Managing Apple Scab Resistance and New Fungicide Updates Mohammad University of Illinois babadoos@illinois.edu Apple Scab in Illinois Apple scab is caused by the fungus Venturia inaequalis) Scab is a common disease of apple in Illinois In 2012, we detected V. inaequalis isolates resistant to major scab fungicides Primary Scab Apple scab Secondary Scab Disease cycle of apple scab Releasing spores by apple scab fungus at early growth stages Infection of apple tissues by ascospores and conidia of the scab fungus 1
Infection at green tip Early infection on sepals Apple leaf infection by scab fungus Apple fruit infection by scab fungus Apple leaf and fruit infection by the scab fungus Defoliation of apple tree infected with the scab fungus Fungicide-resistance of apple scab fungus in Illinois in 2012 2
Selection pressure due to fungicide From: Koller, Wilcox, & Olson. 1996. Down to Earth 51:20-24. Major spring diseases of apple in Illinois: Scab, Powdery Mildew, Rust Fungicide Resistance of Apple Scab Fungus (Venturia inaequalis) Resistant to strobilurin fungicide Sovran, thus other strobilurins ( 11) Resistant to strol-inhibitor (DMI) fungicide Rally, thus other DMIs ( 3) Resistant to Dodine ( M) Fungicides for Apple Scab, Powdery Mildew, Rust (Spring Diseases) - Topsin M (1) - Scala (9) - Bayleton (3) - Vangard (9) - Indar (3) - Cabrio (11) - Super MP (3) - Flint (11) - Procure (3) - Pristine ( 11 + 7) - Rally (3) - Sovran (11) - Topguard (3) - Captan (M) - Vintage (3) - Mancozeb (M) - Fontelis (7) - Polyram (M) - (7 + 11) - Sulfur (M) - (7 + 9) - Syllit (M) - Merivan (7 + 11) - Ziram (M) Efficacy of Fungicides for Apple Diseases Fungicide Scab P. M. Rusts Fungicide Scab P. M. Rusts Bayleton* P E E Pristine* E E E Cabrio* E E --- Procure* E E E Captan G O O Rally* E E E Dithane M45 G O G Scala G --- --- Flint* E G G Sovran* E G E Fontelis E E G Sulfur F G O Indar* E E E Syllit* E O P E E E Topguard* E E E E E G Topsin M* E E O E E G Vanguard G --- --- Merivan E E F-G Vintage* G --- --- Polyram G O G Ziram F O G --- = Unknown or doesn t apply O = none P = poor F = fair G = good E = excellent * Resistance reported; thus may not be effective Fungicides for Apple Diseases Fungicide Active ingredient PHI (Days) Prot/ Eradic Fungicide Active ingredient Bayleton* triadimefon 0 Pro/Er Pristine* pyraclostrobin + boscalid PHI Prot/ (Days) Eradic 0 Pro/Er Cabrio* pyraclostrobin 0 Pro/Er Procure* triflumizole 14 Pro/Er Captan captan 0 Protec Rally* myclobutanil 14 Pro/Er Dithane M45 mancozeb 77 Protec Scala pyrimethanil 72 Pro/Er Flint* trifloxystrobin 14 Pro/Er Sovran* kresoximmethyl 30 Pro/Er Fontelis penthiopyrad 28 Pro/Er Sulfur sulfur 0 Protec Indar* fenbuconazole 14 Pro/Er Syllit* dodine 7 Pro/Er Merivan difenoconazol e + cyprodinil trifloxystrobin pyrimethanil Fluxapyroxad+ pyraclostrobin 72 Pro/Er Topguard* flutriafol 14 Pro/Er 14 Pro/Er Topsin M* thiophanatemethyl 0 Pro/Er 72 Pro/Er Vanguard cyprodinil 0 Pro/Er 0 Pro/Er Vintage* fenarimol 30 Pro/Er Polyram metiram 77 Protec Ziram ziram 14 Protec 3
Efficacy of Fungicides for Apple Diseases Fungicide Scab P. M. Rusts Fungicide Scab P. M. Rusts Bayleton* P E E Pristine* E E E Cabrio* E E --- Procure* E E E Captan G O O Rally* E E E Dithane M45 G O G Scala G --- --- Flint* E G G Sovran* E G E Fontelis E E G Sulfur F G O Indar* E E E Syllit* E O P E E E Topguard* E E E E E G Topsin M* E E O E E G Vanguard G --- --- Merivan E E F-G Vintage* G --- --- Polyram G O G Ziram F O G --- = Unknown or doesn t apply; O = none; P = poor; F = fair G; = good; E = excellent * Resistance reported; thus