Streptocarpus – Water mark
Symptom Look Alikes
Streptocarpus – Impatiens necrotic spot virus (INSV)
Edema and mite injury on Ivy Geraniums are often mistaken.
Schlumbergera – Drip spots
Twisted growth can be caused by physiological or nutritional disorders, broad mites or ethylene.
New Guinea impatiens may exhibit twisted foliage and edge burn as a result of high soluble salts. Cupping and wavy leaves also appear to be favored by dry soil and cool moist air. These symptoms commonly show up in March and April and usually disappear as weather improves later in spring. Orange cultivars appear to be prone to this condition and have exhibited these symptoms in early spring.
Leaf edges turn downward. Broad mites are so small, growers need to look for signs of characteristic damage, which can be confused with herbicide injury, or a physiological disorder or nutritional disorder.
Fact Sheets: Managing Cyclamen and Broad Mites in the Greenhouse on the UConn IPM Web site
Note distorted growing points. May be confused with broad mite injury.
See Managing Cyclamen and Broad Mites in the Greenhouse on the UConn IPM Web site for more information. (click greenhouse on left and then scroll)
Oedema and injury caused by two-spotted spider mites or western flower thrips on Ivy Geraniums are often mistaken.
Oedema blisters form on ivy geraniums when water and solutes build up underneath or possibly within cells, causing the epidermal cells to stretch and collapse. The cells do not rupture as was previously thought. Symptoms of oedema appear as bumps or blisters initially on the undersides of lower or older leaves on a plant. They may then turn brownish or tan and become corky. Severely affected leaves will often turn yellow and fall off the plant.