Cheatgrass Biology, Ecology, and Management

Transcription

1 Cheatgrass Biology, Ecology, and Management Fabián Menalled Montana State

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4 Presentation Outline Biology and identification of brome species Weedy characteristics Management considerations (crops)

5 Terminology For Brome Species Cheatgrass - Downy brome - Bromus tectorum Japanese brome Bromus japonicus Cheat Bromus secalinus Not found in MT

6 Cheatgrass Japanese brome

7 Japanese brome Cheatgrass Pictures from Interactive Encyclopedia of North American Weeds

8 Japanese brome Cheatgrass More hairy, longer hairs, especially on underside of leaf Pictures from Interactive Encyclopedia of North American Weeds

9 Japanese brome Taller ligule and more serrated ligule Cheatgrass Photos: courtesy of Dr. Phil Stahlman, KSU

10 Cheatgrass Wheat Membranous Ligule Auricules

11 Cheatgrass is a winter annual (but can behave as a summer annual)

12 Annuals Seed Reproductive growth Vegetative growth Flower

13 Summer Annuals Seed Spring Reproductive growth Vegetative growth Fall Flower Wild oat

14 Winter Annuals Seed Spring Fall Reproductive growth Vegetative growth Summer Fall Flower Cheatgrass

15 Perennials Seed Reproductive growth Vegetative growth Foxtail barley Flower

16 Presentation Outline Biology and identification of brome species Weedy characteristics Management considerations (crops)

17 Cheatgrass in Montana CRP Crops Rangeland Urban

18 Why Annual Bromes Are Increasing? Reproductive success Conservation tillage Increased fertilization Shorter, less competitive crops Drought years CRP

19 Cheatgrass Reproduction Up to seeds/plant Short soil seed life (2-3 yrs.) Dispersed by wind, contaminated straw, farm machinery, etc

20 Photo courtesy of L. Ziegenhagen, USDA-ARS

21 Why Annual Bromes Are Increasing? Reproductive success Conservation tillage Increased fertilization Shorter, less competitive crops CRP Fires drought conditions

22 Presentation Outline Biology and identification of brome species Weedy characteristics Management considerations (crops)

23 Questions, so far?

24 Management

25 Management

26 Herbicide Options

27 Herbicide Performance Stress reduces herbicide effectiveness Affected by moisture & temperature Risk of crop injury (cold temperatures) Low density weed populations are more easily controlled than high density populations Risk of resistance

28 Cross Resistance to ALS herbicides - Kansas - Resistant Cheatgrass Susceptible Cheatgrass Resistant J. Brome Susceptible J. Brome Olympus 0.9 oz Olympus 9 oz Maverick 0.67 oz Beyond 4 oz PowerFlex 3.5 oz Control D. Peterson KSU

29 Management Resource management

30 No. or lb/acre N Placement on Cheatgrass Wyoming Bdcst Band Plants Dry wt. Downy brome Miller 1990

31 Management Resource management Crop variety Row spacing Seeding density

32 Wheat yield (Bu/A) Row Spacing and Seeding Rate 20 site-years in Oklahoma lb/a lb/a lb/a Row spacing lb/a ---- (inches) Weed Free Cheatgrass Epplin et al. 1996

33 Cultivar Competitiveness Cultivars vary widely in their competitiveness with weeds Plant height associated with increased competitiveness Early plant growth, tillering ability, and leaf area also are important

34 Management Crop rotation Resource management Crop variety Row spacing Seeding density

35 Cheatgrass density (no. m -2 ) Crop Rotation and Cheatgrass Density Year Wheat-canola, no-till Continuous wheat, no-till Wheat-canola, till Continuous wheat, till (After Blackshaw 1994)

36 Crop Safety?

37 Pea field in north central MT Photo Courtesy P. Miller

38 Can We Manage Cheatgrass with SU Herbicides and Rotate Crops? Vs. sulfosulfuron Pyroxsulam

39 PowerFlex Broadleaf weed control kochia, prickly lettuce, wild mustard, tansy mustard, corn gromwell, catchweed bedstraw, common lambsquarters, field pennycress, tumble mustard, henbit Grass weed control Wild oat, cheatgrass, Japanese brome, cheat

40 Crop Rotation Study Herbicide application: May 16, 2007 Crop: winter wheat Stage: Tiller Rotational crops: lentil, chickpea, safflower, field pea, camelina, flax Planting date: Spring No-till Environment: prone to soil carryover with group 2 herbicides

41 FLAX CAMELINA PEA PowerFlex 2X Maverick 1X Maverick 2X PowerFlex 1X

42 CHICKPEA FLAX CAMELINA PEA LENTIL SAFFLOWER PowerFlex 2X Maverick 2X

43 GoldSky Pyroxsulam (PowerFlex) ALS inhibitor Fluroxypyr (Starane) Synthetic auxin Florasulam ALS, AHAS enzyme inhibitor Crop safener Spring wheat product Federal registration: August 2008

44 GoldSky Broadleaf weed control kochia, prickly lettuce, wild buckwheat, wild mustard, Russian thistle, Redroot pigweed, tansy mustard, corn gromwell, catchweed bedstraw, common lambsquarters Grass weed control Wild oat, yellow foxtail, Italian ryegrass, green foxtail, brome species

45 CAMELINA BARLEY CANOLA OAT LENTIL PEA GOLDSKY Crop Rotation Study

46 Visual Damage (%) Lentil Canola Camelina Barley Field Pea Oat GoldSky 1X Goldsky 2X Everest 1x Everest 2x Rimfire 1x Rimfire 2x

47 Management Crop rotation Time of emergence Resource management Crop variety Row spacing Seeding density

48 Relative Time of Control In good stands with adequate resources, low to moderate infestations of cheatgrass that emerge 3 weeks or later than winter wheat do not reduce yield Blackshaw 1996 Stahlman and Miller 1990

49 Relative Time of Emergence

50 Crop rotation Time of emergence Management Time of control Resource management Crop variety Row spacing Seeding density

51 Is Application Timing Important?

52 Bozeman Huntley PowerFlex + Agral 90 + Ammonium sulfate 18.4 g ai/ha + 0.5%v/v kh/ha Olympus + Agral g ai/ha + 0.5%v/v Maverick + Agral g ai/ha + 0.5%v/v Early Fall Late Fall Early Spring Late Spring

53 Cheatgrass Control, Bozeman Fall Spring Fall Spring Fall Spring PowerFlex Olympus Maverick

54 Cheatgrass Control, Huntley Fall Spring Fall Spring Fall Spring PowerFlex Olympus Maverick

55 Integrated Management Weed Management Crop rotation Time of emergence Time of control Resource management Crop variety Row spacing Seeding density

56 Take Home Message Although herbicides provide good control of cheatgrass, you must develop an Integrated Weed Management (IWM) strategy to reduce the spread and impact of this species

57 Questions?