Yield, Quality, and Sucrose Recovery from Sugarbeet Root and Crown 1
R. C. ZIELKE 2 Received for publication May 15, 1973
Since t h e a d v e n t of mechanical harvesting in the late 1940's, an increasing a m o u n t of crown tissue has been processed by the factories.
T h e introduction of crowns into factory processes has long been c o n s i d e r e d undesirable because they contain h i g h e r concentrations of impurities t h a n roots a n d , consequently, f u r t h e r r e d u c e crystallization of sucrose from the juice (6, 12)3. Data compiled from the late 1800's by Stehlik (14) established that the crown contained a c o n c e n t r a t i o n of sucrose only somewhat less than that of the root. It would be desirable if the sucrose in the crown could be crystallized at a net gain to factory o p e r a t i o n s instead of losing it to molasses p r o d u c t i o n .
Early investigators lacked formulae a n d analyses to d e t e r m i n e w h e t h e r sucrose could be recovered if crowns were processed. Now f o r m u l a e are available for calculating sucrose recovery from simulated factory o p e r a t i o n s (2, 15) a n d i m p r o v e m e n t s have been m a d e in the laboratory analyses of certain juice impurities.
T h e objectives of these studies were to ascertain t h e relationship between root and crown in yield, sucrose c o n t e n t , juice purity, a n d recovery of sucrose. Nitrogen fertilization, harvest dates, plant p o p u l a - tions, a n d varietal differences were i n c o r p o r a t e d into the e x p e r i m e n t s because they affect sucrose recovery.
Methods and Materials
1967 field experiment
A factorial split-split-plot design with six replications was a r r a n g e d with two N levels serving as the main-unit t r e a t m e n t . T h e 24-lb/A rate of N was supplied by using 200 lb/A of 12-6-64 as a row fertilizer at p l a n t i n g time. T h e 150-lb rate was the basic rate plus 126 lb of a d d i - tional N applied as a m m o n i u m nitrate on t h e soil surface at t h i n n i n g time a n d cultivated into the soil. Additional a m o u n t s of P a n d K were uniformly applied before p l a n t i n g according to soil test r e c o m m e n d a - tions. Beets were t h i n n e d to a u n i f o r m 120 plants p e r 100 feet of row.
1Cooperative investigation by the Agricultural Research Service, U. S. D e p a r t m e n t of Agricul- t u r e a n d the Michigan Agricultural Experiment Station. Approved for publication as J o u r n a l article # 6 1 6 5 , Michigan Agricultural Experiment Station.
2Research Agronomist, Agricultural Research Service, U. S. D e p a r t m e n t of Agriculture, East Lansing, Michigan 48823.
3N u m b e r s in parentheses refer to literature cited.
4P a n d K expressed on oxide basis.
VOL. 17, No. 4, OCTOBER 1973 333 T h r e e cultivars of s u g a r b e e t (Beta vulgaris L.), c o m p o s i n g t h e s u b u n i t t r e a t m e n t , w e r e p l a n t e d on May 2 n e a r Sebewaing, Michigan.
T h e cultivars w e r e ' S P 6 3 1 9 4 - 0 ' ( N o . 1 in t h e tables), an o p e n - p o l - linated m o n o g e r m ; '02 clone' ( N o . 2), a n o p e n - p o l l i n a t e d m u l t i g e r m ; a n d ' U S H 2 0 ' ( N o . 3), a c o m m e r c i a l m o n o g e r m h y b r i d . Each plot was f o u r rows wide (28-inch rows) a n d 76 feet long. O n e interior-posi- t i o n e d row was r a n d o m l y d i v i d e d into f o u r sections for harvest.
A 13-foot s a m p l e of beets was h a r v e s t e d f r o m e a c h cultivar on Sept. 1 4, Oct. 5, Oct. 24, a n d Nov. 7 for yield a n d l a b o r a t o r y analyses.
1968 field experiment
A factorial d e s i g n involving two N levels, two in-row spacings of beets, two cultivars, a n d two h a r v e s t d a t e s was u s e d with six replica- tions. N i t r o g e n levels w e r e a r r a n g e d as a split-plot a n d t h e r e m a i n i n g eight t r e a t m e n t c o m b i n a t i o n s w e r e r a n d o m l y d i s t r i b u t e d within each split-plot level. Each t r e a t m e n t was 18 feet l o n g a n d six rows wide (28-inch rows).
