Efecto del extracto etanólico de albahaca genovesa (Ocimum basilicum var. Genovese) sobre Cercospora apii Fressen y el tizón temprano del celery (Apium graveolens)

Cercospora apii Fressen causes early blight of celery in warm areas of Venezuela. To study its control, the effect of ethanolic extract (EE) of albahaca genovesa was evaluated on the fungus and the disease. Plants used for EE preparation were grown in the field, its leaves were let dry, grinded and macerated in 96 % ethanol for 48 h; the crude extract was obtained by distillation in a rotoevaporator BrinkmannMR and was stored until biological tests were performed. In vitro test was conducted with EE at 1; 1,5; 2; 2,5; 3 y 4 % concentrations, evaluating the fungus mycelial growth inhibition (ICM), using a complete random design with 4 replicates. In the in vivo test, celery plants, variety Utah 52/70 were inoculated with a suspension of 8 x 104 conidia/mL of C. apii; the EE was applied weekly at 5, 10, 15 y 20% concentration, a control plant was included inoculated and without EE application. A complete random design with 10 replicates was used, and evaluation included incidence and disease severity, the latter one was used to calculate the percentage of disease reduction (RE). Results from the in vitro test indicated that 4% of EE was statistically more effective with100% of ICM reduction. With regard to the in vivo test, it was found that EE at 20% showed the highest RE (100%) at 14 days. Results of the research indicate that leaf extract from this plant might be an alternative to control celery early blight. Cercospora apii Fressen causa el tizón temprano del célery en zonas cálidas de Venezuela. Con el fin de estudiar su control, se evaluó el efecto del extracto etanólico (EE) de hojas de albahaca genovesa sobre el hongo y la enfermedad. Las plantas utilizadas fueron cultivadas en el campo, sus hojas se dejaron secar a la sombra, se pulverizaron y maceraron en etanol (96%) por 48h; se obtuvo el crudo por destilación con un rotoevaporador BrinkmannMR y se almacenó, hasta el momento de las pruebas biológicas. Se evaluó in vitro el EE a 1; 1,5; 2; 2,5; 3 y 4% sobre la inhibición del crecimiento micelial (ICM) del patógeno, utilizando un diseño completamente al azar, con 4 repeticiones. En las pruebas in vivo, plantas de célery, variedad Utah 52/70, fueron inoculadas con una suspensión de 8x104 conidios/mL de C. apii y luego tratadas semanalmente con EE al 5, 10, 15 y 20%. Se utilizó un diseño completamente al azar con 10 repeticiones y se evaluó la incidencia y la severidad de la enfermedad. Los resultados de la prueba in vitro indicaron que la concentraci