Greenhouse and field evaluation of the natural saponin CAY-1 for control of several strawberry diseases.

The steroidal saponin from cayenne pepper, CAY-1, was tested as a potential fungicide in detached-leaf assays and field trials. Efficacy of CAY-1 against strawberry anthracnose was compared to the commercial fungicide azoxystrobin. Both fungicides prevented anthracnose leaf lesions when applied to the host 24 hours prior to inoculation with Colletotrichum fragariae, but neither prevented lesion development when applied 24 hours after inoculation. CAY-1 reduced the growth of several fungal pathogens in laboratory assays and prevented anthracnose development in detached-leaf assays, but it did not control foliar or fruit-rot diseases of strawberry in field trials.