T w o rates of N, 30 a n d 150 lb/A, w e r e established. Row fertilizer (500 lb/A of 6-24-12)4 s u p p l i e d t h e basic r a t e . An a d d i t i o n a l 120 lb of N was a p p l i e d as in 1967 to p r o v i d e t h e 150-lb r a t e . B e c a u s e t h e P a n d K soil test r e a d i n g s w e r e h i g h , no a d d i t i o n a l a m o u n t s of these two n u t r i e n t s w e r e a p p l i e d . Row fertilizer was placed 2 to 3 inches below t h e seed b o t h years.
T w o i n - r o w s p a c i n g s o f b e e t s w e r e e s t a b l i s h e d t o r e p r e s e n t differences in c o m m e r c i a l beet s t a n d s . At harvest, t h e n a r r o w plant s p a c i n g a v e r a g e d 9.8 inches (122 plants p e r 100 feet of row) a n d t h e wide s p a c i n g 15.4 inches (78 plants).
T w o h y b r i d cultivars p l a n t e d o n April 3 0 n e a r Saginaw, Michigan used t h e Fi m o n o g e r m female S L ( 1 2 9 x 133)cms. ' S P 6 3 2 2 - 0 ' was t h e pollinator for cultivar N o . 3 (US H 2 0 ) a n d 02 clone for cultivar N o . 4.
T h e harvest d a t e s w e r e Sept. 2 3 a n d Oct. 2 1 . S e v e n t e e n feet o f row w e r e h a r v e s t e d from each plot with t h e wide in-row s p a c i n g a n d 13.5 feet f r o m each with n a r r o w s p a c i n g to p r o v i d e 14 to 16 beets for yield a n d l a b o r a t o r y analyses.
Laboratory analyses and techniques
Beets w i t h o u t leaf b l a d e s a n d petioles w e r e d e l i v e r e d t o t h e l a b o r a t o r y within 4 h o u r s after h a r v e s t i n g . T h e c r o w n s w e r e p r e p a r e d as s u g g e s t e d by J o r r i t s m a a n d Oldfield (8), i.e., petiole stubs a n d leaf b u d s w e r e r e m o v e d with a knife t o e x p o s e t h e w h i t e c r o w n tissue. T h e beets w e r e w a s h e d free of a d h e r i n g soil a n d a i r - d r i e d briefly. C r o w n s w e r e s e p a r a t e d f r o m t h e roots at t h e lowest o r i g i n a l leaf (7) a n d b o t h p a r t s w e i g h e d . Brei s a m p l e s w e r e collected by c u t t i n g e a c h r o o t in half
334 JOURNAL OF THE A. S. S. B. T.
with a single-bladed saw (16-in. diam.). C r o w n s were q u a r t e r e d with the same saw to obtain sufficient brei. J u i c e samples were o b t a i n e d , quickly frozen in a d r y ice-alcohol bath, a n d later clarified a n d analyzed a c c o r d i n g to t h e DFS m e t h o d (3).
A p p a r e n t sucrose contents of brei a n d clarified j u i c e w e r e d e t e r - m i n e d polarimetrically. Analyses for r e d u c i n g sugars a n d raffinose w e r e m a d e to correct a p p a r e n t sucrose, clear j u i c e purity (CJP), a n d recoverable sucrose as outlined in (4, 16).
Results and Discussion
Yield and proportions of root and crown
Root yields (exclusive of crown) were significantly different within t h e harvest date and cultivar t r e a t m e n t s but did not differ for beet spacings or nitrogen levels (Table 1). T h e lack of r e s p o n s e in r o o t yield to t h e h i g h N levels r e p o r t e d in the last d e c a d e (1, 10, 11, 13) may be a t t r i b u t e d to the g r e a t e r residual N levels a n d total fertility now f o u n d in soils of beet-growing areas of Michigan a n d O h i o .
C r o w n s accounted for 22% of t h e total yield harvested in 1967 a n d 17% in 1968. T h e s e percentages c a n n o t be c o m p a r e d with commercial factory crown tare values because the roots in o u r tests were s e p a r a t e d from t h e crowns with a straight cut across the root instead of the usual c o n e - s h a p e d cut. All t r e a t m e n t s differed significantly for yield of c r o w n . C r o w n material each year was about 1.5 tons p e r acre (35%) m o r e at t h e high N levels t h a n at the low N levels.
