Malheur Experiment Station
|
Information for Sustainable Agriculture
|
KOCHIA CONTROL WITH PREEMERGENCE NORTRON® IN STANDARD AND MICRO-RATE HERBICIDE PROGRAMS
Corey V. Ransom, Charles A. Rice, and Joey K. Ishida
Malheur Experiment Station
Oregon State University
Ontario, OR, 2003
Introduction
The distribution of kochia resistant to UpBeet
(triflusulfuron) herbicide and other acetolactate synthase (ALS)
inhibitors (i.e., sulfonylureas, imidazolinones, and
triazolopyrimidines) has increased in recent years and poses a serious
problem in sugar beet production, as none of the currently registered
postemergence herbicides effectively control ALS-resistant kochia. In
these trials, Nortron (ethofumesate) was evaluated for preemergence
control of kochia in sugar beet. Nortron is a soil-active herbicide
used preemergence or early postemergence to control annual grasses and
broadleaf weeds.
Methods
This trial was established at the Malheur Experiment Station under furrow irrigation on April 4,
2003. Sugar beets (Hilleshog 'PM-21') were planted in 22-inch rows at a
2-inch seed spacing. On April 3, kochia seed was spread over the entire
experimental area to promote an even weed distribution. After planting,
the trial was corrugated and Counter 20 CR was applied in a 7-inch band
over the row at 6 oz/1,000 ft of row. Sugar beets were thinned to
8-inch spacing on May 13 and 14. Plots were sidedressed on June 3 with 176 lb
nitrogen (urea), 96 lb phosphate, 100 lb potash, 38 lb sulfates, 62 lb
elemental sulfur, 2 lb zinc, and 1 lb/acre boron. All plots were
treated with Roundup (0.75 lb ai/acre) on April 11 prior to sugar beet
emergence. On May16, Temik 15G (14 lb/acre) was applied for sugar beet root maggot control. For
powdery mildew control, Headline (12 fl oz/acre) was applied on June 17
and again on July 2 with Super Six liquid sulfur (16 pt/acre). Topsin M
(0.5 lb/acre) was applied on August 4. All fungicide treatments were
applied by air. Herbicide treatments were broadcast applied with a CO2-pressurized
backpack sprayer calibrated to deliver 20 gal/acre at 30 psi. Plots
were four rows wide and 27 ft long and treatments were arranged in a
randomized complete block design with four replicates.
The treatments in this trial consisted of both
standard and micro-rate postemergence weed control programs applied
with or without a preemergence application of Nortron at either 16.0,
24.0, or 32.0 oz ai/acre with and without postemergence UpBeet. UpBeet
was omitted from selected treatments to simulate ALS resistance and to
better evaluate preemergence Nortron efficacy on kochia. Nortron was
applied preemergence on April 11. The standard rate program included
three applications with the first applied to full cotyledon sugar beets
on April 23, the second to 2-leaf sugar beets on April 30, and the
third application to 10-leaf sugar beets on May 16. Progress
(ethofumesate + phenmedipham + desmedipham) was applied at 4.0, 5.4,
and 6.75 oz ai/acre in the first, second, and third applications,
respectively. UpBeet was applied at 0.25 oz ai/acre in all three
applications except those treatments where UpBeet was omitted. Stinger
(clopyralid) was applied in the second and third applications at 1.5 oz
ai/acre. The micro-rate program consisted of four applications with the
first applied to cotyledon sugar beets on April 19, the second to
cotyledon to 2-leaf sugar beets on April 26, the third applied to 2- to
4-leaf sugar beets on May 1, and the fourth to 10-leaf sugar beets on
May 16. In the micro-rate program, Progress was applied at 1.28 oz
ai/acre in the first two applications and at 2.0 oz ai/acre in the last
two applications. All four micro-rate applications included UpBeet at
0.08 oz ai/acre (excluding treatments where UpBeet was omitted),
Stinger at 0.5 oz ai/acre, and a methylated seed oil (MSO) at 1.5
percent v/v.
Sugar beet injury and weed
control were evaluated throughout the season. Sugar beet yields were
determined by harvesting the center two rows of each plot on October 6
and 7.
Root yields were adjusted to account for a 5 percent tare. One sample
of 16 beets was taken from each plot for quality analysis. The samples
were coded and sent to Hilleshog Mono-Hy Research Station in Nyssa,
Oregon, to determine beet pulp sucrose content and purity. Sucrose
content and recoverable sucrose were estimated using empirical
equations. Data were analyzed using analysis of variance
procedures and means were separated using protected LSD at the 95
percent confidence interval (P = 0.05). The untreated control was not
included in the analysis of variance for weed control or crop response.
