American Potato Journal

, Volume 67, Issue 7, pp 419–425 | Cite as

Influence of potato cultivars on the effectiveness of fungicide control of early blight

  • B. J. Christ


Three potato cultivars differing in degree of susceptibility to early blight were grown under crop management practices typical for Pennsylvania in 1987 and 1988. There were three experimental treatments: no fungicides, mancozeb with weekly applications initiated at 7 or 8 weeks after planting (early treatment), and weekly applications initiated at first symptoms of disease (late treatment). The no-fungicide control treatment had significantly higher AUDPC values than either treatment with fungicides and the no-fungicide treatment had significantly lower yield in 1987 but not in 1988. Tubers from the no-fungicide control had lower specific gravity. Norchip, the cultivar most susceptible to early blight examined in this study, responded the most in yield increases by the increased fungicide applications.

Additional key words

Solanum tuberosum Alternaria solani area under disease progress curve specific gravity 


Tres cultivares de papa, con diferentes grados de susceptibilidad al tizón temprano, fueron cultivados en 1987 y 1988 bajo prácticas de cultivo tÍpicas para Pennsylvania. El experimento comprendió tres tratamientos: testigo sin fungicidas, mancozeb con aplicaciones semanales iniciadas siete u ocho semanas después de la siembra (tratamiento temprano) y mancozeb con aplicaciones semanales iniciadas al aparecer los primeros síntomas de la enfermedad (tratamiento tardío). El tratamineto testigo, sin fungicidas, tuvo valores de AUDPC (Area Under Disease Progress Curve) significativamente mayores que los tratamientos con fungicidas. El mismo tratamiento tuvo en 1987 rendimientos significativamente menores, lo que no ocurrió en 1988. Los tubérculos del testigo sin fungicidas tuvieron una gravedad específica más baja. Norchip, el más susceptible al tizón temprano de los cultivares estudiados, fue el que más incrementó sus rendimientos con el aumento en las aplicaciones del fungicida.


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Copyright information

© Springer 1990

Authors and Affiliations

  • B. J. Christ
    • 1
  1. 1.Department of Plant PathologyThe Pennsylvania State UniversityUniversity Park

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