T h e overall crown/root ratios (0.29 in 1967 a n d 0.21 in 1968) show that a sizable portion of the total growth can be a t t r i b u t e d to crowns.
T h e difference between the two ratios (0.08) suggests t h a t environ- m e n t a l effects condition the d e v e l o p m e n t of root a n d crown in respect to each o t h e r . A n o t h e r indication of e n v i r o n m e n t a l effects is that the crown/root ratio was h i g h e r in 1967, w h e n t h e overall stand of beets was d e n s e r (120 p e r 100 feet) r a t h e r t h a n in 1968, w h e n stands were less d e n s e (100 p e r 100 feet). Results of the spacing t r e a t m e n t in 1968 indicate that t h e ratio should be h i g h e r w h e n beets a r e spaced f a r t h e r a p a r t .
In addition to e n v i r o n m e n t a l effects, the crown/root ratio varied significantly with all t r e a t m e n t s except harvest dates. T h e greatest d i v e r g e n c e in ratios for each year was between t h e two N levels (0.09 in 1967 a n d 0.06 in 1968) a n d reflects, primarily, t h e large increase in crown yield at h i g h N with little increase in root yield. Fort a n d Stout (5) a n d Loomis a n d Ulrich (9) also r e p o r t e d large increases in crown yield at high N levels. G r o w t h rates of t h e root a n d crown a r e a p p a r e n t l y p r o p o r t i o n a l d u r i n g t h e harvest season because t h e c r o w n / r o o t ratio did not c h a n g e significantly between m i d - S e p t e m b e r a n d m i d - N o v e m - b e r in 1967.
Table 1.—Effect of nitrogen, plant spacing, cultivar, and harvest date on yield of sugarbeet root and crown.
1967 Treatment
N Applied 24 lb/A 150 lb/A
Cultivar 1 2 3 Harvest Sept. 14 Oct. 5 Oct. 24 Nov. 7
Test Avg.
Root
17.9 17.5
17.5 17.0 18.6
**
15.1 17.7 18.8 19.2
**
17.7 Yield Crown - Tons/Acre -
4.4 5.9
5.2 4.3 5.9
4.3 5.2 5.4 5.7 5.1
Total
22.3 23.4
*
22.7 21.3 24.5
19.4 22.9 24.2 24.9
**
22.8
Crown/Root Ratio
0.25 0.34
0.30 0.25 0.32
0.29 0.29 0.29 0.30 ns 0.29
1968 Treatment
N Applied 30 lb/A 150 lb/A Spacing
9.8 in.
15.4 Cultivar
3 4
Harvest Sept. 23 Oct. 21
Test Avg Root
17.9 18.9 ns 18.4 18.4 ns 19.0 17.8
17.0 19.8
18.4 Yield Crown - Tons/Acre -
3.3 4.6'
3.8 4.1
4.3 3.6
3.7 4.2
3.9 Total
21.2 23.5
22.2 22.5 ns 23.3 21.4
**
20.7 24.0
22.3
Crown/Root Ratio
0.18 0.24
0.20 0.22
**
0.23 0.20
0.22 0.21 ns
0.21
*, ** F test significant at the 5 and 1 percent levels of probability, respectively, ns F test not significant.
335 VOL. 17, No. 4, OCTOBER 1973
336 JOURNAL OF THE A. S. S. B. T.
T h e t e c h n i q u e for t o p p i n g e x p e r i m e n t a l beets s h o u l d be t h o r - oughly c o n s i d e r e d before harvesting begins because the p r o p o r t i o n of crown to root, sucrose content, a n d juice purity can be easily influenced by t r e a t m e n t s a n d location (year) effects.
Sucrose content
Average sucrose content for root a n d crown differed by 2.0 p e r c e n t a g e points in 1967 a n d 1.7 in 1968 but t h e weighted average sucrose c o n t e n t s for the whole beet were only 0.4 lower t h a n for roots alone (Table 2). T h u s , sucrose c o n t e n t for t h e whole beet was not seriously lowered by the addition of crown material.
Overall crown/root sucrose c o n t e n t ratios (0.88 both years) indi- cate a stable, environmentally i n d e p e n d e n t relationship between the root a n d crown for sucrose content. Nitrogen t r e a t m e n t s did not affect t h e crown/root ratio, which is in contrast to their effect on t h e yield ratio.
