This document discusses common diseases that affect mushrooms. It describes 4 bacterial diseases - bacterial blotch caused by Pseudomonas fluorescens, bacterial rot caused by Pseudomonas alcaligens, brown spot caused by Pseudomonas stutzeri, and yellow blotch caused by Pseudomonas agarici. It also discusses viral diseases in general and 4 main fungal diseases - wet bubble caused by Mycogone pernicious, dry bubble caused by Verticillium fungi, green moulds caused by Trichoderma species, and cobweb disease caused by Clabotryum dendroides. Finally, it lists some common abiotic disorders that affect mushrooms.

1. K.Shalini [B.sc Microbiology]

2.  The mushroom diseases can be caused by
both fungi and bacteria.
 Once the disease is introduced in the farm,
secondary infection can be carried out by
different agents such as air, water, machines,
unhygienic equipments and handlers.
 The important fungal, bacterial and viral
diseases and their causative organisms ,
symptoms and control measures are
followed.

3. 1.BACTERIAL BLOTCH:
 It is a common bacterial disease in button
mushroom generally known as bacterial
spot.
 This disease is common in mushroom farms
where there is no healthy crops and poor
ventilation system.
 When lower temperature in the cropping
room , bacterial blotch is common.
 It may cause total loss of crops.

5. Causative agent:
 Pseudomonas fluorescens biotype G.
(syn. Phytomonas tolaasu)
Symptoms:
 The pathogens produce deep pale yellow
colouration on mushrooms. Later it may
change into golden yellow or chocolate
brown.
 Affected mushrooms are become sticky.
 Splitting at the blotched area are also noticed.

6.  Causing material before and after mixing
should be stored in area free from pathogens.
 Diseased mushroom should be removed.
 Area should be steralized.
 Pickers should wash there hands before
picking.
 Spraying with chlorinated water spraying with
streptomycin 200ppm or oxytetracycline
300ppm to control disease.

7. 2.BACTERIAL ROT:
 The bacterium pseudomonas alcaligens is the
causative agents of bacterial rot in pleurotus
sajor-caju.
 The symptoms include water-soaked spots
and yellowish brown discolouration.
 Rotting starts from the center of the
sporophores towards periphery.
 The gills on the lower surface turn yellow.
 The cap become crinkled and rolls upward
and inward.

9. 3. BROWN SPOT:
 Pseudomonas stutzeri is reported as
cpmpetitive bacterium on paddy straw
substrate used for the cultivation of pleurotus
sajor-caju.
 It induced brown spots in substrate and
caused 25-60 per cent yield reduction.
 dipping in streptocycline solution [100ppm]
or formalin[25ppm] controlled this bacterium.

11. 4.YELLOW BLOTCH:
 Yellow blotch on P.sajor-caju is reported to
be caused by pseudomonas agarici.
 It cause complete crop failure and the disease
as blotches of varying sizes on pileups.
 The blotches are depressed , yellow and
hazel-brown or orange in colour.
 Infected fruit rot become rot, shiny, emit bad
odor at higher temperature and humid
conditions.
 Controlled by spraying oxtetracycline,
streptocycline or sodium hypochlorite.

13.  Casing material and air-borne dust are the
primary source of infection.
 It is present in the causing soil even after
pasteurization.
 Bacteria on the mushroom cap will reproduce
easily.
 High humidity and low tempeature of 8-80°C
favour for infection.
 Secondary spread is through hands of
pickers, tools, ladders, debris, chalk, mites,
peats, etc…...

14.  They are serious infection in button
mushrooms.
Causative agents:
 Spherical virus particles have been reported
in P.ostreatus, P.sapidus, P.columbinus and
P.florida.
 Polyhedral virus reported in volvariella
volvacea.
 Rod&spherical virus reported in lentinus
edodes.

16. Symptoms:
 Due to virus infection the mycelium
disappears after the surface of the casing
layer.
 Sporosphores have off-white caps and
mature early.
 Strips are slightly bent elongated and watery
in nature.
 Gills become hard and give out musty smell.

