1 / 53

Weed Control in Green Peas

Weed Control in Green Peas. Tim Miller WSU Mount Vernon NWREC. Positive Attributes of Green Peas. Many herbicides available Densely-growing crop competes well with weeds Short-season crop Lower soil N may decrease weed growth.

hewitt
Download Presentation

Weed Control in Green Peas

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Weed Control in Green Peas Tim Miller WSU Mount Vernon NWREC

  2. Positive Attributes of Green Peas • Many herbicides available • Densely-growing crop competes well with weeds • Short-season crop • Lower soil N may decrease weed growth

  3. Preplant-incorporated Herbicides Available for Use in Green Peas • Treflan (trifluralin) • Far-Go (triallate) • Buckle (trifluralin + triallate) • Pursuit (imazethapyr) • Prowl (pendimethalin) • Sharpen (saflufenacil)

  4. Preemergence Herbicides Available for Use in Green Peas • Pursuit (imazethapyr) • Prowl (pendimethalin) • Dual Magnum (s-metolachlor) • Command (clomazone) • Sencor (metribuzin) • Sharpen (saflufenacil)

  5. Postemergence Herbicides Available for Use in Green Peas • Pursuit (imazethapyr) • Sencor (metribuzin) • MCPA • MCPB • Basagran (bentazon) • Poast (sethoxydim) • Assure II (quizalofop)

  6. Green Pea Studies • Competitive Ability of Green Pea • Reduced Rate Herbicide Trials • Stale Seedbed Trials • Spartan and Chateau Trials (if there is time…)

  7. Pea Interference Study • 'Charo' green pea • Weeds removed from plots at weekly intervals and kept weed-free until harvest • 1, 2, 3, 4, 5, and 6 weeks after emergence • Weedy and weed-free plots

  8. Pea Density and Pea Weight2001-03

  9. Pod Production and Pea Yield2001-03

  10. Pea Interference Studies • Pea plant density slightly reduced by weed interference • Pea size not reduced by duration of weed interference, but pod number decreased • No yield loss if weeds were controlled by 5 weeks after emergence

  11. Reduced Rate Herbicide Trials2001-03 • ‘Snake’ pea seeded early May • PRE herbicides applied shortly after seeding • POST herbicides applied late May to early June • Weed control and crop injury estimated • Peas and weeds harvested in late July/early August • Sampling within a 1 m2 quadrat • Pea yield and plant biomass calculated • Weed biomass calculated • Seeds from weeds germinated in the greenhouse

  12. Reduced Rate Herbicide Trials • Tested herbicides were: • Command, PRE • Sencor, PRE and POST • Basagran, POST • MCPA, POST • Various combinations of these products were tested at various rates

  13. Reduced Rate Herbicide Trials • Six “full rate” treatments: • Command (1.3 pt/a, PRE) • Sencor (5.3 oz/a, PRE) • Sencor (2.7 oz/a, POST) • MCPA (8 fl. oz/a, POST) • Basagran (1.5 pt/a, POST) • Command + Basagran (1.3 pt/a + 1.5 pt/a, PRE + POST)

  14. Reduced Rate Herbicide Trials • 14 “partial rate” treatments: • Command (11 fl. oz/a, PRE) • Sencor (2.7 oz/a, PRE) • Sencor (1.3 oz/a, POST) • MCPA (4 fl. oz/a, POST) • Basagran (12 fl. oz/a, POST)

  15. Reduced Rate Herbicide Trials • 14 “partial rate” treatments (cont.): • Command + Sencor • 5.4 fl. oz/a + 1.3 oz/a, PRE • Command + Sencor • 5.4 fl. oz/a + 0.7 oz/a, PRE + POST • Command + Basagran • 5.4 fl. oz/a + 12 fl. oz/a, PRE + POST • Command + MCPA • 5.4 fl. oz/a + 2 fl. oz/a, PRE + POST

  16. Reduced Rate Herbicide Trials • 14 “partial rate” treatments (cont.): • Sencor + Basagran • 1.3 oz/a + 12 fl. oz/a, PRE + POST • Sencor + MCPA • 1.3 oz/a + 2 fl. oz/a, PRE + POST • Sencor + Basagran • 0.7 oz/a + 12 fl. oz/a, POST • Sencor + MCPA • 0.7 oz/a + 2 fl. oz/a, POST • Basagran + MCPA • 12 fl. oz/a + 2 fl. oz/a, POST

  17. Pea Yield2001-03 tons/a a a ab ab ab g

  18. Biomass Returned to the Field2001-03 tons/a abc a ab ab abc bcd ghi hij g ij ij j

  19. Pea:Weed Biomass Ratios • Divide the pea biomass by the weed biomass • If ratio is >1.0, more pea residue than weeds returned • If ratio is <1.0, more weeds than peas returned

  20. Pea:Weed Biomass Ratio2001-03 a b cd bc d d

  21. Common Lambsquarters Germination Counts2002 only weeds/m2

  22. Pineappleweed Germination Counts2002 only weeds/m2

  23. Shepherd’s-purse Germination Counts2002 only weeds/m2

  24. Reduced Rate Herbicide Trial—Total Weed Seed Germination Counts weeds/m2

  25. Reduced Rate Herbicide Trial—Total Weed Seed Germination Counts weeds/m2

  26. Reduced Rate Herbicide Trial—Total Weed Seed Germination Counts weeds/m2

  27. Weed Seed Germination • So in this case, return of weed seed to field would have resulted in: • Command + Basagran (PRE + POST) • 3 weeds/m2 (12,000/acre) • Sencor (PRE) • 469 weeds/m2 (1.9 million/acre) • Untreated check • 8055 weeds/m2 (32.6 million/acre)

