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Calla Lily (Zantedeschia spp.) - Soft Rot
Cause Pectobacterium carotovorum, a bacterium that survives on plant debris. The disease is widely distributed but infrequent.
Symptoms Flowers do not form or open irregularly and rot. Flower stalks frequently rot at the base. The top of the bulb may be rotted.
Cultural control Spread and development of the disease can be controlled only by the application of an integrated strategy involving the use of pathogen-free propagation material, disinfection of equipment and other hygienic measures.
- Store bulbs under dry, well-ventilated conditions. Do not heat or freeze.
- Plant only sound bulbs and dispose of any rotted bulbs.
- Plant correctly in the fall with the pointed side of the bulb facing up. Note - wear gloves when handling bulbs as some people are sensitive resulting in skin irritation.
- Avoid overwatering.
Chemical control A preplant bulb soak only after all bulbs have been sorted and diseased bulbs have been destroyed may be helpful for soft rot that occur during the season while a post harvest soak may be useful for rot that develops in storage.
- KleenGrow at 0.15 to 1.5 fl oz/gal water. Soak for 30 seconds and allow to drain.
Reference Jafra, S., Przysowa, J., Gwizdek-Wiśniewska, A., and Van Der Wolf, J.M. 2009. Potential of bulb-associated bacteria for biocontrol of hyacinth soft rot caused by Dickeya zeae. Journal of applied microbiology, 106:268-277.