Tame the Late Blight, Protect Your Potato Prosperity
Potato (Solanum tuberosum L.) is one of the world’s most vital food crops. According to FAO, global production surpassed 359 million tons in 2020. However, potato yields face a major threat from Phytophthora infestans, the destructive pathogen behind Late Blight—the most economically devastating disease in potato production.
Know the Enemy: Recognizing Late Blight in the Field
1. Early Foliar Symptoms (Fig. A)
Small, light-to-dark green, water-soaked spots appear, often starting on lower leaves.
Lesions typically form near leaf tips or edges where moisture lingers.
2. Progressive Leaf Damage (Fig. B)
Under cool, humid conditions, lesions rapidly expand into large, dark brown or black patches with a greasy appearance.
The infection spreads quickly, unrestricted by leaf veins, and entire leaves may blight within days.
3. Sporulation Signs (Fig. C)
In humid weather, white, fuzzy mold (sporangia and sporangiophores) develops along lesion margins or petioles, signaling active sporulation.
4. Tuber Infection (Fig. D)
Tuber symptoms include irregular, slightly sunken patches with brown to purplish skin discoloration.
The Disease Cycle: A Relentless Threat
Late blight never truly disappears. The pathogen survives between seasons in infected tubers, whether stored, left as volunteer plants, or discarded in cull piles. Under cool and moist conditions, these infected tissues become reservoirs for new infections. Once established, the pathogen releases thousands of airborne spores, which can infect foliage within 12 hours of leaf wetness. In optimal weather, the disease can complete a full infection and sporulation cycle in just 5–7 days, leading to explosive epidemics. Spores may also wash down into the soil, infecting healthy tubers through their eyes and perpetuating the next generation of disease.
Strategic Defense Plan
I. Control Disease Sources
Eliminate infected seed, waste, and volunteer potatoes.
Always plant certified disease-free seed tubers to prevent initial infection.
II. Manage Field Practices
Optimize irrigation — avoid excessive or nighttime watering to reduce leaf wetness.
Select well-drained, easily accessible fields, avoiding low or shaded sites that trap moisture.
III. Monitor and Apply Fungicides Wisely
Scout regularly, prioritizing low-lying, humid, or historically infected zones.
Track weather forecasts — initiate preventive sprays when conditions (cool, humid) favor infection, even before visible symptoms.
Apply fungicides correctly:
Maintain a regular, continuous spray schedule based on local risk and disease models.
Once late blight appears, switch to or mix with a systemic fungicide offering curative action.
Rotate fungicides with different modes of action to delay resistance development.
Destroy infected hot spots immediately through deep burial, burning, or chemical desiccation.
For dependable control of Late Blight, rely on King’s Captan, King’s Patrol and King’s Soldier. Their proven protective and curative activity provides powerful, long-lasting defense — keeping your potato fields healthy, productive, and profitable. (Always read and follow label directions before use.)
IV. Manage Harvest and Storage
Ensure vines are fully dead before harvest, allowing 10-14 days for skin set.
After harvest, apply phosphorous acid treatment to tubers before storage to strengthen protection and maintain post-harvest quality
Since 2003, King Quenson has been thriving to introduce the latest technologies to agricultural industries and farmers to achieve mutual development and prosperity. With years of dedication and rich experience, King Quenson devotes more than 20 years to crop protection and offers solutions.
If you have a need, you can contact us at any time:
Email: info@kingquenson.com
Tel: 86-755-86612760, 86-755-86612793
