Scab (Cucurbits) Description: Scab is seedborne, and it also survives in the soil. Scab usually develops in warm weather after midseason, when wet weather conditions exist. Spores can spread over long distances when the air is moist. Solution: As with many diseases, it helps to plant cucurbits where other cucurbits have not been planted for at least two years. […]
Rust (Roses) Description: Although rust is widespread, it is most consistently a problem in western states. Yellow “rust” spots appear on the topsides of leaves during cool weather in spring or late fall. Infected leaves become twisted and dry. Spores infect leaves when rain, dew or fog occurs at temperatures from 55° to 75°F. Solution: When rust is first noticed, […]
Root-Knot Nematodes Description: So-called “eel-worms” are only 1/50″ long, with thin, translucent bodies. Over 990 species of plant-attacking nematodes are known. Occurring naturally in large numbers throughout the U.S., especially in the Southeast, they plague vegetables, ornamental plants and trees. Infested plants are usually stunted, lighter in color, and lower in yield than healthy plants. Roots have swellings, galls, or […]
Aphids Description: Tiny bugs are light or dark green, or black; with or without wings. The largest is 1/6″ long, the smallest is barely visible. They cluster on stems and under leaves. Aphids may cause more crop damage than any other insect, and there are few plants they don’t like. Infested leaves curl and turn yellow; plant is weakened in […]
Rhizoctonia Root Rot (on Beans) Description: Primarily attacks seedlings and young plants. Reddish-brown spots appear on lower stems. Most infected plants die as seedlings. Solution: Shallow seeding depth and planting in thoroughly warm soil helps. Sprinkle SoilGardTM Microbial Fungicide over bean seed at time of sowing, before covering seed with soil.
Pythium Wilt (Lettuce) Description: Dark yellow-brown roots, stunting, yellow of outer leaves. Root system decline. Solution: Provide good drainage; raised beds are ideal. Sprinkle SoilGard over seed at time of sowing, before covering seed with soil. When starting seed indoors, mix SoilGard with potting soil before seed is sown.
Pythium Rot (Damping-Off, Stem Rot) on Tomatoes Description: Damping-off occurs at or before germination, causing rapid decline and death of seeds or young seedlings. On older plants, disease causes severe wilting and black stem, beginning at ground level, resulting in severe stunting or death of plants. Solution: Maintain soil pH at 6.5 to 7.0. Test soil pH; if it is […]
Pythium Root Rot (Damping-Off, Seed Rot) (Peas) Description: A watery rot is characteristic. Plants are often stunted and light green because of the lack of root development. Solution: Plant as early in the season as possible. Peas are a cool-season crop, while pythium disease is most severe at temperatures from 64°-75°F, which is higher than preferred for pea germination. Sprinkle […]
Pythium Root Rot (Damping-Off) (Beans) Description: Yellowing, stunted growth, sudden seedling wilting (damping-off) and death. Can also kill seedlings before emergence. Pythium spores occur in the soil almost everywhere beans are grown. Solution: Sprinkle SoilGardTM Microbial Fungicide over seed at time of sowing, before covering seed with soil.
Powdery Mildew (Roses) Description: Powdery mildew and black spot are the “one-two punch” on roses. Powdery mildew is a problem in all parts of the U.S. Powdery mildew usually first appears on new growth, in periods of warm, dry days followed by cool, damp nights. The new leaves may become curled or twisted, and the shoots will look badly deformed. […]