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, email: rgreenla@ndsuext.nodak.edu
Richard Greenland
Table 42. Weed control and crop injury
Table 43. Number of roots and yield of carrots
Table 44. Carrot root characteristics and quality
Tables of pesticides used at the Oakes Irrigation Research Site -- Trade names and common names
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 five additional herbicides, Authority, Outlook, Dual II Magnum, Dacthal, and Valor, for their usefulness in carrot production.
MATERIALS AND METHODS
Soil: |
Embden loam and Maddock sandy loam; pH=7.3; 2.1% organic matter; soil-P and soil-K were very high; soil-S was medium. |
Previous crop: |
2001 - potato; 2000 - pepper, onion, edible bean, field corn, sweetcorn, soybean, carrot, and cabbage; 1999 - field corn and ornamental corn. |
Seedbed Preparation: |
Coulter chiseled 15 inches deep twice – once on Apr 17 and again on Apr 18. Multiweeded (field cultivated) three times; once May 16 to smooth seedbed and twice May 20 to incorporate herbicide. |
Planting: |
Direct seeded Bolero carrots on May 21 with a Monosem precision vacuum planter set to plant a row of barley cover crop between 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 800,000 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 18, broadcast 18 lbs N/acre and 20 lbs S/acre as 21-0-0-24. Side dressed 50 lbs N/acre as urea on July 3. |
Irrigation: |
Overhead sprinkler irrigation as needed. |
Pest control: |
Treflan (1.5 pt/acre on May 20) and Poast + Dash (1.5 pt + 1 pt/acre on June 17) were applied to all plots. Check plots were hand weeded. See Table 42 to 44 for other weed control treatments. Sprayed Asana (8 oz/acre on July 15, July 30 and Aug 13) and Sevin (1 qt/acre on Aug 27) to control leafhopper. |
Harvest: |
Carrots were harvested on September 11 to17. The harvest area was 3 ft of the center two rows of each plot. |
Goal applied at either PRE or POST1 (carrots 1.5 inches tall) injured carrot plants and reduced carrot stand and yields. Valor injured carrot plants and reduced carrot stand and yields if applied PRE or POST1, but not when applied POST2 (carrots 3 inches tall). The best weed control and highest yields were with Lorox applied PRE and POST2, or with Dacthal applied EPOST followed by Lorox at POST2. The Lorox PRE followed by Valor POST2 treatment also produced good weed control and high yields. Authority applied POST2 did not control hairy nightshade and slightly injured carrots, resulting in lower carrot yields.
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Table 42. Weed control and crop injury for the Oakes Irrigation Research Site 2002 carrot weed control study.
Herbicide(s) |
Rate |
Application timing2 |
June 24 ratings1 |
July 3 ratings1 |
|||||
crop injury |
Colq3 |
Hns3 |
Ebns3 |
