Publication 360, Fruit Production Recommendations:
Grape Calendar > 3-5 leaves unfolded, 10-15 cm shoot length

Table of Contents

1. 3-5 leaves unfolded, 10-15 cm shoot length
   • Phomopsis cane and leaf spot
   • Black rot
   • Powdery mildew
   • Precautions
2. Other grape calendar sections
   • Bud burst to first leaf
   • Shoot length, 20-25 cm
   • Trace bloom (first cap fall)
   • 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 and diseases
   • Mating disruption (MD) technology for grape berry moth
   • Table 6-4. Products used on grapes
     
   • Table 6-5. Relative susceptibility of grape cultivars to diseases
   • 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

Phomopsis cane & leaf spot (3-5 leaves unfolded, 10-15 cm shoot length)

• Materials: Use one of :
  • Supra Captan 80 WDG (see label)
    or Maestro 80 DF @ 2.0 kg/ha
  • Folpan 80 WDG @ 1.25 kg/ha
• Comments: Spray susceptible varieties, especially if the weather is wet or there is a history of phomopsis in the vineyard. See Table 6-5. Relative Susceptibility of Grape Cultivars to Diseases. Use enough water to ensure complete coverage. Alternate row spraying will not give adequate protection from phomopsis.

Black rot (3-5 leaves unfolded, 10-15 cm shoot length)

• Materials: Use one of :
  • Nova 40 W @ 200 g/ha
  • Ferbam 76 WDG (see label)
• Comments: Spray susceptible varieties, especially where there is a history of black rot and conditions are wet. Use enough water to ensure complete coverage. Alternate row spraying will not give adequate protection from black rot.

Powdery mildew (3-5 leaves unfolded, 10-15 cm shoot length)

• Materials: Use one of :
  • 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. Alternate row spraying will not give adequate protection from powdery mildew.
  Nova: For resistance management, use no more than two applications per season.
  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).

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 insects and diseases
• 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: Grape