Update on Impatiens Downy Mildew

Transcription

1 Update on Impatiens Downy Mildew Jan Couch Territory Manager Syngenta Flowers, Home & Garden

2 Impatiens are popular plants in the landscape Rechcigl Rechcigl 2

3 Historical Background Plasmopara obducens present in the US since late 1800 s Reported on Impatiens pallida and I. capensis (native species of N. America) First reported as problem in UK (2003) Often a devastating disease outside of North America Found in US greenhouse production in spring of reports included locations in the US: CA, IN, MI, MN, MS, MO, WI and WV and Manitoba and Quebec in Canada Sporadic reports in US since 2004 More severe in 2011 and reported in: coastal southern CA; HI; northeast IL; northern IN; Cape Cod, MA; Minneapolis/St. Paul, MN; NY; eastern PA; and northern WI Outside of North America and Europe, reported in: Australia, Asia, Africa, Central and South America 3

4 Impatiens Downy Mildew Causal Agent: Plasmopara obducens (primary) Cool, moist conditions (59-73 F/15-23 C) conducive to sporangia formation and zoospore germination Period between infection and visible sporulation varies between 5-14 days Produces aerial spores Sporangia released in response to light, temperature and/or humidity changes (dispersed through air and water) Hausbeck 4

5 Impatiens Downy Mildew Produces oospores in the stems and leaves - Overwintering spores (5F) USDA Zone 5 - Concern regarding overwintering in the landscape - Remove infected plants from the landscape!! Focus should be on prevention & early detection OOSPORES Trolinger Impatiens showing wilt due to IDM infection 5

6 Symptoms Yellow to pale green foliage and mild, inconspicuous mottling Can be mistaken for: - Nutritional imbalance - Spray injury - Chilling - Spider mite infestation Advanced symptoms - Stunting of plant growth/malformation of leaves and flower buds - Downward curling/distortion of foliage - Wilting - Plant collapse - Severe defoliation Symptoms can be delayed or masked by high fertility levels. Trolinger Rechcigl Mosdell 6

7 Heavy sporulation on the underside of the leaves Rechcigl 7

8 Young Plant Infected with Plasmopara obducens Mitchell 8

9 2011 Landscape Reports of Impatiens Downy Mildew 5 * 2011 Landscape States with IDM 9

10 2012 Landscape & Greenhouse Reports of Impatiens Downy Mildew 5 * States with reported IDM 10

11 2013 Landscape & Greenhouse Reports of Impatiens Downy Mildew 5 * States with reported IDM in Greenhouse & Landscape Landscape Only None reported As of August Syngenta. Document Classification: Public

12 Impatiens Species with DOWNY Impatiens flanaganiae Impatiens capensis Impatiens hochstettleri Impatiens auricoma Impatiens arguta Impatiens balsamina Impatiens walleriana Margery Daughtrey - Cornell Impatiens balsamina Courtesy of Margery Daughtrey Cornell CES Syngenta. Document Classification: Public

13 Balsam impatiens just shows yellow patches in leaves 13 Courtesy of Margery Daughtrey Cornell CES

14 Another host to think about First noted July 11, 2012 DM on Balsam impatiens Impatiens balsamina 14 Courtesy of Margery Daughtrey Cornell CES

15 Impatiens pallida Impatiens capensis Courtesy of Margery Daughtrey Cornell CES Syngenta. Document Classification: Public

16 Products for Control of Downy Mildew in Production MOA (FRAC#) Product Active Ingredient Activity Application REI Company 4 Subdue MAXX Mefenoxam Systemic Spray Drench 48 hr REI exemptions (0 hr) for certain drench applications Syngenta 11 Heritage Azoxystrobin Systemic Spray 4 hr Syngenta 11 Disarm O Fluoxastrobin Systemic Spray 12 hr OHP 11 Fenstop Fenamidone Systemic Spray 12 hr OHP Greenhouse Use Only 11+7 Pageant Pyraclostrobin + Boscalid Translaminar (11) + Spray 12 hr BASF Systemic (7) 21 Segway Cyazofamid Translaminar Spray 12 hr FMC 33 Aliette Fosetyl-AL Systemic Spray 12 hr OHP/Bayer 33 Alude Potassium salts of Phosphorous Acid Systemic Spray 4 hr Cleary Chemical Corp. 40 Micora Mandipropamid Translaminar Spray 4 hr Syngenta 40 Stature SC Dimethomorph Translaminar Spray 12 hr BASF 43 Adorn Fluopicolide Systemic Spray 12 hr Valent Drench M Protect DF Mancozeb Contact Spray 24 hr Cleary Chemical Corp. NOTES: Always test products on a small area before using on an entire crop. For brevity some products with the same mode of action have been omitted. Micora is not currently registered for sale or use in all states. 16

