Poinsettia -- Bacterial Stem Rot

Cause: Erwinia carotovora subsp. carotovora, a bacterium that can spread by workers' hands, cutting tools, or contaminated water supplies. It also can survive in plant debris. Any factor that stresses cuttings favors the disease.
Symptoms: Cuttings develop a soft, mushy rot beginning at the basal end. Symptoms can develop in 24 to 48 hours when conditions are optimal for disease development. If infected plants survive the cutting phase, stunting and vascular browning may occur later. Stems and leaves also may wilt, darken, and look water-soaked, followed by complete plant collapse.

Cultural control:
1.Destroy plant debris in and around the greenhouse.
2.Avoid waterlogging the rooting medium.
3.Keep temperatures below 90oF.
4.Wash hands, and keep cutting tools disinfected.
5.Give stock plants moderate nitrogen fertility.
6. Disinfect cutting knives, containers, and benches frequently when harvesting cuttings.

Chemical control: Focus on cultural controls.
1. Phyton 27 at 1.5 to 3.5 oz/10 gal water. 24-hr reentry