Publication 360, Fruit Production Recommendations:
Grape Calendar - Trace bloom (first cap fall)

Table of Contents

1. Trace bloom (first cap fall)
   • Grape berry moth (1st generation)
   • Japanese beetle
   • Leafhoppers
   • Phylloxera (leaf form)
   • Black rot
   • Powdery mildew
   • Downy mildew
   • Botrytis bunch rot
   • Precautions
     
2. Other grape calendar sections
   • Bud burst to first leaf
   • First leaf, 1.25-5.0 cm shoot length
   • 3-5 leaves unfolded, 10-15 cm shoot length
   • Shoot length, 20-25 cm
   • Immediate post-bloom to early fruit set
   • Berries pea-sized
   • Berry touch to cluster closure
   • Beginning of ripening (veraison) through harvest
   • Special sprays (when monitoring indicates the need)
     
3. Other topics on Grapes
   • Grape growth stages
   • Grape nutrition
   • Notes on grape insects & diseases
   • Mating disruption (MD) technology for grape berry moth
   • Table 6-4. Products used on grapes
   • Table 6-5. Relative disease susceptibilities of grape cultivars
   • Table 6-6. Activity of fungicides on grape diseases
4. Grape calendar (PDF 172 kb)
5. Pub 360 - Chapter 6 Grapes (PDF 225 kb)
6. Related Links

Grape berry moth (1st generation) (Trace bloom (first cap fall))

• Materials: Use one of:
  • Delegate WG @ 280 g/ha
  • Success 480 SC @ 182 mL/ha
  • Altacor @ 285 g/ha
  • Dipel 2X DF @ 1.125 g/ha
  • Pounce @ 360 mL/ha
  • Perm-Up @ 360 mL/ha
  • Ambush 500 EC @ 275 mL/ha
  • Imidan 50 WP @ 1.9 kg/ha
  • Diazinon 50 W @ 3.375 kg/ha
  • Sevin XLR @ 5.25 L/ha
  • Guthion 50 WSB (see label) or Sniper (see label)
• Comments: Where there is a history of early-season grape berry moth injury, apply an insecticide for first generation, in enough water to ensure complete coverage. For resistance management, do not use insecticides from the same group for more than one generation. Within a generation, only one chemical group should be used.
  Dipel 2X DR: Re-application may be required 7-10 days later. See Biopesticides and reduced risk products for insect control.
  Delegate and Success: Provide suppression rather than control of grape berry moth. See Table 2-6. Efficacy Ratings for Pesticides.
  Altacor, Delegate, Success and Dipel: Apply at first egg hatch (first sustained moth catch in pheromone traps), earlier than the traditional timing (upswing in moth numbers captured in traps) used for Guthion, Sniper, Diazinon, Pounce or Imidan. A second application may be necessary if flight is extended.
  

Japanese beetle (Trace bloom (first cap fall))

• Materials: Use one of:
  • Imidan 50 WP @ 1.9 kg/ha
• Comments: Japanese beetle is a sporadic pest that feeds on over 300 plant species. Monitor to determine beetle presence and extent of feeding damage. Where damage is localized, spot-treatment may be adequate for control. Watch for re-infestation after treatment.

Leafhoppers (Trace bloom (first cap fall))

• Materials: Use one of:
  • Assail 70 WP @ 80 g/ha
  • Pounce @ 175 mL/ha
  • Perm-Up @ 175 mL/ha
  • Ambush 500 EC @ 140 mL/ha
  • Diazinon 50 W @ 3.375 kg/ha
  • Sevin XLR @ 5.25 L/ha
  • Guthion 50 WSB (see label) or Sniper (see label)
  • Surround WP @ 50.0 kg /ha
    
• Comments: Grape leafhopper (GLH), potato leafhopper (PLH) and three banded leafhopper (TBLH) are the three main species of leafhoppers that feed on grapes. In some vineyards, Guthion or Sniper no longer give control of GLH. All products listed provide control of PLH.
  Surround WP may delay sugar accumulation. Closely monitor harvest parameters to determine best time to harvest. Use 50 kg/ha of Surround for the first two applications to establish the protectant layer, followed by 25 kg/ha in subsequent sprays. Reapply to maintain complete coverage following heavy rain. Applications after veraison (when grapes begin to ripen) will adhere better to berries. Do not apply Surround postbloom on table grapes. See Kaolin clay (Surround WP).