Results and Discussion
Kochia control with the standard rate and
micro-rate programs without preemergence Nortron was 97 and 96 percent,
respectively (Table 1). All treatments including both preemergence
Nortron and postemergence UpBeet provided 100 percent control of kochia
66 days after treatment (DAT) on July 21. Kochia control with standard
rate treatments without UpBeet gave 92-98 percent control and did not
improve with increasing Nortron rates. Applying Nortron preemergence at
16, 24, or 32 oz ai/acre followed by the standard rate program minus
UpBeet gave similar kochia control compared with the standard treatment
with UpBeet. The micro-rate program minus UpBeet gave 85, 89, and 93
percent kochia control with preemergence Nortron at 16, 24, and 32 oz
ai/acre, respectively. When Nortron was applied prior to the micro-rate
treatment minus UpBeet only, the 32 oz ai/acre rate provided similar
kochia control compared to the micro-rate with UpBeet. Results from
previous trials at the Malheur Experiment Station showed that Nortron
applied preemergence at 48 oz ai/acre as part of a standard or
micro-rate program minus UpBeet provided kochia control similar to both
standard and micro-rate programs with UpBeet. The kochia population in
this year's trial was less than in previous years and control obtained
with Nortron at the evaluated rates may not hold up under greater
kochia pressure. These data suggest that in field situations where
ALS-resistant kochia is present, preemergence Nortron can improve
control. Higher Nortron rates are required when using a micro-rate
versus a standard rate program.
All herbicide treatments gave 100 percent control
of common lambsquarters and hairy nightshade. Pigweed control (i.e.,
Powell amaranth and redroot pigweed) was good to excellent (92-100
percent) with all treatments. The removal of UpBeet from the micro-rate
program resulted in a significant decrease in barnyardgrass control
compared to the micro-rate treatments with or without preemergence
Nortron. The standard rate program with UpBeet following Nortron at 16
oz ai/acre provided 45 percent greater barnyardgrass control than the
same treatment without UpBeet. Increasing the preemergence Nortron rate
from 16 to 24 oz ai/acre and from 16 to 32 oz ai/acre in the standard
rate program without UpBeet resulted in 33 and 40 percent greater
barnyardgrass control, respectively.
Sugar beet injury on May 5, 4 days after the
third micro-rate application and 5 days after the second standard rate
application, ranged from 25 to 33 percent with the micro-rate
treatments and from 15 to 19 percent with the standard rate treatments
(Table 2). By June 2, 17 days after the last application, sugar beet
injury was similar among all treatments. Sugar beet injury was not
related to increasing Nortron rates. Sugar beet root yields ranged from
44.8 to 49.7 tons/acre in herbicide-treated plots (Table 2). Nortron
applied at 16 oz ai/acre followed by the micro-rate without UpBeet
produced 44.8 tons/acre root yield, which was significantly less than
Nortron at 32 oz ai/acre followed by the standard with UpBeet and
Nortron at 24 oz ai/acre followed by the micro-rate with UpBeet, both
of which produced root yields of 49.7 tons/acre. These treatments
represent the only significant differences in root yield among all
herbicide treatments. The herbicide treatment with the lowest root
yield, as mentioned above, also provided the lowest kochia control of
any treatment at 85 percent. In this trial, each additional 5 percent
increase in kochia control resulted in a sugar beet root yield increase
of 1.56 tons/acre. When we combined data from the last 3 years of
kochia control trials at the Malheur Experiment Station, there is an
increase in root yield of 1.7 tons/acre with each additional 5 percent
kochia control (Fig. 1).
There were no differences among treatments with
regard to percent sucrose content or percent extraction (Table 2).
Estimated recoverable sucrose (ERS) yields ranged from 11,514 to 13,648
lbs/acre in herbicide-treated plots (Table 2). Nortron at 24 oz ai/acre
preceding the standard program with UpBeet resulted in a significantly
higher ERS yield than the total postemergence standard rate treatment
with UpBeet. Nortron applied at 16 oz ai/acre followed by the
micro-rate with UpBeet resulted in 1,932 and 1,972 lbs/acre greater ERS
than Nortron applied at either 16 or 24 oz ai/acre followed by the
micro-rate without UpBeet.
