| MICHIGAN AGRICULTURAL EXPERIMENT STATION|
Michigan State University
East Lansing, Michigan
December 23, 1968
NOTICE TO HYBRID CARROT SEED PRODUCERS REGARDING RELEASE OF CARROT INBRED
LINE, MSU 9541, AND THE THREE-WAY PROCESSING-TYPE HYBRID, SPARTAN BONUS,
(MSU 1558 x MSU 5931) x MSU 9541
The Department of Horticulture, Michigan Agricultural Experiment Station,
announces the release of carrot inbred line MSU 9541 and the processing hybrid
SPARTAN BONUS. MSU 9541 was developed from a selection of the variety Danvers
126. The selection was selfed one generation and subsequently selected and
massed under screen isolation for four additional generations. The roots are
a uniform deep orange color, approximately seven inches in length with a medium
taper, stump tip and slightly indented crown. The plants are vigorous during
flowering with numerous, large umbels and abundant pollen.
The F1 seed parent, MSU 1558 x MSU 5931, is a male-sterile of the petaloid
type developed with the original wild carrot cytoplasm provided for our program
by Dr. H. M. Munger, Cornell University. The inbred lines MSU 1558 and MSU 5931
used in the seed parent were released in 1963 and 1968, respectively.
The three-way hybrid, SPARTAN BONUS, has been tested experimentally for
four years. In 1968, it produced acceptable yields with good processing quality
in several commercial trials. The primary advantages are good flavor and re-
lative freedom from both exterior and interior color defects.
MSU 9541 is released with the following understanding:
1. This line is considered fully released and may be used by seedsmen for
development of hybrid combinations with lines of their own origin or
other sources. The combination, (MSU 1558 x MSU 5931) x MSU 9541 will
be sold or otherwise distributed only under the name SPARTAN BONUS.
2. The hybrid carrot seed producer will inform the Michigan Agricultural
Experiment Station of the extent to which this inbred is used in
3. Since MSU 9541 has shown promise as an open-pollinated variety the
Michigan Agricultural Experiment Station reserves the right to name
and release it as a commercial variety.
4. Any seed producer accepting seed under this agreement will thereby
bind itself to the above stipulations. The Michigan Agricultural
Experiment Station reserves the privilege of refusing, for an in-
definite period, additional releases to seedsmen failing to observe
Seed from greenhouse cage increases of MSU 9541 will be distributed to
hybrid seed producers and seed of the hybrid, SPARTAN BONUS, to carrot pro-
dessors and growers, who make a request in writing to Dr. L. R. Baker,
Department of Horticulture, Michigan State University, East Lansing, Michigan
48823, before March 1, 1969. The inbred lines and hybrid were developed by
Dr.C.E. Peterson, presently Leader of Carrot and Onion Investigations, USDA,Dept.
Horticulture,Univ. of Wisconsin, Madison.
S. H. Wittwer, Director
Michigan Agricultural Experiment Station