Sucrose contents of the root a n d crown were significantly lower at t h e high N level. C o n t e n t s were 0.7 p e r c e n t a g e point less in 1967 a n d a b o u t 1.0 less in 1968. Loomis a n d Ulrich (9) r e p o r t e d g r e a t e r differ- ences in sucrose c o n t e n t between the root a n d crown at low N levels w h e n beets were grown in pots but differences between the root a n d crown were t h e same in both of my tests.
D u r i n g t h e harvest season, sucrose increased in both the r o o t a n d crown in nearly a p r o p o r t i o n a l m a n n e r as evidenced by t h e n a r r o w r a n g e in crown/root ratios.
Clear juice purity (CJP)
C J P for roots averaged 94.3 in 1967 a n d 93.8 in 1968 (Table 3).
Purities for crowns were lower t h a n for roots in both tests, but those for t h e whole beet were well within the r a n g e n e e d e d for processing fresh beets. C r o w n CJP/root C J P indicated only a small r a n g e in ratios (0.946 to 0.966) for the two tests.
Roots a n d crowns h a d lower C J P at t h e high N level t h a n at the low N. H i g h N, however, caused a p r o p o r t i o n a t e l y g r e a t e r concentration of impurities in the crown than in the root as c o m p a r e d with low N. In contrast, a previous r e p o r t indicated g r e a t e r differences between t h e r o o t a n d crown at a low N level (9).
In 1967, C J P of root a n d crown increased 1.9 a n d 1.6 p e r c e n t a g e points, respectively, between the first two harvest d a t e s ; b u t after t h e second harvest, C J P t e n d e d to stabilize.
S u b s t a n t i a l raffinose a n d i n v e r t c o r r e c t i o n s w e r e m a d e o n a p p a r e n t sucrose a n d on a p p a r e n t C J P in 1967 as harvest dates p r o -
VOL. 17, No. 4, OCTOBER 1973 337
1967 Treatment
N Applied 24 lb/A 150 lb/A
Cultivar 1 2 3 Harvest Sept. 14 Oct. 5 Oct. 24 Nov. 7
Test Avg.
Root
16.6 15.9
**
16.0 16.4 16.3
**
15.7 16.3 16.4 16.6
**
16.2
Sucrose Content Crown
Percent - 14.6 13.9
**
14.3 14.3 14.2 ns 14.2 14.2 14.1 14.5 14.2
W t d A v g
16.2 15.4
**
15.6 16.0 15.8
15.3 15.8 15.9 16.1 15.8
Crown/Root Ratio
0.88 0.87 ns
0.90 0.87 0.87
0.91 0.87 0.86 0.87 0.88
1968 Treatment
N Applied 30 lb/A 150 lb/A Spacing
9.8 in.
15.4 in.
Cultivar 3 4
Harvest Sept. 23 Oct. 21
Test Avg.
Root
15.2 14.2
**
14.9 14.5
14.6 14.8
**
13.7 15.8
**
14.7
Sucrose Content Crown
Percent- 13.6 12.4
**
13.0 12.9 ns 12.8 13.2
**
11.8 14.2
**
13.0
W t d A v g
15.0 13.8
**
14.6 14.2
14.3 14.5
**
13.3 15.5
**
14.4
Crown/Root Ratio
0.89 0.87 ns 0.87 0.89
0.87 0.89 ns
0.86 0.90
**
0.88 Table 2.—Effect of nitrogen, plant spacing, cultivar, and harvest date on sucrose content of sugarbeet root and crown.
*, ** F test significant at the 5 and 1 percent levels of probability, respectively, ns F test not significant.
338 JOURNAL OF THE A. S. S. B. T.
1967 Treatment
N Applied 24 lb/A 150 lb/A
Cultivar 1 2 3 Harvest Sept. 14 Oct. 5 Oct. 24 Nov. 7
Test.
Root 94.8 93.8
94.0 94.1 94.8
92.9 94.8 94.7 94.8 Avg. 94.3
CJP Crown
90.6 89.0
90.2 89.4 89.7
88.9 90.5 89.7 90.1 891}
W t d A y g 94.0 92.6
93.1 93.2 93.6
92.0 93.8 93.6 93.7 9 1 3
1968 Treatment
N Applied
" l o l b / A "
150 lb/A Spacing 1Fin7 15.4 in.
