Oakes Irrigation Research Site
Carrington Research Extension Center * North Dakota State
University
P.O. Box 531, Oakes, ND 58474-0531, Voice: (701) 742-2189, FAX:
(701) 742-2700, E-mail: Leonard.Besemann@ndsu.edu
CARROT WEED CONTROL STUDY
Richard Greenland
Table 54. Carrot weed control treatment application data
Table 55. Herbicide treatments
Table 56. Carrot root characteristics
Table 57. Carrot injury, stand, lambsquarters, and hairy nightshade ratings
Table 58. Number of roots and yield of carrots
Only a few herbicides are available for weed control in carrots. Treflan, Lorox, Poast and Fusilade are the most commonly used. In this study we evaluated several new herbicides and herbicide combinations for use in carrots.
MATERIALS AND METHODS
|
Soil: |
Egeland loam and Maddock sandy loam; pH=7.5; 2.2% organic matter; soil-P and soil-K was very high; soil-S was low. |
|
Previous crop: |
2004 - soybean; 2003 -onion; 2002 - sweet corn. |
|
Seedbed Preparation: |
Chisel plow on April 14. Disked on May 3. Multiweeded (field cultivated) three times; once on May 3 to smooth seedbed and incorporate fertilizer and twice on May 4 to incorporate herbicide treatments. |
|
Planting: |
Direct seeded ‘Niagra’ carrots on May 4 with a Monosem precision vacuum planter set to plant a row of barley cover crop between and parallel to the carrot rows. Carrot planting pattern was 3 lines per row (2 inches between lines in the row) with rows on 18-inch centers. Planting rate was about 790,000 seeds/acre for carrot and 0.45 bu/acre for barley. |
|
Plots: |
Plots were 17 ft long by 6 ft wide with a 2-ft border between plots. There were 4 reps. |
|
Fertilizer: |
On April 15 broadcast 26 lbs N/acre and 30 lbs S/acre as 21-0-0-24. Fertigate 40 lbs N/acre on June 18 and 50 lbs N/acre on July 7 as 28-0-0. |
|
Irrigation: |
Overhead sprinkler irrigation as needed. |
|
Pest control: |
Treflan (1.5 pt/acre preplant incorporated on May 4) and Fusilade + NIS (12 oz/acre + 0.5% v/v on June 9) were applied to all plots. Check plots were hand weeded. See Table 57 for other weed control treatments. Sprayed Sevin XLR (1 qt/acre on July 14 and August 3) to control leafhopper. |
|
Harvest: |
Carrots were harvested September 12 to September 19. Harvest area was a 3-ft section from the center two rows from each plot. |
Raptor did not injury carrots when applied PRE, but injured carrots when applied 4 to 6 weeks after planting. The injury increased as the rate increased. Hairy nightshade control was poor when Raptor was applied PRE and was good to excellent (depending on application rate) when applied POST. Upbeet injured carrots and did not control hairy nightshade. Authority and Valor injured carrots. Authority didn’t control hairy nightshade. Valor reduced carrot stands, but the carrots that remained grow larger so yield was not reduced. Upbeet and Raptor applied POST reduced carrot yields. Raptor applied PRE did not reduce carrot yield. Lorox and Dacthal did not injure carrot or reduce carrot yield and gave good control of hairy nightshade. Lorox applied both PRE and POST, and the Lorox/Dacthal combinations gave the highest carrot numbers, yield, and root size. None of the new herbicides performed as well as these standards.
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Table 54. Carrot weed control treatment application data at the Oakes Irrigation Research Site in 2005.
|
Application timing |
Date |
Time |
Barley height |
Carrot height |
Carrot growth stage |
Weed height |
Weed growth stage |
|
|
|||||||
|
PPI |
May 4 |
9:45 am |
0 |
0 |
0 |
0 |
0 |
|
PRE |
May 5 |
9:25 am |
0 |
0 |
0 |
0 |
0 |
|
POST1 |
May 26 |
9:05 am |
3" |
1 |
cot. |
1/4 to 1/2" |
cot to 2 lf |
|
POST2 |
June 6 |
3:50 pm |
7" |
2" |
2.5 lf |
1 to 2" |
2 to 6 lf |
|
POST3 |
June 16 |
11:35 am |
5" (dying) |
5" |
5 lf |
2 to 6" |
4 to 10 lf |
Treatments
were applied with a CO2 backpack sprayer using AI 110-04
flat fan nozzles, 23 gpa, at 51 psi. Weed ratings were taken on
June 15 and June 28.
