Early blight/brown spots fungal spores associated with Alternaria solani and Alternaria alternata (A) were detected in both passive and active spore traps strategically placed in potato commercial fields at St. Johns and Putnam Counties, indicating potential disease risks under favorable conditions. However, late blight spores, usually associated with Phytophthora sp. (P), were not detected across all traps, suggesting no immediate risk for late blight at the time of sampling.
The detection of fungal spores highlights the importance of proactive field monitoring and data-driven decision-making for effective disease management. Growers are encouraged to stay vigilant and refine their management strategies, using spore reports as a guide tool, alongside prevailing environmental conditions, to mitigate potential risks.
Environmental Conditions Favoring Disease Development
Early Blight (Alternaria solani) Spore germination and infection primarily occur under favorable temperatures range of 68–86°F (20 to 26°C), high humidity, and extended leaf wetness. Frequent dew formation, overhead irrigation, fog, poor airflow, and rainfall increase disease risk.
Brown Spot (Alternaria alternata) Long dew periods, humid environments, and temperatures between 64- 86°F (18 to 30°C) are favorable for spore germination and penetration. Disease severity increases with frequent wet-dry cycles, especially when rainfall or irrigation prolongs leaf surface moisture.
Late Blight (Phytophthora infestans) The pathogen favors cool to moderate temperatures ranging from 50–75°F (10 to25°C) with high relative humidity (≥90%) or leaf wetness periods exceeding 10 hours. Risk increases during cool nights with dew, fog, or persistent moisture. Sporangia, as inoculum, are easily dispersed by wind and wind-driven rain, facilitating the disease to spread rapidly.
Spore Report Alert System
🔴 Red: Spores detected, indicating a potential disease risk.
🟡 Yellow: Spores detected in 1-2 spore traps, indicating close monitoring.
🟢 Green: No spores detected, indicating no immediate concern.
March 24, 2025
Alternaria early blight and brown spot fungal spores, associated withAlternaria solani and Alternaria alternata(A), respectively, were detected in all four passive and active spore traps placed strategically in commercial potato fields and experimental station in St. Johns County. Meanwhile, spores of these diseases were detected in three spore trap samplers at Putnam County. This widespread detection suggests a potential risk of disease development under favorable environmental conditions.
Additionally, Phytophthora sp. (P), usually associated with potato late blight in potato fields, was detected at Location No. 2 in St. Johns County from two spore traps and Location No. 3 in Putnam County from one active spore trap. The detection highlights close monitoring/ moderate risk of late blight, particularly if weather conditions continue to favor pathogen activity.
The detection of fungal spores highlights the importance of proactive field monitoring and data-driven decision-making for effective disease management. Growers are encouraged to stay vigilant and refine their management strategies, using spore reports as a guide tool alongside prevailing environmental conditions to mitigate potential risks.
Environmental Conditions Favoring Disease Development
Early Blight (Alternaria solani) Spore germination and infection primarily occur under favorable temperatures range of 68–86°F (20 to 26°C), high humidity, and extended leaf wetness. Frequent dew formation, overhead irrigation, fog, poor airflow, and rainfall increase disease risk.
Brown Spot (Alternaria alternata) Long dew periods, humid environments, and temperatures between 64- 86°F (18 to 30°C) are favorable for spore germination and penetration. Disease severity increases with frequent wet-dry cycles, especially when rainfall or irrigation prolongs leaf surface moisture.
Late Blight (Phytophthora infestans) The pathogen favors cool to moderate temperatures ranging from 50–75°F (10 to25°C) with high relative humidity (≥90%) or leaf wetness periods exceeding 10 hours. Risk increases during cool nights with dew, fog, or persistent moisture. Sporangia, as inoculum, are easily dispersed by wind and wind-driven rain, facilitating the disease to spread rapidly.
Spore Report Alert System
🔴 Red: Spores detected, indicating a potential disease risk.
🟡 Yellow: Spores detected in 1-2 spore traps, indicating close monitoring.
🟢 Green: No spores detected, indicating no immediate concern.
March 31, 2025
Pathogen
Disease
Detection Summary*
Alternaria solani
Alternaria Alternata
Early blight
Brown Spot
Detected in all traps – St. Johns Co.
Detected in 3 traps – Putnam Co.
Phytophthora infestans
Late Blight
Detected in 2 traps – St. Johns Co.
Detected in 1 trap – Putnam Co.
*Spore presence = potential, not guarantee. Combine spore data with crop stage, cultivar susceptibility, and local weather to guide your actions.
