COLOKADO ExI’ERIMEXT STATION 
i^O 
and it is only necessary that this seed be sown for the plant to 
become established, 'ihere has been starred a practice in some 
parts of the Siate cf allowing alfalfa fields too badly infested 
with milkweed to be used for hay, to go to seed. This procedure 
cannot be too strongly condemned, because whi.e the milkweed 
seed may be cleaned fronr the alfalfa, these fields will become 
breeding grounds for seed to be blown by the wind and carried by 
water. Furthermore, seed buyers will learn to discriminate 
against such sections, and their sale of seed will be injured. 
GEKMINATION OP MILKWEED SEEDS 
The accompanying table shows the germination of whorled 
milkweed seed gathered in the Montezuma Valley in August, 
1918. Part of this seed was gathered from pods which had ma- 
tured on the plant, the rest from pods which were not maturea 
at the time the plants were cut, but which burst open after the 
plants had lain on the ground for a week or ten days. There was 
no difference in germination between these lots of seeds. These 
were produced in an extremely dry and unfavorable season. 
TABLE I 
Germination of Seeds of Asclepias ^alioides 
Date Begun Per Cent Germination 
3 days 5 days 14 days 
A 
Sept. 17, 1918 .'.30 
Sept. 17, 1918 28 
Oct. 16, 1918 91 
May 6, 1919 93 
May 20, 1919 93 
June 3, 1919 95 
June 16, 1919 94 
June 30, 1919 .95 
July 14, 1919 92 
July 28, 1919 95 
Aug. 11, 1919 96 
Aug. 25, 1919 95 
Aug. 8, 1919 96 
Aug. 22, 1919 98 
— All lots triftfl in Se.Dtember an 
cent at the end of 20 days. 
B 
A 
B 
A 
B 
42 
46 
59 
57 
64 
31 
67 
63 
71 
65 
42 
92 
93 
92 
93 
92 
93 
94 
94 
94 
94 
97 
96 
97 
96 
97 
95 
94 
95 
91 
95 
98 
95 
98 
95 
98 
96 
92 
96 
93 
96 
97 
95 
97 
95 
97 
95 
97 
95 
98 
95 
93 . 
97 
94 
97 
94 
98 
96 
98 
96 
98 
98 
98 
98 
98 
98 
October, 
1918, 
germinated 
over 90 
per 
I he germination tests were canied out to answer three ques- 
tions: (1) What percentage of the milkweed seed is viable? 
(2) How soon after being shed from the plant are the seeds 
viable? (3) For how long a time do the milkweed seeds keep 
their viability? 
An answer to the first question was desired in order that 
some gauge might be had by which to determine the importance 
of the seed in dissemination. Fitted as it is for dispersal, the 
milkweed requires only that an appreciable percentage of the seed 
will germinate in order for it to become easily established in a 
new territory. The results as shown in Table I prove that milk- 
weed seed has a high percentage of germination. It is believed 
that this is generally true. 
