Diseases |
Symptoms |
Control |
ANTHRACNOSE (Collectotrichum and Gleosporium species) |
Rusty spots on stems, leaves, or fruits, usually accompanied by a dieback of the plant. When wet the spots may be pinkish and produce an ooze. |
Remove diseased leaves. Do not mist leaves. Spray plant with benomyl 50% wettable powder (WP) at a rate of one tablespoon per gallon. |
| CERCOSPORA LEAF SPOT (Cercospora sp.) |
Pin point swellings are produced on the underside of the leaf. Symptoms resemble oedema and spider mite feeding. Eventually the leaf turns yellow and falls from the plant. |
Remove diseased leaves. Do not mist leaves. Spray plant with benomyl 50% wettable powder (WP) at a rate of one tablespoon per gallon. . |
| BACTERIAL LEAF SPOT (Erwinia chrysanthemi) |
Plants infected with bacteria have watersoaked spots, sometimes with a yellow halo, usually uniform in size and sometimes with a sticky ooze. The spots enlarge and will run together under wet conditions. Under drier conditions the spots do not enlarge but dry out and turn reddish brown, giving a speckled appearance. |
Remove diseased leaves and spray with Streptomycin at 200 ppm. See label for mixing directions. (This will not control a systemic infection). |
| FUNGAL LEAF SPOTS |
Several fungi can cause leaf spots. Symptoms include small, brown spots with yellowish margins on the leaves. Spots may have a concentric ring or target pattern. Small black dots (fruiting bodies of the fungi) may be visible in dead tissue. Sometimes the lesions run together and the entire leaf dies. The fungi survive on dead and decaying plant matter in the soil. |
Remove and destroy infected plant material. Provide good air circulation around the plants. Avoid splashing water on the foliage since this spreads the fungi. |
| ROOT ROT AND STEM ROT (Rhizoctonia, Pythium, Botrytis, Phytophthora, Alternaria and Sclerotinia ) |
With both root and stem rot, leaves and stems show a noticeable wilt. Stems may be girdled at or near soil level by a ring of brown or black tissue. Infected roots are brown to black and may be soft. The fungi survive in the soil or on infected plant debris in the soil. Their spores can be spread by wind, splashing water or the moving of infested soil. |
Use sterilized soil and pots. Do not overwater the plants, since too much water increases the occurrence of root rot. If only a few roots are infected, cut out these roots and repot the plant in sterile soil. |
| POWDERY MILDEW (Oidium) |
The formation of a white, powdery growth or dry, brown, papery leaf spots. Initial infections usually come from fungi surviving in dead and decaying plant materials or from airborne spores from wild or cultivated hosts out doors. |
Since the disease develops most rapidly under humid conditions, proper ventilation and not overwatering will help control this disease. Remove severely infected leaves. |
| *The genus Ficus includes many commonly grown houseplants such as the rubber plant, F. elasoica and the weeping fig, F. benjamina. |