Treflan
(1.5 pt/A on May 4) and Fusilade + NIS (12 oz/acre + 0.5% on June 9)
applied to entire study.
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Table 55. Herbicide treatments in the Oakes Irrigation Research Site 2005 carrot weed control study.
|
Treat- ment No. |
Herbicide(s) |
Application Rates |
Application timing1 |
|
|
|||
|
1 |
Raptor fb Lorox |
0.5 oz fb 1.5 lb |
PRE fb POST3 |
|
2 |
Raptor fb Lorox |
1.0 oz fb 1.5 lb |
PRE fb POST3 |
|
3 |
Raptor fb Lorox |
2.0 oz fb 1.5 lb |
PRE fb POST3 |
|
4 |
Lorox fb Upbeet + NIS |
1 lb fb 1/4 oz + 1/4 % |
PRE fb POST2 |
|
5 |
Lorox fb Upbeet + NIS |
1 lb fb 1/2 oz + 1/4 % |
PRE fb POST2 |
|
6 |
Lorox fb Upbeet + NIS |
1 lb fb 1 oz + 1/4 % |
PRE fb POST2 |
|
7 |
Lorox fb Raptor + NIS + 28% N |
1 lb fb 1/2 oz + 1/4 % + 2.5 % |
PRE fb POST2 |
|
8 |
Lorox fb Raptor + NIS + 28% N |
1 lb fb 1 oz + 1/4 % + 2.5 % |
PRE fb POST2 |
|
9 |
Lorox fb Raptor + NIS + 28% N |
1 lb fb 2 oz + 1/4 % + 2.5 % |
PRE fb POST2 |
|
10 |
Lorox fb Raptor + NIS + 28% N |
1 lb fb 1/2 oz + 1/4 % + 2.5 % |
PRE fb POST3 |
|
11 |
Lorox fb Raptor + NIS + 28% N |
1 lb fb 1 oz + 1/4 % + 2.5 % |
PRE fb POST3 |
|
12 |
Lorox fb Raptor + NIS + 28% N |
1 lb fb 2 oz + 1/4 % + 2.5 % |
PRE fb POST3 |
|
13 |
Lorox fb Authority + NIS |
1 lb fb 1 oz + 1/4 % |
PRE fb POST2 |
|
14 |
Lorox fb Valor + NIS |
1 lb + 1 oz + 1/4 % |
PRE fb POST2 |
|
15 |
Lorox fb Authority + NIS |
1 lb fb 1 oz + 1/4 % |
PRE fb POST2 & POST3 |
|
16 |
Lorox fb Valor + NIS |
1 lb + 1 oz + 1/4 % |
PRE fb POST2 & POST3 |
|
17 |
Lorox + Dacthal |
1 lb + 8 lbs |
PRE + POST1 |
|
18 |
Dacthal + Lorox |
8 lbs + 1.5 lb |
POST1 + POST3 |
|
19 |
Lorox + Lorox |
1 lb + 1.5 lbs |
PRE + POST3 |
|
20 |
Hand weeded check |
|
|
1See Table 54 for explanation of application timings.
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Table 56. Carrot root characteristics for the Oakes Irrigation Research Site 2005 carrot weed control study.
|
Treatment number1 |
Average root length |
Average root size |
Multiple root |
US #1 yield |
Uniformity |
Overall score |
|
|
inches |
oz/root |
------------- % ------------ |
1 to 5 |
1 to 10 |
|
|
|
||||||
|
1 |
7.3 |
3.6 |
11 |
82 |
3.0 |
6.0 |
|
2 |
7.1 |
3.8 |
16 |
78 |
3.1 |
6.1 |
|
3 |
7.8 |
4.0 |
15 |
80 |
3.0 |
6.0 |
|
4 |
6.8 |
2.7 |
11 |
81 |
2.8 |
5.9 |
|
5 |
6.8 |
2.7 |
4 |
81 |
2.6 |
5.6 |
|
6 |
7.3 |
2.8 |
5 |
87 |
3.0 |
6.0 |
|
7 |
6.7 |
3.0 |
9 |
85 |
3.1 |
6.1 |
|
8 |
6.9 |
3.3 |
10 |
82 |
2.9 |
5.9 |
|
9 |
7.4 |
3.5 |
19 |
74 |
3.1 |
6.1 |
|
10 |
6.9 |
2.5 |
10 |
84 |
2.8 |
5.8 |
|
11 |
6.8 |
3.3 |
7 |
85 |
2.9 |
5.9 |
|
12 |
7.0 |
3.2 |
7 |
65 |
2.4 |
5.3 |
|
13 |
7.2 |
3.4 |
12 |
80 |
2.9 |
5.9 |
|
14 |
7.7 |
6.0 |
14 |
80 |
3.0 |
6.0 |
|
15 |
7.3 |
4.0 |
11 |
84 |
3.0 |
6.0 |
|
16 |
7.5 |
5.5 |
12 |
84 |
3.0 |
6.0 |
|
17 |
7.5 |
4.3 |
20 |
76 |
2.9 |
5.9 |
|
18 |
7.4 |
3.8 |
11 |
83 |
3.4 |
6.6 |
|
19 |
7.5 |
3.9 |
19 |
77 |
3.1 |
6.1 |
|
20 |
8.0 |
5.1 |
10 |
84 |
3.1 |
6.1 |
|
|
||||||
|
Probability |
0.15 |
<.0001 |
0.003 |
0.15 |
0.001 |
0.002 |
|
C.V. (%) |
8 |
21 |
47 |
10 |
9 |
5 |
|
LSD (0.05) |
ns |
1.1 |
8 |
ns |
0.4 |
0.4 |
1See Table 55 for weed control treatments.
