Plant Problems to Watch for in May

Here are some diseases we observed in the clinic during the month of May. The hypertext links will lead you to specific information about a certain disease or about diseases in a certain crop.

Field Crops

Corn Nematodes, Nutritional problems, cold and chemical injury
Cotton Rhizoctonia damping-off
Soybean Pythium root rot
Tobacco Rhizoctonia diseases: Target spot, Sore shin, Root/stem rot. Anthracnose, Granville wilt, Southern blight, Tomato spotted wilt, Weather fleck

Small Grains

General BYDV, Glume blotch, Oat red leaf, Soilborne wheat mosaic
Oats Loose smut
Wheat Glume blotch, Septoria leaf spot, Scab (Fusarium sp.), Take-all

Turfgrass

General High soluble salts, Drought/hydrophobic soils, cold injury
Centipedegrass Brown patch, Centipedegrass decline (disease complex), Ground pearls (insects), Fairy ring
Bermudagrass Spring dead spot, Smut on seed heads
St. Augustinegrass Brown patch

Woody Ornamentals

General shrubs Cold injury, Secondary leaf spots, Nematodes (nursery, landscape), Powdery mildew
Horse-Sugar, Azalea, Sasanqua, and Camellia Exobasidium leaf gall
Azalea, Boxwood, Rhododendron, Juniper (esp. "Shore") Phytophthora root rot
Dogwood Spot anthracnose, Dogwood anthracnose, Powdery mildew
Chinese elm Black spot (leaf blight)
Indian Hawthorn, Red-Tip Photinia, Ornamental Pear Entomosporium leaf spot
Japanese holly Black root rot
Liriope Anthracnose (secondary)
Leyland cypress Cypress canker, Botryosphaeria canker
Maple Phyllosticta leaf spot, Secondary leafspots
Southern magnolia Normal leaf drop of oldest leaves
Ornamental pear, Cotoneaster and Crabapple Fire blight
Oaks Leaf blister
Pines Needle rust, Needle casts
Eastern redcedar Cedar-apple rust, Kabatina tip blight, Quince rust
Roses Cold injury, old cane blight and stress from black spot, Mosaic virus
Sycamore and Maple Anthracnose

Herbaceous Ornamentals

Perennials, general Cold injury, Fertilizer injury, Low pH, Powdery mildew, Rhizoctonia root/stem rot
Iris Cladosporium leaf spot, Stem collapse due to rapid growth, excess nitrogen and cloudy weather
English ivy Anthracnose, Phytophthora root rot
Liriope Anthracnose
Madagascar Periwinkle Botrytis blight, Phytophthora blight
Oxalis Rust
Pachysandra Volutella blight
Peony Botrytis blight, Bullnose (failure to bloom)
Annuals/Foliage plants in greenhouse Rhizoctonia root/stem rot, Pythium root rot, Impatiens necrotic spot, Powdery mildew

Fruit

Apple Burr knot, Cedar-apple rust, Fire blight, Frogeye leaf spot, Powdery mildew, Root galls due to Rosy Apple aphid
Pear Entomosporium leaf spot, Fire blight
Peach Brown rot, Leaf curl, Short life complex
Plum and Wild Cherry FDIN-002 Disease and Insect Management in the Home Orchard
Strawberry Anthracnose, Botrytis diseases, Red stele, Southern blight, Phomopsis fruit rot/blight, Powdery mildew, Angular leafspot (Xanthomonas)
Blackberry/Raspberry Anthracnose, Rust

Vegetables

Seedlings Rhizoctonia/Pythium damping-off
Older plants in field Southern blight, Rhizoctonia sore shin, Sunscald, Chemical injury
Cucurbits Angular leaf spot, Trichothecium leaf spot, Choanephora wet rot, Bacterial wilt, Gummy stem blight
Crucifers Sclerotinia disease, Club root, Downy mildew, Alternaria leaf spot
Pepper Bacterial spot, Phytophthora stem rot
Potato PVY, Seed piece decay, Late blight, Air pollution injury
Tomato (greenhouse/field) Blossom-end rot, Botrytis blight, Early blight, Late blight, Pith necrosis, Sclerotinia disease, Southern bacterial wilt, Fusarium wilt, Fusarium root/crown rot, TSWV, Tobacco mosaic virus

For further information, see the main index of Plant Disease Information Notes.

Other Links

Plant Clinic Summaries
Plant Disease Information Notes
Plant Disease and Insect Clinic

Last modified on May 2000