Diagnosing Plant Disorders: Diagnosing Plant Disorders Normal vs. abnormal Symptoms of abnormality Pattern of abnormality Sign of causal agent 7 insect damage categories


What is normal?- Form: What is normal?- Form Know your plant The balls at the tip of the twigs are the fruit of the baldcypress tree


What is normal?- Form: What is normal?- Form The abnormal bumps on these base of these spruce twigs are called galls


What is normal? -Color?: What is normal? -Color? Know your plant Yellow leaf of this coleus is a variety characteristic


What is normal? –Leaf Senescence: What is normal? –Leaf Senescence Know your plant Pine needles yellow before they drop Linden flower sepals yellow in August


Pattern of abnormality –Uniform discolor Abiotic Cause: Pattern of abnormality –Uniform discolor Abiotic Cause Tire tracks in turf


Pattern of abnormality –Clumped discolor Biotic Cause: Pattern of abnormality –Clumped discolor Biotic Cause Flagging from Dutch Elm Disease


Pattern of abnormality –Uniform curl: Pattern of abnormality –Uniform curl Wilted terminals On multiple species


Pattern of abnormality –Uniform curl: Pattern of abnormality –Uniform curl Wilted terminals On group of trees


Leaf Symptoms- Interveinal discoloration: Leaf Symptoms- Interveinal discoloration Pigment removed between leaf veins


Leaf Symptoms- Stippling: Leaf Symptoms- Stippling Specks of leaf tissue discolored


Leaf Symptoms- Discoloration: Leaf Symptoms- Discoloration Entire leaf is discolored


Leaf Symptoms- Defoliation= Parts missing: Leaf Symptoms- Defoliation= Parts missing Skeletonization (all veins remain) Complete defoliation (all leaf tissue consumed)


Leaf Symptoms- Leaf notching: Leaf Symptoms- Leaf notching Irregular pattern Circular pattern


Leaf Symptoms- Stunting distortion: Leaf Symptoms- Stunting distortion Stunted new growth


Leaf Symptoms- Scorch: Leaf Symptoms- Scorch


Leaf Symptoms- Galls: Leaf Symptoms- Galls


Leaf Symptoms- Leaf mining: Leaf Symptoms- Leaf mining


Trunk and branch symptoms- Dieback: Trunk and branch symptoms- Dieback


Trunk and branch symptoms- Holes: Trunk and branch symptoms- Holes Wood borers


Trunk and branch symptoms- Hollowed stems or petioles: Trunk and branch symptoms- Hollowed stems or petioles


Trunk and branch symptoms- Peeled bark: Trunk and branch symptoms- Peeled bark


Trunk and branch symptoms- Girdling: Trunk and branch symptoms- Girdling


Trunk symptomsRows of holes in trunk: Trunk symptoms Rows of holes in trunk Sapsucker injury


Signs- Fruiting Bodies= Fungal Disease: Signs- Fruiting Bodies= Fungal Disease


Signs- The Insect Itself : Signs- The Insect Itself


Signs- Shed Insect Skin : Signs- Shed Insect Skin


Signs- Liquid Excrement of Sucking Insects and Sooty Mold: Signs- Liquid Excrement of Sucking Insects and Sooty Mold


Signs- Insect Webbing: Signs- Insect Webbing


Signs- Insect Excrement Pellets: Signs- Insect Excrement Pellets


Signs- Insect Eggs: Signs- Insect Eggs


How Insects Injure Plants: How Insects Injure Plants Discolor by sucking plant sap Distort by damaging growing tissues Lay eggs in plant (Oviposition) Defoliate by chewing Feed between upper and lower leaf surfaces Cut off vascular tissue by feeding in stems Transmit disease


Seven Categories of Insect and Mite Pests: Seven Categories of Insect and Mite Pests Agents of leaf distortion and discoloration Producers of honeydew, spittle, unsightly wax and insect remains Producers of bumps or swellings on twigs Defoliators Leaf miners Twig leader and trunk feeders Agents of disease transmission and rapid decline