University of Florida Extension Key Plants and Key Pests in North Florida Landscapes Podocarpus, Gardenia, Camellia, and Pyracantha Rebecca McNair University of Florida Extension

IPM Integrated Pest Management Natural processes of control are emphasized Host plant resistance Pest exclusion Prevention and through cultural practices Physical Control Biological control through natural enemies Chemical control as a last resort Tolerance Monitoring

Podocarpus Nageia nagi

Podocarpus- Key Pests Diseases Mushroom root rot Other Nematodes Magnesium deficiency

Mushroom Root Rot Slow decline, thinning of canopy Gray-green color White mycelia under bark at soil line Armillaria tabescens

Armillaria tabescens fruiting body appears in fall. Root Rot Management Remove diseased plants and roots Fumigate soil before replanting Armillaria tabescens fruiting body appears in fall.

Root nodules Beneficial nitrogen-fixing blue green algae Often mistaken for root knot nematodes Active nodules have a pink milky fluid in their centers Hemoglobin within the nodule fixes atmospheric nitrogen. When exposed to oxygen, the fluid inside changes from blue to pink!

Roots infected with Meloidogyne are swollen. Root Knot Nematodes Endoparasitic nematode Feeds on root tissues Dieback, decline, chlorosis Identify under microscope Roots infected with Meloidogyne are swollen.

Nematode Management Fumigate Solarize soil egg mass Fumigate Solarize soil Buy plants grafted with resistant varieties Provide adequate water and fertilizer Remove and replace plants and soil Meloidogyne sp.

Magnesium Deficiency Management Increase pH with dolomite Yellow inverted “V” Occurs on mature leaves Low soil pH Lack of soil Mg Management Increase pH with dolomite Apply Epsom salts or Mg fertilizers

Gardenia augusta Acid loving plant Fragrant flowers

Gardenia- Key Pests Diseases Stem Canker Other Nematodes Manganese deficiency Environmental stress

Stem Canker Sudden wilting Chlorosis Leaf spots Yellow halo around lesions Stem cankers Galls, usually at the soil line Girdling may occur

Stem Canker Management Fungus pathogen enters injured tissue Spores spread by splashing water Management Minimize plant injury Avoid overhead irrigation Phomopsis gardeniae Notice the yellow halo around the leaf spots on this gardenia.

Nematodes Roundworms Root Knot nematodes live inside plant roots All live in liquids, i.e. water in soil Feed on plant sap Damage roots Inhibit growth

Decline due to root knot nematodes compared to a healthy gardenia. Decline and thinning of canopy Roots brown, stunted and galled Decline due to root knot nematodes compared to a healthy gardenia.

Nematode Management Fumigate Solarize soil Buy plants grafted with resistant varieties Provide adequate water and fertilizer Remove and replace plants and soil Meloidogyne sp

Manganese Deficiency Management Interveinal chlorosis on new growth Reduced leaf size Necrotic distortion of new growth Common in alkaline soils high in phosphorous Management Use a complete fertilizer with micronutrients

Environmental Stress Management Excessive water or fertilizer Cold or temperature fluctuation Nutrient Deficiency Drought High pH Mechanical damage Management Correct cultural problems Provide cold protection Prune and re-grow Chlorosis Bud drop

Camellia japonica Acid loving Prefers partial shade Fragrant flowers from late winter to early spring

Camellia- Key Pests Diseases Crown Gall Petal blight Leaf spot Other Twig dieback Other Environmental stress

Gall Galls can appear on any plant part and may be due to bacteria, fungi, nematodes, or insects. Agrobacterium tumefaciens is a common soil bacterium that causes crown gall disease by transferring some of its DNA to the plant host. This has enabled scientists to genetically manipulate plants, a technique called transformation.

Petal Blight Irregular, brown spots Dark veins Blighted flowers drop Prefer warm, moist conditions Ascospores are spread by water Fungus overwinters as sclerotia, a hard black structure that remains viable for 5 years Cibornia camelliae (formerly Sclerotinia) Sclerotia

Cibornia camelliae fruiting body. Petal Blight Control Suppress sclerotia development Remove all infected flowers, leaves, and litter Promptly burn or bury diseased materials (at least 1 ft deep) Limit overhead irrigation Cibornia camelliae fruiting body.

Fungal Leaf Spot Management Circular or irregular lesions Margins raised Brown - gray Fungus favors high humidity and partial shade Management Limit overhead irrigation Avoid crowding Copper fungicides Cerscospora caloloma

Algal Leaf Spot Wide host range Smooth leathery leaves are more prone to infection One of the few green algae parasitic on higher plants Management Limit overhead irrigation Cephaleuros virescens

Twig Dieback Fungus Summer-winter: cankers Spring: Young shoots wilt and die Brown leaves remain on the dead shoots Glomerella cingulara Twig dieback and a healthy camellia.

Twig Dieback Management Prune infected areas, including cankers Leaf scars are most common point of entry Often confused with root rots Plants can be infected by both Root rot increases the severity of twig dieback Management Prune infected areas, including cankers Fungicides

Environmental Stress High heat and light Temperature fluctuation Drought Mechanical damage Management Maintain adequate water Bud Drop

Pyracantha coccinea Firethorn Prefers full sun Will grow in partial to fairly heavy shade Fast growing

Pyracantha- Key Pests Diseases Fireblight

Fireblight Bacterium New shoots wilt suddenly and die Dead leaves remain on the shoots Spread by bees and splashing water Erwinia amylovora

Fireblight Management Bacteria enter through flowers and infection spreads into the stem Management Limit overhead irrigation Remove infected branches Use resistant varieties

Acknowledgements Authors: Rebecca McNair Reviewers: Dr. Russ Mizell, Dr. Norman Leppla, Dr. Doug Caldwell, Celeste White, and Christine Kelly- Begazo Funding: Florida Yards and Neighborhoods Photos: Thanks to the Florida Dept. of Agriculture and Consumer Services, Division of Plant Industry, and University of Florida Extension faculty for providing photographs, including: Dr. James Castner Dr. Catherine Mannion Dr. Lance Osborne Dr. Avas Hamon Dr. Norman Leppla Dr. George Agrios Bill Graves Dr. Doug Caldwell Holly Glenn Dr. Tim Schubert Dr. Eileen Buss