crop injury |
Colq3 |
Hns3 |
|||
|
|
|
------------------------------------------- 0 to 10 -------------------------------------------- |
||||||
|
|||||||||
Lorox |
1 lb |
PRE |
0.8 |
9.3 |
7.8 |
9.8 |
0.5 |
9.3 |
7.0 |
Dacthal + Lorox |
8 lbs + 1.5 lb |
EPOST + POST2 |
0.3 |
10.0 |
7.3 |
10.0 |
0.3 |
10.0 |
9.8 |
Lorox + Dacthal |
1 lb + 8 lbs |
PRE + EPOST |
1.0 |
10.0 |
9.8 |
10.0 |
0.8 |
10.0 |
10.0 |
Goal 2XL |
1 pt |
PRE |
4.8 |
10.0 |
10.0 |
10.0 |
3.5 |
10.0 |
10.0 |
Goal 2XL |
1 pt |
POST1 |
4.3 |
10.0 |
10.0 |
10.0 |
3.3 |
10.0 |
10.0 |
Goal 2XL |
2 pt |
PRE |
7.8 |
10.0 |
10.0 |
10.0 |
8.0 |
10.0 |
10.0 |
Goal 2XL |
2 pt |
POST1 |
5.3 |
10.0 |
10.0 |
10.0 |
4.8 |
10.0 |
10.0 |
Valor |
0.5 oz |
PRE |
2.0 |
9.8 |
9.5 |
10.0 |
1.3 |
9.5 |
9.5 |
Valor |
1 oz |
PRE |
2.8 |
9.8 |
10.0 |
10.0 |
3.0 |
10.0 |
10.0 |
Lorox + Valor |
1 lb + 1 oz |
PRE + POST1 |
3.8 |
10.0 |
10.0 |
10.0 |
3.5 |
10.0 |
10.0 |
Lorox + Valor |
1 lb + 2 oz |
PRE + POST1 |
5.0 |
10.0 |
10.0 |
10.0 |
5.3 |
10.0 |
10.0 |
Lorox + Valor |
1 lb + 1 oz |
PRE + POST2 |
1.8 |
9.5 |
8.5 |
10.0 |
1.0 |
9.3 |
8.8 |
Lorox + Valor |
1 lb + 2 oz |
PRE + POST2 |
0.8 |
9.3 |
8.0 |
10.0 |
0.8 |
9.3 |
8.8 |
Lorox + Authority |
1 lb + 1 oz |
PRE + POST2 |
0.5 |
9.8 |
7.5 |
10.0 |
2.0 |
10.0 |
8.0 |
Lorox + Authority |
1 lb + 2 oz |
PRE + POST2 |
0.8 |
10.0 |
8.5 |
10.0 |
2.5 |
10.0 |
9.3 |
Lorox + Lorox |
1 lb + 1.5 lbs |
PRE + POST2 |
1.0 |
9.8 |
8.8 |
10.0 |
1.3 |
10.0 |
10.0 |
Lorox |
0.5 lb |
PRE |
0.0 |
9.8 |
7.5 |
10.0 |
0.0 |
9.8 |
6.8 |
Valor + Valor + Lorox |
0.5 + 2.0 oz +1.5 lbs |
PRE + POST1 + POST2 |
6.0 |
10.0 |
10.0 |
10.0 |
6.0 |
10.0 |
10.0 |
Authority |
1 oz |
POST2 |
0.0 |
9.0 |
4.0 |
9.0 |
2.0 |
9.5 |
4.3 |
Authority |
2 oz |
POST2 |
0.0 |
8.8 |
4.5 |
9.8 |
2.8 |
9.8 |
5.8 |
Hand weeded check |
0.0 |
10.0 |
10.0 |
10.0 |
0.0 |
10.0 |
10.0 |
||
|
|||||||||
LSD (0.05) |
1.3 |
0.6 |
1.2 |
0.3 |
1.7 |
0.5 |
1.6 |
||
Probability |
<.0001 |
0.001 |
<.0001 |
<.0001 |
<.0001 |
0.002 |
<.0001 |
||
C.V. (%) |
39 |
5 |
10 |
2 |
47 |
4 |
12 |
1Ratings are from 0 to 10: 0 = no weed control or crop injury, 10 = complete weed control or all carrots dead.
2PRE was on May 23. EPOST was on June 4 (barley 3 to 5" tall, carrot ½ to 1” tall, weeds ½” tall). POST1 was on June 14 (carrots 1.5"
tall, weeds 1" tall). POST2 was on June 25 (carrots 3 to 4" tall, weeds (mostly hairy nightshade) 2 to 3" tall (previously treated) or 4
to 7" tall (previously untreated). Treflan (1.5 pt/A on May 20) and Poast + Dash (1.5 pt + 1 pt/A on June 17) applied to all treatments.
3Colq is common lambsquarters; Hns is Hairy nightshade; Ebns is Eastern black nightshade.
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Table 43. Number of roots and yield of carrots in the Oakes Irrigation Research Site 2002 carrot weed control study.