Cultivar 3 4
Harvest Sept. 23 Oct. 21
Test Root 94.5 93.1
94.2 93.4
93.8 93.8 ns
93.6 94.0
**
Avg. 9 3 l CJP Crown 90.9 89.2
90.1 90.0
89.6 90.5
**
89.3 90.8
**
90T
W t d A v g 93.9 92.3
93.5 92.8
93.0 93.2 ns
92.8 93.4
**
93T Table 3.—Effect of nitrogen, plant spacing, cultivar, and harvest date on clear juice purity (CJP) of sugarbeet root and crown.
*, ** F test significant at the 5 and 1 percent levels of probability, respectively, ns F test not significant.
VOL. 17, No. 4, OCTOBER 1973 3 3 9
gressed. For example, apparent CJP values for roots were adjusted downward by 1.4 percentage points and for crowns by 2.2 percentage points for the third harvest in 1967. On the comparable date (late October) in 1968, root values were reduced an average of 0.6 per- centage points and crown values by 0.8 percentage points. The correc- tions were due to increases in raffinose concentration during colder weather. Corrections for the September harvests were small in 1967 and negligible in 1968.
Recoverable sucrose per ton (RSPT)5
Crowns yielded 226 pounds of RSPT in 1967 and 208 pounds in 1968 (Table 4). The RSPT for roots was about 50 pounds higher than for crowns both years. Weighted average RSPT yields, which include the proportionate weight of crowns per ton of whole beets sliced, were only 10 to 15 pounds less than for roots alone.
The high N level lowered the overall beet quality. Roots grown at high N produced 18 pounds less RSPT in 1967 and 26 pounds less in 1968 and crowns produced 20 pounds less in 1967 and 27 less in 1968.
The RSPT of roots and of crowns increased more between the two harvests in 1968 than between any two harvest dates in 1967. A period of rainy weather in early October 1967 resulted in static sucrose ac- cumulation and RSPT did not increase for the last two harvest dates.
Nitrogen x harvest date interactions for roots were significant both years. RSPT from roots was considerably less (27 pounds in 1967 and 26 pounds in 1968) at high than at low N for the first harvest each year. Differences between low and high N on other dates both years were about 15 pounds per ton. Thus, roots accumulate less sugar at high N levels than at low N, especially in the early harvest season.
A nitrogen x cultivar interaction in 1967 showed that cultivars differ in sensitivity to high N. Sucrose per ton was 27 pounds lower at high N as compared with low N for cultivar 2, 17 pounds for cultivar 3, and only 10 pounds for cultivar 1.
Recoverable sucrose per acre (RSPA)
Of the total RSPA produced, crowns contributed 1160 pounds per acre in 1967 and 801 pounds in 1968 (Table 5). The respective average percentage contributions of 19% and 14% from crowns were slightly lower than the percentage weight contributions of 22% and 17% from crowns because of the lower quality inherent in the crown material.
The RSPA from roots was 415 pounds greater at the low N level than at high N in 1967 and 189 pounds greater in 1968. Sucrose yields from crowns were higher both years at high N because of the large increases in crown weight. Total RSPA was, however, not significantly different for the two N levels either year.
5The term "recoverable" as used in this paper refers solely to white crystallized sugar.
Table 4.—Effect of nitrogen, plant spacing, cultivar, and harvest date on recoverable sucrose per ton (RSPT) of sugarbeet root and crown.
1967 Treatment
N Applied 24 lb/A 150 lb/A
Cultivar 1 2 3 Harvest Sept. 14 Oct. 5 Oct. 24 Nov. 7
Test.
Root
296 278
280 289 290
**
268 290 292 296 Avg. 287
RSPT C r o w n
Lb 236 216
230 224 224
220 229 223 232 226
WtdAvg
284 262
269 277 274
258 276 277 282 273
1968 Treatment
N Applied
"~SOlb/A"
150 lb/A Spacing
9.8 in.
15.4 in.
Cultivar 3 4
Harvest Sept. 23 Oct. 21
Test Root
270 244
262 251
254 259 ns
237 276
Avg. 257 RSPT Crown
Lb 221 194
209 207 ns 202 213
184 232
208
WtdAvg
262 234
253 243
245 251
227 269
248
*, ** F test significant at the 5 and 1 percent levels of probability, respectively, ns F test not significant.
