9
Official Sugarbeet Variety Trials
K.A. Rykbost', H.L. Carlson', and R.L. Dovel'
INTRODUCTION
The California Beet Growers' Association (CBGA) Seed Committee determines
which cultivars may be planted in each district served by the Association.
Decisions are based on the performance of varieties in officially sanctioned
trials, the severity of various diseases in a district, and varietal response
to major diseases. The University of California Intermountain Research and
Extension Center at Tulelake (IREC) and the Klamath Experiment Station (KES)
conducted official variety evaluation trials in 1991 on behalf of the CBGA.
KES
METHODS
The trial site soil was a Hosely Sandy Loam. Previous crops were
potatoes in 1990, barley in 1989, and several years of alfalfa. Soil analysis
has shown a high level of potassium, low to medium phosphorous, organic matter
content of approximately 0.5 percent, and a soil pH of 7.5 to 8.5 at the site.
High soluble salt content occurs in portions of the field, but not in the
location of this trial.
The field was plowed on April I. Gypsum at 1.0 T/A (ton/acre) and 16-1616 analysis fertilizer at 320 lbs/A were broadcast and harrow-incorporated on
April 15. The seedbed was firmly compacted with a brillion roller on May 2.
Twenty-four varieties were planted (May 3) in a randomized complete block
design with four replications on. Seed was planted at approximately 0.5 inch
depth at 8 to 12 seeds/foot with a hand-operated planet-junior type planter in
22-inch rows. Individual plots were two rows, 15 feet long.
Betamix herbicide (1.3 lbs ai/gal) was applied at 2.0, 3.0, and 4.0
pints/A on May 23, May 29, and June 3, respectively. Hand weeding was needed
to control escapes, primarily Filaree. A flea beetle infestation was effectively controlled with Sevin applied at 1.5 pints/A on May 29. Stands were
hand-thinned to approximately 8-inch plant spacing on June 10. Nitrogen, at 80
lbs N/A (solution 32), was applied with a conventional ground sprayer and
incorporated with sprinkler irrigation on July 2. Irrigation, supplied with
solid-set sprinklers, totalled 20.2 inches for the season. Rainfall from
planting to harvest was 2.4 inches.
1/ Superintendent/Associate Professor and Assistant Professor, respectively,
Klamath Experiment Station, Klamath Falls, OR.
2/ Superintendent/Farm Advisor, University of California Intermountain
Research and Extension Center, Tulelake, CA.
Acknowledgments: Financial support for these studies from the CBGA, American
Crystal Sugar Company, Betaseed Inc., HilleshOg Inc., Holly Sugar Corporation,
Seedex Inc., and Spreckels Sugar Company Inc. is gratefully recognized.
Appreciation is also expressed to Holly Sugar Corporation for providing
laboratory analysis of sugar content.
10
Beet tops were removed with a flail chopper immediately prior to harvest.
Beets were hand-harvested on October 15. All beets from both rows of each
plot were counted and weighed. All beets from one row were analyzed for
percent sucrose, nitrate-N content, and tare by Holly Sugar Corporation.
Yield, sugar content, and beet population data were statistically analyzed
using MSU Stat software.
IREC
The trial was established on Tulebasin Fine Silty Loam soil with approximately 12 percent stable organic matter content. This is a very fertile site
capable of producing high yielding field and vegetable crops. Soil reaction
is near neutral. The previous crop history was fallow with fall oat cover in
1990 and potatoes in 1989.
Field preparation consisted of primary tillage with a roto-harrow preceded by a broadcast application of 200 lbs/A of 16-20-0 and 400 lbs/A of 210-0. Beets were seeded into raised 24-inch wide beds on April 27 using a
research adapted small plot cone planter. Seeding rates were adjusted for
seed size so that 95,000 seeds/A were sown for all varieties evaluated.
Planting depth was approximately 0.5 inches. Individual plots were three rows
25 feet long. The trial was arranged in a randomized complete block design
with four replications.
A postemergence application of Betamix herbicide at 51/2 pints/A was made
on June 1. Weeds not controlled were removed by hand on June 6. The trial
area was treated with Seven at 2 pints/A for control of flea beetles on May 24
and May 31, and for armyworm control on July 17. Elemental sulfur was applied
at 12 lbs/A on August 21 and September 5 for control of powdery mildew.
