Our Wine Grape Knowledge

This past season has seen some of the best flowering conditions and fruit-set, resulting in record yields across most of the country. The result of this is that growers are faced with two unique considerations for future vine health.

• Early summer is a critical period for disease prevention with most varieties flowering over the next two months. Reduce the risk of late season, post fruit-set outbreaks with a robust spray programme. Consider spring conditions in your vineyard. Warm temperatures and moderate to high humidity increase the likelihood of either powdery or downy mildew reproducing faster and earlier, and will require the interval between cover sprays to be shortened accordingly, especially when using sulphur products such as Unishield or Kumulus.
• Ensure you apply an effective powdery mildew cover at the 80 percent (E-L25) growth stage. Products such as Miravis Prime or Luna Sensation provide a very high degree of protection for Botrytis or powdery mildew, or both in the case of Miravis Prime. Alternative botryticides include Switch (AP chemical group) or Teldor, but these must be mixed with a strong powdery mildew product such as Luna Sensation or a DMI (Group 3) such as Belanty. Consult both your winery and the ‘New Zealand Winegrowers 2025/26 Spray Schedule’ for pre-harvest intervals and any use limitations on individual products. (Note: applications of Miravis Prime and Switch must ensure a 90-day PHI). Discuss timing and the best mix of options with your Fruitfed Supplies Technical Horticultural Representative.

• Carefully consider your choice of all spray
  products during this period and monitor
  the growth stage very carefully, according
  to your nil residue or MRL spray schedule.
  Growth stage E-L 18 (pre cap-fall) is the
  cut-off for the use of some products such
  as those containing buprofezin like Mortar
  and Ovation.
  
  
• If you are applying Movento (90-day
  PHI) to control mealybugs over this
  period, remember timing of application
  is important. To achieve maximum
  efficacy, apply in cool, overcast conditions
  wherever possible.