Publication 360, Fruit Production Recommendations:
Currant and Gooseberry Calendar - Just before blossoms open

Table of Contents

1. Just before blossoms open
   • Leaf spot
   • Powdery mildew
   • Sawfly (imported currant fruitworm)
   • Blister aphid
   • Botrytis grey mould
   • Precautions
2. Other Currant and Gooseberry Calendar Sections
   • Bloom
   • Postbloom: as soon as bloom is complete
   • 10 days after postbloom spray
   • Postharvest
3. Other Information on Currants and Gooseberries
   • Currant and Gooseberry Nutrition
   • Table 5-11. Products Used on Currants
   • Table 5-12. Disease Ratings on Selected Currant and Gooseberry Varieties
4. Currant and Gooseberry Calendar - PDF 91 kb
5. Pub 360, Chapter 5, Berry Crops - PDF 364 kb
6. Related Links

Just before blossoms open

Leaf spot (Just before blossoms open)

Leaf spots develop on susceptible varieties, reducing yield and vigour. Rake or cultivate to bury old infected leaves before bud-break. Apply fungicides to susceptible varieties at weekly intervals if weather is wet. Ferbam is not labelled for gooseberries.

• Materials: Apply one of;
  • Ferbam 76 WDG @ 6.75 kg/ha
  • Copper 53 W @ 5.0 kg/1,000 L plus hydrated lime @ 4.0 kg lime/1,000 L

Powdery mildew (Just before blossoms open)

• Materials: Apply one of;
  • Microscopic Sulphur @ 5.0 kg/ha
  • Pristine WG @ 1.60 kg/ha
• Comments: Resistant varieties are available, see Table 5-12. Disease Ratings on Selected Currant and Gooseberry Varieties. Prune out infected twig tips in fall and avoid excessive nitrogen.
  Pristine: is registered for suppression, rather than control of powdery mildew.
• Learn more:
  • Notes on Currants and Gooseberries Insects and Diseases
    • Powdery mildew

Sawfly (Just before blossoms open)

• Materials: Diazinon 50 W @ 1.00 kg/ 1,000 L water or Diazinon 500 E @ 1.00 L/ 1,000 L water
• Comments: Adults lay eggs in May and June. Green larvae quickly devour foliage at the green fruit stage. Gooseberries are the preferred host; black currants are not attacked. Do not apply Diazinon after the first bloom opens.
• Learn more:
  • Notes on Currants and Gooseberries Insects and Diseases
    • Imported currantworm (currant sawfly)

Blister aphid (Just before blossoms open)

• Materials: Malathion 25 W @ 2.50 kg/1,000 L water
• Comments: Aphids feeding on new growth can cause leaf curl and red blisters. Spray if aphids are abundant. Ensure good coverage of undersides of curled leaves.

Botrytis grey mould (Just before blossoms open)

• Materials: Apply one of;
  • Pristine WG @ 1.30-1.60kg/ha
  • Lance WDG @ 560 g/ha
  • Elevate 50 WDG @ 1.70 kg/ha
    
  • Serenade ASO 4.00-15.0 kg/ha
• Comments: Botrytis infection during bloom causes early fruit drop, or "runoff" in currants. Apply fungicides at 7-10 day intervals during bloom. Choose fungicides from different fungicide groups to reduce the development of resistant strains of Botrytis.
  Pristine and Lance: Both include active ingredients in the same fungicide group. Do not alternate Pristine with Lance.
  Serenade ASO: Provides suppression, rather than control. Expect best results when used in multiple applications or rotation with other products. See notes on Bacillus subtilis (Serenade ASO, Serenade MAX).
  

Precautions

Read the product label and follow all safety precautions.
Always consult the product label for suggested water volumes. Otherwise, use enough water to ensure thorough spray coverage. Where the product rate is listed in amount per 1,000 L and if a water volume is not provided on the label, use enough water to wet the foliage to the near-drip point.

Products are listed according to insecticide and fungicide family groups. Use of products from different groups helps prevent the development of pest resistance. For resistance management refer to Pest Resistance to Insecticides, Fungicides, Miticides.

For preharvest interval, re-entry period, maximum number of applications and chemical group, see Table 5-11. Products Used on Currants.

Related Links

• Notes on Currant and Gooseberry Diseases and Insects
• OMAFRA Berry Crops Index page
• 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: Berry Crops