The trial area was irrigated with solid set sprinklers until July 7 and
by furrow flooding through the remainder of the season. A total of 3.5 acre
feet of water was applied for the season through irrigation and rainfall.
Stands were hand-thinned on June 25 to approximately 7-inch spacing.
On October 21 beets from the center 18 feet of the center row were dug
and topped by hand, counted, and weighed. All harvested beets from each plot
were sent to Holly Sugar Corporation for percent sucrose, nitrate-N, and tare
determinations.
Crop Establishment:
KES
RESULTS AND DISCUSSION
Poor emergence occurred in selections 90N 146-012 and 90N 163-028. All
other selections achieved stands of 3 to 8 plants per foot of row with uniform
emergence. Plant stands after thinning ranged from approximately 33,000 to
39,000 plants/A (Table 1) on selections other than 90N 146-012 (18,800
plants/A) and 90N 163-028 (25,700 plants/A).
Plant vigor was rated on a scale of 1 (worst) to 5 (best) on May 30
(Table 1). Selections showing the best early season vigor were ACH 870332,
ACH 177, WS 62, Beta 1996, and ACH 191. Poor vigor was noted for 90N 146-012
and 90N 163-028.
11
IREC
The modified seeder planted weighed amounts of seed in each plot; however, seed distribution was systematically clumped at approximately 12-inch
intervals in the row. Final plant populations fell below the target stand of
35,000 plants/A in many plots due to poor crop emergence and clumping of seed
by the planter. Prethinning populations ranged from a low of 15,100 plants/A
for 90N 163-028 to a high of 55,000 plants/A for H 90695 (Table 1).
Plant vigor was rated on the 1 to 5 scale used at KES on May 28. Exceptionally good vigor was noted, for H 90695 and poor vigor was observed in 90N
163-028, H 90801, and 90N 146-012 (Table 1).
Summary Across Locations
Minimum air temperatures below 32 ° F were recorded at the KES weather
station on 12 days in May and 4 days in June. The lowest temperature observed
was 24 F, which occurred on May 3, May 9, and May 19. Tulelake experienced
lows of 26, 25, and 33 F on these dates. The May 9 frost coincided with
emergence at IREC and probably accounts for a portion of the stand loss.
Emergence at KES occurred during a period of less cold stress and frosts were
not a factor in crop establishment.
The poor performance of 90N 146-012 and 90N 163-028 at both locations
indicates a weakness in seed quality or in adaptation. While several selections exhibited better than average seedling vigor they were not the same
selections at both locations. The H 90695 selection was clearly superior to
all others at IREC, but below average in vigor at KES. Those selections with
the best vigor at KES were average at IREC.
Overall, crop establishment and early development was quite good at both
locations in a year when air temperatures were several degrees below long-term
means throughout May and June. Trials at both locations were maintained
relatively free of weeds and pests. With the exception of stand variability
at IREC, crop performance was largely a reflection of varietal response to
soil and climatic factors.
Yield and Sugar Production:
KES
Beet yields at KES ranged from 20.9 to 26.5 tons/A (Table 2). Six
entries, including the two standards, Monohikari and HH 55, exceeded 25.5
tons/A. None of the selections that exhibited superior early season vigor
were among the six with the highest yields. H 90695, which had the best early
vigor at IREC, achieved the lowest yield of all entries at KES. Poor stands
in 90N 146-012 and 90N 163-023 did not seriously impact yields. With 58
percent and 80 percent of population means for the trial, respectively, yields
were 94 percent of the mean yield for the trial.
Sugar content ranged from 15.7 percent to 17.8 percent at KES. Low sugar
content was noted for 90N 146-012, 90N 163-028, SX 1, HH 55, ACH 203, and HH
50. The low sugar content in 90N 146-012 and 90N 163-028 was partially due to
large beet size related to poor stands. Sugar content was lower than typical
levels observed in commercial crops in 1991, but very similar to results
obtained at IREC.
12
Total sugar production at KES ranged from 70.4 cwt/A for 90N 146-012 to
89.9 cwt/A for Monohikari (Table 2). H 89719 and SX 1401 ranked second and
third behind Monohikari in sugar production. High sugar yields for Monohikari
were consistent with results observed in two other trials at KES in 1991 and
in a 12-entry variety trial in 1990.
