The following are highlights and updates about sample submissions for our different services (identification or Plant problem diagnosis from fruit, vegetables, and ornamentals), and questions recently received in the Plant and Insect Diagnostic Clinic. Visit the PIDC's Facebook page for updates and more pictures. For more information on a particular disease or insect problem listed, follow the article cited.
Plant Problem diagnosis (with links to articles)
Host Category | Plant | Identification or Diagnosis |
Coniferous trees | Spruce | Stigmina needle cast, suspected environmental stress, fungal cankers |
Scots Pine | Diplodia Tip Blight and Canker, suspected Pine wilt | |
Arborvitae | Suspected environmental stress Phomopsis tip blight | |
Broadleaf trees | Eastern Redbud | Transplant stress, Poor Planting Practices and Post-planting Care |
ornamental pear | Fire Blight | |
Ornamental prunus | Black Knot | |
Crababple | Scab | |
Lilac | Pseudocercospora Leaf Spot, Powdery Mildew | |
Magnolia | Magnolia Scale | |
Maple | Girdling roots ![]() ![]() | |
Willow | Willow anthracnose | |
Oak (various) | Bur Oak Blight, Anthracnose on shade trees, suspected wetwood or slime flux, Suspected Physiological scorch, Bot twig canker, Tubakia leaf spot in Oaks, Oak decline Japanese Beetle feeding damage | |
Fruit (small and tree) | Apple | Cedar-Apple Rust |
Japanese Beetle feeding damage | ||
Phoma leaf spot | ||
Suspected chemical injury, phytoplasma or virus | ||
pear | Pear rust and various fungal spots | |
Strawberry | Phomopsis blight | |
Cherry | suspected decline | |
Vegetables | Garlic | Fusarium basal rot, Stem and Bulb nematode, Bulb mites, Purple blotch |
Kale | Alternaria leaf spot | |
Muskmelon | Alternaria spot and leaf blight | |
Onion | Soft rot | |
Pepper | Cutworm damage, Secondary soft rot | |
Tomato | Bacterial canker, see Tomato Diseases and Disorders | |
Phytotoxicity suspected | ||
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Leaf mold | ||
Suspected herbicide injury | ||
Perennials and Annuals | Sedum | Pythium root rot |
Clematis wilt/ blight |
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Turf/Lawn | Various grasses | Curvularia blight, anthracnose |
Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Yard and Garden, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on August 16, 2019. The information contained within may not be the most current and accurate depending on when it is accessed.