Developing a Spray Program

1. Developing a Spray Program Stephen Jordan UW-Madison

2. Considerations when developing a spray program • Varietal susceptibility to disease • Vineyard disease history • Fungicide options • Restricted Use Pesticides (RUPs) • Certified pesticide applicators or persons under their direct supervision • http://ipcm.wisc.edu/Default.aspx?alias=ipcm.wisc.edu/pat • Organic • Organic Materials Review Institute (OMRI) • Environmental impact • Fungicide resistance management • Cost vs product efficacy • Re-entry Interval (REI) and Pre-harvest Interval (PHI)

3. Variety Susceptibility Most of these ratings were taken from research and observations from other states Unsure about a variety? talk to someone nearby who is growing it Resistant? Yes. Immune? Probably Not!

4. Protectant and Systemic Fungicides • Protectant fungicides act as a barrier to infection on the surface of the tissue • Must be applied prior to inoculum reaching the vine • Does not protect new growth and must be re-applied • Prone to environmental degradation • Rain, UV etc.. • Systemic fungicides enter the plant tissue • Varying levels of penetration • Varying levels of “curative” power (dose dependent) • Can act as a protectant • Limited protection of new growth after application • Less prone to environmental degradation

5. Fungicide Resistance Management • Multi-target mode of action vs single target mode of action • Fungicide Resistance Action Committee (FRAC) code on labels (not all!) • Mix at-risk materials with materials that have different modes of action • Alternate at-risk materials with materials that have different modes of action (different FRAC codes) • Avoid using low rates with marginal control. • Get complete coverage so that all parts of the plant receive an effective dose.

6. Anne DeMarsay, PhD

7. FRAC Code

8. FRAC Code

9. Mancozeb • Dithane, Dithane DF Rainshield , Manex II, Manzate, Penncozeb • ethylene(bis) dithiocarbamate (EBCD fungicide) • Broad spectrum protectant, no worries about resistance • Workhorse of early-season disease control • 66 day Post-harvet Interval (PHI) • 24 hr Restricted Entry Period (REI)

10. Alternatives to mancozeb • Captan • Can be used later in the season than mancozeb (0 day PHI) • Protectant • 3 day REI can make working in the vineyard a problem • 24 lb/acre/year limit • Can not be used with crop oils • Ziram • Protectant • 48h REI, 21 day PHI • Great for black rot • Overall less effective than mancozeb

11. Sterol inhibitor fungicides • The other work horse • Also known as DMI fungicides • Systemic, excellent post-infection activity (“kick-back”) • requires fungicide resistance management • Relatively affordable • Highly effective against black rot and powdery mildew, effective against phomopsis • Rally (Nova) (myclobutanil) • 24h REI, 14 day PHI • Elite (tebuconazole) • 12h REI, 14 day PHI

12. Strobilurins • Very effective, great protectant activity, poor “kick-back” activity • Slightly systemic • Tend to be more expensive • Must use fungicide resistance management (no more than 2 applications in a row, and do not rotate with another strobilurin) • Limited to 3 applications in a season (at max label rate)

13. Strobilurins • Abound (azoxystrobin) • 4 hr REI, 14 day PHI. • Sovran (kresoxim methyl) • 12 hr REI, 14 day PHI • Pristine (pyraclostrobin + boscalid) • 12 hr REI, 14 day PHI, 5 day REI when cane tying, turning, girdling • Potentially phytotoxic to labrusca • Flint (trifloxystrobin) • Less effective

14. Mefenoxam • Ridomil formulations with mancozeb, copper • Expensive • Very effective for downy mildew control • Very systemic, curative • With copper, effective against powdery mildew (but PHI of 42 days)

15. Sulfur • Sulfur is very effective for powdery mildew control • Can be mixed with most other fungicides except crop oils • Does not work well below 65°F and can be phytotoxic to vines at temperatures over 85°F • Some cultivars are sulfur sensitive (Foch) • Ask your winemaker

16. Coppers • Several different formulations (copper sulfate, copper hydroxide) • Cool temperatures can lead to phytotoxicity • Work well in controlling downy mildew infections, ok control of powdery mildew • Only use on copper-tolerant cultivars • Ask your winemaker

17. Phosphonates • Phosphorous acid fungicides • Agri-fos (potassium phosphate) • Aliette (fosetyl-Al) • Phostrol, Prophyt (Na, K, NH3 phosphites, phosphorous acids) • Work very well against downy mildew (good products for cleaning up foliage), some efficacy against other grape pathogens, • Broad spectrum fungicides (?)

18. Other fungicide options • Vangard, Elevate, Endura, and Rovral • Most effective for Botrytis bunch rot control • Quintec • Powdery mildew product, protectant • Topsin M • Effective for powdery mildew, anthracnose, not effective for black rot and downy mildew control • Quadris Top, (new product for grape) • Mix of an SI fungicide and a strobilurin • Revus Top (new product for grapes) • Mix of mandipropamid and difenoconazole (SI fungicide) • University efficacy trials show excellent control of black rot, downy and powdery mildew

19. Other fungicide options • Crop Oils (JMS Stylet Oil, Saf-T-Side, etc) • Effective for powdery mildew control and some insects • Can remove the “bloom” from berries, not advisable for table grapes • Biologicals • Serenade, Sonata • May play a role in organic production, not as effective as conventional fungicides • Potassium Salts • Armicarb, Nutrol • Some efficacy for powdery mildew only, short-lived protectants • Hydrogen Peroxide (Oxidate) • Surface anti-sporulant, not a protectant