IREC
Beet yields were significantly higher at IREC than at KES, but were also
more variable, due in part to stand variability. Low yields were observed in
H 90801, ACH 177, Monohikari, HH 55, and 9BG 6272 (Table 2). HH 50, ACH 203,
ACH 199, and SX 1 achieved the highest yields at IREC. As was noted for KES,
the entries rated high in early season vigor, H 90695 and WS 41, were not
among the top yielding selections.
Sugar content was similar to percentages observed at KES. Low sugar
content was noted for NH 55, ACH 203, SS 502, Monohikari, and H 90801 at IREC
(Table 2). WS 26, Beta 1996, and 9BG 6276 achieved the highest percent sugar.
Total sugar production was approximately 20 cwt/A higher at IREC than at
KES. HH 50, 9BG 6276, ACH 199, and SX 1 were among the varieties with the
highest sugar yields. The lowest sugar production was observed in H 90801, HH
55, and Monohikari. Sugar yields were significantly different between these
high and low yielding groups.
Summary Across Locations
Higher yields at IREC are probably largely due to a two-week longer
growing season at IREC. The trial was planted one week earlier and harvested
one week later at IREC. Results from planting date experiments at both locations suggest that the earlier planting date would account for at least 50
percent of the difference in yields and sugar production.
Variety performance was clearly influenced by location in many cases.
Monohikari was among the top selections at KES but one of the poorest at IREC,
while the reverse was true for HH 50. Three selections, SX 1, H 89719, and
9BG 6276, performed quite well at both locations.
The effects of plant population on yield and sugar production were
undoubtedly a factor in variety performance at IREC. However, the relationship between population and yield, over a wide range of plant populations,
does not appear to be as important as might be expected. Results from both
variety trials and planting date experiments at two locations in 1991 have
shown that stands as low as 50 percent of target populations are capable of
achieving over 90 percent of yields at target stands. In fact, results
suggest that target stands of 35,000 plants/A may be too high for this shortseason area. Some of the smaller beets recovered in hand-harvested trials
would be lost in commercial harvests. Lower populations would result in fewer
small beets.
13
Conclusion
The IREC results must be interpreted with caution due to low and variable
populations. However, the data suggest that HH 55 and Monohikari are not
appropriate selections for organic soils. Both selections were low in yield
and sugar content at populations near the average for this trial. Six
selections achieved significantly higher total sugar production than either NH
55 or Monohikari.
In contrast, Monohikari achieved the highest sugar production of all
entries in the KES trial. It was also ranked first in a second trial with 12
entries in 1991 and in a 12-entry trial in 1990. NH 55 has consistently
produced relatively high beet yields but low sugar content at KES. In
consideration of the high transportation costs this is a serious limitation
for HH 55. Susceptibility to curly top virus will be a limitation for
Monohikari if this disease becomes a problem in the future.
Several of the entries in this study performed well at both locations.
The top seven in total sugar production include H 89719, 9BG 6276, SX 1, HH
50, ACH 203, ACH 199, and SS 502. These seven entries should be included in
1992 trials for further evaluation. Low sugar content detracted from excellent beet yields in SX 1, ACH 203, and SS 502. Other entries worthy of
further evaluation include 9G 6915, Beta 1996, WS 26, and SX 1401.
14
Table 1. Plant vigor and populations for 24 varieties in
official sugarbeet variety trials at Klamath Falls,
OR and Tulelake, CA, 1991.