JOURNAL OF THE A. S. S. B. T. 340
Table 5.—Effect of nitrogen, plant spacing, cultivar, and harvest date on recoverable sucrose per acre (RSPA) from sugarbeet root, crown, and whole beet.
1967 Treatment
N Applied 24lb/A 150 lb/A
Cultivar 1 2 3 Harvest Sept. 14 Oct. 5 Oct. 24 Nov. 7
Root
5299 4884
4916 4939 5419
4045 5144 5486 5691 Test Avg. ~5097
RSPA Crown Lb 1047 1273
1200 955 1325
933 1192 1198 1317 1160
Total
,
6346 6157 ns
6117 5894 6744
4978 6336 6683 7008 6251
1968 Treatment
N Applied 30 lb/A 150 lb/A Spacing
9.8 in.
15.4 in.
Cultivar 3 4
Harvest Sept. 23 Oct. 21
Root
4818 4629
4823 4623 ns 4834 4613 ns
4003 5444
**
Test Ave. 4724 RSPA Crown Lb 729 873
**
764 839
854 748
**
665 938
**
801
Total
5547 5502 ns 4487 5462 ns 5688 5361 ns
4668 6381
**
5525
*, ** F test significant at the 5 and 1 percent levels of probability, respectively, ns F test not significant.
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342 JOURNAL OF THE A. S. S. B. T.
Sucrose yields increased substantially between the early a n d late harvest d a t e s each year. In 1967, increases for b o t h t h e r o o t a n d crown w e r e highest between the first two dates because of a c o m p l e m e n t a r y c o m b i n a t i o n of increasing weight a n d R S P T . After O c t o b e r 5, in- creases in weight of root a n d crown w e r e m o r e i m p o r t a n t t h a n quality factors in increasing t h e RSPA.
Summary
C r o w n s c o n t r i b u t e d substantially to total sucrose yields. Average sucrose p e r c e n t a g e in the crown was 14.2 in 1967 a n d 13.0 in 1968, a n d clear j u i c e purities were a b o u t 9 0 % b o t h years. With these sucrose c o n t e n t s a n d juice purities, a ton of crowns would p r o d u c e an average of 217 p o u n d s of recoverable sucrose. H a r v e s t i n g 4 to 5 tons of crowns p e r acre would, t h e n , increase the average RSPA by 800 to 1000 p o u n d s .
N i t r o g e n fertilization affected yields, sucrose c o n t e n t , a n d j u i c e purity of roots a n d crowns. A l t h o u g h root yields w e r e not significantly different at t h e two N levels in e i t h e r test, 200 to 400 m o r e p o u n d s of sucrose p e r acre were p r o d u c e d in t h e root at t h e low N level because of h i g h e r sucrose a n d juice purity. C r o w n yields w e r e 3 5 % g r e a t e r at t h e h i g h N level both years; despite lower sucrose a n d juice purity, this gave 150 to 230 m o r e p o u n d s of sucrose p e r acre from crowns at t h e h i g h N level t h a n at t h e low. T o t a l RSPA p r o d u c e d in e i t h e r test did not differ significantly between low a n d high N.
Delaying harvest from m i d - S e p t e m b e r to late O c t o b e r both years increased root a n d crown yields, sucrose content, a n d juice purity a n d increased total RSPA a p p r o x i m a t e l y 1700 p o u n d s .
S p a c i n g plants 9.8 a n d 15.4 inches a p a r t in 1968 subtly b u t significantly affected roots a n d crowns. Root yields were not different at t h e two spacings b u t both sucrose c o n t e n t a n d clear juice purity were h i g h e r at t h e close spacing. Yield of crowns was slightly h i g h e r at t h e wide spacing b u t sucrose c o n t e n t a n d juice purity were not different at the two spacings. T h e increase in crown weight at wide spacing only partly offset t h e influence of h i g h e r root quality at close spacing so that total RSPA was slightly, b u t not significantly, h i g h e r at close spacing.
T h e results indicated that cultivars or hybrids could be d e v e l o p e d t h a t would p r o d u c e smaller p r o p o r t i o n s of crown to root. Even using different pollinators on t h e same Fi female altered the p r o p o r t i o n of c r o w n . Root yields would have to be increased, at least p r o p o r t i o n a t e l y , to c o m p e n s a t e for r e d u c t i o n in crown weight so that total RSPA can be m a i n t a i n e d o r increased.
