Wheat Varieties and Management of Stripe Rust Stephen Guy, Washington State University sguy@wsu.edu 2012 Direct Seed Conference Spokane, WA
Pathogen Environment - Host Stripe Rust Weather - Variety
Stripe rust management program 1. Prepare a stripe rust management program as used for weed or fertility management 2. Integrate a program of: variety selection genetic resistance crop management healthy plants Disease understanding forecasts, weather, scouting Fungicide applications in response to disease 3. Modify program and update regularly for both spring and winter crops 4. Choose and buy inputs that give an economic return.
Stripe rust damage can be minimized with a well thought out management program
Yield Loss by Stripe Rust and Increase by Fungicide on Winter Wheat, Pullman, WA 2011 Acreage in 2011 Yield (BU/A) Yield loss (%) Yield Inc. (%) Cultivar Acres a % Check Fungicide Difference by stripe rust by fungicide Madsen 65,300 4 112 110-1 -1-1 Bruehl 164,400 9 122 127 5 4 4 Finley 7,300 0 84 92 8 8 9 AP700CL 97,450 6 92 101 9 9 10 Farnum 57,900 3 93 106 12 11 13 Stephens 26,100 1 76 87 11 13 14 Cara 17,900 1 102 117 15 13 15 Westbred 528 189,200 11 88 102 14 14 16 Chukar 13,200 1 101 117 16 14 16 Rod 26,400 1 80 94 14 15 17 Brundage 96 47,800 3 90 109 19 18 22 Paladin 9,900 1 68 85 17 20 25 Cashup 6,100 0 71 90 19 21 26 Bauermeister 10,500 1 74 94 20 21 27 Eltan 243,700 14 75 99 24 24 31 Masami 39,350 2 73 99 26 26 36 ORCF-103 46,100 3 56 83 27 33 48 Xerpha 154,810 9 69 106 37 35 54 ORCF-102 243,850 14 68 106 39 36 57 Tubbs 12,930 1 58 93 35 37 59 Eddy 17,000 1 45 77 32 42 72 Tubbs 06 12,770 1 52 91 39 43 75 PS 279 0 0 5 51 46 90 878 WA Acreage Mean 85 79 99 20 18 29
Summary of 2011 Winter Wheat Yield Loss and Fungicide Study Yield losses >90% without resistance Yield loss >18% in current WA acres without fungicides These are underestimates! Data based on only a single fungicide application
Yield Loss by Stripe Rust and Increase by Fungicide on Spring Wheat, Pullman, WA 2011 Acreage in 2011 Yield (BU/A) Yield loss (%) Yield Inc. (%) by stripe Cultivar Acres % Check Fungicide Difference rust by fungicide WA8074 (HRS) 0 0 85 87 1 1 2 WA8124 (SWS) 0 0 90 95 5 5 6 Louise 193,650 33 72 76 4 5 6 JD 6,400 1 68 74 5 7 8 Whit 6,700 1 77 83 6 8 8 Jefferson 39,750 7 69 77 8 10 11 Kelse 18,300 3 66 74 8 11 13 Hollis 32,900 6 72 82 9 11 13 WPB 926 10,400 2 58 67 8 13 15 Diva 0 0 74 85 11 13 15 Babe 3,900 1 63 75 12 16 19 Tara 2002 14,200 2 49 60 11 19 23 Nick 63,850 11 52 68 15 22 29 Alpowa 15,500 3 52 68 16 23 31 Hank 19,700 3 41 61 21 34 51 Lemhi 0 0 31 57 25 45 80 WA Acreage Mean 72 62 72 10 9 19
Summary of Spring Wheat Yield Loss and Fungicide Study Yield losses >45% without resistance Yield loss >15% in current WA acres without fungicides These are underestimates! Data based on only a single fungicide application
What can we do about stripe rust? 1. Grow resistant varieties Variety trial data - http://variety.wsu.edu/ (including sites where fungicides were applied) shows that highly resistant lines have consistently yielded higher the past two years Impractical to completely control stripe rust with fungicides on moderately susceptible to susceptible varieties: timing, weather, input costs, label restrictions, product availability, application availability, inadequate monitoring
Winter Wheat Stripe Rust Severity in 2011 (5 locations) Distributed by Rust Update email list: ratings do change! Look at max or average severities in addition to categorical rating If a other agronomic factors are a coin toss, select varieties with lower severity, high HTAP Soft Winter Wheat Rating Severity (%) HTAP MADSEN R 4 High LEGION R 11 High SKILES R 14 High BRUNEAU MR 12 High AP 700 CL MR 13 High BITTERROOT MR 14 High WB-528 MR 17 Moderate ELTAN MR 18 Moderate BRUNDAGE 96 MR 28 Moderate FINCH MR 30 Moderate ORCF-103 MR 30 Low ROD MR 32 Moderate MASAMI MR 34 Low ORCF-102 MR 34 High STEPHENS MR 40 High XERPHA MS 54 Low LAMBERT MS 56 Low UICF-BRUNDAGE S 40 Moderate AP BADGER S 50 No TUBBS 06 S 62 Moderate AP LEGACY S 68 Moderate
