EICE CULTURE IN CALIFORNIA 
17 
ries 2) had a good deal of water grass and sprangletop present each 
year. The plats irrigated in the old way (series 3) were foul in 1922, 
very foul in 1923, and extremely foul in 1924. 
Table 10 presents the annual and average acre yields for the rate- 
of-seeding and method-of-irrigation experiments during the three 
years, 1922, 1923, and 1924. 
The annual yields reported in Table 10 are for single fifth-acre 
plats each year. The plat sown at the rate of 190 pounds in series 
1 is more favorably located with reference to drainage than the other 
plats, and this may have influenced yields. 
In 1922 on fallow land the average acre yield, including all rates of 
seeding, was about the same for all series. In 1923 the average acre 
yield, including all rates of seeding, was higher for series 1 than for 
series 2 and considerably higher than for series 3. In 1924 the aver- 
age acre yield, including all rates of seeding, was 2,502 pounds for 
series 1,947 pounds for series 2, and 566 pounds for series 3. It is 
interesting to note that the average acre yield, including all rates of 
seeding for series 1, was higher in 1924 than in either 1922 or 1923, 
while the average acre yield, including all rates of seeding for series 
2, was 16 per cent lower in 1923 and 60 per cent lower in 1924 than in 
1922. For series 3 the average acre yield, including all rates of seeding, 
was 30 per cent lower in 1923 and 75 per cent lower in 1924 than in 
1922. The results show that during the period of cropping covered 
by the experiment yields were maintained at about 2,200 to 2,500 
pounds when water grass and other weeds were reasonably well con- 
trolled. Where weeds were not controlled there was a rapid decrease 
n yield, the decrease being proportional to the increased weed growth, 
i 
Table 10. — Yields oj Color o rice obtained in the rate-of -seeding and method-of-irri- 
gation experiments at the Biggs Rice Field Station in 1922, 1923, and 19 ?4 
Rate of seeding 
Acre yields (pounds) 
Series i 
Series 2 
Sown lllv Sown 
May 5, , h a5 MavS, 
sub- J"; sub- 
merged m "ppd merged 
Ma >' 9 > \i!v Ma y 
1922 n.1923 10 ' 1924 
Series 3 
Sown : Sown Sown Sown Sown Sown 
April ADril April April April April 
26, 30, 26, 26, 30, 26, 
sub- sub- sub- sub- sub- sub- 
merged merged merged merged merged merged 
May May May June June June 
23, 1922 25, 1923 20, 1924 18, 1922 14, 1923 12, 1924 
Three-year averages 
Series 
1 
Series 
2 
Series 
3 
115 pounds 
130 pounds 
150 pounds 
175 pounds 
190 pounds 
1,840 
1,860 
2,980 
1,815 
3,125 
2, 325 2, 580 
2, 285 2, 710 
2,075 2,335 
si,800 2 1,740 
2, 555 3, 145 
1 1, 350 1, 830 
2, 650 2, 300 
2,735 2,140 
2 2,380 2 1,690 
2,605 1.845 
Average .. 2, 324 2, 208 2, 502 2, 344 1, 
935 
1,065 
1,060 
2 650 
1,025 
1,690 
2,925 
2,660 
2,295 
1,720 
1, 355 
1,805 
1,730 
1,530 
1,435 
460 2, 248 
700 2, 285 
630 2, 463 
530 1. 785 
510 2, 942 
1,372 
2,005 
1,978 
i, :»7;^ 
1,825 
1.168 
1,810 
1, 452 
1,222 
947 
2,258 1,571 
566 
1 Yield reduced by leaf miners. 
2 Yields probably reduce 1 by nonuniform land. 
In general, rice growers agree that it requires more seed to obtain 
good stands when sown broadcast than when drilled. The three- 
year average acre yields in Table 10 show that the plats sown broad- 
cast in series 1 gave the highest yields from sowing at the rate of 1 oil 
69574— 26f 3 
