Rhizoctonia solani Plant in pasteurized potting mix. Discard infected plants. Apply PCNB or iprodione as a soil drench to protect healthy plants. Thielaviopsis Root Rot Small black spots form on roots. Gradually, the entire root system browns.
Old leaves die while younger leaves yellow.
Thielaviopsis basicola Plant in pasteurized potting mix. Discard infected plants. Viruses Leaves may be mottled, yellowed, or have dead spots or be curled. Plants are stunted. Flower color may break.