Vol. 15—1961 - NorthEastern Weed Science Society

336.
DATEOF BERRYHARVESTAS IT AFFECTSSEEDMATURITY
OF:gORSENETTLE(Solanum caro11nense)
Thomas F. Tisdell l, Richard D. Ilnicki
2 and William F. Meggitt 3
ABSTRACT
Horsenettle berries were collected from August 1959,
through March 1960, at monthly intervals in one location, in
order to determine seed maturity by germination tests. Seed
harvested in August exhibited no initial or subsequent germination.
Seed harvested in September, OctOber, November and
January had very poor initial germination, which improved after
several months of storage. Seed obtained from berries collected
in December Qada low per oent germination, that remained unchanged
over'a period of six months. Seeds collected 1n
February and;March had good initial germination.
Subsequent studies were designed to determine the age of
the seed and ,its effect on germination. Individual berries
were identified by their flowering dates. Berries were also
collected from two different sets of plants. One set had been
started with rootstocks from New York State, while the other
set was native to New Jersey. Seeds collected, on six different
dates, f~om 45 to 135 days after the opening of flowers
showed very poor initial germination, while seeds collected
160 days after flowering had a somewhat higher initial germination.
When the seed from the first and second collections was
again tested in November the germination had not changed , The
seed from the third and fourth collections showed a slightly improved
germination. At this time the New York seed from the
sixth collection was found to have a considerably higher germination
than that observed initially. In most cases of low germination
the number of hard seeds 1s high; therefore, it seems that a
large number of these ungerminated seeds are still viable. Most
of these seeds imbibe water. Any dormancy phenomenon which exists
is probably centered in the embryo. This seed dormancy is apparently
broken by exposure to over-winter1r~ conditions or to
several months of dry storage. The results of these germination
studies together with other measurements, suggests the possible
existence of different strains of horsenett1e.
1 ~ .
'~esearch Assis~ant and Associate Research Specialist in
Weed Control, respectively, New Jersey Agricultural Experiment
Station, Department of Farm Crops, Rutgers--the State University,
New BrunSWick, New Jersey.
3FormerlY Assistant Research Specialist, Rutgers; now in
Farm Crops Department, Michigan State University" East Lansing,
Michigan. . .