Summary
Spray schedules for early blight in which fungicidal applications were initiated or terminated at various periods during the growing season have demonstrated that as few as two to three applications timed properly can control early blight infection in potatoes equally as well as five to seven applications. Early sprays were shown to be of little importance in the overall blight control program. Effective spray schedules were those which happened to begin at or near the time of secondary spread, as measured by spore trapping techniques. This timing proved superior to schedules begun earlier or later than this date in that equal or better blight control was attained at reduced cost. The possible role of spore traps as guides for timing initial applications of fungicides on a commercial scale is suggested by these and other studies.
Sumario en Español
Los programas de aplicación de fungicida para el control del tizón temprano de la papa, iniciados y terminados durante varios períodos de crecimiento de la planta, demostraron que con la aplicación del fungicida a su debido tiempo, dos o tres tratamientos controlan la enfermedad tan eficazmente como cinco o siete tratamientos. En general, las aspersiones demasiado tempranas resultaron de poca importancia en el control del tizón. Los programas de aspersiones más efectivos fueron aquellos en que la aspersión inicial coincidió con el desarrollo de la infección secundaria, estimada por técnicas de capturas de esporas. La elección del tiempo oportuno se tradujo en resultados superiores a los obtenidos en programas iniciados más temprano o más tardiamente, puesto que se obtuvo igual o mejor control del tizón a un costo más reducido. Por estos estudios se sugiere el posible papel de las trampas de esporas como guías para la elección del tiempo oportuno para las aplicaciones de fungicida en escala comercial.
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Published with the approval of the Director, Colorado Agricultural Experiment Station as Scientific Journal Series No. 1017.
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Harrison, M.D., Livingston, C.H. & Oshima, N. Control of potato early blight in Colorado. I. Fungicidal spray schedules in relation to the epidemiology of the disease. American Potato Journal 42, 319–327 (1965). https://doi.org/10.1007/BF02869697
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DOI: https://doi.org/10.1007/BF02869697