17. Mode of transmission:
 Viruses spread through mycelium, spores,
and germ tubes of mushroom and through
vectors.
 Phorid flies and mites help in introduction of
virus particles trays free virus infection.
Control:
 Agaricus bitorquis has been reported to be
immune to all viruses affecting A.bisporus.

18.  There are four important fungal diseases of
the cultivated mushrooms , particularly they
infect to agaricus bisporus.
1.WET BUBBLE:
 Wet bubbles also called as mycogone disease,
white mould and bubble disease.
 It is a serious disease of white button
mushroom.

20. Causative agent: Mycogone pernicious
Symptoms:
 When pin heads are infected, whole massof
mushroom become destroyed.
 Brown as scleroderma mass of white and
fluffy.
 Due to formation of chlamydospores it
become brown and decay.
 White mycelial patches occur.
 Brown stalks are found on the stalk and gills.

21. MODE OF TRANSMISSION:
 Infection comes from soil and air on the
atmosphere.
 Chlamydospores survive on the soil for the
year.
 Infected mushroom spread by air, water
splashes, flies, mites and by pickers.
CONTROL:
 Use of sterilized casing soil, pasteurixed
compost and proper disposal of spent
compost.
 Spray formalin and maintain proper
temperature.

22. 2.DRY BUBBLE:
 Dry bubble also called as verlicillium disease.
 It delays the pin-head formation, reduce the
number of sporophores and the yield of white
button mushroom.
 If not controlled, it may destroy the crop in two
to three weeks.
Causative agent: verticillium fungi cola var.
Symptoms:
 Vary with time of infection.
 Grayish yellow pin head stage the whole tissue is
look like bubble.
 Dark brown lesions and cracks found in lesions
on the caps.

24. TRANSMISSION :
 By infected casing soil.
 Conidia are produced in sticky clusters and
sticks easily to any contact.
 Spores in air and soil.
 Conidia spread by splashing and running
water.
CONTROL:
 Use of sterilized casing soil and pasteurized
compost.
 Spraying mancozeb or zineb.

25. 3.GREEN MOULDS:
 Green mould Trichderma viridae was first
reported in india on Agaricus bisporus.
Causative agent: all different Trichoderma Spp.
SYMPTOMS:
 it appears as gren patches on the spawned
and cased trays.
 Green mould symptom compost on casing
soil, in spawn bottle and on grain after
spawning.

27. MODE OF TRANSMISSION:
 Addition of un-sterilized supplements
introduces green moulds.
 Dead mushroom tissues in the beds and cut
stipes help in the infections.
 High humidity, poor nitrogen and more
quantity of carbohydrate.
 Air-borne dust&mites are main infection
route.
CONTROL:
Spraying zineb, dead and infected mushroom
should be cut and removed.
Proper sterilization.

28. 4.COBWEB DISEASE:
 It is otherwise known as soft decay,dactylium
and mildew disease.
 Reported in white button mushroom.
 The disease caused 50% loss in yield.
Causative agent:
Clabotryum dendroides or daetylium
dendroides, mycelium is hyaline, branched
and septate.
SYMPTOMS:
Small, circular, white patches of mycelium of
the fungus appears, flufy white moulds ,
mushroom turns brown rot and pathogenic
fungus turn in to pink or red.

30. MODE OF TRANSMISSION:
 The pathogen is soil-borne and spread
through contaminated soil.
 In the farm spores are spread through
contaminated soil.
 High humidity and temperature favors
cobweb disease.
CONTROL:
 Zineb or mancozeb at00/100mg or spray
formalin to prevent fungal infection.
 Discart the infectious mushroom.

31.  Scales & crocodile skin.
 Browning
 Stroma
 Weepers
 Flocks
 Hollow core & brown pith
 Rose comb

32. A) BACTERIAL DISEASE:
1. Bacterial blotch
2. Bacterial rot
3. Brown spot
4. Yellow blotch
B) VIRUAL DISEASE
C) FUNGAL DISEASE:
1. Wet bubble
2. Dry bubble
3. Green mould
4. Cobweb disease
D) ABIOTIC DISORDER