Citrus Citrus Fungal DiseasesFungal Diseases

Citrus Citrus GumosisGumosis

Citrus GumosisCitrus Gumosis

Phytophthora Fruit Rot( Brown Phytophthora Fruit Rot( Brown

rot )rot )

Pleospora rot Splits and black rot Alternaria Pleospora rot Splits and black rot Alternaria

rotrot

Botrytis blossom blight and ridging of fruitBotrytis blossom blight and ridging of fruit

CitrusCitrus Nematode DiseaseNematode Disease

Tylenchulus semipenetrans

Tylenchulus semipenetrans

Tylenchulus semipenetrans

Citrus Citrus Bacterial & Bacterial &

Fastidious DiseasesFastidious Diseases

Citrus Blast and a more virulent Black Pit organismCitrus Blast and a more virulent Black Pit organism

Canker pustules, caused by Xanthomonas axonopodis pv. Canker pustules, caused by Xanthomonas axonopodis pv.

citri,strain A on the underside of a grapefruit leaf citri,strain A on the underside of a grapefruit leaf

Canker on a grapefruit ,strain A (Valencia orange&Satsuma Canker on a grapefruit ,strain A (Valencia orange&Satsuma mandarins are more resistant ,),mandarins are more resistant ,),

Various chlorotic patterns on leaves of sweet orange Various chlorotic patterns on leaves of sweet orange trees affected by stubborn trees affected by stubborn

Small , lopsided sweet oranges from a stubborn – Small , lopsided sweet oranges from a stubborn –

affectedaffected tree ( left and center ) and a normal fruit tree ( left and center ) and a normal fruit

( right )( right )

Severe stunting of a sweet orangeSevere stunting of a sweet orange tree due to infection tree due to infection

with stubborn while thewith stubborn while the tree was youngtree was young

Lime Witch’s Broom (Phytoplasma aurantifolia ,cand) Roodan , Bandar Abbas

Lime Witch’s Broom ( Mexican lime ) Roodan , Bandar Lime Witch’s Broom ( Mexican lime ) Roodan , Bandar AbbasAbbas

Lime Witch’s Broom ( Mexican lime ) Roodan , Bandar Lime Witch’s Broom ( Mexican lime ) Roodan , Bandar AbbasAbbas

Citrus Virus Citrus Virus DiseasesDiseases

AB

Psorosis bark Psorosis bark

symptoms(vector:Aphid!!!)symptoms(vector:Aphid!!!)

B

Citrus sinensis Citrus sinensis tree in tree in

Argentina Argentina infected with infected with

"naturally "naturally spread" spread"

psorosis. Bark psorosis. Bark scaling scaling

typically typically associated with associated with citrus ringspotcitrus ringspot

and some forms and some forms of psorosis. of psorosis.

Concave GumConcave Gum

Oak-leaf pattern of concave Common flecking type Oak-leaf pattern of concave Common flecking type gum disease of gum disease of

psorosispsorosis

Tristeza , Thomson navel and unshiu on sour orange , Tristeza , Thomson navel and unshiu on sour orange , Mahdasht , Sari , MazandaranMahdasht , Sari , Mazandaran

Tristeza destruction of trees onsour orange rootstock

•South America – approx. 40 million killedsince 1930 (BCA)

•Spain – 45 million since 1960 (No BCA) •Florida – 3 million in 2000-02

•Total worldwide – over 100 million •Italy – 98% on sour – decline widespread

(No BCA) •200 million to go? (TX, Mex., Med.)

Tatterleaf

Major Citrus Virus & Virus-likeAgents/Vectors

•Tristeza Quick decline; stem pitting - Citrus tristeza virus /Aphids

•Huanglongbing (Greening) - Liberibacter spp./ Psylla •Psorosis/Scaly bark- Citrus psorosis virus/ Fungus?

•Stubborn - Spiroplasma citri / Leafhoppers •Leprosis -Citrus leprosis virus / Mites

•Variegated chlorosis- Xylella fastidiosa / Sharpshooters •Witches’ broom of lime - Phytoplasma / Leafhopper

•Blight – cause / vector unknown •Exocortis - Citrus exocortis viroid / Mechanical

•Cachexia - Hop stunt viroid / Mechanical •Tatterleaf – Citrus tatterleaf virus / Mechanical

Other Virus & Virus-like Diseases •Concave gum, Cristacortis, Impietratura

•Infectious variegation, Leaf rugose •Vein enation/Woody gall (Aphids)

•Satsuma dwarf, Citrus mosaic (soil vector?) •Citrus yellow mosaic (Mealy bugs)

•Dweet mottle (= Citrus leaf blotch?) •Rubbery wood

•Multiple sprouting •Measles

•Chlorotic dwarf (Whitefly) •Indian ringspots + other ringspot diseases

•Concentric ring blotch/Zonate chlorosis (mites) •Gum pocket, gummy bark, Kassala

•Corky vein •Yellow vein clearing/ Yellow mottle

•Australian decline (leafhopper?) •Sudden death –NEW – SERIOUS (aphids?) Etc.

Tristeza , Thomson navel on sour orange , Mahdasht , Tristeza , Thomson navel on sour orange , Mahdasht ,

Sari , MazandaranSari , Mazandaran

Early symptoms of TristezaEarly symptoms of Tristeza

Tristeza , Honey combing , Mahdasht orchards , Sari , Tristeza , Honey combing , Mahdasht orchards , Sari , MazandaranMazandaran

Vein clearing in a Mexican lime leaf in response to Vein clearing in a Mexican lime leaf in response to tristeza infectiontristeza infection

Melon aphid (Aphis gossypii) on critrus Melon aphid (Aphis gossypii) on critrus leaves ,Sari ;Mazandaranleaves ,Sari ;Mazandaran

Control of Tristeza Epidemy in North of IranControl of Tristeza Epidemy in North of Iran

Control of Tristeza Epidemy in North of IranControl of Tristeza Epidemy in North of Iran

Citrus Viroid Citrus Viroid DiseasesDiseases

Gum pockets in the inner bark and pits in exposed wood Gum pockets in the inner bark and pits in exposed wood of an alemow rootstook infected with cachexiaof an alemow rootstook infected with cachexia

The figure shows severe gumming in the bark and The figure shows severe gumming in the bark and wood of parson’s special mandarin as a rootstock wood of parson’s special mandarin as a rootstock

under a grapefruit scion infected with a severe strain of under a grapefruit scion infected with a severe strain of the CACHEXIA VIROID(300nt)the CACHEXIA VIROID(300nt)

Exocortis , Clementine on Poncirus , Behshahr , Exocortis , Clementine on Poncirus , Behshahr , MazandaranMazandaran

Citrus Citrus Physiological Physiological

DisordersDisorders

Mangenese deficiency Mangenese excess Magnesium Mangenese deficiency Mangenese excess Magnesium defficiencydefficiency

General starvation Iron deficiency Zinc deficiencyGeneral starvation Iron deficiency Zinc deficiency

Boron exess Boron deficiencyBoron exess Boron deficiency