20. Approximate fungicide costs/acre (2010) Red = OMRI approved

21. Spray program options • No spraying • Prepare to be disappointed • Calendar Schedule • Fungicide application every x number of days • 10-14 day intervals is the norm • In areas with high disease pressure and susceptible varieties, this could be every 7 days • Phenological Schedule • Sprays are based on the growth stage of the vines • Can be problematic with vines at different stages • Ideally, we would use a combination of the calendar and phenological schedules with a large dose of flexibility • Non-bearing vs bearing fruit

22. Dormant spray • Recommended for anthracnose, phomopsis and some insects • Might decrease powdery mildew inoculum • Won’t eliminate the disease from your vineyard • Lime sulfur • Caustic (hard on sprayer) • Expensive when used as a dormant spray • Does not store well (crystallizes, need hot water to mix) • Stinks! • Is anthracnose and phomopsis a problem in your vineyard? • Yes, Apply lime sulfur • No, Save your money

23. 1” Shoots to pre-bloom

24. 1” Shoots to pre-bloom • Goal is to protect the young, growing shoots • Black rot, powdery mildew, anthracnose, Phomopsis, downy mildew • 14 day spray intervals should be adequate • Use a good protectant such as mancozeb or captan • Black rot problems or variety susceptibility, use mancozeb • Downy mildew problems, use captan • If you miss a spray, or wet weather is delaying a spray, add an SI fungicide (Rally, Elite, etc…) to the tank mix for “kick-back” or post-infection activity

25. Pre-bloom to 5-6 weeks post-bloom • Immediate prebloom through 5 to 6 weeks post-bloom is the most critical period for fungicide sprays

26. Pre-bloom to 5-6 weeks post-bloom

27. Pre-bloom to 5-6 weeks post-bloom • Primary goal is to protect the young, susceptible fruit • we want the rest of the vine to be protected as well • 3 sprays should cover this period (14 day intervals) • mancozeb or captan + SI fungicide (captan for the last spray?) • strobilurin in the rotation • Rainy, warm weather and susceptible variety, shorten to 10 days (strobilurin more rain fast) • Don’t rely only on a strobilurin fungicide during this period • 3 applications total for the season, only 2 sprays in a row • fungicide resistance management

28. 5-6 weeks post-bloom to harvest (and beyond)

29. 5-6 weeks post-bloom to harvest (and beyond) • Fruit should now be resistant to most pathogens • Powdery and downy mildew on foliage • How much disease can you tolerate • Reduce over-wintering inoculum • Bunch rots • Botrytis, sour rot, ripe rot • Switching from mancozeb (66 day PHI) to captan as primary protectant • Typically, a drier late summer can help you reduce # of sprays • Strobilurin fungicides are good for powdery mildew, downy mildew and bunch rots

30. Example program – vines bearing fruit • 1” shoots, May 1st , mancozeb ($20) • 6” shoots, May 15th mancozeb ($20) • Prebloom/bloom, June 1st mancozeb + SI ($35) • 1st Cover Spray, June 15th strobilurin ($40) • 2nd Cover Spray, July 1st captan + SI ($35) • 3rd Cover Spray, July 15th strobilurin ($40) • 4th Cover Spray, (veraison) Spray August 1st, captan ($20) • Clean-up Spray for downy mildew in September, Phosphorous Acid ($20) • Total cost per acre in fungicides - $230

31. Fungicide program for non-bearing fruit • Not worried about fruit or harvest, so PHI goes out the window • Grow tubes are an ideal environment for disease • Warm and humid • Scout for foliar symptoms • Downy and powdery mildew are the greatest threat • Anthracnose, black rot, and phomopsis may have come in on the nursery stock • Spray as needed

32. What I would keep in my fungicide storage shed • mancozeb and captan • mancozeb for early season, captan for late season • A sterol-inhibitor fungicide • Rally, Elevate, etc… • Tank mix with one of the above protectants during the “CRITICAL PERIOD” • A strobilurin or strobilurin containing product • Effective for both powdery and downy mildew • Good for late season control of bunch rots • Perhaps a Phosphorus acid fungicide (Phostrol, Prophyt, etc..) • Good for downy mildew on the leaves and affordable • A powdery mildew fungicide

33. What about insects? • Scouting is critical • Scouting for phylloxera at the end of May • Insecticides are applied as needed with scheduled fungicide sprays • 2011 Midwest Small Fruit and Grape Spray Guide is a great reference

34. Phylloxera insecticide trial - 2010 $27 All foliar applications 2x after bloom $17 Number of galls per leaf $28 $55

35. Making tank mixes • Fill the tank ¼ - ½ full and begin agitation • When mixing chemicals, add in the following order: • Wettable Powders • Dispersible Granules • Flowables • Emulsifiable Concentrates • Solutions • Crop oils or surfactants • The mixture should be agitated after each addition.

36. Reminders for proper tank mixing • Familiarize yourself with the adjustments specific to your sprayer, not all sprayers operate the same and are adjusted differently • Be sure the sprayer is parked on a level surface • Know the exact tank volume • Mark the tank volumes where they can easily be read • Calibrate the sprayer • Choose a formulation that best meets the need of a particular application • Read the label and be aware of mixing precautions and personal protection equipment • Mix only what is needed for that day • Fill half the tank with clean water, never add concentrated chemicals to an empty tank • Start the agitation before adding any chemicals

37. Reminders for proper tank mixing • To avoid back-siphoning of chemicals, there should be no direct connection between the water source and the sprayer tank • Properly measure and add the chemicals to the tank • If using different formulations, follow the mixing order above • Sometimes it is easier to premix the chemicals into a slurry before adding to the tank • Rinse any mixing containers and pour the rinsate into the tank • Fill the tank to its final volume, avoid over-filling the tank • Properly dispose of all empty pesticide containers • Properly clean-up and dispose of any spilled chemical or pesticide solution • Apply the pesticide according to labeled directions

38. Stephen Jordan608-228-6932sjordan3@wisc.edu