PEDIGREED FIBEE FLAX. 21 
week in October at Mayaguez, P. R. An increase of only 4 times 
was secured, because the winter dry season caught the flax early in 
December, before it had completed its growth. An increase of nearly 
200 times in one year from two of the selections was obtained, so 
that there was nearly a bushel of each, or enough for a commercial 
test in 1919. Flax was again grown as a winter crop in Porto Rico 
in 1919 and the seeding made a month earlier, in order that it might 
make most of its growth in advance of the dry season. The tor- 
rential downpours of the terminating rainy season drowned most of 
the seed and the young plants and resulted in a poor growth in the 
rest of the stand, so that less seed was harvested than was put in the 
ground. Further trials were then made in other localities. 
SEED INCREASE BY GROWING TWO CROPS A YEAR. 
On November 5, 1920, 2^ bushels of pedigreed fiber-flax seed which 
had been harvested the preceding August at East Lansing, Mich., 
was sown near Fairhope, Ala., 2^ miles east of Mobile Bay. The 
winter was mild and no temperature below 28° F. was experienced. 
The flax grew to a height of 6 inches by December 15 and then lay 
practically dormant until early in February. From that time it 
made a rapid growth and at maturity on April 20 had reached a 
total height of 3 feet. From the 2^ bushels sown about 20 bushels 
of clean seed was secured. The flax was thrashed on May 3 and 
resown in Michigan on May 18. While normally an increase of only 
6 to 25 times is expected with flax, by means of the two-crops-a-year 
method this flax was increased 200 times. Observations do not show 
that there is any loss of vitality in the seed from flax which has 
been grown twice the same year and then replanted shortly after the 
second harvest. 
The results from a similar sowing of the fiber flax at Paradis, La., 
were also favorable from the experimental viewpoint and demon- 
strated that under mild winter conditions a second crop of flax can 
be matured in the South so as to increase the supply of seed of pedi- 
greed flax varieties. 
SUMMARY. 
The object of the work described in this bulletin has been to de- 
velop improved strains of fiber flax. 
Parent plants for beginning the work of breeding fiber flax were 
first selected in the commercial flax fields of eastern Michigan in 1909. 
The progeny of these selected plants was carefully bred by 
elimination of all except the best types through several successive 
generations. 
