Stem - blue-black rotting on parts of stems. Leaves drop, then stems partially recover and produce new leaves at the terminals. In the case of Verticillium stem dieback, affected stems do not recover. The two diseases are confused easily.

Leaf - depending on the variety affected, symptoms are either round spots or angular dead areas. Spots may initially appear as small translucent pustules similar to those characteristic of oedema. Round spots are dark green to black, about 0.0625 to 0.125 inch in diameter, and slightly sunken. Affected leaves wilt and die; leaves may stay on the plant for some time afterward. Angular, dead areas occur when sectors of leaves bounded by the veins die. This symptom is accompanied by a wilting of leaf edges. Bacteria from leaf spots may spread down the petiole, into the stem, then back to the top of the plant. Ivy geranium foliage loses luster and develops symptoms suggesting nutrient deficiency or mite infestation.

1. Use bacteria-free stock plants. Vascular-inhabiting bacteria are carried over in cuttings from symptomless infected plants, from obviously diseased plants, or from recently infested soil.
2. Insist that workers not handle Pelargonium or Geranium spp. in other locations prior to working in the greenhouse. Have them wash their hands if they do.
3. Do not grow Geraniums around or near the greenhouse production area.
4. Set out stock in sterilized soil or soilless planting media.
5. Prevent contaminating stock plants by disinfecting cutting knives and other tools frequently. Soak tools for 60 sec in 10% bleach (Clorox) or shellac thinner (70% ethyl alcohol) or quaternary ammonium (Physan 20).
6. Keep plants from different propagators separate as an outbreak may be confined to only one source.
7. Prevent or minimize splashing when watering plants.
8. Use no more than 63^oF bottom heat. Do not use bottom heat for pelargoniums.
9. Do not put ivy geraniums in hanging baskets over geraniums on the bench.
10. Scout often for early detection. Remove and test any plants that look suspect.
11. Carefully remove and discard any symptomatic plants or those that test positive for the bacteria. Also remove and discard adjacent plants.
12. Discard all remaining geraniums at the end of the production cycle and keep greenhouse free of geraniums for as long as possible before resuming geranium production.

1. Phyton 27 at 1.5 to 5 oz/10 gal water. Higher rates may cause severe leaf burns. 24-hr reentry.

1. Cease or Rhapsody at 8 qt/100 gal water. Active ingredient is a protein from Bacillus subtilis strain QST 713. Was useful in California and Georgia trials. 4-hr reentry.