Weed IPM (IWM) K. Neil Harker Agronomy Update Jan. 18, 2012

Transcription

1 Weed IPM (IWM) K. Neil Harker Agronomy Update Jan. 18, 2012

2 IPM Definition a decision-based process involving coordinated use of multiple tactics for optimizing the control of all classes of pests (insects, pathogens, weeds, vertebrates) in an ecologically and economically sound manner. R. J. Prokopy Agric. Ecosyst. Environ. 94:

3 Weed Control Tactics Chemical (herbicides, biofumigants, etc.) Physical (tillage, flaming, blasting, etc.) Cultural (clean seed, diverse crop rotation, competitive crops, etc.) Biological (classical insects, inundative pathogens)

4 Weed IPM (IWM) - rather idealistic Chemical Biological Physical Cultural

5 Weed IPM (IWM) - most common combination Chemical Cultural

6 The Other IWM Herbicide Management PRE POST 3 MOAs Tankmixing

7 Real IWM Ehler (2006) Pest Manag. Sci. 62: Is NOT just tank-mixing herbicides (the Other IWM ) Is NOT just rotating herbicide modes of action (the Other IWM ) Is NOT just applying PRE herbicides before POST herbicides (the Other IWM ) Is using non-herbicide tools in addition to herbicides (Real IWM)

8 We have incredible cultivars, hybrids, herbicides, fungicides, & insecticides! Who needs IPM?

9 The Other IPM In the U.S. we are putting 150 Million Pounds of Glyphosate on 100 Million Acres of Cropland every year. What do you think is going to happen? John Wilcut, NC State (2007)

10 GR Palmer Amaranth in Tennessee - An example of the Other IPM 4 fields of continuous cotton for 6 yr (Steckel et al Weed Technol. 22: ) Herbicide regime Preseed Burn-off: Gly (0.84 kg/ha) + dicamba 1 st In-crop: Gly (0.84 kg/ha) early POST 2 nd In-crop: Gly (0.84 kg/ha) prior to 5 leaves 3 rd In-crop: Gly (0.84 kg/ha) + diuron POST-directed (PD) Some years 4 th In-crop: Gly (0.84 kg/ha) + diuron PD All 4 fields with 2x to 4x rate Palmer amaranth resistance to glyphosate Palmer amaranth populations in Georgia are confirmed resistant to 12x rates of glyphosate (Culpepper et al Weed Sci. 54: ) and now, much more!

11 Glyphosate-Resistant Weeds USA Lolium multiflorum Italian ryegrass (3) Kochia scoparia Kochia (1) Lolium rigidum Rigid ryegrass (1) Echinochloa colona Junglerice (1) # GR Biotypes CA OR Amaranthus tuberculatus (syn. rudis) Tall waterhemp (7) WA NV ID AZ UT Conyza bonariensis Hairy fleabane (1) MT WY NM CO ND SD NE KS TX OK Sorghum halepense Johnsongrass (3) MN IA MO AR LA Ambrosia artemisiifolia Common ragweed (7) WI IL MS IN TN MI AL KY OH GA WV Amaranthus palmeri Palmer amaranth (12) SC PA VA NC FL NY VT NH CT RI NJ DE MD Poa annua Annual bluegrass (1) ME MA Ambrosia trifida Giant ragweed (9) Conyza canadensis Horseweed (20) Eleusine indica Goosegrass (2) - adapted from (Sep 27, 2011)

12 Ontario ALS Inhibitors 4 - Synthetic auxins 5 - PS II Inhibitors - Triazines 6 - PS II Inhibitors - Nitriles 7 - PS II Inhibitors - Ureas 9 - Glycines 22 - Bipyridiliums Giant ragweed Ambrosia trifida

13 Ontario ALS Inhibitors 4 - Synthetic auxins 5 - PS II Inhibitors - Triazines 6 - PS II Inhibitors - Nitriles 7 - PS II Inhibitors - Ureas 9 - Glycines 22 - Bipyridiliums Horseweed Conyza canadensis