Herbicide(s) |
Rate |
Application timing1 |
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 --------------- |
||||||
|
||||||||||
Lorox |
1 lb |
PRE |
24 |
80 |
129 |
166 |
4.3 |
5.6 |
10.5 |
13.3 |
Dacthal + Lorox |
8 lbs + 1.5 lb |
EPOST + POST2 |
80 |
59 |
145 |
198 |
14.9 |
5.5 |
20.6 |
29.7 |
Lorox + Dacthal |
1 lb + 8 lbs |
PRE + EPOST |
57 |
34 |
102 |
160 |
10.3 |
3.3 |
14.0 |
22.0 |
Goal 2XL |
1 pt |
PRE |
51 |
33 |
87 |
126 |
9.8 |
2.9 |
12.9 |
19.6 |
Goal 2XL |
1 pt |
POST1 |
65 |
58 |
132 |
161 |
11.6 |
5.2 |
17.0 |
21.2 |
Goal 2XL |
2 pt |
PRE |
8 |
7 |
16 |
33 |
2.4 |
0.6 |
3.0 |
8.3 |
Goal 2XL |
2 pt |
POST1 |
47 |
30 |
83 |
121 |
8.9 |
3.1 |
12.1 |
18.4 |
Valor |
0.5 oz |
PRE |
64 |
56 |
126 |
162 |
13.0 |
4.8 |
18.0 |
23.4 |
Valor |
1 oz |
PRE |
30 |
23 |
56 |
110 |
6.1 |
1.9 |
8.1 |
16.3 |
Lorox + Valor |
1 lb + 1 oz |
PRE + POST1 |
67 |
30 |
110 |
142 |
13.1 |
2.8 |
16.4 |
22.2 |
Lorox + Valor |
1 lb + 2 oz |
PRE + POST1 |
44 |
18 |
68 |
96 |
8.5 |
1.8 |
10.5 |
16.3 |
Lorox + Valor |
1 lb + 1 oz |
PRE + POST2 |
61 |
53 |
123 |
160 |
10.7 |
5.0 |
16.1 |
20.3 |
Lorox + Valor |
1 lb + 2 oz |
PRE + POST2 |
70 |
96 |
180 |
219 |
12.2 |
7.8 |
20.4 |
24.8 |
Lorox + Authority |
1 lb + 1 oz |
PRE + POST2 |
51 |
85 |
149 |
189 |
8.8 |
7.3 |
16.5 |
20.6 |
Lorox + Authority |
1 lb + 2 oz |
PRE + POST2 |
56 |
56 |
115 |
155 |
10.0 |
4.3 |
14.4 |
18.6 |
Lorox + Lorox |
1 lb + 1.5 lbs |
PRE + POST2 |
59 |
68 |
136 |
175 |
11.4 |
6.5 |
19.0 |
25.3 |
Lorox |
0.5 lb |
PRE |
53 |
79 |
161 |
198 |
9.7 |
6.9 |
17.3 |
19.9 |
Valor + Valor + Lorox |
0.5 + 2.0 oz + 1.5 lbs |
PRE + POST1 +POST2 |
33 |
12 |
46 |
73 |
7.6 |
0.9 |
8.6 |
15.5 |
Authority |
1 oz |
POST2 |
7 |
96 |
137 |
179 |
0.9 |
4.9 |
6.5 |
7.5 |
Authority |
2 oz |
POST2 |
15 |
131 |
179 |
209 |
2.2 |
8.0 |
11.0 |
12.2 |
Hand weeded check |
90 |
85 |
185 |
244 |
16.7 |
8.7 |
25.8 |
32.7 |
||
|
||||||||||
LSD (0.05) |
30 |
47 |
65 |
76 |
5.6 |
3.9 |
7.5 |
9.0 |
||
Probability |
<.0001 |
<.0001 |
<.0001 |
<.0001 |
<.0001 |
0.0007 |
<.0001 |
<.0001 |
||
C.V. (%) |
43 |
59 |
39 |
34 |
43 |
59 |
38 |
33 |
1PRE was on May 23. EPOST was on June 4 (barley 3 to 5" tall, carrot ½ to 1” tall, weeds ½” tall). POST1 was on June 14 (carrots 1.5"
tall, weeds 1" tall). POST2 was on June 25 (carrots 3 to 4" tall, weeds (mostly hairy nightshade) 2 to 3" tall (previously treated) or 4
to 7" tall (previously untreated). Treflan (1.5 pt/A on May 20) and Poast + Dash (1.5 pt + 1 pt/A on June 17) applied to all treatments.
Go to top of carrot weed control report
Table 44. Carrot root characteristics and quality for the Oakes Irrigation Research Site 2002 carrot weed control study.
