Melanie L. Lewis Ivey and Rachel Kaufman Fruit Pathology Program Department of Plant Pathology The Ohio State University-Wooster Campus Wooster, OH

Transcription

1 Plant Pathology Series No. 147 February 2019 elanie L. Lewis Ivey and Rachel Kaufman Fruit Pathology Program Department of Plant Pathology The Ohio State UniversityWooster Campus Wooster, OH Revised February 2019

2 Table of Contents Table of Contents...1 General Comments...2 Fungicide Spray Program...2 Dmant... Bud break to Prebloom... Immediate prebloom to early bloom...5 First and Second postbloom...6 Third and Fourth postbloom...7 Fifth postbloom to Veraison...9 Postharvest...9 Product, FRAC, PHI and REI Table...10 Spray ProgramAtaGlance...12 Stages of Grape Berry Development...1 Acknowledgements...14 Contact Infmation...14

3 General Comments 1. All spray programs should be designed to enhance an integrated disease management program. Very rarely do chemicals alone prevent slow disease to a level that minimizes economic losses. There is no single chemical that is effective against all foliar diseases, which means that a combination of products in a spray program is necessary to optimize disease management. 2. A spray program should be designed with the critical periods of target diseases in mind. F example, in anthracnose is a problem in the vineyard, dmant fungicide applications are very imptant f season long control. F successful Phomopsis control, early season fungicides (1 to 5 inch shoot growth) are critical. After bloom, the threat of Phomopsis infection is greatly reduced. The period from immediate prebloom through 4 to 5 weeks after bloom is the OST CRITICAL PERIOD f controlling fruit infection by black rot, powdery mildew and downy mildew. Four to five weeks after bloom, the fruit become resistant to black rot, powdery mildew and downy mildew; however, the leaves and rachises (cluster stems) remain susceptible to both powdery and downy mildew f the rest of the season. Therefe, fungicide protection against both downy and powdery mildew may be required through harvest. F tight cluster Vinifera grape varieties an additional fungicide treatment should be added during bloom to protect against Botrytis bunch rot.. A spray program should be thoughtfully developed to prevent and slow the development of fungicide resistant pathogens in the vineyard. Fungicides that have a sitespecific mode of action are classified as medium to high risk f fungicide resistance development. Fungicides with Fungicide Resistance Action Committee (FRAC) codes numbers 1, 2,, 4, 7, 9, 10,, 1, 16, 4, 47, 49, U06, and U08, are medium to high risk fungicides and no me than two sequential applications of a highrisk fungicide should be applied befe alternating to a fungicide with a different mode of action. Do not over use fungicides (there are restrictions on how frequently highrisk fungicides can be applied) and only apply fungicides at the recommended manufacturer rates. It is unlawful to apply fungicides in a manner that is inconsistent with the product label. The powdery mildew, downy mildew and Botrytis bunch rot fungi are the most problematic with respect to fungicide resistance problems on grapes. Usually the first indication of resistance in the vineyard is when a fungicide does not provide the same level of control compared to previous years, especially on susceptible varieties. In the wstcase scenario, the material provides no control and the crop is lost due to disease. It is imptant to continually monit (scout) the vineyard f signs and symptoms of reduced disease control. There are no commercial labaties that screen pathogens f fungicide resistance. If you suspect that resistant fungi are present in the vineyard please contact Dr. elanie Lewis Ivey f assistance in confirming resistance and developing an alternative fungicide spray program to slow prevent additional resistance development in your vineyard. 4. Be aware of incompatible chemicals. ixing pesticides can save time and lab costs but not all pesticides are compatible and may result in undesirable reactions. F example, the mixing of incompatible chemicals may reduce the effectiveness of one me of the active ingredients in the mixture, cause an unwanted (and sometimes dangerous) chemical reaction, injure the plant (i.e. phytotoxicity). It is illegal to mix pesticides with other products (such as other pesticides, adjuvants, carriers) when such mixtures are expressly prohibited on the label. The following 1