Alternaria early blight and brown spot fungal spores, associated with Alternaria solani and Alternaria alternata(A), respectively, were detected in all four passive and active spore traps placed strategically in commercial potato fields and experimental station in St. Johns County. Meanwhile, spores of these diseases were detected in three spore trap samplers at Putnam County. This widespread detection suggests a potential risk of disease development under favorable environmental conditions.
Additionally, Phytophthora sp. (P), usually associated with potato late blight in potato fields, was detected at Location No. 2 in St. Johns County from two spore traps and Location No. 3 in Putnam County from one active spore trap. The detection highlights close monitoring/ moderate risk of late blight, particularly if weather conditions continue to favor pathogen activity.
The detection of fungal spores highlights the importance of proactive field monitoring and data-driven decision-making for effective disease management. Growers are encouraged to stay vigilant and refine their management strategies, using spore reports as a guide tool alongside prevailing environmental conditions to mitigate potential risks.
Environmental Conditions Favoring Disease Development
Early Blight (Alternaria solani) Spore germination and infection primarily occur under favorable temperatures range of 68–86°F (20 to 26°C), high humidity, and extended leaf wetness. Frequent dew formation, overhead irrigation, fog, poor airflow, and rainfall increase disease risk.
Brown Spot (Alternaria alternata) Long dew periods, humid environments, and temperatures between 64- 86°F (18 to 30°C) are favorable for spore germination and penetration. Disease severity increases with frequent wet-dry cycles, especially when rainfall or irrigation prolongs leaf surface moisture.
Late Blight (Phytophthora infestans) The pathogen favors cool to moderate temperatures ranging from 50–75°F (10 to25°C) with high relative humidity (≥90%) or leaf wetness periods exceeding 10 hours. Risk increases during cool nights with dew, fog, or persistent moisture. Sporangia, as inoculum, are easily dispersed by wind and wind-driven rain, facilitating the disease to spread rapidly.
Spore Report Alert System
🔴 Red: Spores detected, indicating a potential disease risk.
🟡 Yellow: Spores detected in 1-2 spore traps, indicating close monitoring.
🟢 Green: No spores detected, indicating no immediate concern.
April 7, 2025
Pathogen
Disease
Detection Summary*
Alternaria solani
Alternaria alternata
Early blight
Brown Spot
Detected in all traps – St. Johns Co.
Detected in 3 traps – Putnam Co.
Phytophthora infestans
Late Blight
Not detected
*Spore presence = potential, not guarantee. Combine spore data with crop stage, cultivar susceptibility, and local weather to guide your actions.
Alternaria early blight and brown spot fungal spores, associated with Alternaria solani and Alternaria alternata(A), respectively, were detected in all four passive and active spore traps placed strategically in commercial potato fields and experimental station in St. Johns County. Meanwhile, spores of these diseases were detected in three spore trap samplers at Putnam County. This widespread detection suggests a potential risk of disease development under favorable environmental conditions.
Additionally, Phytophthora sp. (P), usually associated with late blight in potato fields, was not detected in both Counties, specifying no immediate risk at the time of sampling.
The detection of fungal spores highlights the importance of proactive field monitoring and data-driven decision-making for effective disease management. Growers are encouraged to stay vigilant and refine their management strategies, using spore reports as a guide tool alongside prevailing environmental conditions to mitigate potential risks.
Environmental Conditions Favoring Disease Development
Early Blight (Alternaria solani) Spore germination and infection primarily occur under favorable temperatures range of 68–86°F (20 to 26°C), high humidity, and extended leaf wetness. Frequent dew formation, overhead irrigation, fog, poor airflow, and rainfall increase disease risk.
Brown Spot (Alternaria alternata) Long dew periods, humid environments, and temperatures between 64- 86°F (18 to 30°C) are favorable for spore germination and penetration. Disease severity increases with frequent wet-dry cycles, especially when rainfall or irrigation prolongs leaf surface moisture.
Late Blight (Phytophthora infestans) The pathogen favors cool to moderate temperatures ranging from 50–75°F (10 to25°C) with high relative humidity (≥90%) or leaf wetness periods exceeding 10 hours. Risk increases during cool nights with dew, fog, or persistent moisture. Sporangia, as inoculum, are easily dispersed by wind and wind-driven rain, facilitating the disease to spread rapidly.
Spore Report Alert System
🔴 Red: Spores detected, indicating a potential disease risk.
🟡 Yellow: Spores detected in 1-2 spore traps, indicating close monitoring.
🟢 Green: No spores detected, indicating no immediate concern.
