Publication 360, Fruit Production Recommendations:
Grape Calendar - Beginning of ripening (veraison) through harvest

Table of Contents

1. Beginning of ripening (veraison) through harvest
   • Grape berry moth (about mid-late Aug.)
   • Powdery mildew
   • Downy mildew
   • Botrytis bunch rot
   • Slugs and snails
     
   • 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
   • 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 frapes
     
   • 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

Grape berry moth (about mid-late Aug.) (Beginning of ripening (veraison) through harvest)

• Materials: Use one of:
• Altacor @ 285 g/ha
• Pounce @ 360 mL/ha
• Perm-Up @ 360 mL/ha
• Ambush 500 EC @ 275 mL/ha
• Imidan 50 WP @ 3.1 kg/ha
• Diazinon 50 W @ 3.375 kg/ha
• Guthion 50 WSB (see label)
  or Sniper (see label)
• Success 480 SC @ 182 mL/ha
• Comments: Where mating disruption (MD) for GBM is in place and monitoring indicates good control, an insecticide may not be needed at this time.
  Where berry moth is a regular problem, use one of these products. Apply sprays in high water volumes to ensure complete coverage.
  Check the interval to harvest. A spray may be needed on late varieties to control the brood that emerges in late August. Border sprays of conventional insecticides may be very effective.
  Altacor: Apply at first egg hatch (first sustained moth catch in traps), earlier than the traditional timing (upswing in moth numbers captured in pheromone traps) used for Guthion, Sniper, Diazinon, Pounce or Imidan.
  Success 480: Provides suppression of GBM. See Table 2-6. Efficacy Ratings for Pesticides.

Powdery mildew (Beginning of ripening (veraison) through harvest)

• Materials: Use one of the materials listed under Berry touch to cluster closure.
• Comments:. Vinifera and French hybrid varieties are more susceptible and may require extra sprays.
  Check product labels and Table 6-4. Products Used On Grapes, for days to harvest intervals.

Downy mildew (Beginning of ripening (veraison) through harvest)

• Materials: Use one of the materials listed under Berry touch to cluster closure.
• Comments: Check product labels and Table 6-4. Products Used On Grapes, for days to harvest intervals.

Botrytis bunch rot (Beginning of ripening (veraison) through harvest)

• Materials: Use one of:
  • 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: When late summer or fall weather conditions are wet and humid, protection against Botrytis is necessary during the ripening or veraison period. This is especially important for vineyards designated for late harvest or ice wine. For further information on product choice and use, see comments under Berry touch to cluster closure.
  Vangard and Scala: Do not rotate between these products.
  Pristine: At high rate provides suppression of bunch rot. See Table 2-6. Efficacy Ratings for Pesticides.
  Serenade ASO: Provides suppression of bunch rot . See Table 2-6. Efficacy Ratings for Pesticides and Bacillus subtilis (Serenade ASO, Serenade MAX).

Slugs and snails (Beginning of ripening (veraison) through harvest)

• Materials: Use one of:
  • Sluggo @ 25.0 kg/ha
• Comments: Apply higher rate of 50 kg/ha if population is very high. Apply when infestation begins. Reapply as the bait is consumed or at least every 2 weeks if slugs and snails continue to be a problem.

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: Grapes