4 combinations of fungicides plant protectants can cause serious vine injury when applied to vines at the same time within 14 days of each other: Hticultural oils (i.e. JS Stylet Oil) with sulfur Hticultural oils (i.e. Stylet Oil) with Captan Seven XLR (insecticide) with Captan 5. Spray guides are recommendations only. Product efficacy may vary depending on disease pressure, weather conditions, product coverage, the presence of resistant pathogen populations and/ the grape variety. F any given disease and at any specific application timing there are many registered fungicide options. The fungicides listed in this program are recommendations only and this guide does not include all of the fungicides currently registered f use on grapes. The cost of a fungicide per application and acre can vary significantly. The final fungicide spray program that you develop should consider the cost of specific fungicides selected as well as the targeted diseases and the potential f resistance development in the pathogen population. In this guide, the estimated relative cost of each fungicide per acre per application is provided based on 2019 retail costs (see Table below). The cost of fungicides will vary depending on the supplier and the quantity purchased. Relative Cost Estimates Per Acre above 2

5 Grape Fungicide Spray Program2019 This program emphasizes fungicide resistance management and is intended to provide simultaneous protection against anthracnose (ANTH), Phomopsis cane and leaf spot (PHO), black rot (BR), powdery mildew (P), and downy mildew (D). Specific recommendations f Botrytis bunch rot (BOT) and Phytophtha crown and root rot (PHYT) are also included in this program. The following fungicides should NOT be applied to Concd grapes as crop injury may occur: Flint Extra Inspire Super Intuity Luna Sensation Pristine [Should also not be applied to Noiret.] Quadris Top Sulfur [Should not be applied to sulfur sensitive vinifera varieties.] Revus Top Dmant Growth Stage Product (rate/a) FRAC Code Relative cost (per acre/application) Target Diseases Dmant Sulfix (12 gal) ANTH Ridomil Gold SL (.6 pt) 4 PHYT Bud Break to Prebloom Growth Stage Product (rate/a) FRAC Code Bud break to prebloom ancozeb 75DF ( lb) Relative cost (per acre/application) Target Diseases BR, PHO Captan 50WP ( lb) BR, PHO Ziram 76DF (4 lb) BR, PHO ANY OF THE ABOVE PLUS ONE OF THE FOLLOWING: Aprovia ( fl oz) 7 ANTH, PHO, BR, P Endura 70 WG (4.5 oz) 7 BOT, P Fracture ( fl oz) Inspire Super (1620 fl oz) +9 BOT, P ANTH, BOT, BR, P

6 Or Intuity (6 fl oz) BOT, P JS Stylet Oil (12%) BOT, P Kenja 400SC (2022 fl oz) 7 ANTH, BOT, P Luna Sensation ( fl oz) 7+ BOT, BR, PHO, P erivon Xemium (4 5.5 fl oz) 7+ P ettle (5 fl oz) ANTH, BR, P Potassium salts P Procure 480 SC (48 fl oz) P Quintec 2.08F (4 6.6 fl oz) 1 P Rally 40WSP (4 fl oz) ANTH, BR, P Sulfur PHOP, P TebuStar 45WSP (4 oz) BR, P Topsin WSB ( lb) 1 BR, P Tino 0.85F (.4 fl oz) U6 P Vivando 2.5 F ( fl oz) U8 P OR ONE OF THE PRODUCTS BELOW BY ITSELF Abound ( fl oz) BOT, BR, D, PHO, P Flint Extra (1.54 oz) BOT, BR, D, PHO, P 4

