10.— Annual and average yields obtained in the date-of-seeding experiments with 
Wataribune rice at the Biggs Rice Field Station, Biggs, Calif., for the 9-year period 
from 1918 to 1921, inclusive. 
Yield per acre (pounds). 1 
•Date of 
seeding. 
1 
1915 
1916 
1917 
191S 
1919 
1920 
1921 
Average. 
1913 
1914 
1913 to 
1917. 
1913 to 
1921. 
First 
Second 
Third 
Fourth 
6,380 
5,955 
5,545 
4,885 
5,805 
5,845 
5,400 
5,045 
5,440 
4,985 
4,350 
3,410 
4,283 
4,100 
3,850 
3,450 
4,890 
4,845 
4,540 
4,110 
3,130 
2,760 
2,955 
3,430 
2,700 
1,965 
2,130 
1,920 
1,250 
3,095 
1,965 
780 
5,360 
5,146 
4,737 
4,180 
4,287 
3,897 
3,404 
1 Average yields from duplicated tenth-acre plats each year, with the exception of the third and fourth 
dates in 1917. 
In every year except 1914 the highest yield was obtained from the 
earliest date of seeding. With one exception, 1918, there was a 
marked decrease in yield from each successive date of seeding. 
Rice sown late in the spring, when the temperatures are higher and 
the water warmer than in early spring, germinates quicker, grows 
faster, stools less, and matures at nearly the same time as rice sown 
a month earlier, but the yield is less and the quality poorer than that 
from rice sown earlv- 
DA r EOF 
SEEP/NG 
V/ELD Pr/? si C/?E (P0£/A//?Sj 
E7/?Sr 
Fig. 
Average acre yields of Wataribune rice obtained in the date-of-seeding experiments at the Biggs 
Rice Field Station during the 9-year period from 1913 to 1921, inclusive. 
The highest average yield, 4,287 pounds per acre, was obtained 
from the earliest seeding date. The plats seeded 15 days later gave 
an average yield of 3,897 pounds per acre, and the third date of seed- 
ing gave an average yield of 3,404 pounds per acre. The average 
yields in the date-of-seeding experiments at the Biggs Rice Field 
Station from 1913 to 1921, inclusive, are shown graphically in Figure 6. 
The Wataribune variety was used in this experiment. Wataribune 
is a late-maturing variety, no t well suited for late sowing in this sec- 
tion. An earlv 
variety, 
such as Colusa or Onsen, can be seeded 