Table 1. Kochia control in sugar beets with
preemergence Nortron in standard and micro-rate herbicide programs,
Malheur Experiment Station, Oregon State University, Ontario, OR, 2003.
|
|
|
Weed control‡ |
|
|
|
Kochia |
Pigweed spp.§ |
Lambs- quarters |
Hairy Nightshade |
Barnyard- grass |
Treatment* |
Rate |
Timing† |
6-16 |
7-21 |
7-21 |
7-21 |
7-21 |
6-16 |
|
oz ai/acre |
|
--------------------------------------- % --------------------------------------- |
Untreated control |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
-- |
|
|
|
|
|
|
|
|
|
Standard Rate Program Progress + UpBeet Progress + UpBeet + Stinger Progress + UpBeet + Stinger |
4.0 + 0.25 5.4 + 0.25 + 1.5 6.7 + 0.25 + 1.5 |
3 5 7 |
100 |
97 |
93 |
100 |
100 |
89 |
|
|
|
|
|
|
|
|
|
Micro-Rate Program Progress + UpBeet + Stinger + MSO Progress + UpBeet + Stinger + MSO |
1.28 + 0.083 + 0.5 + 1.5% v/v 1.95 + 0.083 + 0.5 + 1.5% v/v |
2, 4 6, 7 |
98 |
96 |
98 |
100 |
100 |
94 |
|
|
|
|
|
|
|
|
|
Nortron fb Standard with UpBeet |
16.0 -- |
1 3,5,7 |
100 |
100 |
100 |
100 |
100 |
86 |
|
|
|
|
|
|
|
|
|
Nortron fb Standard with UpBeet |
24.0 -- |
1 3,5,7 |
100 |
100 |
100 |
100 |
100 |
90 |
|
|
|
|
|
|
|
|
|
Nortron fb Standard with UpBeet |
32.0 -- |
1 3,5,7 |
100 |
100 |
100 |
100 |
100 |
93 |
|
|
|
|
|
|
|
|
|
Nortron fb Standard w/out UpBeet |
16.0 -- |
1 3,5,7 |
98 |
98 |
98 |
100 |
100 |
41 |
|
|
|
|
|
|
|
|
|
Nortron fb Standard w/out UpBeet |
24.0 -- |
1 3,5,7 |
98 |
92 |
100 |
100 |
100 |
74 |
|
|
|
|
|
|
|
|
|
Nortron fb Standard w/out UpBeet |
32.0 -- |
1 3,5,7 |
100 |
96 |
100 |
100 |
100 |
81 |
|
|
|
|
|
|
|
|
|
Nortron fb Micro with UpBeet |
16.0 -- |
1 2,4,6,7 |
100 |
100 |
99 |
100 |
100 |
97 |
|
|
|
|
|
|
|
|
|
Nortron fb Micro with UpBeet |
24.0 -- |
1 2,4,6,7 |
100 |
100 |
98 |
100 |
100 |
95 |
|
|
|
|
|
|
|
|
|
Nortron fb Micro with UpBeet |
32.0 -- |
1 2,4,6,7 |
100 |
100 |
100 |
100 |
100 |
98 |
|
|
|
|
|
|
|
|
|
Nortron fb Micro w/out UpBeet |
16.0 -- |
1 2,4,6,7 |
90 |
85 |
98 |
100 |
100 |
67 |
|
|
|
|
|
|
|
|
|
Nortron fb Micro w/out UpBeet |
24.0 -- |
1 2,4,6,7 |
86 |
89 |
92 |
100 |
100 |
73 |
|
|
|
|
|
|
|
|
|
Nortron fb Micro w/out UpBeet |
32.0 -- |
1 2,4,6,7 |
91 |
93 |
96 |
100 |
100 |
68 |
|
|
|
|
|
|
|
|
|
LSD ( 0.05) |
|
|
7 |
8 |
NS |
NS |
NS |
25 |
*fb = Followed by.
†Application timings were (1) April 11
preemergence, (2) April 19 to cotyledon beets, (3) April 23 to full
cotyledon beets, (4) April 26 to cotyledon to 2-leaf beets, (5) April
30 to 2-leaf beets, (6) May 1 to 2- to 4-leaf beets, and (7) May 16 to
10-leaf beets.
‡The untreated control was not included in the weed control analysis.
§Pigweed species included Powell amaranth and redroot pigweed.Table
2. Sugar beet injury and yield with preemergence Nortron in standard
and micro-rate herbicide programs, Malheur Experiment Station, Oregon
State University, Ontario, OR, 2003.