7 Luna Experience (88.6 fl oz) 7+ BOT, BR, PHO, P Pristine (812.5 oz) 7+ ANTH, BR, D, PHO, P Quadris Top (1214 fl oz) + ANTH, BR, D, PHO, P Revus Top (7 fl oz) 40+ ANTH, BR, D, PHO, P Sovran (.24.8 oz) BR, D, P Immediate Prebloom to Early Bloom Growth Stage Product (rate/a) FRAC Code Immediate prebloom to early bloom (CRITICAL PERIOD) Relative cost (per acre/application) Target Diseases If conditions are highly conducive f downy mildew infections during this period (temperatures above 50 F, rainy and high humidity at night) the addition of a product specific to D should be added to the program. It is very imptant to remember that these materials will need to be tank mixed with other fungicides because they will not provide adequate control of powdery mildew black rot. Spray intervals should not exceed 10 days. Same as f bud break to prebloom PLUS one of the following products f downy mildew: Fum (6 fl oz) 40 D Ranman ( fl oz) 21 D Reason 500SC (2.7 fl oz) D Revus (8 fl oz) 40 D Ridomil Gold SL (2.5 lb) 4 D Ridomil Gold Copper (2 lb) 4+ D Ridomil Gold Z (2.5 lb) 4+ D Sovran (.24.8 oz) D Tanos (8 oz) +27 D 5

8 Zampro (14 fl oz) D First and Second Postbloom Growth Stage Product (rate/a) FRAC Code First and Second Postbloom (CRITICAL PERIOD) Relative cost (per acre/application) Target Diseases The second postbloom spray f many varieties is near the end of the critical period (immediate prebloom through to 4 weeks after bloom) f controlling fruit infection by black rot, powdery and downy mildew. However, cluster stems (rachis) and leaves will remain susceptible to powdery and downy mildew throughout the growing season; therefe, a good fungicide program needs to be maintained throughout the season. Spray intervals should not exceed 10 days. Same as f bud break to prebloom PLUS one of the following products f downy mildew if conditions are highly conducive f downy mildew development: Fum (6 fl oz) 40 D Ranman ( fl oz) 21 D Reason 500SC (2.7 fl oz) D Revus (8 fl oz) 40 D Ridomil Gold (2.5 lb) 4 D Ridomil Gold Copper (2 lb) 4+ D Ridomil Gold Z (2.5 lb) 4+ D Sovran (.24.8 oz) D Zampro (14 fl oz) D OR ONE OF THE PRODUCTS BELOW BY ITSELF Pristine (812.5 oz) 7+ ANTH, BR, D, PHO, P Quadris Top (1214 fl oz) + ANTH, BR, D, PHO, P 6

9 Revus Top (7 fl oz) 40+ ANTH, BR, D, PHO, P Third and Fourth Postbloom Growth Stage Product (rate/a) FRAC Code Third and Fourth Postbloom Relative cost (per acre/application) Target Diseases Do not apply Captan, sulfur copper fungicides within 0 days of harvest the fermentation process may be adversely affected. If dry weather persists and the risk of downy mildew is low, fixed copper will provide good control of both downy and powdery mildew. Spray intervals can be extended to 1014 days unless conditions are highly conducive f downy mildew. Captan 50 W (24 lb) D Fum (6 fl oz) 40 D ancozeb ( lb) D Phosphous acid D Ranman ( fl oz) 21 D Revus (8 fl oz) 40 D Tanos +27 D Zampro (14 fl oz) D ANY OF THE ABOVE PLUS ONE OF THE FOLLOWING: 7

10 Endura 70 WG (4.5 fl oz) 7 P Inspire Super (1620 fl oz) +9 P ettle (5 fl oz) P Potassium salts P Procure 480 SC (48 fl oz) P Quintec 2.08F (46.6 fl oz) 1 P Rally (4 fl oz) P Tino 0.85F (.4 fl oz) U6 P Sulfur P Vintage SC (see label) P Vivando 2.5 F ( fl oz) U8 P OR ONE OF THE PRODUCTS BELOW BY ITSELF Copper (fixed) D, P Pristine (812.5 oz) 7+ D, P Quadris Top (1214 fl oz) + D, P Revus Top (7 fl oz) 40+ D, P 8

