LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot-...

37

Transcript of LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot-...

Page 1: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.
Page 2: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

LIST OF DISEASES

1. Gray Mould - Botrytis cinerea

2. Rhizopus rot - R. stolanifer3. Sour-rot - Geotrichum candidum4. Canker - Didymella lycopersici

5. Anthracnose -C.coccodes, C. gloeosporoides6. Bacterial Canker -Clavibacter michiganense subsp.

michiganense7. Buckeye Rot -Phytophthora nicotianae var. parasitica8. Fusarium rot -Fusarium oxysporum f.sp. lycopersici 9. Phoma Rot -Phoma destructiva10. Soil Rot -Rhizoctonia solani11. Southern Blight -Sclerotium rolfsii

12. Early Blight -Alternaria solani13. Bacterial Soft Rot –Erwinia caratovora sub sp. carotovora14. Late Blight -Phytophthora infestans

Page 3: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

GRAY MOULD (BOTRYTIS CINEREA) Symptoms

Watery lesion area with a light brown or tan-colored central region which contain dark-brown specks

Converted into a soft, watery mass within a few days

Skin is broken, the grayish mycelium and spore clusters develop within a few hours

Page 4: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Fungus Greek botrys, meaning a bunch of grapes One-celled spores are borne on branched conidiophores Sclerotia -measure up to 3 mm - smaller & thinner Germinate to produce conidiophores or, rarely, give rise to small cup-shaped

structures (apothecia)

Favourable condition Optimum RH for spore production is about 90% Spores are produced during the night when the temperature is lower and the

RH is higher than during the day. Ideal Temperatures of 17–23 °C The length of the surface wetness period needs to be longer at the lower

temperatures for disease development

Page 5: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Spread and survival

Botrytis produces sclerotia which survive in soil, dead plant material, or on different host plants

Easily disperse large distances by wind & shorter distances by splashing and windblown rain

Fruit can be infected through the stem scar, growth cracks, or other breaks in the skin

Plants approaching maturity are more susceptible

Control Ensure good drainage facility In the greenhouse, maintain a RH of less than 80%, during the night Remove decaying plant material from the plant bed Avoid bruising during packing and transport Pre harvest spray 0.2% captan at monthly intervals

Page 6: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

RHIZOPUS ROT- R. STOLANIFER Water-soaked lesion which exude a clear liquid

Lesion surface may be covered with thin, cotton-like fungal structures (especially under humid conditions)

Tissues within the lesion are usually held together by relatively coarse strands of fungal hyphae

Dark sporulation may crown the white tuft of Rhizopus

The mycelium can infect adjacent fruit through natural openings or mechanical wounds, creating nests of mold and diseased fruit

Page 7: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Penetration: Wound - cause ripe fruit to rot-Fermentative odour Fruit surf. –extramatrical whiskery mycelium , black sporangia Range of temp. 5, 15 and 25oC reaching disease incidence of

97-100% RH

Spread Air currents pathogen grows very aggressively even on refrigerated fruit. pallets and cartons, and it may survive for months in fruit

residues left in picking containers and field bins.

Page 8: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

ANTHRACNOSE (COLLETOTRICHUM COCCODES, C. GLOEOSPOROIDES, C. DEMATIUM)

Symptoms Symptoms - fruits which are ripe or beginning to ripe

Small, water soaked, circular & depressed spots -enlarge to greater than 12 mm in dia with zonate markings

Lesion surface may appear salmon-colored due to spore production and be dotted with black specks (microsclerotia)

Page 9: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Favorable condition Opt temp- 28 to 32oC Remain latent in green fruits until fruits approach ripening stage RH-85-to100%

Page 10: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Fungus Colonies - darkly pigmented with white aerial mycelium, consisting of

numerous black sclerotia Sclerotia - setose, spherical Conidia - straight, fusiform, attenuated at the ends Appressoria - clavate, brown, variable in shape

Conidia of C. coccodes

Appressoria of C. coccodes

Page 11: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Mode of survival and spread Persist on alternate hosts, crop debris & some weeds Alternate hosts - solanaceous crops (potato, eggplant),cucurbits & soybean Fungus is also seed-borne Spores are usually dispersed by splashing rain Fruits - near the soil surface are most likely to become infected Overhead irrigation - favor development of anthracnose because of RH &

increased duration of leaf wetness

.