|
|
|
Sugar beet |
|
|
|
Injury‡ |
|
Yield |
Treatment* |
Rate |
Timing† |
5-5 |
6-2 |
|
Root yield |
Sucrose |
Extraction |
ERS§ |
|
oz ai/acre |
|
------- % ------- |
|
ton/acre |
------------ % ------------ |
lb/acre |
Untreated control |
-- |
-- |
-- |
-- |
|
20.4 |
14.6 |
91.7 |
4,810 |
|
|
|
|
|
|
|
|
|
|
Standard Rate Program Progress + UpBeet Progress + UpBeet + Stinger Progress + UpBeet + Stinger |
4.0 + 0.25 5.4 + 0.25 + 1.5 6.7 + 0.25 + 1.5 |
3 5 7 |
17 |
11 |
|
47.0 |
13.4 |
90.8 |
11,523 |
|
|
|
|
|
|
|
|
|
|
Micro-Rate Program Progress + UpBeet + Stinger + MSO Progress + UpBeet + Stinger + MSO |
1.28 + 0.083 + 0.5 + 1.5% v/v 1.95 + 0.083 + 0.5 + 1.5% v/v |
2, 4 6, 7 |
25 |
10 |
|
47.7 |
15.0 |
92.1 |
13,125 |
|
|
|
|
|
|
|
|
|
|
Nortron fb Standard with UpBeet |
16.0 -- |
1 3,5,7 |
19 |
13 |
|
48.9 |
14.5 |
91.4 |
12,970 |
|
|
|
|
|
|
|
|
|
|
Nortron fb Standard with UpBeet |
24.0 -- |
1 3,5,7 |
17 |
16 |
|
49.1 |
15.1 |
92.0 |
13,648 |
|
|
|
|
|
|
|
|
|
|
Nortron fb Standard with UpBeet |
32.0 -- |
1 3,5,7 |
15 |
14 |
|
49.7 |
14.6 |
91.6 |
13,306 |
|
|
|
|
|
|
|
|
|
|
Nortron fb Standard w/out UpBeet |
16.0 -- |
1 3,5,7 |
15 |
14 |
|
45.8 |
14.1 |
91.7 |
11,819 |
|
|
|
|
|
|
|
|
|
|
Nortron fb Standard w/out UpBeet |
24.0 -- |
1 3,5,7 |
15 |
15 |
|
47.5 |
14.7 |
91.8 |
12,815 |
|
|
|
|
|
|
|
|
|
|
Nortron fb Standard w/out UpBeet |
32.0 -- |
1 3,5,7 |
19 |
15 |
|
48.9 |
14.0 |
91.4 |
12,495 |
|
|
|
|
|
|
|
|
|
|
Nortron fb Micro with UpBeet |
16.0 -- |
1 2,4,6,7 |
33 |
12 |
|
48.8 |
15.1 |
91.6 |
13,513 |
|
|
|
|
|
|
|
|
|
|
Nortron fb Micro with UpBeet |
24.0 -- |
1 2,4,6,7 |
29 |
9 |
|
49.7 |
14.4 |
91.8 |
13,127 |
|
|
|
|
|
|
|
|
|
|
Nortron fb Micro with UpBeet |
32.0 -- |
1 2,4,6,7 |
27 |
11 |
|
48.5 |
14.4 |
91.8 |
12,892 |
|
|
|
|
|
|
|
|
|
|
Nortron fb Micro w/out UpBeet |
16.0 -- |
1 2,4,6,7 |
30 |
13 |
|
44.8 |
14.0 |
91.7 |
11,581 |
|
|
|
|
|
|
|
|
|
|
Nortron fb Micro w/out UpBeet |
24.0 -- |
1 2,4,6,7 |
25 |
13 |
|
45.7 |
13.6 |
91.6 |
11,514 |
|
|
|
|
|
|
|
|
|
|
Nortron fb Micro w/out UpBeet |
32.0 -- |
1 2,4,6,7 |
29 |
8 |
|
46.8 |
14.0 |
91.7 |
11,991 |
|
|
|
|
|
|
|
|
|
|
LSD (0.05) |
|
|
6 |
NS |
|
3.3 |
NS |
NS |
1,833 |
*fb = Followed by.
†Application timings were (1) April 11
preemergence, (2) April 19 to cotyledon beets, (3) April 23 to full
cotyledon beets, (4) April 26 to cotyledon to 2-leaf beets, (5) April
30 to 2-leaf beets, (6) May 1 to 2- to 4-leaf beets, and (7) May 16 to
10-leaf beets.
‡The untreated control was not included in the sugar beet injury analysis.
§ ERS = Estimated recoverable sucrose.
Figure 1. Response of sugar
beet root yields to percent kochia control combined over a 3-year
period from 2001 to 2003, Malheur Experiment Station, Oregon State
University, Ontario, OR.
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For
additional information about the Malheur Agricultural Experiment
Station, please send an e-mail request to:
Dr. Clinton C. Shock
Clinton.Shock@oregonstate.edu
Malheur Agricultural Experiment
Station
595 Onion Avenue
Ontario, OR 97914
(541) 889-2174
FAX (541) 889-7831
Last updated
Friday August 13, 2004 .
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