VOL. 17, No. 4, OCTOBER 1973 343
A c k n o w l e d g m e n t s
My s i n c e r e g r a t i t u d e a n d a p p r e c i a t i o n is e x p r e s s e d to F. W.
S n y d e r for his g u i d a n c e a n d assistance on this r e s e a r c h , which was c o m p l e t e d as partial fulfillment for t h e P h . D . d e g r e e . Also, t h e h e l p of R. E. Wyse a n d M. G. F r a k e s in c o n d u c t i n g t h e tests a n d p e r f o r m i n g essential l a b o r a t o r y d e t e r m i n a t i o n s is gratefully a c k n o w l e d g e d .
Bibliography
(1) BALDWIN, C. S. 1967. Nitrogen and sugarbeet culture. Proc. 14th E.
Reg. Meetings Am. Soc. Sugar Beet Technol.; pp. 42-46.
(2) CARRUTHERS, A., and J. F. T. OLDFIELD. 1962. Methods for the assess- ment of beet quality. In: T h e Technological Value of the Sugar Beet.
Elsevier Publishing Company, New York, New York.
(3) DEXTER, S. T., M. G. FRAKES, and F. W. SNYDER. 1967. A rapid and practical method of determining extractable white sugar as may be applied to the evaluation of agronomic practices and grower deliveries in the sugar beet industry. J. Am. Soc. Sugar Beet Technol. 14(5):
433-454.
(4) DEXTER, S. T., M. G. FRAKES, and R. E. WYSE. 1969. Damage to sugar- beet roots from various degrees of wilting at various temperatures. J.
Am. Soc. Sugar Beet Technol. 15(6):480-488.
(5) FORT, C. A., and M. STOUT. 1948. Comparative composition of differ- ent parts of the sugar beet root. Proc. Am. Soc. Sugar Beet Technol.
5:651-659.
(6) HADDOCK, J. L., P. B. SMITH, A. R. DOWNIE, J. T. ALEXANDER, B. E.
EASTON, and VERNAL JENSEN. 1959. The influence of cultural practices on the quality of sugar beets. J. Am. Soc. Sugar Beet Technol. 10(4):
290-301.
(7) HAYWARD, H. E. 1938. T h e Structure of Economic Plants. T h e Mac Millan Company, New York, New York.
(8) JORRITSMA, J., and J. F. T. OLDFIELD. 1969. Effect of sugar beet cultiva- tion and extent of topping on processing value. J. Institut Interna- tional De Recherches Betteravieres 3(4):226-238.
(9) LOOMIS, R. S., and A. ULRICH. 1959. Response of sugar beets to nitrogen depletion in relation to root size. J. Am. Soc. Sugar Beet Technol.
10(6):499-512.
(10) NICHOL, G. E. 1965. Progress report on the effect of nitrogen on yield, sucrose content, and purity of sugar beets. Proc. 13th E. Reg. Meetings Am. Soc. Sugar Beet Technol.; pp. 50-57.
(11) RUSSELL, FRED. 1965. The effect of varying rates of nitrogen on beet yields and sugar production. Proc. 13th E. Reg. Meetings Am. Soc.
Sugar Beet Technol.; pp. 44-49.
(12) SKUDERA, A. W. 1952. The sugar beet industry. Proc. Am. Soc. Sugar Beet Technol. 7:22-24.
(13) SNYDER, F. W. 1967. Nitrogen as related to sugar beet quality and yield.
Proc. 14th E. Reg. Meetings Am. Soc. Sugar Beet Technol.; pp. 55-57.
344 JOURNAL OF THE A. S. S. B. T.
(14) STEHLIK, V. 1923. Studies on the distribution of sugar in the beet at the time of harvest and in regard to individual differences. Zeitschrift Fur Die Zuckerindustrie Der Chechoslovakischen Republik. (Translated by H. A. Kuyper.)
(15) Sugar Beet Research, 1964 Report. 1964. Determination of recoverable sugar using a formula proposed by the Great Western Sugar Company Research Laboratorv, Denver, Colorado. USDA-ARS Bluebook, CR-4-64, p. 155.
(16) WYSE, R. E. 1969. Storage of sugar beets: agronomic, physiological and quality aspects. Ph.D. Thesis. Michigan State University, E. Lansing, Michigan.