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
TOMATO WEED CONTROL STUDY, 1999
Richard Greenland
Table 42. Weed control ratings on June 16.
Table 43. Weed control and crop injury ratings, and tomato and weed heights on July 1.
Table 44. Weed control ratings on July 16.
Table 45. Yields of tomatoes harvested August 23 & 24.
Table 46. Yields of tomatoes harvested September 13 & 14.
Tomato and nightshade belong to the solanaceae family. Because of their similarities it is difficult to control nightshade in tomato production, especially with postemergence herbicides. This study evaluated three standard herbicides (Treflan, Tillam, and Lexone) and two new herbicides (rimsulfuron and pyridate) for control of hairy and black nightshades. Rimsulfuron controls hairy nightshade in potato. Pyridate controls hairy and black nightshade but may injure tomatoes. We also looked at pigweed, lambsquarters, and purslane control.
MATERIALS AND METHODS
| Soil: | Maddock sandy loam, Hecla sandy loam; pH=7.7; 2.6% organic matter; soil-P and soil-K were high; soil-S was very low. |
| Previous crop: | 1998 - carrot; 1997 - winter squash and pumpkin; 1996 - cauliflower and cabbage. |
| Seedbed preparation: | Disked on 5 November 1998. Deep chiseled on May 4. Field cultivated three times on June 1, once deep and twice shallow, to incorporate herbicides. |
| Planting: | Tuscany paste tomatoes were seeded in the greenhouse on April 9. Plants were hand transplanted to the field on June 2. Rows were spaced 8 feet apart. In-row spacing was 1.5 ft. As it was planted, each plant received one pint of fertilizer solution (1 gal 10-34-0 in 100 gal of water). |
| Plots: | Plots were 17 ft long by 6 ft (one row) wide with a two-foot wide alleyway between plots. |
| Fertilizer: | On April 7, broadcast 15 lbs N/acre and 75 lbs P2O5/acre as 10-50-0, 18 lbs N/acre and 20 lbs S/acre as 21-0-0-24, and 99 lbs K20/acre as 0-0-60. Sprayed 50 lbs N/acre on May 24, fertigated 50 lbs of N/acre on July 7 and 40 lbs N/acre on July 21 as 28-0-0. |
| Irrigation: | Surface drip irrigation as needed. |
| Pest control: | Weed control treatments are listed in Table 41. We applied Kocide (2.5 lbs/acre on July 14) and Quadris (6 oz/acre on July 26 and Aug 25) for blight control. We applied Asana (8 oz/acre on June 29 and July 14) for insect control. |
| Harvest: | Harvested twice: Aug 23 & 24, and Sep 13 &14. On each date we harvested every tomato in a 5-foot section of row. Tomatoes were sorted into red (any amount of red color on tomato) and green. Percent mature green tomatoes was determined by slicing 10 green tomatoes chosen at random. |
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Pyridate, the only herbicide to injure tomato, caused about 30% crop injury
as leaf burn and stunting. Tomato recovered from the leaf burn in two weeks,
but remained stunted. (We used the wettable powder formulation of pyridate.
The emulsifiable concentrate formulation may cause more crop injury). Pyridate
controlled both hairy and black nightshade. It also controlled pigweed and
lambsquarters. Rimsulfuron (ShadeOut) gave excellent control of hairy nightshade
when applied postemergence but only fair control when applied preemergence.
Rimsulfuron did not control black nightshade. In fact, control of hairy
nightshade by rimsulfuron allowed increased growth of black nightshade, because
hairy nightshade growth suppressed black nightshade growth. Rimsulfuron also
controlled pigweed, lambsquarters, common purslane, and grasses. Tillam improved
control of both hairy and black nightshade, but was not able to completely
control them without other herbicides. Lambsquarters and pigweed were not
controlled with Tillam.
Tomato yields were highest in the hand weeded check and in the Treflan + rimsulfuron + pyridate treatment. Yields were lowest where hairy nightshade control was lowest. The best yields without using hand weeding or pyridate (since pyridate is not labeled and hand weeding is very expensive), is with Treflan applied preplant incorporated plus ShadeOut applied when weeds are about ½ inch tall. However, large black nightshade plants made harvesting in this treatment very difficult. Pyridate delayed tomato maturity, while heavy weed growth, especially hairy nightshade, accelerated maturity.
