Hayes and Garber - Cucurbit Breeding

168 BREEDING CROP PLANTS
1910 to 1914 inclusive. An average of 150 plants was carefully
examined yearly and no aberrant types were observed.
In 1912 about 100 acres were grown by the Windsor Tobacco
Growers' Corporation from seed saved in
1911, and late in the
season three plants were discovered which had produced a high
leaf number and showed no signs of blossoming. One of these
plants when taken to the Connecticut Experiment Station greenhouse
produced 72 leaves and blossomed about January first.
Considerable seed was saved from this plant and one-third acre
of the new type was grown in 1913. The plants were of uniform
appearance. They differed from the normal Cuban in having
leaves of a somewhat lighter green, in having but few basal
suckers, and in a long continued period of growth; whereas
the normal Cuban variety bears a terminal inflorescence
after producing from 14 to 25 leaves on the main stem.
From 25 to 30 acres have been grown yearly by the same tobacco
company. The quality and yield of this giant variety which has
been named Stewart Cuban, have been quite satisfactory. One of
the great difficulties of growing these giant forms is the extra
trouble of obtaining seed. This difficulty has been overcome in
part by studies which show that a reduction of length of day leads
to the production of blossoms. These studies will be briefly described
after giving a short history of the Maryland Mammoth
type.
The Maryland Narrowleaf Mammoth type first appeared in
1907 in the second generation of a cross between two common
varieties of Maryland tobacco (Garner, 1912). One hundred
and fifty-seven plants of this new form were grown in 1908 and
all plants were of mammoth habit. This new variety has been
grown commercially since that time and retains its characteristics
of high leaf number and non-blooming habit under normal field
conditions. 1 Accurate information regarding the acreage of
Mammoth tobacco in southern Maryland is not available but
some hundreds of acres were grown in 1920. The chief limiting
factor in the acreage is the quantity of seed available. As Maryland
tobacco is harvested by cutting and spearing the stalk,
there is little additional cost in harvesting the giant type. The
Mammoth variety will yield 2,000 Ib. or more per acre and the
1
Information kindly furnished by DR. W. W. GARNER, Physiologist,
in Charge of Tobacco and Plant Nutrition Investigations, B. P. United
I.,
States Department of Agriculture.