Control Apple and Cherry Powdery with Kaligreen®

March 21, 2024

Info to Grow
Crop Protection

In the Pacific Northwest, controlling powdery mildew is an annual challenge for apple and cherry orchards. The sign of this pathogen is fuzzy white or gray mycelium on the underside of leaves, on buds, shoots, and even the fruit when under high disease pressure.


Understanding Powdery Mildew


Powdery mildew thrives in the microclimates of the orchards which are warm, but not hot, and humid, but not wet. In the PNW these conditions persist for the better part of the late spring and early summer. This fungus targets the orchard’s new, tender growth, emphasizing the need for continuous control during periods of rapid tree growth. The optimum temperature for powdery mildew disease development is between 66°F and 76°F, but the disease will still develop over a wider range of temperatures. Dormant flowers and shoot buds, particularly in susceptible varieties, serve as overwintering sites, highlighting the importance of a proactive control strategy.


Using Kaligreen to Control Powdery Mildew in Orchard Crops


Kaligreen is an effective solution for fruit tree production. Generally, it’s best used during cover spray timings rotated or applied with a protectant chemistry (the latter is the best choice in a conventional orchard). Kaligreen offers several advantages:


• Immediate Contact Action: Kaligreen’s potassium bicarbonate formulation swiftly unbalances pathogen cells, leading to their rapid demise.
• Enhanced Efficacy: A proprietary surfactant forms contact liposomes, enhances Kaligreen’s affinity for fungal cells, ensuring thorough coverage and effective mildew knockdown.
• OMRI Listed: Certified for organic use.
• Application: Recommended rate of 3 lbs./ac (for best performance maintain a pH between 7 to 8.5 in a tank-mix). Compatible with many pesticides and fertilizers.


Optimizing Your Spray Program


• Proactive Application: Begin applications just after bud break at silver tip, continuing at 7–14-day intervals through new shoot growth.
• Organics: Keep your time between sprays to 7-days during periods of high susceptibility for optimum control. Once the fungus is established in susceptible tissue, it’s generally not possible to eradicate the fungus until the environmental conditions aren’t favorable. However, even in that case, sprays are still important to slow down disease development.
• Post-Harvest Application: A fall spray can be considered, if it fits in with your management program as it can significantly reduce the inoculum load, preparing your orchard for a healthier return the following season.


Controlling Post-Harvest Rots in Apples


Recent research has shown that applying Kaligreen 1-week pre-harvest is an effective means to improve your control of post-harvest apple rot.


Kaligreen Is a Proven Solution in Spray Programs.


Looking to incorporate Kaligreen into your spray program? 


  • Find a Retailer Near You: Discover your nearest Kaligreen supplier. 

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  • Contact a BRANDT Expert: To learn more, contact Nate Britt, Pacific Northwest Territory Sales Manager at 509 494 9778 or email