Population
Selection
Vigor rating'
KES
IREC
KES
6/11
10/15
IREC
6/25
10/21
1000 plants/A
H 89719
H 90695
H 90801
SS 502
2.25
2.25
2.25
2.25
2.75
4.75
1.25
2.25
34.2
34.5
34.9
38.5
34.1
32.9
33.1
33.7
46.7
65.0
22.7
38.8
22.1
28.1
12.7
21.2
9BG 6276
9BG 6272
/ Beta 1996
9G 6915
2.25
2.75
3.50
2.75
2.00
2.50
2.50
2.25
34.5
39.2
39.9
38.0
34.7
37.8
36.3
33.1
38.5
43.2
38.8
23.8
26.9
22.1
22.1
18.1
26
41
62
91
3.00
2.00
3.75
3.25
2.75
3.35
2.50
2.75
35.6
39.0
39.2
35.2
34.2
37.2
35.0
32.7
44.5
55.4
41.7
57.6
24.8
27.2
20.0
28.1
HH 55
, HH 50
90N 146-012
90N 163-028
2.50
2.75
1.75
1.50
2.50
2.00
1.50
1.00
36.8
38.7
18.8
25.7
33.1
34.6
19.2
26.7
42.0
28.5
22.7
15.1
20.0
20.0
16.6
13.9
177
191
199
203
870332
4.00
3.50
2.75
3.25
4.25
2.75
2.00
3.00
3.00
2.75
38.7
38.7
39.7
36.8
38.3
34.1
35.3
34.7
34.4
33.3
39.2
36.9
48.2
45.2
34.1
19.4
18.2
24.8
22.7
18.8
Monohikari
vi SX 1
SX 1401
2.50
2.50
2.25
2.75
3.00
3.00
37.1
35.4
32.8
33.5
33.1
29.9
38.7
37.2
44.3
22.4
23.0
23.9
Mean
CV (%)
LSD (.05)
2.74
19.1
0.74
2.53
28.7
1.03
35.8
9.9
5.0
33.2
10.0
4.70
39.5
21.3
11.8
21.5
18.8
5.70
WS
WS
WS
WS
ACH
ACH
ACH
ACH
ACH
1/ Vigor rating scale - 1.0 = worst, 5.0 = best
15
Table 2. Yield, percent sugar, and total sugar production for 24 varieties in
official sugarbeet variety trials at Klamath Falls, OR and Tulelake,
CA, 1991.
Selection
KES
Beet Yield
Sugar Content Total Sugar Production
IREC Mean KES
IREC Mean KES
IREC
Mean
tons/A
H 89719
H 90695
H 90801
24.5
32.8
28.5
22.2
33.1
29.3
24.7
23.5
17.2
17.5
16.9
17.0
16.8
16.6
17.1
17.1
16.7
89.5
73.1
83.5
9BG 6276
9BG 6272
yeBeta 1996
9G 6915
24.9
24.5
21.4
24.2
32.5
27.8
30.9
31.0
28.7
26.1
26.1
27.6
17.2
17.6
17.5
17.7
17.8
17.5
18.1
17.3
vilS 26
WS 41
WS 62
vWS 91
22.2
22.3
23.5
22.1
30.0
30.2
29.3
28.3
26.1
26.2
26.4
25.2
17.6
17.6
17.2
17.8
HH 55
v'HH 50
90N 146-012
90N 163-028
25.7
22.5
22.3
22.4
27.8
34.5
30.9
31.1
26.8
28.5
26.6
26.7
ACH
ACH
v ACH
v ACH
y'ACH
177
191
199
203
870332
22.8
24.8
22.4
25.6
23.2
26.5
29.0
33.4
33.8
31.2
v Monohikari
`SX 1
SX 1401
25.9
26.5
25.7
Mean
CV (%)
LSD (.05)
23.8
9.1
3.1
%/SS 502
V
-
25.9
20.9
24.8
cwt/A
100.6
84.3
84.6
111.6
95.5
72.8
108.7
78.1
96.7
17.5
17.6
17.8
17.5
85.3
86.3
74.7
85.5
115.7
97.5
111.7
107.0
100.5
91.9
93.2
96.3
18.2
17.2
16.9
17.4
17.9
17.4
17.1
17.6
78.2
78.3
80.8
78.5
109.3
103.3
98.9
98.4
93.8
90.8
89.8
88.4
16.5
16.7
15.7
16.8
15.8
17.4
17.1
16.7
16.1
17.1
16.4
16.8
84.4
74.8
70.4
75.3
87.7
120.6
105.3
103.8
86.0
97.7
87.8
89.5
24.6
26.9
27.9
29.7
27.2
17.8
17.1
17.4
16.3
17.1
17.4
16.9
17.3
16.4
16.8
17.6
17.0
17.4
16.4
17.0
80.7
84.9
77.8
83.5
79.4
92.5
97.8
115.6
110.8
105.1
86.6
91.3
96.7
97.1
92.2
26.9
33.4
29.4
26.4
30.0
27.5
17.4
15.8
16.9
16.6
16.9
17.1
17.0
16.3
17.0
89.9
83.3
87.2
89.3
113.6
100.4
89.6
98.4
93.8
30.2
14.6
6.2
27.0
12.8
3.4
17.1
6.1
1.5
17.1
4.5
1.1
17.1
5.7
1.0
81.2
10.8
12.4
103.0
14.8
21.5
92.1
13.8
12.6
28.8
17.3
16.4
16.8