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Table 57. Carrot injury, stand, lambsquarters, and hairy nightshade ratings in the Oakes Irrigation Research Site 2005
carrot weed control study.
|
Treatment number1 |
Carrot injury rating |
Stand rating |
Lambsquarters rating |
Hairy Nightshade rating |
||||
|
June 15 |
June 28 |
June 15 |
June 28 |
June 15 |
June 28 |
June 15 |
June 28 |
|
|
|
----------------------------------------------------- 0 to 102 -------------------------------------------------- |
|||||||
|
1 |
0.0 a3 |
0.3 ab |
7.3 a |
9.3 a |
9.3 abc |
10.0 a |
6.3 efg |
8.3 b-e |
|
2 |
0.5 ab |
0.3 ab |
7.5 a |
8.8 ab |
9.0 bcd |
10.0 a |
5.5 g |
8.3 bcd |
|
3 |
0.0 a |
0.5 ab |
7.5 a |
9.0 ab |
8.3 d |
10.0 a |
6.0 fg |
8.8 a-d |
|
4 |
4.0 cd |
1.8 c |
7.3 a |
8.8 ab |
9.3 abc |
9.0 cde |
7.8 cd |
5.0 h |
|
5 |
4.3 cde |
3.3 c-f |
7.0 ab |
8.0 abc |
9.0 bcd |
8.5 efg |
8.0 cd |
5.3 h |
|
6 |
4.8 cde |
5.5 fg |
7.0 ab |
7.3 cde |
8.8 cd |
8.3 fg |
8.3 bcd |
6.0 gh |
|
7 |
3.8 cd |
0.8 b |
7.0 ab |
8.8 ab |
8.8 cd |
8.0 g |
8.5 abc |
6.8 efg |
|
8 |
5.0 cde |
3.5 d-g |
6.5 bc |
7.8 bcd |
9.0 bc |
8.3 fg |
8.5 abc |
9.0 abc |
|
9 |
6.0 e |
6.0 g |
6.3 c |
6.8 de |
9.5 abc |
9.3 bcd |
8.5 abc |
10.0 a |
|
10 |
0.5 b |
2.8 cde |
7.0 ab |
8.0 abc |
9.3 abc |
9.5 abc |
7.5 cde |
6.3 fgh |
|
11 |
0.5 b |
5.0 fgh |
7.0 ab |
8.0 abc |
9.0 bcd |
8.8 def |
6.3 efg |
7.3 d-g |
|
12 |
0.3 ab |
5.5 fg |
7.3 a |
7.5 cd |
9.3 abc |
9.0 cde |
7.0 def |
8.8 a-d |
|
13 |
3.8 cd |
2.3 cd |
6.5 bc |
6.8 de |
10.0 a |
9.8 ab |
8.5 abc |
6.3 fgh |
|
14 |
5.3 de |
3.0 c-f |
6.0 c |
6.3 e |
10.0 a |
10.0 a |
10.0 a |
10.0 a |
|
15 |
3.5 c |
4.0 e-h |
6.5 bc |
6.8 de |
10.0 a |
10.0 a |
9.8 ab |
8.8 a-d |
|
16 |
5.5 de |
5.3 fg |
6.0 c |
5.0 f |
10.0 a |
10.0 a |
10.0 a |
10.0 a |
|
17 |
0.0 a |
0.5 ab |
7.0 ab |
8.8 ab |
10.0 a |
10.0 a |
8.3 cd |
7.5 c-f |
|
18 |
0.0 a |
0.0 a |
7.8 a |
9.3 a |
9.8 ab |
10.0 a |
8.5 a-d |
9.3 ab |
|
19 |
0.0 a |
0.8 b |
7.3 a |
9.0 ab |
9.0 bc |
10.0 a |
6.3 efg |
7.8 b-e |
|
20 |
0.0 a |
0.0 a |
7.5 a |
9.0 ab |
8.8 cd |
9.8 ab |
6.3 efg |
9.0 abc |
|
|
|
|
|
|
|
|
|
|
|
Probability |
<.0001 |
<.0001 |
<.0001 |
<.0001 |
<.0001 |
<.0001 |
<.0001 |
<.0001 |
|
C.V. (%) |
24 |
32 |
8 |
10 |
3 |
3 |
7 |
7 |
1See Table 55 for weed control treatments.
