Daily Kennebec journal., 1913-08-01
Agricultural Help
Will Beans ''Mix"
If Close Together?

/ In 1911 the Maine Agricultural Expe-
| riment Station began the study OF
| certain problems of breeding, using the
| common bean plant as the subject. One
of the objects of this study was to pro-
duce if possible an improved strain of
lCld-fashioned yellow-ey which should
| te at once good yieldcr and disease
resistant Several commercial varieties,
| the Old Fashioned Yellow Eye, Golden
WAX Improved yellow Eye and White
Tea beans. procured from growers and
seed dealers were planted in the spring
| of that year to furnish a wide range of
types from which to select promising
individual plants for crossing and
further study At that time the general
| impression prevailed that the bean
flower was so constructed as to ensure
practically Standardization and to pre-
vent cross fertilization by insects. The
pstil and stamens are entirely envclop
ed in a sheath or tube like structure.
Generally the pollen will have ripened
and the ovule will have been fertllzed
before the bud fully opens. Without the
intervention of insects Standardization
would always take place in the bean
blossoms.
I4dSi year Huiliblt tfttS N01t opSNiN-
ed working among the blossoms of the
bean plants in the Stations variety
tests. Humble bees were seen TO light
on the lower petals OF blossoms, which
were borne down by the weight of the
bee, and served as levers, throwing the
stigma and anthers out of the sheath
into full view. The bee brushed its
body against the exposed stigma and
authers and then flew to other bios
SONS again alighting on the lower pet
ais and repeating the operation de-
scribed above. Hence, it seems Just-
fable to conclude that the humble bee
may ee an agent in the crossing of
beans.
The crop of beans harvested in the
fall of 1912 presented marked differ
ences in size. color, shape and type
within the same variety. Even the de-
scendants of single plants supposedly
self -fertlized also showed wide va
riation IN color and shape. Some exhib-
tied an entire lack of uniformity. This
was conclusive evidence that the beans
propasated in the variety tests of 1911
had been crossed and observations of
tho bees lead one to believe that the
beans were again crossed in 1912. In
view of this hybridization it became
necessary to devise ways and means of
protecting bean plants to prevent cross
ing by humble bees, especially if one
desires to study the inheritance of
characters in beans and to originate
new pure strains To accomplish this
screened cage was planned wherein it
would be possible to propagate 500 to
n.kA 90
lines.
Plans were drawn for the construc-
tion of frame work feet high to en-
close an area "A by As feet. Such
frame was made by the joining of by
4 ioists II feet long, bolted 10 by
posts. The by 1 joists being Il feet
long permitted the erection OF the cage
in sections so that additions may be
readily made. Five posts were set In
line for each of the two sides and five
posts also were set midway lengthwise
of the cage. Three lines of by Joists
II feet long were fastened horizontally
to these posts, one line at the top one
midway, and the third line at the bot
tom of the posts. Frames by feet In
size made of pine 3 inches wide and
covered with wire cloth were fastened
with screws TO the outside of tue
framework The roof was enclosed with
screened sections. by l. feet in size.
The sides of each section were made
with tongue and groove so that all sec
tions fitted into one another forming
tight Joints. Now that the cage is com
pleted il prevents the entrance of hum
bile bees and ensures the self-fertiliza-
C L, t1S, 10 fc
son there are $50 bean plants growing
under screens and 1t is hoped that
many of these plants will be supiclehuy
promising to form the basis OF turtAer
studies of breeding.
CHAS. D. WOODS.
Director.
Orono, Maine, July 80, 1915.