Significant losses in commercial snapdragon fields have occurred as a result of Phytophthora nicotianae. Infections of roots and crowns result in wilting, stunting, dieback, and plant death. Research was initiated at two farms growing snapdragons as a cut flower crop. One of the farms had recently planted snapdragon plugs showing Phytophthora symptoms in addition to their established beds with Phytophthora. At these locations, annual fumigation and applications of Subdue are relied upon to provide disease control. Resistance of Phytophthora to Subdue has been documented and is a significant concern to growers managing this disease.
Source: • American Floral Endowment Special Research Reports #102