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Table 41. Treatments for the Oakes Irrigation Research Site 1999 tomato weed control study.
| Treatment number | Herbicide(s) | Rate | Application timing† |
| 1 | Treflan | 1 pt | PPI |
| 2 | Tillam | 3 qts | PPI |
| 3 | Tillam | 6 qts | PPI |
| 4 | Treflan + Lexone | 1 pt + ½ lb | PPI + POST1 |
| 5 | Treflan + rimsulfuron | 1 pt + 3/8 oz | PPI + POST1 |
| 6 | Treflan + rimsulfuron | 1 pt + ¾ oz | PPI + POST1 |
| 7 | Treflan + rimsulfuron | 1 pt + 3/8 oz | PPI + POST2 |
| 8 | Treflan + rimsulfuron | 1 pt + ¾ oz | PPI + POST2 |
| 9 | Treflan + rimsulfuron + rimsulfuron | 1 pt + 3/8 oz + 3/8 oz | PPI + POST1 + POST2 |
| 10 | Treflan + Tillam + rimsulfuron | 1 pt + 3 qts + 3/8 oz | PPI + POST2 |
| 11 | Treflan + pyridate | 1 pt + 0.9 lbs | PPI + POST2 |
| 12 | Tillam + pyridate | 3 qts + 0.9 lbs | PPI + POST2 |
| 13 | Treflan + rimsulfuron + pyridate | 1 pt + 3/8 oz + 0.9 lbs | PPI + POST1 + POST2 |
| 14 | Treflan + hand weed | 1 pt | PPI + as needed |
†PPI - June 1 (one day before transplant); POST1 - June 7 (after transplant); POST2 - June 16 (weeds ¼ to ¾ inches tall).
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Table 42. Weed control ratings on June 16 in the 1999 Oakes Irrigation Research Site tomato weed control study.
| Treatment number† | Hairy nightshade | Black nightshade | Redroot pigweed | Lambs- quarters | Common purslane |
| 0 to 10‡ | |||||
| 1 | 4.0 | 9.3 | 7.3 | 9.5 | 8.8 |
| 2 | 7.3 | 9.0 | 5.3 | 8.5 | 9.0 |
| 3 | 8.8 | 8.8 | 6.3 | 8.5 | 9.3 |
| 4 | 4.8 | 9.0 | 10.0 | 10.0 | 10.0 |
| 5 | 8.5 | 8.0 | 10.0 | 9.8 | 9.5 |
| 6 | 9.3 | 8.3 | 10.0 | 9.8 | 10.0 |
| 7 | 4.3 | 9.0 | 6.8 | 9.3 | 9.0 |
| 8¶ | 5.8 | 9.0 | 7.8 | 9.5 | 8.8 |
| 9¶ | 8.8 | 8.0 | 10.0 | 10.0 | 9.8 |
| 10¶ | 7.5 | 9.0 | 8.5 | 9.8 | 9.3 |
| 11¶ | 4.3 | 9.0 | 8.3 | 10.0 | 8.8 |
| 12¶ | 7.3 | 9.3 | 7.0 | 8.5 | 8.8 |
| 13¶ | 8.0 | 8.5 | 9.8 | 9.8 | 9.3 |
| 14 | 4.8 | 9.0 | 7.8 | 10.0 | 8.5 |
| LSD (0.05) | 1.5 | 0.4 | 1.0 | 0.7 | 1.0 |
| C. V. (%) | 16 | 4 | 8 | 5 | 7 |
| Probability | 0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.04 |
†See Table 41 for description of treatments.
‡Rating are from 0 to 10 with 0 = no control; 10 = no weeds.
¶The last part (POST2) of these treatments had not been applied when these ratings were taken.
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Table 43. Weed control and crop injury ratings, and tomato and weed heights on July 1 in the 1999 Oakes Irrigation Research Site tomato weed control study.
