Pathogens, Fungus, Bacteria and Infections.
You can use use simple preventive controls to keep disease problems from developing.
However, sometimes we have to resort to spraying organically acceptables substance such as sulfur fungicides or copper to control diseases on plants. I Inspect my plants every morning and I carry my magnifying glass in my pocket just in case
A variety of common plant diseases can become a problem in the garden causing symptoms such as spotted or disfigured foliage or rotted stems. I hope the following chart helps to control your plant problems.
It's so frustrating; somedays I will go in the house and everything in the garden is fine, then the next morning, things are not so fine. :(
I hope this helps!
|Anthracnose||Dark circular spots on stems or leaves.||Wet weather promotes spreading as spores are carried by windblown rain or seeds.||Destroy infected plants. Work in the garden only when plants are dry to avoid spreading diseases. Rotate crops.|
|Azalea Petal Blight||Small white or brown spots on petals enlarge, causing entire petal to become slimy. By the second day, flowers have collapsed but remains on plant. Fungus overwinters in dead flowers and soil under shrubs.||Quick-spreading disease, usually affects Azaleas and Rhododendrons or Mountain Laurel. Encouraged by warm, wet and humid conditions.||Pick infected flowers. Avoid overhead watering while the plants are in bloom. Cover soil with mulch.|
|Bacterial Leaf Spot||Small brown or purple spots on leaves. Leaves will turn yellow and fall.||Affects cauliflower, cabbage, turnip and other especially in seedling stage.||Destroy infected plants. Rotate crops in a 3 year cycle to avoid planting susceptible plants in infected beds.|
|Bacterial Wilt||Large irregular patches appear on leaves, which will eventurally wilt. May spread to stems and branches and could cause death to the whole plant.||Attacks all cucurbits such as cucumbers, pumpkins, squash. Transmitted by cucumber beetles.||Cover crops with floating row covers. Rotate crops. Beetles overwinter in soil.|
|Black Rot||Leaves have yellowed, dark veins. Eventually all but top leaves may drop.||Attacks all crucifers. Bacteria transmitted by seeds, soil and rain.||Plant in well drained, nutrient rich soil. Clear away debris and use 3 year crop rotation. Treat homegrown seeds to 30 minute bath at 122°|
|Black Spot||Round black spots. Leaves eventually turn yellow and fall off. It weakens plants as they have to regrow new leaves. Fungus may also cause lesions on canes.||Common diseases on roses. Encourage by moist and wet conditions.||Prune and destroy infected areas in dry weather with sterilized tools. Apply flowable sulfur spray weekly throughout the season. Water early in the morning to avoid wetting leaves and mulch in spring.|
|Canker||Red and Yellow spots on canes or stalks of plants which eventurally dry out and turn brown. Stems may dry back to injury.||Common disease of rose canes.||Prune out diseased areas. Always prune roses just above bud or leaf axil so that plants can heal quickly .|
|Crown Gall||Round, rough galls up to several inches form, usually near soil or graft union.||bacterial disease of many plants. Enters through wounds, encouraged by warm weather and alkaline soil conditions.||Prune diseased areas. Sterilize tools with bleach after each cut.|
|Curly Top Virus||Virus disease of many vegetables and ornamentals.||Transmitted by leet leafhopper. Encouraged by sun and heat, low himidity.||.|
|Damping-off||Water-soaked or necrotic lesions on seedling stems close to soil. Roots look small and rotted. Stems may fall over.||Disease of many seedlings caused by various fungi. Common is wet conditions.||Plant is well-drained pasterized soil. Maintain good air circulation.|
|Downy Mildew||Underside of leaves have downy white or purple mold in wet conditions. Stems may become discoloured.||many plant susceptible. Caused by various fungi.||Dust or spray with sulfur. Water plants at soil level. Avoid watering leaves.|
|Fireblight||New shoots curve downward, trun black or brown and eventually will die.||Bacterial disease spread by rain and insects into flowers, where it spreads throughout tree. My pear and apple this. No fun!||Cut diseased branch 3-12 inches below infected area during dormant season.|
|Fusarium Wilts||Wilting yellow leaves and eventually leaves and steams will die. Rotting roots.||Fungal disease; various plants affected. Encouraged by hot and dry weather.||Rotate Crops for several year intervals. Clear away debris.|
|Grey Mold Blight||Spots on leaves and flowers turn into soft tan or grey mold.||Encouraged by warm, damp, cloudy conditions. Transmitted by wind and water. Attacks fruits, vegetables, flowers and shrubs.||Prune off any leaves touching soil or branches. Maintain good spacing and air circulation. Avoid wetting leaves when watering.|
|Mosaic||Mottled green and yellow foliage of veins. Leaves may be curled or wrinkled. Stunded growth.||Virus disease. Attacks various plants from vegetables to flowers. Often transmitted by aphids or leafhoppers.||Wash hands and clothes after handling. Control aphids and leafhoppers that spread the virus.|
|Powdery Mildew||White powdery spots or blotches on leaves that eventually cover the leaf surface. Fruits may also be covered. Reduced yield. stunded growth.||Fungus disease that affects many plants. Transmitted by wind, splashing rain or on seeds.||Spray with flowable sulfur once "blooms" appear. Rotate crops.|
|Root Rot||Leaves may yellow and plants will wilt and die. Roots become soft and black.||Caused by various fungi. Attacks many plants. Usually transmitted through soil. Encouraged by hot, dry conditions.||Encourage healthy growth maintaining good soil drainage and aeration and providing necessary nutrients.|
|Rust||Reddish-brown powdery spots; yellow leaves.||Fungal diseases that often have specific hosts. Plants such as apples and vegetables are often affected. Transmitted by wind; high nitrogen and humidity encourage infection.||Keep soil moist and space plants appropriately for good air circulation.||Verticillium Wilt||wilting leaves and stems on one or more branches. Leaves curl upwards, turn yellow and drop off.||Fungal disease. Enters through into roots and wounds.||Rotate crops to uninfected soil. Clear debris.|