Vol. 15—1961 - NorthEastern Weed Science Society

352.
7. Fluctuating warm and cold with dry storage conditione. The
seed was placed in a bottle which was alternated between the laboratory
and outside.
-
There was only a slight increase in germination and this occurred only
in the· constant cold-moist or fluctuating warm-cold but moist storage. Aofter
seven "leeks 10 perCent germination was obtained With no increase in the
following 12 weeks. The moist soil conditions and fluctuating temoorature
conditions to which the weeds stored in the field were exposed ihduced germination
but the time when the seed first began germinating is not known. For a
protracted neriod in the winter it was impossible to remove the seed fran the
frozen ground. When tested on May 27, a germination of. 33 nercent was obtained.
Seed pre-treated bV soaking as well as non-soaked seed was held under
each envirornnent. No effect of this initial soakin~ could be found.
Influence
9f SQarifications
A. Scarification - By rubbing seed "lith aandpaper- germination was
increased to 30 percent. The non-scarified seed germinated 15 percent.
B. Scarification by immersion in fuming H2SO4- Immersion in acid
followed by thorouP,h rinsing off of the acid was an effective scarification
technique. Germination' was 7 percent for non-treated seed, 51"tlercent for
one-half hour immersion, and 40 percent for one hour immersion. Microscopic
examination indicated numerous pits eroded thru the lenuna and palea of the
seed.
Influence
orCbemical Treatment:
A. Immersion in indolacetic acid CIAA), thiourea dnd methyl alcohol. ­
The seed was scarified with sand paper prior to immersion for 5 and 24 hour inter=
val,s in solutions ran~ing from .05 to 50 ppn of 1M and from 25 to 50 ppm of
thiourea. No sip"nficant increase in eermination was obtained. Some indication
of reduction was obtained at 25 and 500 ppm thiourea at 24 hours. Seed immersed
in methyl alcohol l-.rare injured Nith no germination occurring.
B. Immersion in nitrogen solutions ­
"1)" Seeds scarified ~~th sand paper immersed for 15.5 hours in
0.5, 1.0 and'2.0 percent KN03germinated 80, 00 and 50 percent
res~ectively. The non-tre~tment seed gave only 15 percent germination,
thus the KN03gave a very pronounced increase. .
2) Seeds scarified with sand.'9Qper immersed in 1 ann 2 percent
NH4N03solutions for 13 hours germinated 55 and 60 nercent reswctively
as compared to lS nercent for the seed immersed in water only. When
immersed in 1 percent KN0 3
for 76 hours, germination was 42 percent
as compared to 19 percent for water soaked seed. In a similar
exooriment in which the seed was not searifted, seed- in 1 and 2
percent NH4N03solutions gave 33 percent germination, in 1 Percent
KN0 29 rercent and untreated, 4 percent. Both nitrogen canpounde
3 ,
~ave a stmilar increase in germination.