Disease Directory
Disease fungi take their energy from the plants on which they live. They are responsible for a great deal of damage and are characterized by wilting, scabs, moldy coatings, rusts, blotches and rotted tissue.
| Disease Name | Images | Causes | Symptoms | Treatment |
|---|---|---|---|---|
| Anthracnose |  | anthracnose is caused by fungi in the genus Colletotrichum, a common group of plant pathogens that are responsible for diseases on many plant species | Infected plants develop dark, water soaked lesions on stems, leaves or fruit. The centers of these lesions often become covered with pink, gelatinous masses of spores especially during moist, warm weather | Spraying the affected plants helps stop further spread of the disease to other healthy animals |
| Apple Scab |  | The fungal disease forms pale yellow or olive-green spots on the upper surface of leaves. Dark, velvety spots may appear on the lower surface | Scabby spots are sunken and tan and may have velvety spores in the center. As these spots mature, they become larger and turn brown and corky. Infected fruit becomes distorted and may crack allowing entry of secondary organisms. Severely affected fruit may drop, especially when young. | For best control, spray liquid copper soap early, two weeks before symptoms normally appear. Alternatively, begin applications when disease first appears, and repeat at 7 to 10 day intervals up to blossom drop. |
| Bacterial Canker |  | The bacterium that causes canker, Pseudomonas syringae, enters trees through injured bark or an existing wound, such as a pruning cut on a twig or branch | If cankers girdle the branches or trunk, the leaves above the diseased area curl and turn yellow. Growth stops and the branch or tree will eventually die. | Organocide Plant Doctor is an earth-friendly systemic fungicide that works its way through the entire plant to combat a large number of diseases on ornamentals, turf, fruit and more. Mix 1/3 to 3/4 oz per gallon of water and paint or spray over pruning wounds and surrounding areas. |
| Crown gall |  | Caused by the bacterium Agrobacterium tumefaciens (synonym Rhizobium radiobacter). Thousands of plant species are susceptible | Symptoms include roundish rough-surfaced galls (woody tumourlike growths), several centimetres or more in diameter, usually at or near the soil line, on a graft site or bud union, or on roots and lower stems. The galls are at first cream-coloured or greenish and later turn brown or black. | Spraying the affected plants helps stop further spread of the disease to other healthy animals |
| Fire blight |  | Caused by the bacterium Erwinia amylovora, that can give infected plants a scorched appearance | Sudden brown to black withering and dying of blossoms, fruit spurs, leaves, twigs, and branches. Very susceptible plants appear as if scorched by fire and may die | Copper blossom sprays can be applied when plants first begin to flower but are of limited effectiveness and can damage fruits. Streptomycin sprays have been used to prevent new infections but have also contributed to antibiotic-resistant outbreaks in some areas |
| Fruit spot |  | Caused by fungi and bacteria | A spot is a definite, localized area. Spots frequently enlarge and merge to form a rot, a softening discoloration and often a disintegration of tissue | Spraying the affected plants helps stop further spread of the disease to other healthy animals |
| Late blight / Potato blight |  | Caused by the water mold Phytophthora infestans. The disease occurs in humid regions with temperatures ranging between 4 and 29 °C | When plants have become infected, lesions appear on the leaves, petioles, and stems. A whitish growth of spore-producing structures may appear at the margin of the lesions on the underleaf surfaces. | The disease can be managed with a timely application of fungicide, though epidemics can occur rapidly once crops are infected |
| Chlorosis |  | It results from failure of chlorophyll to develop because of infection by a virus; lack of an essential mineral or oxygen; injury from alkali, fertilizer, air pollution, or cold; insect, mite, or nematode feeding; gas main leaks; compaction or change in soil level; and stem or root rot | Severely chlorotic plants are stunted, and shoots may die back to the roots | Spraying the affected plants helps stop further spread of the disease to other healthy animals |