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BLACKLEG ON CUTTINGS

An infection by number of organisms, especially Pythium and Rhizoctonia species. The stem becomes blackened at the base and eventually dies. It is usually caused by unhygienic growing techniques such as using dirty pots, tools or unsterilized compost. Waterlogged compost will also encourage it.

Pots should be sterilized with bleach or a similar agent Incorporate drainage in the growing medium and do not overwater. Use freshly drawn mains water as stored water can harbour the pathogenic organisms. Remove any affected cuttings immediately and remove leaves which die back. Space the cuttings well apart to allow a good air flow. Use a rooting agent containing a fungicide or immerse the cutting in a fungicidal solution before planting.

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