FORB RESPONSE TO HERBICIDES FOR SEED PRODUCTION AND RANGELAND RESTORATION. Corey Ransom

Transcription

1 FORB RESPONSE TO HERBICIDES FOR SEED PRODUCTION AND RANGELAND RESTORATION Corey Ransom

2 Objective Seed Production Identify herbicides for weed management in forb seed production. - Astragalus filipies - Dalea ornata - Dalea searlsiae

3 Herbicide Tolerance Trials, 2011 Field trials at USU research farm Planted: 8 lb PLS/acre Acid scarified and mixed with corn hulls Planter: Hege coneseeder Plots size: 5 ft by 30 ft replicated 4 times Applications: CO 2 - backpack sprayer, 20 GPA at 30 psi Astragalus filipies -Basalt Milkvetch Dry River germplasm Dalea ornata - Western Prairie Clover Aridlands germplasm

4 Postemergence Herbicides Astragalus filipies Herbicide lb ai/a Rates product 2,4-DB pt 2,4-DB pt Basagran + COC pt Buctril pt 2,4-DB + Buctril pt Paramount + COC oz Pursuit + COC oz Raptor + COC oz Raptor + Basagran + COC oz pt Planted October 18, Treated June 21, Evaluated 36 days after treatment. COC at 1.0 pt/acre

5 Astragalus filipies injury and density change in response to postemergence herbicides. Evaluations 36 DAT Density Treatment Rate Injury reduction lb ae/or ai/a Untreated ,4-DB ,4-DB Bentazon + COC Bromoxynil ,4-DB + bromoxynil Quinclorac + MSO Imazethapyr + COC Imazamox + COC Imazamox + bentazon + COC % LSD (0.05) 14.7 NS COC at 1.0 pt/acre

6 Challenges of plant persistence appear to be independent of herbicide treatment! Need to better understand seedling survival.

7 Postemergence Herbicides Dalea ornata Herbicide Rates lb ai/a product 2,4-DB pt Basagran + COC pt Buctril pt 2,4-DB + Buctril pt Pursuit + COC oz Raptor + COC oz Raptor + Basagran + COC oz pt COC at 1.0 pt/acre Planted June 15, Application made August 19. Injury evaluated 22 days after treatment.

8 Dalea ornata injury, plant density increase, and flowering in response to postemergence herbicides. Evaluations 22 DAT Density Treatment Rate Injury increase Flowers lb ae/or ai/a % no/plot Untreated ,4-DB Bentazon + COC Bromoxynil ,4-DB + bromoxynil Imazethapyr + COC Imazamox + COC Imazamox + bentazon COC LSD (0.05) NS NS NS COC at 1.0 pt/acre

9 Preemergence Treatments on Dalea ornata Herbicide lb ai/a Rates Product Prowl H2O pt Prowl H2O pt Prowl H2O lb Outlook pt Nortron pt Several plots treated with Prowl H 2 O at 2.1 pt for combination with postemergence treatments Planted August 26, Sprayed August 27, Densities counted October 13, 2011.

10 Dalea ornata plant densities in response to preemergence applied herbicides following August 26, 2011 planting. Treatment Rate Plant density lb ai/a no/plot Untreated Pendimathalin Pendimathalin Pendimathalin Pendimathalin Pendimathalin Pendimathalin Dimethenamid-p Ethofumesate LSD (0.05) NS

11 Preemergence Herbicide Effects on Weed Pressure, August 26, 2011 planting. Untreated Pendimethalin 1.5 lb ai/acre Dimethenamid-p 0.75 lb ai/acre Ethofumesate 1.0 lb ai/acre

12 Visible Injury from Preemergence Herbicides on October 10, Untreated Pendimethalin 1.5 lb ai/acre Dimethenamid-p 0.75 lb ai/acre Ethofumesate 1.0 lb ai/acre

13 Conclusions of Herbicide Trials Astragalus filipies and Dalea ornata appear to be tolerant to several postemergence herbicides. All preemergence treatments caused visible injury. No herbicide treatments reduced stand. Seed yield and viability needs to be evaluated to demonstrate herbicide utility.

14 Objective Rangeland Restoration Evaluate native species response to herbicides applied to control downy brome. How will they handle exposure to these herbicides after seeding?

15 Initiation of Field Establishment Trial, 2009 Nephi, UT Application timings: Spring and Fall 2009 Herbicides: Plateau 1, 2, 4, 6, 8, 10, and 12 fl oz Olympus, Outrider, Matrix, Oust Planting timings: Fall 2009

16 Initiation of Field Establishment Trials, 2009 Species planted at Nephi: Silky lupine Lupinus sericeus Globe mallow Sphaeralcea Sulfur flower BW Eriogonum umbellatum Big blue penstemon Penstemon cyaneus Prairie clover Dalea ornata Searle s Prairie Clover Dalea searlsie Utah sweetvetch Astragalus filipies Anatone Bluebunch wheatgrass Sherman Big bluegrass

17 Basalt Milkvetch Establishment 8 Spring Fall 6 Plants (no/plot) UNTR PLAT PLAT PLAT PLAT 0.94 PLAT PLAT 0.16 PLAT 0.19 OLYMPUS OUTRIDER MATRIX OUST Herbicide

18 Basalt Milkvetch Establishment 8 7 Plants (no/plot) Fall Spring Imazapic rate (lb ai/acre)

19 Conclusions Limited data demonstrates that germination will be influenced by herbicides applied to control downy brome A greater understanding of individual species tolerance and herbicide dissipation rated in different soils are needed

20 Support: Great Basin Native Plant Selection and Increase Project

21 Silky Lupine Establishment 5 4 Spring Fall Plants (no/plot) UNTR PLAT PLAT PLAT PLAT 0.94 PLAT PLAT 0.16 PLAT 0.19 OLYMPUS OUTRIDER MATRIX OUST Herbicide

22 Grass?? Establishment Spring Fall Plants (no/plot) UNTR PLAT PLAT PLAT PLAT 0.94 PLAT PLAT 0.16 PLAT 0.19 OLYMPUS OUTRIDER MATRIX OUST Herbicide