Control Crop rotation with non-host crops and avoid potato, soybean, eggplant &

cucurbit Stake plants to improve air circulation and to reduce leaf and fruit wetness Mulch to reduce soil splash onto fruit and lower leaves Minimize or avoid overhead irrigation to reduce periods of wetness on fruit Hot water treatment - at 50°C for 25 min Following treatment, plunge the hot seeds into cold water, dry on paper, and

dust with thiram

Page 12: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

EARLY BLIGHT (ALTERNARIA SOLANI)

Symptoms • Leaves – circular to angular, dark brown to black spots with

characteristic concentric rings• Spots coalesce and cause drying of leaves• Stem- dark spots at base near the ground and gradually girdled• Spots- juncture of the side branches- easily broken by wind• Fruit become infected-through the calyx or stem attachment, either in

the green or ripe stage• Fruit –dark brown sunken, concentric ringing • Infected fruit frequently drop, and losses of 50% of the immature fruit

may occur

Page 13: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Fungus Mycelium- septate, branched, light brown, become darker with age Conidiophores- 50 to 90μm in length and dark coloured Conidia-beaked, muriform, dark coloured and borne singly

Epidimiology Maximum dispersal of conidia- 9am and 12 noon plants suffering from water stress- susceptible

Page 14: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Mode of spread and survival Spread by wind and rain splashes Under dry conditions- survives in infected plant debris in the soil

for 3 yrs Seed borne

Control Use disease free seeds for sowing Field sanitation Crop rotation with non solanaceous crop Optimum irrigation- to avoid stress condition Seed treatment- thiram 2g/kg 3 sprays with difolatan 0.2 % at fortnightly interval

Page 15: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

BACTERIAL SOFT ROT AND HOLLOW STEM (ERWINIA CAROTOVORA PV. CAROTOVORA)

Symptoms • Inner stem - which becomes brown and slimy, then

disintegrates & becomes hollow • The affected plants wilt and die• Fruit -soft watery decay of fruit, starting at one or

more points, as very small spots• Enlarge-very rapidly until the entire fruit -soft watery

mass• Pathogen liquefies fruit tissue by breaking down the

pectate "glue" that holds plant cells together

Page 16: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.
Page 17: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Bacteria gram-ve, rod with rounded ends Motile with 1 to 6 peritrichous flagella Single-celled - rapidly multiply and spread-in water.

Favorable Conditions During wet weather and High humidity, Heavy rain fall or irrigation Warm temperatures in the (20–30 °C)

Penetration Wounds The connective tissue at the stem end - an entry point for

the bacteria present in the sepals of young tomato fruit

Page 18: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Pathogen Spread They can be spread by rainstorms, insects, harvest crews, picking

containers, and packinghouse equipment.

Soft rot bacteria can even pass from one fiberboard shipping carton to an adjacent carton when the cartons become soaked with the rotten material of decayed fruit.

These bacteria readily disperse from rotten fruit by direct contact or movement of juices or water

Management Prevent the occurrence of insect wounds by controlling the pests Crop rotation with crops of bean, maize and soybean Disinfect hands and tools when pruning tomato plants and wash

contaminated clothing Use chlorinated water to reduce the risk of infection during

washing. This will not reduce soft rot development in fruit already infected with the organism

Harvest during dry weather and minimize fruit injury at harvest

Page 19: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

LATE BLIGHT (PHYTOPHTHORA INFESTANS)

• Leaves, stems and fruits are attacked

• Brown to purple black lesions – leaflet, stem, fruit

• Early russet brown marbled areas appear on the green fruits which becomes completely brown & shriveled

Page 20: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Fungus Mycelium- hyaline and coenocytic Sporangiospore – slender, hyaline, thick walled and

branched Sporangia – multinucleate, thin walled, hyaline Sporangia- wind borne, germinate usually by formation of

zoospores, which are biflagellateMode of spread & survival Survival - diseased crop debris under wet condition Very moist weather- white weft of fungus develops in fruit

cracksEpidemiology Develops quickly in rainy season High humidity conditionControl Field sanitation Avoid overhead irrigation Effective control of blight in foliages Spraying @ 7 days interval- mancozeb 0.2 %,Zineb 0.2%