may not be effective Efficacy of Fungicides for Apple Diseases Fungicide Scab Powdery Mildew Rusts Active ingredient Protectant PHI (Day) Captan G O O captan Protectant 0 Dithane M45 G O G mancozeb Protectant 77 Fontelis E E G penthiopyrad E E E difenoconazol e + cyprodinil E E G trifloxystrobin E E G pyrimethanil Merivan E E F-G Fluxapyroxad+ pyraclostrobin Polyram G O G metiram Protectant 77 O = none; F = fair; G = good; E = excellent 28 72 14 72 0 Properties of Fungicides Multi-site fungicides (M classes) Captan (M4) EBDC (M3) - mancozeb, ziram Sulfur (M2) Copper (M1) Site-specific (different classes) DMI (3) strol-inhibitors QoI (11) - strobilurins AP (9) - anilinopyrimidine SDHI (7) New Fungicides Demethylation inhibitors (DMI) (3): Indar,, Procure, Rally, Tebuzol, Topguard, Vintage Systemic fungicides Effective against scab, powdery mildew, and rusts Resistance development (reported) Quinone outside inhibitors (QoI) (11): Cabrio, Flint, Sovran, Pristine Translaminar or penetrant fungicides Effective against scab, powdery mildew, and rusts Resistance development (reported) Anilinopyrimidines (AP) (9): Scala, Vangard Systemic fungicides Provide 48-72 hr post-infection activity Best use with protectants (e.g., captan, mancozeb) Resistance developed 4
Anilinopyrimidines (AP) (9): Scala, Vangard Systemic fungicides Provide 48-72 hr post-infection activity Best use with protectants (e.g., captan, mancozeb) Resistance developed Succinate dehydrogenase inhibitor fungicides (SDHI) (7): Endura (BASF), Fontelis (DuPont), (Bayer), (Bayer), Merivan (BASF) New fungicides, systemic Effective against scab and powdery mildew Target Crop Diseases Cabrio pyraclostrobin 20EG (BASF) 11 Apple Scab, PM Apple Scab, PM, Rusts, & Alternaria spot, Pear Fontelis 1.67SC (DuPont) penthiopyrad 7 Stone Fruit Strawberry Blueberry (blossom & fruit), PM, Scab, Shot hole,... Gray mold, PM Gray mold, PM, Brown leaf spot, Leaf rust,. 4.20SC (Bayer) trifloxystrobin 7 + 11 Crop Target Diseases Scab, PM, Rust, Alternaria spot, Apple Fruit rots (bitter, black), Soot blotch, Flyspeck Cherry (blossom & fruit), (sweet PM, Leaf spot, & tart) Scab, Shot hole, Anthracnose Nut crops See the label Privilege 4.16 SC (Bayer) 4.16 SC (Bayer) fluopyram 7 pyrimethanil Crop Target Diseases Scab, PM, Sooty Apple blotch, Flyspeck (blossom & fruit), Cherry PM, Leaf spot, Scab, Shot hole, Green fruit rot 7 + 9 Apple Scab, PM Torino 10SC (BASF) cyflufenamid U6 Crop Target Diseases Grape Powdery mildew Straw Powdery mildew -berry Cabrio is no longer labeled for blueberry 5
Merivon 2.09 SC (BASF) fluxapyroxad + pyroclostrobin 7 + 11 Crop Target Diseases Scab, PM, Rusts, Alternaria blotch, Apple Rots (bitter, black, & Pear white), Sooty blotch, Flyspeck Stone fruit Alternaria leaf spot, Anthracnose, (blossom & fruit), Gray mold, Leaf spot, PM, Rust, Scab, Shot hole Pathogen Resistance and Disease Management in Apples Disease forecasting Watchdog Leaf Wetness/ Temperature Logger Research Money (Acknowledgements) Dr. and Mrs. Lovett Jim Eckert DuPont Crop Protection 2013 Illinois Summer Hort Day 13 June, 9 a.m. - 4 p.m., Champaign-Urbana Morning at Curtis Orchard (3902 S. Duncan Rd., Champaign, IL 61822; 217-359-5565): apple and pumpkin production and marketing Afternoon at the University of Illinois Fruit Research Farm: production and IPM of fruit crops (apple, pear, peach, grape, small fruit); rootstocks of apples and peaches; hightunnel vegetable production; and more For more information, contact Don Naylor (309-828- 8929) or Mohammad (babadoos@illinois.edu) Questions/Comments 6