Cagwin & Dorward Landscape Contractors

Camellia petal blight, caused by the fungus Ciborinia camelliae can be a damaging disease on both common and sasanqua camellia. The Disease development is favored by frequent rain showers, high humidity, and mild temperatures during bloom. All camellias are equally susceptible to this disease. Camellia petal blight is introduced into landscape plantings from diseased plant material.

Symptoms

Within 24 hours of infection, small brown spots appear on the expanding flower petals, The veins, which usually are darker than the surrounding tissues, often give the blooms a distinctive netted appearance. This netted pattern can be used to distinguish petal blight from cold injury. These spots quickly increase in size until the entire blooms turns a dull brown. The blighted petals are dry or somewhat leathery but do not cruble when handled. Once the blooms are killed, they will fall intact to the ground.

Disease Cycle

Small black bodies,called sclerotia, appear at the base of the blighted petals several weeks after the blooms fall to the ground. Black sclerotia are usually seen on the decaying petals. The following fall or winter some sclerotia may produce a small, mushroom-like structure called an apothecia, while other remain dormant for up to 5 years. Spores which are released by the apothecia, are spread to camellia flower buds by wind currents, germinate under favorable weather conditions, and rapidly infect the petals.

Control Practices

Once introduced into a planting of camellia, the fungus cannot be eradicated. A combination of sanitation, cultural practices, and fungicide treatments usually are required to control camellia petal blight.

Collect and destroy all diseased blooms on and beneath the plant.
Each spring remove any old mulch or top dressings, and then lay a 1 inch layer of fresh bark or mulch around the base of the camellias. The bark or mulch will interfere with the spread of spores from the apothecia to the flower buds.
Foliar sprays and drenches of selected fungicides may give some protection from camellia petal blight and should only be used in conjunction with the sanitation and cultural practices already described.

**Table 1. Chemical Control Of Camellia Flower Blight.**
	Rate
Fungicide	per gal.	per 100 gal.	Comments
Foliar Sprays
mancozeb Dithane T/O 80W Fore 80W Protect T/O 80W	2 t. 2 t. 2 t.	1.5 lb. 1.5 lb. 1.5 lb.	Apply when blooms show color and repeat at 10- to 14-day intervals. Also, spray ground under plant.
thiophante-methyl 3336 50W 3336 4.5F	1/2-1 t.	12-16 oz. 10-20 fl.oz.
triadimefon Bayleton 25W		8-16 oz.	Make first application when buds show color and repeat at 7- to 14-day intervals.
Soil Drenches
PCNB Terraclor 75W Defend 75W		1 c./100 sq.ft. 1 c./100 sq.ft.	Spray or dust around base of plant. Apply enough water to cover area in late November to mid-December.

Foliar sprays of selected fungicides will provide additional protection from camellia petal blight, particularly in valued landscape plantings. The first applications should be made when the buds begin to show color. Repeat the foliar sprays during bloom at the rates and intervals listed in Table 1. Spray the ground under each plant with any remaining fungicide spray mixture in the spray tank.

Garden -

Garden - Camellia Petal Blight

Symptoms

Disease Cycle

Control Practices