28 
BULLETIN 1387, U. S. DEPARTMENT OF AGRICULTURE 
obtained from these varieties grown by the old method of irrigation. 
When grown by continuous submergence after broadcast Feeding less 
time is required to reach maturity. The shortening of the required 
season varies from about 5 to 10 days, depending upon the date of 
seeding. 
VARIETIES GROWN ON SMALL INCREASE PLATS 
The yields of 17 varieties and strains of short-grain rice grown on 
small increase plats during the five-year period from 1920 to 1924, 
inclusive, are shown in Table 16. Of the 17 varieties 2 are early, 11 
are mid-season, and 4 are late maturing. 
Each year the increase varieties were grown on fallow land. 
In 1920 and 1921 the varieties were grown on single sixtieth-acre 
plats, in 1922 on single thirtieth-acre plats, in 1923 on single thirty- 
iourth-acre plats, and in 1924 on three thirty-third-acre plats. 
During the four-year period from 1921 to 1924, inclusive, the 
highest average acre yields were produced by the mid-season rices, 
Selections No. 138, No. 139, No. 218, and No^233. Selection No. 
138 was not grown in 1920 and is not includeu-ln the five-year aver- 
ages from 1920 to 1924, inclusive. During this period Selections 
Nos. 139, 218, and 233 of the same group were leaders. The aver- 
age acre yield of Omachi (C. I. No. 2316), a late-maturing variety, 
was nearly as high as that of the highest yielding mid-season vari- 
eties for the five-year period. These results, like those from the 
varietal experiments on larger plats, show that the best mid-season 
short-grain varieties yield as well as those of the late short-grain 
group, if not a little better. The highest average acre yields in 
these experiments, as in the regular varietal experiments, were from 
mid-season short-grain varieties or selections of the Wataribune type. 
Table 16. — Yields of 17 varieties and selections of short-grain rice grown in small 
increase plats at the Biggs Rice Field Station during the five-year period from 1920 
to 1924, inclusive 
C. I. 
No. 
1920 
Acre yields (pounds) 
Group and variety 
1921 
1922 
1,350 
1923 
1924 
Average 
1920 to 
1924 
1921 to 
1924 
Early group: 
2,488 
2,686 
3,638 
2,686 
2,788 
2,788 
2,448 
2,448 
2,584 
2,796 
3,434 
2, 958 
2,618 
2,788 
2,550 
2,414 
2,244 
1,996 
3,217 
3,163 
2,937 
2, 882 
3,234 
2,920 
2,788 
3,333 
3, 795 
3,102 
2,673 
2,376 
2,387 
1,991 
2,354 
Mid-season group: 
Selection No. 139 
3,498 
3,696 
3,531 
3,465 
3,267 
3,069 
2,574 
i 1, 730 
3,000 
3,180 
3,120 
3.060 
3,000 
2,880 
2,700 
2,760 
2,820 
2,820 
2,520 
3,300 
2,700 
2,150 
2,400 
2,970 
3,420 
3,480 
3,480 
3,000 
2,730 
3,180 
2,910 
3,480 
3,240 
3,210 
3,750 
3,480 
3,570 
3,000 
3,265 
3,229 
3,171 
3,135 
2,990 
2,809 
2,765 
*2, 706 
"""" 
3,129 
2,910 
2,515 
3,206 
Selection No. 218 
Selection No. 233 
3,112 
3,081 
3,052 
Selection No. 214 
"*2329~ 
"1561-1" 
2,920 
2,745 
Selection No. 129 
Caloro 
2,813 
2,950 
3,382 
Selection No. 171 
Selection No 176 
Late group: 
Omachi - — 
Shiratama — 
Takenari 
Takenaria 
2316 
2307 
2295 
2338 
3,432 
3,432 
2,450 
3,030 
2,755 
3,053 
2,779 
2,531 
2,499 
Yield from tenth-aiTe plat 