Phylloxera (leaf form) (Trace bloom (first cap fall))

• Materials: Use one of:
  • Movento 240 SC @ 365 mL/ha
    
• Comments: Movento works slowly so control may not be apparent for 2-3 weeks. Movento will redistribute to young leaves as they develop. Consecutive applications should be at least 30 days apart. See the Movento label for additional details

   

   

Black rot (Trace bloom (first cap fall))

• Materials: Use one of:
  • Nova 40 W @ 200 g/ha
  • Sovran @ 240 g/ha
  • Flint 50 WG @ 140 g/ha
  • Polyram DF (see label)
  • Ferbam 76 WDG (see label)
• Comments: Fruit clusters are highly susceptible to black rot from bloom to 4 weeks postbloom.
  Pristine, Sovran and Flint: Do not alternate Pristine with Sovran or Flint. For resistance management, use no more than two applications of any of this group per season.
  Sovran is phytotoxic to some varieties of cherries (see label); do not let product drift onto sensitive crops.
  Flint: Do not apply to Concord grapes or crop injury may occur.
  Pristine: Do not use on Concord, Fredonia or related varieties due to possible injury.

Powdery mildew (Trace bloom (first cap fall))

• Materials: Use one of:
  • Sovran @ 300 g/ha
  • Flint 50 WG @ 140 g/ha
  • Pristine WG @ 420-735 g/ha
  • Lance WDG @ 315 g/ha
  • Nova 40 W @ 200 g/ha
  • Dikar @ 5.5 kg/ha
  • Microscopic Sulphur (see label)
    or Kumulus DF @ 12.6 kg/ha
  • MilStop @ 2.8 kg/ha
  • Serenade ASO @ 9.0-15.0 L/ha
    
• Comments: Spray at 7-10 day intervals to protect expanding leaves and developing fruit clusters. Spray at 7 day intervals in rainy weather. Fruit clusters are highly susceptible to powdery mildew from bloom through 5 weeks postbloom.
  Sovran is phytotoxic to some varieties of cherries (see label); do not let product drift onto sensitive crops.
  Flint: Do not apply to Concord grapes or crop injury may occur.
  Pristine: For resistance management, use the 735 g/ha rate. Do not use on Concord, Fredonia or related varieties due to possible injury.
  Pristine, Sovran and Flint: Do not alternate among this group. For resistance management, use no more than two applications of any of these products per season. Do not use if sporulating lesions are visible.
  Pristine and Lance: Do not alternate Pristine with Lance. For resistance management, use no more than two sprays of either product per season.
  Nova: For resistance management, use no more than two applications per season. Do not use if sporulating lesions are visible.
  MilStop: Apply in 500 L water per ha. MilStop creates a mildly alkaline solution. Do not tank mix with pH adjusters, oil, or products not compatible with mild alkaline solutions. MilStop works as an eradicant and has no protective activity.
  Serenade ASO: Provides suppression of powdery mildew. See Table 2-6. Efficacy Ratings for Pesticides, and Bacillus subtilis (Serenade ASO, Serenade MAX).

 

Downy mildew (Trace bloom (first cap fall))

• Materials: Use one of:
  • Revus @ 500 mL/ha
  • Pristine WG @ 675-735 g/ha
  • Sovran @ 300 g/ha
  • Dikar @ 5.5 kg/ha
  • Polyram DF (see label)
  • Maestro 80 DF @ 2.0 kg/ha
    or Supra Captan 80 WDG (see label)
  • Folpan 80 WDG @ 1.25 kg/ha
  • Gavel 75 DF @ 2.25 kg/ha
• Comments: Fruit clusters are highly susceptible to downy mildew from bloom until 4 weeks postbloom. Spray at 7-10 day intervals to protect expanding leaves and developing fruit clusters. Spray at 7 day intervals in rainy weather.
  Revus: The use of a non-ionic adjuvant is recommended (0.125% volume: volume). Do not use Revus plus adjuvant tank-mixed with sulphur on sulphur-sensitive varieties. For resistance management, rotate to a different fungicide group after each application of Revus. Do not use if sporulating lesions are present. Use no more than four applications per season.
  Pristine WG: For resistance management, use the high rate. Do not use on Concord, Fredonia or related varieties due to possible injury.
  Sovran is phytotoxic to some varieties of cherries (see label); do not let product drift onto sensitive crops.
  Pristine and Sovran: Do not alternate Pristine with Sovran. For resistance management, use no more than two applications of either of product per season. Do not use if sporulating lesions are present

