Plant-Food Elements in Sugar Beets Throughout the Growing Season

90 AMERICAN - SOCIETY SUGAR-BEET TECHNOLOGISTS
we undertook an introductory study of this subject for sugar beets.
The publication in question dealt only with tomatoes, potatoes, corn
and tobacco, drawing upon experimental data from various American
journals, and experiment station reports.
Object
In this study our object was to gain further information on feeding
sugar beets, from analyses of sugar beets at various stages of
growth. It was an attempt to see what is in the average sugar-beet
plant at "various stages" in order to get some indication of the rate
of plant-food absorption during the growing season.
Plan
The plan was to utilize sugar-beet plants growing under normal
Ontario conditions and select random samples whose analyses would
indicate the plant-food elements taken in by the plants up to that
particular stage of growth.
A commercial field in each of our factory areas was used and
samples taken at about 3-week intervals. In the early stages of
growth a definite length of row was taken and the data calculated
on an acre basis. When the beets were of sufficient size, a definite
number of beets were taken and correlated with average stand and
yield per acre. The data were then calculated back to a l5-tons-peracre
crop.
Roots and tops were weighed and analyzed separately at each
of 7 stages of development. The items investigated were fresh and
dry weights, nitrogen, phosphoric acid, potash and calcium.
Photographs were taken of the beet plants at each of the 7 stages
analyzed. and cover the normal growing period of 170 days in Ontario.
Methods
Fresh weights were taken of tared beets and tops as soon as
lifted in the field and dry weights were obtained after chopping and
drying in an electric oven at 65º C.
Ashing and preparation of 1 he solution for analysis for P 2 O 5 ,
K 2 O and CaO were made by method of C. F. Rivas, published in
"Scientific Agriculture," Vol. 19, No. 4, 1938.
Analyses for nitrogen, P 2 O 5 , CaO and K 2 O were made by the
A. O. A. C. methods, 1940 edition.
Results
The analytical results of these samples, made in duplicate, were
averaged for two experimental fields, one a Clyde clay and the other
a Thames clay loam. Since it was impossible to analyze the same
beets throughout the growing season, there is considerable variation
in the contents found. The stages of growth, however, were distinct
and show the relative composition of the sugar beets at approximately
3-week intervals.