Page 21: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

PHOMA ROT (PHOMA DESTRUCTIVA)

• Leaves- small, dark, irregular spots – yellow and wither prematurely

• Fruits- circular, depressed water soaked spots • Become black an leathery on the surface bearing

numerous black specks• specks - pycnidia or fruiting bodies of the fungus

Fungus • Mycelium- septate, branching & hyaline, becoming

dark with age• Pycnidia – subcutaneous and later erumpent, dark

subglobose• Pycnospores- hyaline, subglobous

pycnidia in the lesion center

Page 22: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Favorable Conditions moderate temperature and high humidity. Most rapid decay on ripe fruits @ 21oC, but since tomatoes

ripen more rapidly at about 23oC, the disease may be more promptly in the ripening room

Pathogen spread Seed borne By infected transplants or rain-splashed from infected crop

debris Fruits – wounds, stem scars Progress is more in ripe than in green fruits

Page 23: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Control Seed treatment – ceresan dust (5% ethyl mercury

phosphate) Seed be sanitation Do not harvest when plants are wet To ctrl contamination in packing process- 5% borax

solution containing 0.5 % liquid tar soap as washing medium

Page 24: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

SOIL ROT (RHIZOCTONIA SOLANI)

This fungus causes the fruit to decay in all stages of development

penetrates the fruit through wounds or the unbroken epidermis and invades the tissue,

causing numerous small, brown, sunken spots on the side of the fruit that is in contact with the soil.

Usually there is a single point of invasion by the fungus, and as this spot enlarges it becomes zonate with concentric brown rings, somewhat typical of buckeye rot.. With this disease, the zoning is extremely definite and more pronounced.

In most cases, the epidermis is ruptured at the center of the spot in soil rot,

The buff to brown mycelium of the fungus may be evident where the epidermis has ruptured

Page 25: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Pathogen spread soilborne and rain-splashed.

Favorable conditions wet, moderately warm (75-80 F.) weather

Controls

Trichoderma harzianum, when to added to soil or applied as a coating on tomato fruits, at a con. of 109 conidia /ml. provided significant control of fruit rot caused by R. solani and the secondary bacterial invader causing soft rot.

This disease is seldom of importance in fields where the plants are staked, pruned and/or grown on plastic mulch.

Fruit losses in transit can be controlled by careful grading.

Page 26: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

SOUTHERN BLIGHT (SCLEROTIUM ROLFSII)

Mature plants are attacked just below the soil surface and are completely girdled

The tops wilt and die rapidly

Mycelium often grows over the diseased tissue and surrounding soil forming a white mat of mycelial threads with the typical tan-to brown, at the crown mustard-seed-sized sclerotia

Often the entire root system is destroyed

Page 27: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Southern Blight

Page 28: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Fungus is exceedingly destructive on ground crops and attacks the fruit where they contact the soil.

Slightly sunken, yellow spots develop on invaded fruit, which rapidly decay, collapse, and become covered by a white fungal mass with numerous sclerotia.

Pathogen spread Soil borne, machinery or water-moved infested soil, survives on

numerous weed and crop hosts

Favorable Conditions wet periods of high temperatures (85-95 F.)

Page 29: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

BACTERIAL CANKER (CLAVIBACTER MICHIGANENSE SUBSP.

MICHIGANENSE)

Leaves: general chlorosis, drying & wilting Stem, Shoots & petiole – long, brownish stripes Pith- creamy white, yellow or reddish brown discoloration

of cavities & exude bacteria Fruit: Birds eye spot (Small, round white raised spots) Later –light brown roughened centre surrounded by white

halo

Brown lesion on stem and vascular discolouration

Wilting and necrosis & death of lower leaves

Bird's-eye" like spots on fruit

Page 30: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Bacterium G+ve, non-motile, 0.7x0.6μm, produce capsules in culture.