  28. Reduced Rate Herbicide TrialConclusions, 2001-03 • All herbicide treatments resulted in at least 2 tonsof harvested peas/a (6 full rates, 14 partial rates) • Based on dry biomass production, only 8 of 20 treatments adequately controlled weeds (4 full rates, 4 partial rates) • Weed dry biomass in the remaining 12 treatments exceeded pea dry biomass • Even in a short-season crop like green peas, only 1 of 20 treatments prevented tremendousreturn of weed seed to the field (full rate of Command + Basagran)

  29. Stale Seedbed Allow weed seeds to germinate, then kill them with herbicide or flame prior to crop emergence

  30. Stale Seedbed Trial Overview2007-09 • Seedbed preparation: • Two weeks prior to seeding (14 d) • One week prior to seeding (7 d) • Three days prior to seeding (3 d) • Same day as seeding (0 d) • Seeding dates (‘Snake’) • 5/2507, 7/1/08, and 5/21/09

  31. Stale Seedbed Trial Overview2007-09 • PREPO treatments (PRE to pea, POST to weeds): • Glyphosate (1 lb ae/a, 2 pt/a) • Paraquat (0.75 lb ai/a; 2.4 pt/a) • Glufosinate (0.5 lb ai/a; 4 pt/a) • Pyraflufen (0.004 lb ai/a; 2.5 fl.oz/a) • Flame (propane, open flame) • None

  32. Stale Seedbed Trial Overview2007-09 • PRE treatments (residual herbicides applied at same time as the PREPO treatments): • Command (0.5 lb ai/a; 1.3 pt/a) • Prowl H2O (1.52 lb ai/a; 3.2 pt/a) • Sencor (0.38 lb ai/a; 8.1 oz/a) • None

  33. Stale Seedbed Trial Overview2007-09 • Herbicide/flame application dates (days after seeding) • 2007: 8 days • 2008: 5 days • 2009: 16 days • Years were significantly different, so data are presented separately by year

  34. Stale Seedbed Trial2007 Results • Weed control at 21 DAT generally good at all seedbed timings • Glyphosate, 93 to 95% • Paraquat, 94% • Glufosinate, 86 to 94% • Pyraflufen, 54% (14 d); 71 to 86% • Flame, 70% (14 d); 83 to 88% • None, 0% (14 d); 60 to 76% • By harvest, weed control was poor to good

  35. Weed Control At Pea HarvestJuly, 2007 % 67% 83% 80% 78%

  36. Stale Seedbed Trial2008 Results • Green pea vine and pod fresh weight were not greatly affected by herbicide choice (ranged from 3.46 kg/m2 for no herbicide to 3.90 kg/m2 for glyphosate) • Seedbed timing made no significant difference on green pea vine and pod fresh weight (3.54 to 3.79 kg/m2)

  37. Weed Control At Pea Harvest September, 2008 % 86% 83% 86% 79%

  38. Stale Seedbed Trial2009 Results • Peas in stale seedbeds prepared 14 days prior to seeding were injured up to 70% by initial POST herbicides and flame (shallower seeding in firm seedbeds?) • Pea vine and pod weight was reduced the most by glyphosate and paraquat • Residual products provided 85 to 89% weed control, better than the 81% resulting when no residual product was used • Green pea vine and pod fresh weight were not greatly affected by residual herbicide choice (about 2.8 kg/m2)

  39. Weed Control At Pea HarvestJuly, 2009 % 97% 96% 53% 94%

  40. Stale Seedbed Conclusions2007-09 • Weed control was generally good regardless of herbicide choice or flame • In 2007, flame and pyraflufen performed worse than other herbicides, particularly with 14 d seedbed • Ranged from 75 to 89% among all treatments in 2007-08 and from 80 to 99% in 2009 • Injury was 70% for 14 d seedbeds in 2009, and was worse with glyphosate and paraquat on those seedbeds in 2009 • Green pea did not respond greatly to seedbed timing any year • Weed control was slightly improved with 0 to 7 d seedbeds compared to 14 d seedbeds

  41. Spartan and Chateau Trial2003 • Two newer soybean herbicides with good nightshade activity and were tested for selectivity in pea • Spartan (sulfentrazone, FMC) • Chateau (flumioxazin, Valent) • Tests conducted in Mount Vernon, Paterson (Rick Boydston), and Pullman (Joe Yenish) on green peas, dry peas, lentils, and chickpeas

  42. Spartan and Chateau Trial • Mount Vernon trial, 2003 • ‘Snake’ pea seeded May 6 • Herbicides applied alone and at 4 rates each June 4, as well as in mixture with Prowl or Dual Magnum at 2 rates each • Weed control and crop injury estimated • Peas and weeds harvested in late July • Sampling within a 1-m2 quadrat • Pea yield calculated

  43. Common Lambsquarters Counts Chateau weeds/m2 Counted 14 days after treatment

  44. Common Lambsquarters Counts Spartan weeds/m2 Counted 14 days after treatment

  45. Mount Vernon Results • No significant difference in weed control • No significant difference in pea injury • No significant difference in pea yield

  46. Spartan and Chateau Trial • Paterson trial, 2003 • ‘Snake’ pea seeded April 21 • Herbicides applied April 25 at same rates and combinations as at Mount Vernon • Weed control and crop injury estimated • Peas and weeds harvested in late July • Sampling within a 1-m2 quadrat • Pea yield calculated

  47. Pea Injury Chateau % Injury 35 days after treatment

  48. Pea Yield Chateau tons/a

  49. Pea InjurySpartan % Injury 35 days after treatment

  50. Pea YieldSpartan tons/a

More Related