| Treatment number† | Nightshade | Red root pigweed | Lambs- quarters | Common purslane | Crop injury | Tomato height | Weed height | |
| hairy | black | |||||||
| 0 to 10‡ | % | inches | ||||||
| 1 | 3.8 | 9.0 | 8.0 | 9.5 | 8.5 | 0 | 24.0 | 22.0 |
| 2 | 7.8 | 9.0 | 7.3 | 9.3 | 9.0 | 0 | 22.8 | 20.3 |
| 3 | 8.3 | 9.1 | 7.3 | 8.8 | 9.3 | 0 | 21.3 | 16.5 |
| 4 | 5.0 | 9.3 | 10.0 | 10.0 | 10.0 | 0 | 23.0 | 18.8 |
| 5 | 7.5 | 8.5 | 10.0 | 10.0 | 9.8 | 0 | 21.5 | 15.8 |
| 6 | 8.5 | 8.8 | 10.0 | 9.8 | 9.5 | 0 | 22.5 | 12.8 |
| 7 | 10.0 | 8.0 | 10.0 | 10.0 | 10.0 | 0 | 21.5 | 12.0 |
| 8 | 10.0 | 8.8 | 10.0 | 10.0 | 10.0 | 0 | 21.5 | 11.0 |
| 9 | 10.0 | 8.3 | 10.0 | 10.0 | 10.0 | 0 | 22.0 | 13.0 |
| 10 | 10.0 | 9.0 | 10.0 | 10.0 | 10.0 | 0 | 21.0 | 10.0 |
| 11 | 10.0 | 10.0 | 10.0 | 9.8 | 9.3 | 28 | 17.5 | 4.3 |
| 12 | 10.0 | 10.0 | 10.0 | 10.0 | 10.0 | 28 | 17.8 | 3.5 |
| 13 | 10.0 | 10.0 | 10.0 | 10.0 | 10.0 | 30 | 18.5 | 2.3 |
| 14 | 10.0 | 10.0 | 10.0 | 10.0 | 10.0 | 0 | 20.8 | 0.0 |
| LSD (0.05) | 0.7 | 0.6 | 0.5 | 0.7 | 0.5 | 4 | 1.8 | 2.4 |
C. V. (%) |
6 | 4 | 4 | 5 | 4 | 49 | 6 | 15 |
| Probability | 0.0001 | 0.0001 | 0.0001 | 0.023 | 0.0001 | 0.0001 | 0.0001 | 0.0001 |
†See Table 41 for description of treatments.
‡Rating are from 0 to 10 with 0 = no control; 10 = no weeds.
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Table 44. Weed control ratings on July 16 in the 1999 Oakes Irrigation Research Site tomato weed control study.
| Treatment number† | Hairy nightshade | Black nightshade | Red root pigweed | Lambs- quarters | Common purslane | Grasses |
| 1 to 10‡ | ||||||
| 1 | 1.0 | 9.6 | 6.8 | 9.1 | 10.0 | 9.5 |
| 2 | 6.0 | 6.5 | 6.6 | 7.0 | 10.0 | 9.9 |
| 3 | 7.0 | 6.0 | 7.0 | 8.4 | 9.4 | 10.0 |
| 4 | 0.8 | 8.8 | 9.3 | 9.9 | 10.0 | 9.8 |
| 5 | 6.0 | 5.0 | 9.4 | 9.4 | 9.8 | 10.0 |
| 6 | 8.4 | 5.8 | 9.9 | 9.3 | 9.6 | 10.0 |
| 7 | 10.0 | 4.8 | 10.0 | 9.9 | 10.0 | 10.0 |
| 8 | 10.0 | 6.0 | 10.0 | 10.0 | 10.0 | 10.0 |
| 9 | 10.0 | 5.8 | 10.0 | 10.0 | 10.0 | 10.0 |
| 10 | 10.0 | 6.3 | 10.0 | 9.9 | 9.9 | 10.0 |
| 11 | 9.3 | 9.4 | 9.6 | 9.5 | 5.5 | 9.0 |
| 12 | 9.1 | 9.5 | 9.5 | 9.3 | 7.3 | 9.6 |
| 13 | 9.8 | 9.1 | 10.0 | 9.5 | 9.4 | 10.0 |
| 14 | 10.0 | 10.0 | 10.0 | 10.0 | 10.0 | 10.0 |
LSD (0.05) |
1.3 | 1.6 | 0.7 | 0.7 | 0.7 | 0.3 |
C. V. (%) |
12 | 15 | 5 | 5 | 6 | 2 |
Probability |
0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.0001 |
†See Table 41 for description of treatments.
‡Rating are from 0 to 10 with 0 = no control; 10 = no weeds.
