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
HERBICIDE CARRYOVER
STUDY
Richard Greenland and Leonard Besemann
As vegetable production increases in North Dakota, vegetables will be planted in rotations with field corn and soybean. Many of the herbicides applied to corn and soybean could carry over and injure vegetable crops planted the next year. Chemical companies, recognizing this potential for injury, have placed rotation restrictions on their herbicide labels. These labels restrict planting vegetables for one to four years after applying the herbicide to corn or soybean. But little information is available to verify the need for such restrictions, especially on highly permeable, loam or sandy loam soils that are irrigated. This is the second study conducted at the Oakes Irrigation Research Site to determine herbicide injury to vegetables planted after applying certain herbicides to corn or soybean. In 1996, we applied Accent, Broadstrike + Dual, and Scorpion III to field corn, and Pursuit and Raptor to soybean. In 1997, we planted potatoes, cabbage, carrots, onions, tomatoes, and acorn squash as subsequent crops to the field corn and soybean. We planted those same vegetables again in 1998, but changed the plot assignments (in 1998 potatoes were planted where squash was in 1997, etc. See Table 67). This allowed us to test the effects of these herbicides on vegetables planted two years after herbicide application.
Table 67. Planting, seed preparation, and harvest date for herbicide carryover study.
Table 68. Fertilizer rate and pest control for herbicide carryover study.
Go to Oakes Irrigation Research Site Weed Control Studies page
MATERIALS AND METHODS
| Soil: | Gardena loam, Embden loam, and Embden sandy loam; pH 7.3; 2.8% organic matter; soil-P and soil-K were very high; soil-S was low. |
| Previous Crops: | 1996 - field corn and soybean; 1995 - edible beans, potato, onion; |
| Plots: | Plots were 7.5 ft. wide by 17 ft. long. The study had 4 reps. |
| Irrigation: | Overhead sprinkler irrigation as needed. |
Table 67. Planting, seed preparation, and harvest date for herbicide carryover study. All dates are 1998 unless otherwise specified.
| Crop | Planting Date | Seedbed preparation | Harvest Date | |
| Date | Activity | |||
| Carrot (1997 crop: cabbage) |
April 30 |
Oct 31, 1997 April 29 |
disk multiweed (thrice) |
Oct 22 |
| Cabbage (1997 crop: carrot) |
April 30 |
Oct 31, 1997 April 29 April 29 |
disk multiweed (deep) multiweed (twice) |
Aug 10 |
| Tomato (1997 crop: Onion) |
May 27 |
Oct 31, 1997 May 21 May 26 |
disk disk multiweed (thrice) |
Sept 2, 3 and 9 |
| Onion (1997 crop: Potato) |
April 20 |
Oct 31, 1997 April 13 |
disk multiweed |
Pulled Sep 17 Bagged Oct 14 & 15 |
| Winter squash (1997 crop: Tomato) |
May 19 |
Oct 31, 1997 May 18 June 4 |
disk Multiweed (deep) multiweed (twice) |
Not harvested (poor seed) |
| Potato (1997 crop: winter squash) |
April 24 |
Oct 31, 1997 April 23 |
disk multiweed |
Oct 9, 19 and 20 |
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Study
Table 68. Fertilizer rate and pest control for herbicide carryover study
| Crop | Fertilizer applications | Pest control | ||
