Presentation on theme: "University of Florida Extension"— Presentation transcript:
1University of Florida Extension Key Plants and Key Pests in North Florida Landscapes Podocarpus, Gardenia, Camellia, and PyracanthaRebecca McNairUniversity of Florida Extension
2IPM Integrated Pest Management Natural processes of control are emphasizedHost plant resistancePest exclusionPrevention and through cultural practicesPhysical ControlBiological control through natural enemiesChemical control as a last resortToleranceMonitoring
5Mushroom Root Rot Slow decline, thinning of canopy Gray-green color White mycelia under bark at soil lineArmillaria tabescens
6Armillaria tabescens fruiting body appears in fall. Root Rot ManagementRemove diseased plants and rootsFumigate soil before replantingArmillaria tabescens fruiting body appears in fall.
7Root nodules Beneficial nitrogen-fixing blue green algae Often mistaken for root knot nematodesActive nodules have a pink milky fluid in their centersHemoglobin within the nodule fixes atmospheric nitrogen. When exposed to oxygen, the fluid inside changes from blue to pink!
8Roots infected with Meloidogyne are swollen. Root Knot NematodesEndoparasitic nematodeFeeds on root tissuesDieback, decline, chlorosisIdentify under microscopeRoots infected with Meloidogyne are swollen.
9Nematode Management Fumigate Solarize soil egg massFumigateSolarize soilBuy plants grafted with resistant varietiesProvide adequate water and fertilizerRemove and replace plants and soilMeloidogyne sp.
10Magnesium Deficiency Management Increase pH with dolomite Yellow inverted “V”Occurs on mature leavesLow soil pHLack of soil MgManagementIncrease pH with dolomiteApply Epsom salts or Mg fertilizers
13Stem Canker Sudden wilting Chlorosis Leaf spots Yellow halo around lesionsStem cankersGalls, usually at the soil lineGirdling may occur
14Stem Canker Management Fungus pathogen enters injured tissue Spores spread by splashing waterManagementMinimize plant injuryAvoid overhead irrigationPhomopsis gardeniaeNotice the yellow halo around the leaf spots on this gardenia.
15Nematodes Roundworms Root Knot nematodes live inside plant roots All live in liquids, i.e. water in soilFeed on plant sapDamage rootsInhibit growth
16Decline due to root knot nematodes compared to a healthy gardenia. Decline and thinning of canopyRoots brown, stunted and galledDecline due to root knot nematodes compared to a healthy gardenia.
17Nematode Management Fumigate Solarize soil Buy plants grafted with resistant varietiesProvide adequate water and fertilizerRemove and replace plants and soilMeloidogyne sp
18Manganese Deficiency Management Interveinal chlorosis on new growth Reduced leaf sizeNecrotic distortion of new growthCommon in alkaline soils high in phosphorousManagementUse a complete fertilizer with micronutrients
19Environmental Stress Management Excessive water or fertilizer Cold or temperature fluctuationNutrient DeficiencyDroughtHigh pHMechanical damageManagementCorrect cultural problemsProvide cold protectionPrune and re-growChlorosisBud drop
20Camellia japonica Acid loving Prefers partial shade Fragrant flowers from late winter to early spring
21Camellia- Key Pests Diseases Crown Gall Petal blight Leaf spot Other Twig diebackOtherEnvironmental stress
22GallGalls 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.
23Petal Blight Irregular, brown spots Dark veins Blighted flowers drop Prefer warm, moist conditionsAscospores are spread by waterFungus overwinters as sclerotia, a hard black structure that remains viable for 5 yearsCibornia camelliae (formerly Sclerotinia)Sclerotia
24Cibornia camelliae fruiting body. Petal Blight ControlSuppress sclerotia developmentRemove all infected flowers, leaves, and litterPromptly burn or bury diseased materials (at least 1 ft deep)Limit overhead irrigationCibornia camelliae fruiting body.
25Fungal Leaf Spot Management Circular or irregular lesions Margins raisedBrown - grayFungus favors high humidity and partial shadeManagementLimit overhead irrigationAvoid crowdingCopper fungicidesCerscospora caloloma
26Algal Leaf Spot Wide host range Smooth leathery leaves are more prone to infectionOne of the few green algae parasitic on higher plantsManagementLimit overhead irrigationCephaleuros virescens
27Twig Dieback Fungus Summer-winter: cankers Spring: Young shoots wilt and dieBrown leaves remain on the dead shootsGlomerella cingularaTwig dieback and a healthy camellia.
28Twig Dieback Management Prune infected areas, including cankers Leaf scars are most common point of entryOften confused with root rotsPlants can be infected by bothRoot rot increases the severity of twig diebackManagementPrune infected areas, including cankersFungicides
29Environmental Stress High heat and light Temperature fluctuation DroughtMechanical damageManagementMaintain adequate waterBud Drop
30Pyracantha coccinea Firethorn Prefers full sun Will grow in partial to fairly heavy shadeFast growing
32Fireblight Bacterium New shoots wilt suddenly and die Dead leaves remain on the shootsSpread by bees and splashing waterErwinia amylovora
33Fireblight Management Bacteria enter through flowers and infection spreads into the stemManagementLimit overhead irrigationRemove infected branchesUse resistant varieties
34AcknowledgementsAuthors: 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 MannionDr. Lance Osborne Dr. Avas HamonDr. Norman Leppla Dr. George AgriosBill Graves Dr. Doug CaldwellHolly Glenn Dr. Tim SchubertDr. Eileen Buss