Mode of spread and survival Seed borne, diseased pl. debris, Survival in Soil-1 to 4 years. Enters through wounds-stem or roots Caused by rain splashes or overhead irrigation

Epidimiology Air & soil temp. 100c to 360c. Opt. temp. 280c Survives in solanaceous weed

Control Field sanitation Crop rotation – 3 yrs Seed treatment- chemical or hot water treatment 2 to 4 sprays of streptomycin to the bed followed by weekly field

field sprays of copper sulphate 53 %

Page 31: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

BUCKEYE ROT PHYTOPHTHORA NICOTIANAE VAR.

PARASITICASymptoms Brownish, circular spots – immature green spots at blossom end lesion- concentric rings, dark brown and light brown bands Severe stage- internal rotted tissue is semi watery, external

retains brown, firm consistency with no extramatrical mycelium unless the surface is ruptured

Pathogen Hyphae – 9μm wide Sporangiospores – thinner than vegetative hyphae, irregularly

branched Sporangia – papillate, ellisoid to spherical Antheridia- amphigynous Yellowish brown oogonia

Page 32: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Mode of spread and survival Survives in soil in the form of resting spores from one season to another Pathogen- soil borne and internally seed borne Spreads by splash transmission of soil When fruits come in contact with the ground

Epidemiology Common in poorly drained fields High humidity & rainfall Disease appears within 4 days at 22.5oC

Management Good drainage facility Remove Lower leaves and fruits – to avoid soil contact Staking of plants Mulching with some straw Soil sterilization with chloropicrin Weekly spray- 0.2 % captafol Better result – combination of mulching and 0.3 % difolatan spray

Page 33: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

FUSARIUM ROT (F. O F. SP. LYCOPERSICI RACES 1-3)

Yellowing of lower leaves in initial stage & discolouration of younger leaves soon follows

Leaves-droop, wilt and die Vascular tissue of a diseased plant is dark brown in color Fruit infection occasionally occurs and can be detected by the

vascular tissue discoloration within the fruit Fruits ripen prematurely

Page 34: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Fungus Mycelium-septate, hyaline at first becoming cream coloured

with age Microconidia- one celled, hyaline, ovoid to ellipsoid

Mode of spread and survival Soil borne and seed borne Soil-survive as chlamydospores or as saprophytically growing

mycelium in infected crop debris for more than 10 yrs Spread by seedlings raised in infected soil Wind borne spores, surface water and agricultural implements-

field to field spread

Epidemiology Alternating low and high soil temperature and high humidity Opt. temperature- 28oC Other favorable factors- light sandy soil, low soil moisture and

ph

Control Remove infected plant debris an destroy Seed treatment- carbendazim 2g/kg

Page 35: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

SOUR-ROTGEOTRICHUM CANDIDUM

Growth on lesions on fruit resembles a thick, gelatinous mass similar in appearance to cottage cheese.

Lesions themselves may initially be relatively firm as in pickled tomatoes, but later the tissues break down much like bacterial soft rot.

Odor of these lesions is similar to that produced by lactic acid bacteria, hence the disease name, sour rot.

Max. disease incidence -25OC

Page 36: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

CANKER DIDYMELLA LYCOPERSICI

Stem – lesions near the ground Cankers may girdle the stem and wilting follows Fruit – rotting, lesions at stem end

Fungus Perithecia-subglobose, asci- cylindrical Ascospores – spindle shaped, hyaline, uniseptate Pycnidia- 100 to 270μ; pycnospores- unicellular,

hyaline

Page 37: LIST OF DISEASES 1. Gray Mould- Botrytis cinerea 2. Rhizopus rot- R. stolanifer 3. Sour-rot- Geotrichum candidum 4. Canker - Didymella lycopersici 5.

Spread & Survival

Penetrates - wounds and stomata Survives on plant debris in the soil and spreads from the

infected lesions on the collar and the stem through the tools handled in cutting and land works, air draught and water splash.

Dissemination occurs mainly through conidia (produced by the pycnidia) and not through ascospores

Rarely seed-borne

Favourable condition Optimum temperature - 19 - 20°C.

Its outbreak is more severe in heavy moist land and in crops sown in cold soil.

Control Seed treatment Field sanitation Soil treatment- formaldehyde