14 Alberta ACCase Inhibitors 2 - ALS Inhibitors 3 - Dinitroanilines 4 - Synthetic auxins 8 - Thiocarbamates 9 - Glycines Kochia Kochia scoparia

15 Some REAL IWM Careful seeding & fertilizing Using competitive crop cultivars Early TWR Crop diversity & rotation Combining optimal agronomics Careful harvesting

16 Careful Seeding

17 Canola Emergence & IWM? Hybrid 4 mph 1 cm Hybrid 4 mph 4 cm IWM is careful seeding A 2 nd Herbicide Application is much more likely to be needed here June 7 Photo (April seeded)

18 Careful Fertilizing During Seeding Barley Cover - June 20, 2002 Trt 13; Plot % 90 kg/ha N in seed row Trt 17; Plot % 90 kg/ha N pre plant band (seeding rate = 300 seeds/m2, seeding date = May 20)

19 Cultivar Differences Both plots treated with - imazethapyr / imazamox at 3-4 Leaf pairs Leafy Grande Harker et al. (2008) Weed Technol. 22: Semi-leafless Carrera

20 Dandelion Germination - with 2 light sources % Diffuse Light Plant Canopies Days after Exposure T. Górski Germination of seeds in the shadow of plants. Physiol. Plant 34: rhubarb, rye, barley, dense currant, and wild shrubs canopies

21 Lacombe Plots - Cool/Moist Site-Year July 24, 2006 Vivar Barley

22 Lacombe Plots - Cool/Moist Site-Year July 24, 2006 IWM is planting competitive cultivars 45H21 RR Canola Hybrid

23 Early TWR

24 Time of Weed Removal - Canola Yield (bu/ac) to 2 3 to 5 6 to 7 Canola Leaf Stage Means of 10 western Canada locations CCC Agronomists - large-scale plots (9 x 122 m) in grower fields Harker et al Weed Technol. 22:

25 Waiting to Spray $ lost / half section 6-7 Leaf $650/t 3-5 Leaf $250/t $ Lost

26 Combining Optimal Agronomics

27 ICM Crop Health - Factors 3 Locations: Lacombe, Beaverlodge, Brandon Rotation Continuous Barley or B-C-B-P Varieties/Cultivars Short ( Peregrine or Vivar ) Tall ( AC Bacon or AC Lacombe ) Seeding Rate 1X or 2X (200 or 400 seeds/m 2 ) Herbicide Rate ¼, ½, or 1X (ACCase or ALS) Treatments applied to same plots year after year cumulative treatment effects

28 Year 5

29 Wild Oat BM Maturity ¼ X Rate 2005 (3-site means after 5 years) 2000 kg/ha Continuous Rotation 82 LSD (0.05) = 614 Short 200 Tall 200 Short 400 Tall 400

30 Combining Optimal Factor Synergy - Wild oat biomass Reduction # Factors Description (x) Mean 1 1x to 2x 2.9 Short to Tall 1.9 Cont to Rot x-Short to 2x-Tall 6.3 1x-Cont to 2x-Rot 7.7 Short-Cont to Tall-Rot x-Short-Cont to 2x-Tall-Rot Harker et al Weed Sci. 57:

31 August 23, 2005 IWM is combining optimal agronomics - Short seeds - B-B-B-B-B - ¼ Rate Tall 400 seeds B-C-B-P-B ¼ Rate

32 Careful Harvesting IWM?

33 Seed Losses (#/m 2 ) Location Averages 7000 Error bars are S.E.s Edmonton Lacombe Saskatoon Winnipeg

34 Yield Loss (bu/ac) Location Averages Error bars are S.E.s Edmonton Lacombe Saskatoon Winnipeg

35 Combine Type Comparison 3 - Lost seed (bu/ac) ANOVA P value = Error bars are S.E.s Conventional (22) Rotary (50) Hybrid (4)

36 Summary Using different herbicides is NOT IWM Using herbicides in addition to the following practices is IWM Seeding & fertilizing carefully Growing competitive cultivars Early TWR Combining optimal agronomics Harvesting carefully Etc.

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