Herbicide(s) |
Rate |
Application timing1 |
Average root length |
Average root size |
Multiple root yield |
US #1 yield |
Overall score |
|
|
|
inches |
oz/root |
tons/acre |
% |
1 to 10 |
|
|||||||
Lorox |
1 lb |
PRE |
5.7 de |
2.8 def |
1.7 d-g |
83 ab |
6.6 a |
Dacthal + Lorox |
8 lbs + 1.5 lb |
EPOST + POST2 |
6.9 a-d |
4.8 abc |
5.8 a |
69 b-e |
5.0 abc |
Lorox + Dacthal |
1 lb + 8 lbs |
PRE + EPOST |
6.3 bcd |
4.4 bc |
5.5 ab |
63 def |
4.0 bcd |
Goal 2XL |
1 pt |
PRE |
6.9 a-d |
4.8 ab |
4.6 a-e |
67 b-e |
6.4 a |
Goal 2XL |
1 pt |
POST1 |
6.7 a-d |
4.4 bc |
2.2 b-g |
80 abc |
6.3 ab |
Goal 2XL |
2 pt |
PRE |
7.2 abc |
6.3 a |
4.2 a-e |
40 g |
1.5 e |
Goal 2XL |
2 pt |
POST1 |
6.8 a-d |
4.6 bc |
4.1 a-e |
68 b-e |
6.5 a |
Valor |
0.5 oz |
PRE |
6.7 a-d |
4.5 bc |
3.1 a-g |
78 a-d |
6.6 a |
Valor |
1 oz |
PRE |
6.7 a-d |
4.9 ab |
5.3 abc |
50 fg |
2.5 de |
Lorox + Valor |
1 lb + 1 oz |
PRE + POST1 |
7.6 a |
5.1 ab |
3.5 a-g |
74 a-d |
5.3 abc |
Lorox + Valor |
1 lb + 2 oz |
PRE + POST1 |
7.1 abc |
4.9 ab |
4.4 a-e |
63 c-f |
5.0 abc |
Lorox + Valor |
1 lb + 1 oz |
PRE + POST2 |
6.2 cd |
4.4 bcd |
1.9 c-g |
78 a-d |
4.8 a-d |
Lorox + Valor |
1 lb + 2 oz |
PRE + POST2 |
6.4 a-d |
4.0 bcd |
3.0 a-g |
82 ab |
7.0 a |
Lorox + Authority |
1 lb + 1 oz |
PRE + POST2 |
6.1 cd |
3.6 b-e |
1.2 efg |
81 ab |
6.3 ab |
Lorox + Authority |
1 lb + 2 oz |
PRE + POST2 |
6.5 a-d |
4.5 bc |
2.5 a-g |
78 a-d |
5.9 ab |
Lorox + Lorox |
1 lb + 1.5 lbs |
PRE + POST2 |
7.0 abc |
4.6 bc |
3.6 a-f |
74 a-d |
5.6 ab |
Lorox |
0.5 lb |
PRE |
5.7 de |
3.2 cde |
1.2 efg |
86 a |
6.0 ab |
Valor + Valor + Lorox |
0.5 + 2.0 oz + 1.5 lbs |
PRE + POST1 + POST2 |
7.5 ab |
6.3 a |
5.7 a |
53 efg |
3.1 cde |
Authority |
1 oz |
POST2 |
4.2 f |
1.5 f |
0.1 g |
87 a |
4.9 abc |
Authority |
2 oz |
POST2 |
4.8 ef |
2.0 ef |
0.6 fg |
90 a |
7.0 a |
Hand weeded check |
6.6 a-d |
4.6 bc |
4.8 a-d |
77 a-d |
6.1 ab |
||
|
|||||||
LSD (0.05) |
1.2 |
1.6 |
3.5 |
17 |
2.3 |
||
Probability |
<.0001 |
<.0001 |
0.02 |
<.0001 |
0.0001 |
||
C.V. (%) |
13 |
26 |
74 |
16 |
30 |
1PRE was on May 23. EPOST was on June 4 (barley 3 to 5" tall, carrot ½ to 1” tall, weeds ½” tall). POST1 was on June 14 (carrots 1.5"
tall, weeds 1" tall). POST2 was on June 25 (carrots 3 to 4" tall, weeds (mostly hairy nightshade) 2 to 3" tall (previously treated) or 4
to 7" tall (previously untreated). Treflan (1.5 pt/A on May 20) and Poast + Dash (1.5 pt + 1 pt/A on June 17) applied to all treatments.
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