industry. The following table shows that the acreage of mulberry farms has
been constantly on the increase of late.
Year Total Cultivated Land ~~ Mulberry Farms Percentage
1913.........- 014.104 830 acres 1,107 060 acres 78%
1918... 0 14,743,310 acres 1,247,030 acres 85%
1924.....5 0550 15,162,912 acres 1,343,467 acres 89%
Silkworm Rearing
At present more than one-third of the Japanese farmers are engaged in
raising cocoons, their number reaching nearly two millions.
Number of
Farmers engaged in
Year Total Farmers Sericulture Percentage
1913. ys 3 710 1,500,280 289,
O18 ae = 5,481,187 1 942 252 359,
ir A ne: 5,532,429 ( 890,166 349,
Three crops of cocoons are raised, the Spring crop, the Summer crop,
and the Autumn crops. Silkworms for the Spring crop are hatched during
the season usually beginning at the end of April and ending in the middle
of Mav. They are reared for about 30 days at the temperature of 72 to 73
degrees Fahrenheit, at the end of which period they make cocoons. The
Summer crop 1s raised from silkworms hatched during June and July. They
mature after having been reared for about 25 days at the temperature of
75 degrees F. The Autumn crop is from silkworms hatched during August
and September. The period of rearing is about 20 days, and the temperature
about 80 degrees F.
Until some fifteen years ago, the Spring crop amounted to more than
two-thirds of the total production, but with the recent increase of the Autumn
crop, the Spring crop has decreased to one-half of the total, the other half
being composed of the Summer and Autumn crops combined.
Production of Cocoons (unit Kan)
Year Spring Crop ~~ Summer Crop Autumn Crop Total
1913.......... BN25,953,030 5,343,220 14,619,230 45,915,480
1918... WW. 710 6,441,000 26,336,530 68,320,240
10923. iia JD G27 307 42,271,461 85,198,768
(1 Kan = 814 pounds.)
Percentage
Year Spring Crop ~~ Summer and Autumn Crops Total
1913..... 427. 579% 129 319 1009
19185. 529 997, 399 1009
1923.25.50... 509, 509, 1009,
sr 25 Le
Shia