Botrytis bunch rot (Trace bloom (first cap fall))

• Materials: Use one of:
  • Rovral @ 1.5 kg/ha
  • Vangard 75 WG @ 750 g/ha
  • Scala @ 2.0 L/ha
  • Elevate 50 WDG @ 1.12 kg/ha
  • Pristine WG @ 420-735 g/ha
  • Serenade ASO @ 5.0-15.0 L/ha
    
• Comments: If the bloom/postbloom period is wet, spray immediately to control latent infections in susceptible varieties (Gamay Noir, Pinot Noir, Pinot Gris, Riesling, Chardonnay and Seyval Blanc). Direct this spray at the fruiting zone.
  Vangard or Scala: Use once and then rotate to a different group. Use no more than two applications of either product per season.
  Elevate: Do not apply Elevate if rainfall is expected within six hours after application.
  Pristine WG: At high rate provides suppression of bunch rot. See Table 2-6. Efficacy Ratings for Pesticides.
  Serenade ASO: Provides suppression of botrytis bunch rot. See Table 2-6. Efficacy Ratings for Pesticides and Bacillus subtilis (Serenade ASO, Serenade MAX).

   

---

Do not apply insecticides while grapes are in bloom.
See Bee Poisoning.

---

Precautions

• Read the product label and follow all safety precautions. Some grape varieties are sensitive to Sulphur, Thionex, Copper, Dikar, Flint, Pristine, Dikar plus Zolone, or other products. See Table 6-5. Relative Susceptibility of Grape Cultivars to Diseases, for specific information.
• For preharvest intervals, re-entry periods, maximum number of applications and chemical groups, see Table 6-4. Products Used on Grapes.
• Resistance management: To delay development of resistance to fungicides, miticides and insecticides, follow resistance management guidelines outlined in Pest Resistance to Insecticides, Fungicides, Miticides. In addition, take the following steps to avoid rapid development of fungicide resistance:
  • Do not reduce rates below those specified on the label.
  • Do not use Nova, Sovran, Flint, Lance, Revus, or Pristine as eradicants when sporulating lesions of the target disease are present.
  • Use sufficient water to provide thorough coverage.
• Preharvest intervals: Contact the processors and wineries directly in regard to their preharvest interval policy. Preharvest intervals listed in Table 6-4. Products Used on Grapes are taken from product labels. In some cases, regulations on residues in finished products (e.g. wine) are much more stringent. Many processors require longer preharvest intervals than stated on product labels. Some processors and wineries also have special restrictions for certain pest control products regarding number of applications or application after a certain crop stage. Consult the grape purchaser for more details.
• Spray water volumes: Sufficient water volumes are necessary to provide complete coverage with grape fungicides, miticides and insecticides. Increased water volumes are necessary as the season progresses and canopies grow. Canopy management through hedging, leaf-pulling and shoot thinning, as well as proper sprayer calibration, are critical to ensure proper spray coverage. Sufficient coverage and efficacy are not possible if water volumes are inadequate. Some types of sprayers are able to provide sufficient coverage with less water than others. Consult equipment dealers or professional crop consultants about the amount of water needed to ensure adequate coverage. Read and follow water volume requirements on all product labels.

---

Related Links

• Notes on Grape Pests
• Grapes in Ontario
• Integrated Pest Management (IPM)
• Pesticide Application and Safety
• Pesticide Companies and Agents
• Search the PMRA website
• Ontario Minor Use Program
• OMAFRA Publication 505: Ontario Weeds
• OMAFRA Publication 75: Guide To Weed Control: Grapes