Rust Pressure in Southern Highbush Blueberries — Why It Matters
Leaf rust (caused by Thekopsora minima) is a serious foliar disease in southern highbush blueberry systems, especially under evergreen production in warm climates.
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In Florida, rust can persist year-round on living foliage, producing spores through the mild winter and into harvest, leading to defoliation, reduced photosynthesis, and yield loss.
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Severe rust stress can reduce floral bud differentiation, lower fruit quality, and even blemish fruit when pustules appear on ripening berries.
UF/IFAS emphasizes that preventative management — combining cultural controls with well-timed fungicides — is key to keeping rust pressure below damage thresholds.
While conventional fungicides are commonly used, UF/IFAS notes that organic options such as copper-based products may be employed preventively — before rust outbreaks become severe.
Introducing Magna-Bon CS 2005: Organic Copper for Rust Prevention
Magna-Bon CS 2005 is an OMRI-listed copper sulphate pentahydrate in-solution formulation. Its characteristics make it well-suited for integration into organic and low-residue blueberry programs:
1. Proven Disease Prevention
Blueberry rust thrives in Florida and other warm, humid growing regions, persisting year-round and putting foliage — and ultimately yields — at risk. UF/IFAS research stresses that prevention is the key to management, as fungicides work best before rust infections establish. Magna-Bon CS 2005 offers a reliable copper solution that shields leaves and reduces the spread of new infections.
2. Organic & Sustainable Option
With limited effective organic tools available, Magna-Bon CS 2005 stands out as an OMRI-listed, organically accepted fungicide. Growers looking to reduce reliance on conventional growing practices — while still demanding results — can count on CS 2005 to fit seamlessly into organic or reduced-residue programs.
3. Reduced Defoliation & Stronger Plants
Rust can cause premature defoliation, robbing the plant of energy needed for fruit development and quality. By helping protect the canopy, CS 2005 allows plants to maintain healthier foliage throughout the season, supporting stronger growth, bud set, and improved berry size and quality.
4. Reliable Performance Across Conditions
The advanced micronized copper formulation ensures excellent leaf coverage and adhesion, even under high rust pressure. This means growers can rely on consistent results — fewer lesions, lower disease incidence, and improved harvests — season after season.
5. Fits into an Integrated Program
Rust control requires multiple strategies — cultural practices, irrigation management, and fungicide rotation. Magna-Bon CS 2005 is highly compatible with integrated programs, providing copper protection without disrupting broader disease management plans.
6. Backed by Research & Field Experience
University guidance (UF/IFAS) confirms that copper fungicides are an effective organic option against blueberry rust when applied preventively. Field use of Magna-Bon CS 2005 consistently shows healthier canopies, lower rust incidence, and improved yield outcomes compared to untreated blocks.