BIOTIC DISEASES AND THEIR MANAGEMENT
Bacteria, fungi, nematodes, mites and insects are most commonly encountered biotic causes of
disorders. The involved organisms/cause should be correctly identified before attempting to
control the problem. It’s essential to understand the biology of the organism, wherever involved
(how it gained entry, how its spread, how it can control) and after this, a suitable method of
controlling the pest or pathogen should be devised. Basically farm hygiene is the best approach
to the control of mushroom disorders.
The incidence and severity of the pest problem are directly related to the degree of control
of the growing environment. The available technology of air conditioning, air movement,
humidification, air filtration, insulation and post-harvest storage have mad pest management
much easier. The availability to preciously control the production environment can lead to the
production of pest-free pesticide-free and high quality mushroom at reasonable cost.
FUNGAL DISEASES
(A) DRY BUBBLE
Causal organism- Verticillium fungicola
SYMPTOMS
Whitish mycelial growth appear on the cashing soil which turn greyish yellow. If
infection take place in an early (pin head stage), the typical onion shaped mushroom are
produced.
The stem is thicker than the cap, which is often not distinguishable from the stem.
At the later stages of infection crooked and deformed mushroom can be seen.
When a part of the cap is affected hare-lip symptoms is noticed. The affected mushroom
turn greyish.
CONTROL
Use of sterilized casing soil, proper dispose of spent compost, control of
insects/nematodes/mites and better hygiene are essential to avoid primary infection.
Spraying with Dithane Z-78, Sporgon at 1.5g/m2 nine days after casing, Topsin M,
Chlorothalonil, Prochloraz and Daconil are effective in checking dry bubble.
Control local infection by spraying the affected patch with 2% commercial formalin.
Dry bubble can be managed effectively by adopting strict hygienic measures, using
properly pasteurized compost and sterilized casing mixtures and maintaining ideal
environmental condition.
, (B) COBWEB DISEASE
Causal organism- Clodobotryum dendroides
SYMPTOMS
Small circular, white patches of the mycelium are first seen on the surface of the casing.
As the disease progresses, a fluffy white mould grows over the mushroom. Eventually
mushroom effected by cobweb disease turn brown, being to rot and die off.
In severe attacks a dense white mould develops over casing and mushroom change from
a fluffy cobweb to dense mat of mycelium. The white colour can turn pink or red with
age.
CONTROL
Thoroughly disinfect the casing soil with live steam or formaldehyde and/or treat with
150g Benomyl per 100m2 upon casing.
Sterilizing the casing mixture even at 50ºC for 4 hours can kill the pathogen.
Temperature and humidity during picking should not go beyond 60ºF and 90% respectively.
Fungicides can be applied to the surface of casing, Benzimidazole and prochloraz manganese
and chlorothalonil can be applied in the initial casing mixture or spread on between flushes.
Use of Bavistin+TMTD at g/m2 is better. Dust between flushes with zineb or mancozeb, 100
g/m2 once in a week or spray the beds with a weak solution of formalin (0.2%-0.3%).
Treat the small spots of cobweb mould immediately with salt or formaldehyde.
(B) WET BUBBLE DISEASE
Causal organism- Mycogone perniciosa
SYMPTOMS
Young pinheads develops monstrous shaped which often don’t even resembles
mushroom. The short, curly, pure white fluffy mould of mycogene can easily be observed
on and around the infected mushroom.
The colour of infected area becomes greenish brown due to the formation of dark colour
chlamydospores. Clear, brown coloured drops caused by putrefying bacteria exude from
the bubble. At this stage, bubble is weak or completely rotten and emits unpleasant odour.
CONTROL
Good hygiene, use of properly sterilized casing soil and spraying with Diathane Z-78
(0.3%) at weekly interval provide good control.
Bacteria, fungi, nematodes, mites and insects are most commonly encountered biotic causes of
disorders. The involved organisms/cause should be correctly identified before attempting to
control the problem. It’s essential to understand the biology of the organism, wherever involved
(how it gained entry, how its spread, how it can control) and after this, a suitable method of
controlling the pest or pathogen should be devised. Basically farm hygiene is the best approach
to the control of mushroom disorders.
The incidence and severity of the pest problem are directly related to the degree of control
of the growing environment. The available technology of air conditioning, air movement,
humidification, air filtration, insulation and post-harvest storage have mad pest management
much easier. The availability to preciously control the production environment can lead to the
production of pest-free pesticide-free and high quality mushroom at reasonable cost.
FUNGAL DISEASES
(A) DRY BUBBLE
Causal organism- Verticillium fungicola
SYMPTOMS
Whitish mycelial growth appear on the cashing soil which turn greyish yellow. If
infection take place in an early (pin head stage), the typical onion shaped mushroom are
produced.
The stem is thicker than the cap, which is often not distinguishable from the stem.
At the later stages of infection crooked and deformed mushroom can be seen.
When a part of the cap is affected hare-lip symptoms is noticed. The affected mushroom
turn greyish.
CONTROL
Use of sterilized casing soil, proper dispose of spent compost, control of
insects/nematodes/mites and better hygiene are essential to avoid primary infection.
Spraying with Dithane Z-78, Sporgon at 1.5g/m2 nine days after casing, Topsin M,
Chlorothalonil, Prochloraz and Daconil are effective in checking dry bubble.
Control local infection by spraying the affected patch with 2% commercial formalin.
Dry bubble can be managed effectively by adopting strict hygienic measures, using
properly pasteurized compost and sterilized casing mixtures and maintaining ideal
environmental condition.
, (B) COBWEB DISEASE
Causal organism- Clodobotryum dendroides
SYMPTOMS
Small circular, white patches of the mycelium are first seen on the surface of the casing.
As the disease progresses, a fluffy white mould grows over the mushroom. Eventually
mushroom effected by cobweb disease turn brown, being to rot and die off.
In severe attacks a dense white mould develops over casing and mushroom change from
a fluffy cobweb to dense mat of mycelium. The white colour can turn pink or red with
age.
CONTROL
Thoroughly disinfect the casing soil with live steam or formaldehyde and/or treat with
150g Benomyl per 100m2 upon casing.
Sterilizing the casing mixture even at 50ºC for 4 hours can kill the pathogen.
Temperature and humidity during picking should not go beyond 60ºF and 90% respectively.
Fungicides can be applied to the surface of casing, Benzimidazole and prochloraz manganese
and chlorothalonil can be applied in the initial casing mixture or spread on between flushes.
Use of Bavistin+TMTD at g/m2 is better. Dust between flushes with zineb or mancozeb, 100
g/m2 once in a week or spray the beds with a weak solution of formalin (0.2%-0.3%).
Treat the small spots of cobweb mould immediately with salt or formaldehyde.
(B) WET BUBBLE DISEASE
Causal organism- Mycogone perniciosa
SYMPTOMS
Young pinheads develops monstrous shaped which often don’t even resembles
mushroom. The short, curly, pure white fluffy mould of mycogene can easily be observed
on and around the infected mushroom.
The colour of infected area becomes greenish brown due to the formation of dark colour
chlamydospores. Clear, brown coloured drops caused by putrefying bacteria exude from
the bubble. At this stage, bubble is weak or completely rotten and emits unpleasant odour.
CONTROL
Good hygiene, use of properly sterilized casing soil and spraying with Diathane Z-78
(0.3%) at weekly interval provide good control.