11 Fifth Postbloom to Veraison Growth Stage Product (rate/a) FRAC Code Fifth postbloom to veraison Relative cost (per acre/application) Target Diseases On tight clustered Botrytis bunch rot susceptible cultivars the addition of a product specific to Botrytis should be added to the program. The first spray should be made when symptoms are first observed at veraison ( shtly thereafter). A second spray should be made if conditions fav disease development (wet, cool weather) at least 14 days after the first spray. On late maturing varieties, a third spray may be required. Rates listed are to be used f Botrytis control only. Other rates and restrictions apply f additional diseases, refer to the label f me infmation. Same as f fourth and fifth postbloom PLUS one of the following: Elevate 50WG (1 lb) 17 BOT Endura 70WG (8 fl oz) 7 BOT Pristine (18.52 fl oz) +7 BOT Scala 5SC (918 fl oz) 9 BOT Switch 62.5 WG (14 fl oz) 9+12 BOT Vangard 75WG (10 fl oz) 9 BOT OR Rovral 4F (1.52 pt) PLUS Latron B1956 (6 fl oz/100 gal) 2 BOT Postharvest Growth Stage Product (rate/a) FRAC Code Postharvest Relative cost (per acre/application) Target Diseases Foliage should be protected from new downy mildew and powdery mildew infections until a frost event natural senescence causes the leaves to drop. Postharvest products and rates should be the same as preharvest products and rates f downy mildew and powdery mildew. Check the labels f season limits on the quantity of product that can be used. 9

12 Table 1. List of fungicides included in the 2019 grape fungicide spray guide Trade Name (Product) Common Name FRAC Preharvest Interval (PHI) Reentry Interval (REI) Abound azoxystrobin 14 4 Aprovia benzovindiflupyr Aliette fosetylal Captan 50WP captan 0 48 Dithane 45, others Elevate 50 WDG mancozeb fenhexamid Endura boscalid Flint Extra trifloxystrobin Fum dimethomph Fracture Banda de Lupinus albus doce (BLAD) 1 4 Inspire Super difenoconazole + cyprinil Intuity mandestrobin JS Stylet Oil oil 0 12 Kenja 400SC isofetamid Luna Experience erivon Xemium fluopyram + tebuconazole see label fluxapyroxad + pyraclostrobin ettle 125E tetraconazole 14 see label Pristine pyraclostrobin + boscalid see label Procure 480SC triflumizole 7 24 Prophyt, Phostrol, Agri Fos, Legion, Rampart Quadris Top phosphous acid 0 4 difenoconazole + azoxystrobin Quintec quinoxyfen Rally 40WSP myclobutanil Ranman 400SC cyazofamid Reason 500SC fenamidone 0 12 Revus mandipropamid

13 Trade Name (Product) Revus Top Ridomil Gold Z WG Ridomil Gold SL Ridomil Gold Copper Rovral 4 Flowable Common Name difenoconazole + mandipropamid FRAC Preharvest Interval (PHI) Reentry Interval (REI) mefenoxam + mancozeb mefenoxam mefenoxam + copper iprodione Scala SC pyrimethanil Sovran kresoximmethyl Sulfix calcium polysulfide 0 48 Sulfur (wettable) Switch 62.5 WG sulfur 0 24 cyprodinil + fludioxonil Tanos famoxadone + cymoxanil TebuStar 45 WSP tebuconazole Topsin WSB thiophanate days Tino cyflufenamid U6 4 Vangard WG cyprodinil Vintage SC Fenarimol Vivando metrafenone U Zampro ametoctradin + dimethomph Ziram 76DF ziram 21 48

14 2019 Spray Program AtaGlance The fungicides listed in this program are recommendations only and this figure does not include all of the fungicides currently registered f use on grapes. 12

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16 Acknowledgements The spray program provided in this guide was developed using recommendations published by the idwest Fruit Pest anagement Guide and fungicide efficacy data from experimental trials conducted in Ohio and throughout the Ntheastern United States. Rachel Kaufman provided the relative fungicide cost data. Dr. elanie Lewis Ivey Assistant Profess State Fruit Pathology Specialist State Fresh Produce Safety Specialist The Ohio State UniversityWooster Campus 1680 adison Avenue Selby Hall Wooster, OH Office Phone: Facebook: facebook.com/ohiograpeip Contact Infmation CFAES provides research and related educational programs to clientele on a nondiscriminaty basis. F me infmation, visit cfaesdiversity.osu.edu. F an accessible fmat of this publication, visit cfaes.osu.edu/accessibility. 14