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Table 45. Yields of tomatoes harvested August 23 & 24 in the 1999 Oakes Irrigation Research Site tomato weed control study.
| Treatment number† | Marketable yield | Total yield | Red size | Percent of total yield | |||
| red | mature green | total | red | mature | |||
| tons/acre | oz/fruit | % | |||||
| 1 | 2.7 cd‡ | 6.8 fg | 9.5 g | 12.0 h | 2.8 | 24 ab | 81 |
| 2 | 3.8 abc | 6.0 g | 9.8 fg | 15.2 gh | 2.9 | 30 a | 70 |
| 3 | 3.5 abc | 11.8 d-g | 15.3 d-g | 18.7 fgh | 2.8 | 19 bc | 83 |
| 4 | 2.5 cde | 9.9 efg | 12.3 efg | 16.7 fgh | 3.0 | 16 cd | 75 |
| 5 | 3.0 a-d | 12.8 d-g | 15.8 d-g | 20.3 efg | 3.3 | 17 c | 77 |
| 6 | 2.8 bcd | 15.1 cde | 17.9 def | 24.1 def | 2.9 | 13 cd | 76 |
| 7 | 3.4 abc | 14.5 de | 17.9 def | 22.5 d-g | 2.9 | 16 cd | 81 |
| 8 | 4.3 a | 22.5 bc | 26.8 bc | 32.8 bc | 3.4 | 13 cd | 80 |
| 9 | 3.5 abc | 13.8 def | 17.3 d-g | 22.7 d-g | 3.2 | 16 cd | 76 |
| 10 | 3.6 abc | 19.7 cd | 23.3 bcd | 27.6 cde | 3.2 | 13 cd | 85 |
| 11 | 1.1 ef | 17.5 cd | 18.6 cde | 30.0 bcd | 3.1 | 4 e | 62 |
| 12 | 1.0 f | 18.3 cd | 19.3 cde | 28.5 cd | 2.9 | 4 e | 69 |
| 13 | 1.5 def | 28.1 ab | 29.6 ab | 38.2 ab | 3.1 | 4 e | 77 |
| 14 | 4.2 ab | 31.8 a | 36.0 a | 46.6 a | 3.3 | 9 de | 77 |
C. V. (%) |
33 | 32 | 30 | 22 | 11 | 34 | 19 |
Probability |
0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.25 | 0.0001 | 0.71 |
†See Table 41 for description of treatments.
‡Values in the same column followed by the same letter are not significantly different at the 0.05 level. If no letters in a column, there are no significant differences between values in that column.
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Table 46. Yields of tomatoes harvested September 13 & 14 in the 1999 Oakes Irrigation Research Site tomato weed control study.
| Treatment number† | Marketable yield | Total yield | Red size | Percent of total yield | |||
| red | mature green | total | red | mature | |||
| tons/acre | oz/fruit | % | |||||
| 1 | 9.4 g‡ | 2.1 g | 11.5 h | 13.2 g | 3.0 de | 71 ab | 87 |
| 2 | 12.3 efg | 2.7 g | 15.0 gh | 17.1 fg | 3.0 de | 74 ab | 89 |
| 3 | 11.6 fg | 5.2 fg | 16.7 gh | 19.0 fg | 2.8 e | 65 bcd | 91 |
| 4 | 11.3 fg | 1.9 g | 13.3 h | 15.0 g | 3.1 cde | 78 a | 91 |
| 5 | 18.0 cd | 5.1 fg | 23.1 efg | 26.1 def | 3.1 cde | 70 ab | 89 |
| 6 | 13.3 d-g | 5.6 fg | 18.9 fgh | 21.6 efg | 3.0 de | 66 bc | 89 |
| 7 | 19.2 c | 7.7 efg | 27.0 ef | 30.0 de | 3.1 cde | 65 bcd | 90 |
| 8 | 25.9 b | 12.5 de | 38.3 bc | 42.5 bc | 3.2 b-e | 63 bcd | 91 |
| 9 | 16.4 c-f | 13.1 de | 29.5 cde | 33.8 cd | 3.1 b-e | 51 e | 89 |
| 10 | 18.0 cd | 10.8 ef | 28.8 de | 32.2 cde | 3.4 a-d | 58 cde | 91 |
| 11 | 16.0 c-f | 21.8 bc | 37.8 bcd | 47.7 b | 3.7 a | 34 f | 80 |
| 12 | 16.5 cde | 24.3 b | 40.8 b | 48.5 b | 3.5 abc | 35 f | 85 |
| 13 | 18.1 c | 35.2 a | 53.3 a | 60.6 a | 3.7 a | 30 f | 88 |
| 14 | 34.7 a | 17.9 cd | 52.6 a | 65.7 a | 3.6 ab | 56 de | 82 |
C. V. (%) |
19 | 37 | 22 | 22 | 10 | 12 | 6 |
Probability |
0.0001 | 0.0001 | 0.0001 | 0.0001 | 0.003 | 0.0001 | 0.10 |
†See Table 41 for description of treatments.
‡Values in the same column followed by the same letter are not significantly different at the 0.05 level. If no letters in a column, there are no significant differences between values in that column.
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