2Ratings are from 0 to 10: 0 = no crop injury or weeds completely cover plot, 10 = all carrots dead or no weeds in plot.
3Values in the same column followed by the same letter are not significantly different at the 0.05 level.
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Table 58. Number of roots and yield of carrots in the Oakes Irrigation Research Site 2005 carrot weed control study.
|
Treatment number1 |
Number of carrot roots (by carrot dia.) |
Carrot yield (by carrot diameter) |
||||||
|
>1.5" |
1 to 1.5" |
US #1 |
total |
>1.5" |
1 to 1.5" |
US #1 |
total |
|
|
|
--------------------- 1000s/acre ----------------------- |
------------------------- tons/acre ----------------------- |
||||||
|
1 |
69 |
250 |
336 |
428 |
13.8 |
24.1 |
38.7 |
46.9 |
|
2 |
64 |
182 |
260 |
351 |
12.3 |
18.1 |
31.1 |
40.4 |
|
3 |
77 |
185 |
284 |
380 |
15.2 |
19.2 |
35.2 |
44.3 |
|
4 |
17 |
167 |
224 |
313 |
3.7 |
14.6 |
19.8 |
24.1 |
|
5 |
34 |
134 |
203 |
312 |
5.9 |
11.6 |
18.7 |
22.3 |
|
6 |
33 |
148 |
213 |
309 |
5.5 |
11.8 |
18.5 |
21.4 |
|
7 |
58 |
224 |
325 |
415 |
10.2 |
18.9 |
30.8 |
36.0 |
|
8 |
62 |
173 |
252 |
341 |
10.9 |
14.4 |
25.9 |
31.5 |
|
9 |
65 |
145 |
225 |
332 |
12.0 |
12.8 |
25.3 |
34.1 |
|
10 |
35 |
198 |
298 |
375 |
5.8 |
15.7 |
24.0 |
28.4 |
|
11 |
42 |
162 |
232 |
300 |
7.4 |
14.9 |
23.4 |
27.8 |
|
12 |
41 |
121 |
174 |
327 |
7.3 |
10.6 |
18.2 |
28.1 |
|
13 |
45 |
152 |
211 |
324 |
9.6 |
12.8 |
22.9 |
29.0 |
|
14 |
90 |
96 |
197 |
264 |
23.3 |
11.8 |
35.5 |
44.7 |
|
15 |
77 |
188 |
284 |
378 |
16.6 |
17.5 |
34.7 |
41.6 |
|
16 |
114 |
121 |
236 |
290 |
26.5 |
12.3 |
38.9 |
46.2 |
|
17 |
76 |
143 |
249 |
327 |
16.2 |
13.9 |
31.2 |
41.5 |
|
18 |
65 |
257 |
355 |
433 |
13.8 |
26.4 |
41.5 |
49.8 |
|
19 |
63 |
206 |
293 |
380 |
13.0 |
19.8 |
33.8 |
43.7 |
|
20 |
109 |
134 |
260 |
327 |
24.6 |
14.6 |
40.0 |
48.0 |
|
|
||||||||
|
Probability |
0.004 |
<.0001 |
0.0003 |
0.02 |
<.0001 |
<.0001 |
<.0001 |
<.0001 |
|
LSD (0.05) |
45 |
61 |
77 |
91 |
9.2 |
6.0 |
10.1 |
11.6 |
|
C.V. (%) |
51 |
26 |
21 |
19 |
51 |
27 |
24 |
22 |
1See Table 55 for weed control treatments.
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study
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