TIME OF YEAR TO PLANT MOTHER BEETS FOR SEED 
PRODUCTION 1 
By Dean A. Pack 
Plant Breeder, Sugar-Plant Investigations, Bureau of Plant Industry , United 
States Department of Agriculture 
INTRODUCTION 
In the development of the sugar- 
beet seed industry for this country, 
the quantity and quality of seed 
should be among the first considera¬ 
tions. Some American seed companies 
have failed or lost heavily because of 
insufficient yield or poor quality of 
seed, which may have been due to 
many causes, such as poor storage, 
unfavorable weather conditions, poor 
care, or late planting. At the Salt 
Lake City Station (Utah) the writer 
has found that the quantity and quality 
of seed produced may vary greatly 
with the time of the year when the 
mother beets are planted. Beets 
planted early produce abundant seed, 
while those planted later produce little 
or no seed. 
MATERIAL 
Beets of the same variety and uni¬ 
form as to weight, per cent of sugar, 
shape, and physical conditions were 
selected,- analyzed, stored over winter, 
and planted during the next summer. 
The beets planted as late as September 
were apparently in as good condition 
as those planted in March. The 
apparently perfect condition of all 
beets at the time of planting was 
indicated by the fact that an unusually 
high percentage of the beets grew, 
all living beets produced seed, and 
there were no “trotzers,” this being 
the reverse of conditions experienced 
by some investigators who have had 
from 50 to 90 per cent vegetative and 
unfruitful beets. 
EXPERIMENTS 
During 1922 and 1923 similar lots of 
beets were taken from storage each 
month, from March to September, in¬ 
clusively, and carefully planted in rows 
on the same plot of ground. The soil 
was kept at a uniform moisture con¬ 
tent throughout the summer. Records 
were kept on the physical condition 
and development of the plants. Data 
for the following physical conditions 
were obtained: Soil and air tempera¬ 
tures, soil moisture, evaporation, rela¬ 
tive humidity, wind movement, sun¬ 
light conditions, and relative length of 
day. The plant was studied as to 
storage material, root, vegetative leaf, 
seed stalks, flowering, and quantity 
and quality of seed produced. 
Table I.— Average data for vegetative 
growth and seed production for 1922- 
1923 
Time of 
planting 
Vege¬ 
tative 
foliage 
Height 
of seed 
stalks 
Num¬ 
ber of 
seed 
stalks 
per 
beets 
Weight 
of seed 
pro¬ 
duced 
per 
beets 
Ger¬ 
mina¬ 
tion of 
balls 
Per cent 
Cm. 
Gm. 
Per cent 
Mar. 1 
100 
\ 170 
18 
290.0 
97.0 
Apr. 1 
90 
170 
18 
293.0 
99.0 
May 1 
80 
125 
17 
I 228.2 
96.0 
June 1 
40 
90 
12 
| 81.0 
71.0 
July 1 
10 
| 80 
7 
40.0 
50.0 
Aug. 1 
0 
40 
3 
(«) 
Sept. 1 
100 
! 40 
1 
3 
(a) 
a These did not mature. 
The results given in Table I indicate 
that the quantity and quality of seed 
depend on the time of year when the 
beets are planted. Beets planted early 
produced the most and best seed. 
There appears to be very little dif¬ 
ference in the results obtained from 
April and March plantings in these 
respects. The data also indicate that 
the quantity and quality of seed pro¬ 
duced is directly proportional to the 
vegetative foliage (except for very late 
planting), height of seed stalks, and 
number of seed stalks developed during 
the second year. Shaw’s 2 work in¬ 
dicates that the vegetative develop¬ 
ment is indirectly proportional to the 
1 Received for publication July 2, 1924; issued June, 1925. 
2 Shaw, H. B. climatic control of the morphology and physiology of beets. Sugar 19: 387-391, 
431-434, illus., 1917; 20: 23-27, 68-70, 109-112, 150-154, illus., 1918. 1917-18. 
Journal of Agricultural Research, 
Washington, D. C. 
(811) 
Vol. XXX, No. 9 
May 1,1925 
Key No. G—435 