17 Products for Control of Downy Mildew in Landscapes MOA (FRAC#) Product Active Ingredient Activity Application Company 4 Subdue MAXX Mefenoxam Systemic Spray Drench Syngenta 11 Heritage Azoxystrobin Systemic Spray Syngenta 11 Disarm 480 SC Fluoxastrobin Systemic Spray Arysta 11+7 Pageant Pyraclostrobin + Boscalid Translaminar (11) + Systemic (7) Spray 21 Segway Cyazofamid Translaminar Spray FMC BASF 33 Aliette Fosetyl-AL Systemic Spray OHP/Bayer 33 Alude Potassium salts of Phosphorous Acid Systemic Spray Cleary Chemical Corp. 43 Adorn Fluopicolide Systemic Spray Valent Drench M Protect DF Mancozeb Contact Spray Cleary Chemical Corp. NOTES: Always test products on a small area before using on an entire crop. For brevity some products with the same mode of action have been omitted. Micora is not currently registered for sale or use in all states. 17

18 Fungicide Evaluation for Control of Downy Mildew (Plasmopara obducens) on Impatiens in Production Treatments Rate/100 gal Wilt 12/6 Wilt 1/17 Oospores (stem) Inoculated Control 1.3 a 2.7 a + Non-inoculated Control 1.2 a 1.8 a + Micora Subdue MAXX Subdue MAXX Heritage + Capsil Stature SC 8 oz (Spray) 1 fl.oz (Spray) 1 fl.oz (drench) 4oz + 4oz (Spray) 12.8oz (Spray) 0 b 0 b - 0 b 0 b - 0 b 0 b - 0 b 0 b - 0 b 0 b - Wilt rating 0 4 scale; 0 = no wilt; 1=25%; 2=25-75%; 3=75-99%; 4 = completely wilted plant 10 reps/trt 2011 Daughtrey, Cornell University 18

19 # Leaves with Sporulation Evaluation of Fungicide Treatments for Control of Impatiens Downy Mildew (Plasmopara obducens) in Production b 4 weeks after treatment & inoculation Rates given per 100 gal 2012 Hausbeck, MSU Plants treated and inoculated May 14, 2012 Evaluation date: June 18, WAT 19

20 % Disease Incidence & Leaves with Sporulation Residual Efficacy of Fungicide Drench Treatments for Control of Impatiens Downy Mildew (Plasmopara obducens) Plants inoculated 14 days after fungicide drench applications Rates given per 100 gal 2012 Warfield, Ball Horticultural Co. 20

21 Example of a Downy Mildew Prevention Rotation in Production Crop Week (post-transplant) 4 inch pot or smaller 1 6 inch pot Larger containers Additional week if needed Final week (final week) (final week) Application FRAC # Fungicide (example) Recommended treatment (drench) Recommended treatment (spray) Recommended treatment (spray) Recommended treatment (spray) Recommended treatment (spray) Recommended treatment (drench) Recommended treatment (spray) Recommended treatment (spray) Recommended treatment (drench) Recommended treatment (spray) Recommended treatment (spray) Recommended treatment (drench) 4 Subdue MAXX M 40 + M** 11+ M** 40 +M** or 4+43 Protect DF Micora Protect DF optional Heritage Protect DF optional Micora Protect DF optional Potassium Phosphite + Adorn Micora Protect DF optional Heritage Protect DF optional Subdue MAXX + Potassium Phosphite OR Subdue MAXX + Adorn Target Diseases Pythium, Phytophthora, Downy Mildew Downy Mildew, Leafspots, Botrytis Downy Mildew **Leafspots, Botrytis Downy Mildew, Leafspots, Botrytis Downy Mildew, **Leafspots, Botrytis Downy Mildew, *Pythium, Phytophthora Downy Mildew **Leafspots, Botrytis Downy Mildew Leafspots, Botrytis Downy Mildew, *Pythium, Phytophthora 40 Micora Downy Mildew 11 or 21 Heritage OR Segway 4+33 or 4+43 Subdue MAXX + Potassium Phosphite OR Subdue MAXX + Adorn Downy Mildew, Leafspots, Botrytis Segway: Downy mildew only Downy Mildew, *Pythium, Phytophthora * Additional diseases controlled with a drench application Micora is not currently registered for use or sale in all states **A mancozeb product may be added to the suggested spray treatments for additional protection as plant tolerance and production schedules allow 21