Spring Wheat Stripe Rust Severity 2010-2011 (Average flag leaf infection at 8 locations) Soft Spring Wheat Severity (%) JD 3 WA 8124 9 Alturas 15 Eden 20 Diva 21 Louise 23 Wakanz 31 Whit 34 UI-Cataldo 35 Babe 36 Alpowa 39 Zak 52 Nick 71 LEMHI 90 Hard Spring Wheat Severity (%) Lassik 4 WA 8123 5 BR7030 12 Buck Pronto 14 WA 8074 (Glee) 19 UI Winchester 22 Kelse 28 Jefferson 29 Hollis 34 Bullseye 35 Otis 40 Westbred 926 41 WB-Fuzion 60 Tara 2002 65 Hank 77 LEMHI 90
WA8124 Alpowa Can fungicides substitute for genetic resistance to control stripe rust?
2011 Hard Spring Wheat Yield in 16-20 Zone Two fungicide applications Dayton Mayview Walla Walla Average Lassik 92 55 66 71 WA8074 88 53 69 70 Scarlet 91 51 68 70 Kelse 90 51 67 69 Buck Pronto 85 53 66 68 Bullseye 87 46 69 67 UI Winchester 83 50 64 66 10Fx Inc.1 84 49 62 65 Tara 2002 79 50 66 65 WB-Fuzion 84 46 63 64 Jefferson 82 47 63 64 Westbred 926 80 47 65 64 IDO702 83 47 60 63 Cerere 86 46 57 63 WA8148 76 48 64 63 Hollis 79 47 60 62 Hank 79 43 60 61
2009 Hard Spring Wheat Yield in 16-20 Zone
What else can we do about rust? 3. Spray fungicides based on rust levels crop development variety/resistance level weather, previous and future production goals costs for material and application Scout, Scout, Scout, Scout, Scout, Scout, Scout
What can we do over the next 10 years? 1. Grow resistant varieties 2. Scout fields/watch rust updates pathology and Extension 3. Spray fungicides as needed 4. Select resistant elite lines breeders will be breeding for a combination of seedling and adult-plant resistance 5. Keep track of races and race changes - pathologists
What would I do in 2012? 1. Know the level and type of resistance of the varieties. 2. Keep up on stripe rust updates. 3. Plan to apply inexpensive fungicide with winter wheat herbicide if there is stripe rust in the region. 4. Scout all fields on foot every two-four days if conditions are SR condusive starting after herbicide application and through flowering. 5. Apply fungicides at flag leaf timing if there is stripe rust infection in the field and HTAP is not working (for MR+ varieties). 6. If fungicide is not applied at flag leaf, scout closely until flowering and apply if SR kicks in; or if applied, scout and assess necessity of application at flowering (SR levels, variety susceptibility, weather). Be ready to apply fungicide, but only if needed. 7. After flowering, get ready for harvest, your SR management is done for this year, but it s time to assess variety selection for next year and how your strip rust management paid off.
Thanks! WSU and USDA Collaborators Washington Grain Commission WSU Extension Variety Testing: http://variety.wsu.edu/ sguy@wsu.edu
What is Stripe Rust? Puccinia striiformis f.sp. tritici Obligate parasite it does not live without a host Wheat is the host for wheat stripe rust Reproduces by spores what you see as rust Spores can survive for weeks Spores need water to infect Usually 10-14 days from infection to sporulation Ideal temperatures 50-70⁰F Many rust races that determine virulence
Stripe Rust 2011 season was the perfect storm! 2010 stripe rust was higher than average. 2010 crop was harvested late in some areas. Fall 2010 planting was early and allowed fall stripe rust infections that overwintered. Spring 2011 was cool and moist a stripe rust conducive environment. Race shifts in stripe rust increased overall virulence on currently grown cultivars. Fungicide applications started early and were widespread to protect the valuable crop.
Disease Environment - Host