Cercospora Leaf Spot (fungus – Cercospora pittospori): Small, angular-shaped, yellowish-to-brownish spots. Spots may coalesce to form large irregular spots. Fungus fruits in fawn colored patches on lower surface. Most prevalent on older leaves. May cause premature leaf drop. Control is best obtained by protective spraying with recommended fungicides.
Leaf Spots (fungi – Alternaria tenuissima, Phyllosticta sp.): Small, circular dark-brown necrotic spots surrounded by chlorotic areas. Generally affects shrubs in poor physiological condition. Control is best obtained by maintaining shrubs in good growing condition. Applications of a protective fungicide are effective.
Cotton Root Rot (fungus – Phymatotrichum omnivorum): Plants suddenly wilt and die. When plants are pulled from the soil, the outer bark is decayed. Rhizomorphs of the fungus may be observed. (See the section on Cotton Root Rot)
Root Knot Nematode (fungus – Meloidogyne sp.): Plants usually lack vigor, are often stunted and pale yellow. Plants may wilt quickly under moisture stress. Roots have small-to-large swellings, galls or knots. These are generally spherical and cannot be easily removed from the roots. (See the section on Root Knot Nematodes)
Virus: Three virus diseases, a mosaic on the leaves, one which causes a variegation of the leaves and one which causes rough bark have been reported on Pittosporum.
Southern Blight (fungus – Sclerotium rolfsii): Reported in Texas.