22 2012 Impatiens Downy Mildew Trial UF/TREC Homestead, FL Objectives of the trial: 1. Evaluate the efficacy of different fungicide rotations (including the Syngenta Fungicide Rotation) for prevention of impatiens downy mildew. 2. Evaluate the performance of Exp. Phosphite for prevention of impatiens downy mildew. 3. Assess the residual activity provided by the fungicide rotations for extended protection in the landscape. 4. Evaluate Subdue GR as a planting bed incorporation treatment for extended protection against impatiens downy mildew in the landscape. 22

23 Evaluation of Fungicide Rotations for Prevention of Impatiens Downy Mildew in Production & Landscape TREC, Homestead, FL Week Rotation 1 Rotation 2 Rotation 3 Rotation 4 Control 1 Adorn 2 floz + Subdue Maxx 1 floz (Drench) Aliette 2 lb + Subdue Maxx1floz (Drench) Adorn 2 floz + Subdue Maxx 1 floz (Drench) Micora 8 floz (Spray) Untreated Control 2 Dithane 24 oz (Spray) Dithane 24 oz (Spray) Dithane 24 oz (Spray) Micora 8 floz (Spray) Untreated Control 3 Micora 8 floz (Spray) Exp. Phosphite 20 floz (drench) Heritage 4oz + Capsil 4oz (Spray) Heritage 0.9oz + Acibenz oz (Drench) Untreated Control 4 Exp. Phosphite 10 floz + Subdue Maxx 1 floz (Drench) Exp. Phosphite 20 floz (Drench) Micora 8 floz (Spray) Micora 8 floz (Spray) Untreated Control 5 Plants were transplanted into landscape beds Rates given per 100 gals 23

24 Impatiens Downy Mildew Trial ~ Homestead, FL Palmateer 2012 Palmateer (UFL - TREC) Palmateer 24

25 Evaluation of Fungicide Rotations for Prevention of Impatiens Downy Mildew Untreated Control Treatment # 3 Plants Inoculated: 2/19/ Palmateer (UFL - TREC) Palmateer Treatment 3: (started 2/17/2012) 1st App: Adorn 2 oz + Subdue 1 oz (Drench) 2nd App: Dithane DF 24 oz (Spray) 3rd App: Micora SC 8 oz (Spray) 4th App: Exp. Phosphite + Subdue 1 oz (Drench) 25

26 Evaluation of Fungicide Rotations for Prevention of Impatiens Downy Mildew in Production TREC, Homestead, FL Rotation Treatment and Rate (per 100 gal) 1 Adorn 2 floz + Subdue Maxx 1 floz (Drench) Dithane 24oz (Spray) Micora 8 floz (Spray) Exp. Phosphite + Subdue Maxx 1 floz (Drench) 2 Subdue Maxx 1 floz + Aliette 2 lbs (Drench) Dithane 24 oz (Spray) Exp. Phosphite 20 floz (Drench) Exp. Phosphite 20 floz (Drench) 3 Adorn 2 oz + Subdue Maxx 1 floz (Drench) Dithane 2 lbs (Spray) Heritage 4oz + Capsil 4oz (Spray) Micora 8 floz (Spray) Disease Incidence Disease Severity 0 b 0 b 0 b 0 b 0 b 0 b 4 Micora 8 floz (Spray) Micora 8 floz (Spray) 0 b 0 b Heritage 0.9oz + Acibenzolar 0.125oz (Drench) Micora 8 floz (Spray) Non-treated, Non-Inoculated 23 a 99 a Non-treated, Inoculated Control 24 a 99 a 2012 Palmateer, UF-TREC Disease appeared 8 days after inoculation in control groups 26

27 Impatiens Downy Mildew Landscape Trial TREC, Homestead, FL March 20, 2012 Syngenta Trial 14 day Rotation Trial 14 day Rotation Trial Syngenta Trial Impatiens transplanted: March 16, 2012 Last fungicide treatment applied March 9, 2012 TREC= Tropical Research & Education Center - Homestead, FL Picture by A. Palmateer 27

