Patterns of terminal growth and fruit set differ among growing regions. Likewise, the response to Apogee or Kudos 27.5 WDG appears to differ between regions. Therefore, the rate and calendar date of application may vary between regions. For more information, visit ontario.ca/apples and click on Plant Growth Regulators for Fruit Crops.
See [Suggested Apogee or Kudos 27.5 WDG Rates (g product per ha)](/supporting-information/apples/thinning-and-plant-growth-regulators/suggested-apogee-or-kudos-27.5-wdg-rates-g-product-per-ha) for rates. The application rate is determined primarily by tree size, vigour, and whether protection against shoot blight is an objective.
Follow the steps on the label to adjust rates for tree-row volume dilute applications. [Suggested Apogee or Kudos 27.5 WDG Rates (g product per ha)](/supporting-information/apples/thinning-and-plant-growth-regulators/suggested-apogee-or-kudos-27.5-wdg-rates-g-product-per-ha) shows various rates for sprays applied at 1,000 L per ha (dilute). Apogee has been used effectively when applied in more concentrated sprays, provided thorough wetting of the canopy is achieved. Low-volume spraying of plant growth regulators and chemical thinners is not recommended.
Adjuvants and hard water
Include the spray adjuvant, Agral 90, with Apogee or Kudos 27.5 WDG to improve the uptake of the prohexadione-calcium molecule by the leaf. In addition, if the spray water source is hard water and contains high levels of calcium or magnesium, include an equal amount of ammonium sulphate (AMS) fertilizer by weight with Apogee or Kudos 27.5 WDG. Use a high-quality, greenhouse grade of AMS to avoid plugging of nozzles.