| date | rate and fertilizer | date | pesticide/operation | |
| Cabbage 1998 |
April 13 June 5 June 30 |
140 lbs 10-50-0 156 lbs 0-0-60 78 lbs 21-0-0-24 50 lbs N/acre as 28-0-0 50 lbs N/acre as 28-0-0 |
April 29 May 11 May 26 Jun 11, Jul 16 May 20 June 11 June 3 Jun 25, July 1,7,13,20 July 27 |
Treflan (1 pt/acre) Dacthal (10 lbs/acre) Poast + Dash (1.5+1.5 pts/acre) hand weeded Sevin (1.5 pt/acre) Lentagran (2 lbs/acre) Agree (1 lb/acre) DiPel (1 lb/acre) Malathion (2 pt/acre) |
| Carrot 1998 |
April 13 June 5 June 30 |
140 lbs 10-50-0 156 lbs 0-0-60 78 lbs 21-0-0-24 50 lbs N/acre as 28-0-0 50 lbs N/acre as 28-0-0 |
April 29 May 1 & June 3 May 28
Jul 9, 30, Aug 21 |
Treflan (1.5 pt/acre) Linex (1 lb/acre)&(1.5 lbs/acre) Fusilade + nonionic surfactant (12 oz/acre + 1 pt/25 gal) Sevin (1 qt/acre) Asana (8 oz/acre) |
| Onion 1998 |
April 13 June 5 June 30 |
140 lbs 10-50-0 156 lbs 0-0-60 78 lbs 21-0-0-24 50 lbs N/acre as 28-0-0 50 lbs N/acre as 28-0-0 |
May 11 May 19 May 28, June 25 June 25 July 10 June 26 Jun 29, Jul 15, 28 Aug 13 July 7 |
Prowl (1.5 pt/acre) Poast + Dash (1.5+1.5 pts/acre) Buctril + Goal (1.5 and 0.6 pt/A) Fusilade + nonionic surfactant (1 pt/acre + 1 pt/25 gal) Goal (0.6 pt/acre) Ridomil MZ (2.5 lbs/acre) Manzate (3 lbs/acre) Manzate (3 lbs/acre) Dithane (2.2 qt/acre) |
| Potato 1998 |
April 13 April 22 June 5 June 30 |
140 lbs 10-50-0 156 lbs 0-0-60 78 lbs 21-0-0-24 70 lbs N/acre as 28-0-0 50 lbs N/acre as 28-0-0 50 lbs N/acre as 28-0-0 |
May 18; 27 April 24 May 19 May 22 May 28 Jul 7, 16, 23, 30 Aug 6, 13 Aug 14, 17 Sep 7 |
Drag off; hilling Admire (18.9 oz/acre) Poast + Dash (1.5+1.5 pts/acre) Matrix + nonionic surfactant (1 oz/acre + 1 pt/25 gal) Dual + Prowl (1.5 + 1.5 pt/acre) Bravo Zn (1.5 pt/acre) Bravo Zn (1.5 pt/acre) Hand weed Diquat (1 pt/acre) |
| Tomato 1998 |
April 13 June 5 June 30 |
140 lbs 10-50-0 156 lbs 0-0-60 78 lbs 21-0-0-24 50 lbs N/acre as 28-0-0 50 lbs N/acre as 28-0-0 |
May 26 May 26 June 3 July 9, 23, 30 July 15 July 14, 30 July 23 |
Tillam (3 qt/acre) Treflan (1 pt/acre) Lexone (0.5 lb/acre) Sevin (1 qt/acre) Asana (8 oz/acre) Maneb (1.5 lbs/acre) Benlate (2 lbs/acre) |
| Winter Squash 1998 |
April 13 June 5 June 30 |
140 lbs 10-50-0 156 lbs 0-0-60 78 lbs 21-0-0-24 50 lbs N/acre as 28-0-0 50 lbs N/acre as 28-0-0 |
June 16 Jun 26, Jul 23, 30 July 7 July 15 July 7, 23 July 16, 28 |
Thiodan (2 qt/acre) Sevin (1 qt/acre) Ambush (8 oz/acre) Asana ( 8 oz/acre) Benlate (2 lb/acre) Maneb (1.5 lbs/acre) |
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There was no evidence of any herbicide injury to vegetables planted two years after application of herbicides to the field corn or soybean. This indicates that some of the rotational restrictions given in the herbicide labels may be too restrictive and could be shortened. However, the years this study was conducted were wetter than average and we had a couple of major precipitation events that could have leached the herbicides out of the soil.
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Go to Oakes Irrigation Research Site Weed Control Studies
Go to Oakes Irrigation Research Site Rotation Studies
Go to Oakes Irrigation Research Site 1998 annual report