28 Disease Incidence Disease Incidence in Non-Amended Landscape Bed Mar 26-Mar 60 5 weeks 5 weeks 5 weeks 5 weeks 2-Apr 10-Apr Apr 26-Apr 20 2-May 9-May 0 Non- Inoc Control Inoc Control Rotation 1 Rotation 2 Rotation 3 Rotation 4 Last fungicide treatment applied March 9, 2012 Disease incidence = avg. number of leaves with sporulation 2012-Palmateer, UF/TREC 28

29 Disease Incidence Disease Incidence in Subdue GR Amended Landscape Beds Mar 26-Mar weeks 6 weeks CLEAN 8 weeks CLEAN 8 weeks 2-Apr 10-Apr 20-Apr 26-Apr 20 2-May 9-May 0 Non- Inoc Control Inoc Control Rotation 1 Rotation 2 Rotation 3 Rotation 4 Last fungicide treatment applied March 9, Palmateer, UF/TREC 29

30 Non-Amended Landscape Bed at TREC 3/20/2012 Palmateer 30

31 Subdue GR Amended Bed at TREC 3/20/2012 Palmateer Pictures by Palmateer 31

32 Landscape Beds at TREC 4/5/2012 (4 weeks after treatment) Untreated Subdue GR 30oz/1000sqft Pictures by A.Palmateer 32

33 Infected Plants in Landscape Trial Rechcigl Rechcigl 33

34 Landscape Beds at TREC 4/16/2012 Untreated Subdue GR 30oz/1000sqft Exp NC NC Exp. 1 Exp IC IC 2 4 Exp. 2 Numbers and letters in boxes represent rotations and other treatments tested Pictures by Palmateer 34

35 Landscape Beds at TREC 4/24/2012 Untreated Subdue GR 30oz/1000sqft Pictures by Palmateer 35

36 Landscape Beds 5/1/2012 (8 weeks after treatment) Untreated Subdue GR 30oz/1000sqft Exp NC NC Exp.1 Exp IC IC 2 4 Exp.2 Numbers and letters in boxes represent rotations and other treatments tested Pictures by Palmateer 36

37 Dr. Ann Chase Landscape Recommendations Incorporate Subdue G just prior to planting 4 weeks later spray with 4 ounces/100 Heritage 4 weeks later spray with Aliette or similar chemistry 4 weeks later repeat Heritage if needed Do no plant replant Impatiens into the same bed where infection has already occurred for at least one season Irrigate to minimize the time that leaves stay wet, do not irrigate later in the day or at night Syngenta. DOCUMENT CLASSIFICATION: PUBLIC

38 Impatiens Downy Mildew ~ What have we learned? 1. Downy mildew on Impatiens is an aggressive disease. Prevention is key to success in production and in the landscape. 2. Drench applications early in the crop with Subdue MAXX or a combination of Subdue MAXX + Adorn are important for extended protection. 3. Spray applications on a 14 day interval do not provide enough protection/control under high pressure. 4. Fungicide rotations trialed provided control in production and in the landscape for 4-8 weeks. 5. Subdue GR provided excellent control of this disease in the landscape. 6. Recommend impatiens not be replanted into landscape beds where the downy mildew was identified the previous season 38

39 How Syngenta is addressing impatiens downy mildew Guidance on identification and preventative measures Industry updates and recommended control rotational programs with supporting trial data 39

40 Legal Disclaimer 2012 Syngenta. Important: Always read and follow label instructions before buying or using Syngenta products. The label contains important conditions of sale, including limitations of warranty and remedy. All products may not be registered for sale or use in all states. Please check with your state or local extension service before buying or using Syngenta products. Syngenta supports a FIFRA Section 2(ee) recommendation for the use of Heritage for control of downy mildew on bedding plants caused by Plasmopara spp. Please see the Section 2(ee) recommendation to confirm that the recommendation is applicable in your state. Some or all of the varieties may be protected under one or more of the following: Plant Variety Protection, United States Plant Patents, Utility Patents, and/or Plant Breeders Rights and may not be propagated or reproduced without authorization. Heritage, Micora and Subdue MAXX are trademarks of a Syngenta Group Company. Disarm and Fenstop are trademarks of OHP, Inc. Pageant and Stature are trademarks of BASF. Segway is a trademark of Ishihana Sangyo Kaisha, Ltd. Aliette is a registered trademark of Bayer CropScience. Alude and Protect are trademarks of the Cleary Chemical Corporation. Adorn is a registered trademark of Valent U.S.A. Corporation. Vital is a registered trademark of Phoenix Environmental Care, LLC. Capsil is a registered trademark of Aquatrols. 40