Fall-blooming asters
provide one of the last colorful treats of the season before winter’s cold
kiss. They are hardy plants with sturdy dispositions and are rarely bothered
seriously by pests or disease. Aster rhizoctonia rot, however, is one disease
that crops up in the plants from time to time. This fungus is found in many
types of plants and causes a variety of symptoms.
What is Aster Root Rot?
Rhizoctonia affects many types of ornamental perennials and
even a few herbs and shrubs. This widespread fungus causes blights, rots, and damping
off. Aster stem rot information indicates the disease as starting in soil.
The stem rot can progress in the plant to leaves and blooms.
Aster stem and root rot is a result of the fungus Rhizoctonia solani. The pathogen is a
soil borne organism that occurs in many types of soil. It remains in soil as
mycelium and sclerotia that spread when soil is disturbed.
The fungus can attack roots, stems and leaves. It can be
difficult to identify when the disease starts in the roots unless you dig the
plant up. The first obvious signs might be on any leaves touching the soil
where the leaf wilts and turns dark brown. Stems will develop sunken areas of
decay that turn reddish brown. If you pull the plant up, the roots will be dark
brown and mushy.
Conditions Favoring Aster Rhizoctonia Rot
In a greenhouse, rhizoctonia rot can spread rapidly due to
shared potting medium and spores that can splash into other containers in
crowded situations. It is most prevalent in warm, moist weather followed by dry
conditions. Crowding and lack of air flow promote the formation of spores.
In the garden, the fungus can persist in the soil for years
and attacks many types of plants, which makes crop
rotation mostly ineffective. It can even survive in contaminated pots and
containers, or gardening tools and boots.
Good cultural care of the plant can minimize some of the
damage from the disease but, eventually, the plant will succumb to aster stem and
root rot.
Controlling Aster Rhizoctonia
Because this is a soil borne pathogen, control starts with
your soil. If you are using a potting mix, make
sure it is sterile and do not reuse old soil from other plants. Before
planting anything, thoroughly clean
all containers and tools.
In the greenhouse, space plants well away from each other
and use a fan to increase air circulation. Also, avoid watering the plants from
overhead.
Give plants correct cultural care, as healthy plants are
less bothered by the fungus than stressed specimens. If necessary, apply a
fungicide soil drench. Another method of control includes solarization
of soil. The key is sanitation to avoid spreading the disease.
Fall-blooming asters
provide one of the last colorful treats of the season before winter’s cold
kiss. They are hardy plants with sturdy dispositions and are rarely bothered
seriously by pests or disease. Aster rhizoctonia rot, however, is one disease
that crops up in the plants from time to time. This fungus is found in many
types of plants and causes a variety of symptoms.
What is Aster Root Rot?
Rhizoctonia affects many types of ornamental perennials and
even a few herbs and shrubs. This widespread fungus causes blights, rots, and damping
off. Aster stem rot information indicates the disease as starting in soil.
The stem rot can progress in the plant to leaves and blooms.
Aster stem and root rot is a result of the fungus Rhizoctonia solani. The pathogen is a
soil borne organism that occurs in many types of soil. It remains in soil as
mycelium and sclerotia that spread when soil is disturbed.
The fungus can attack roots, stems and leaves. It can be
difficult to identify when the disease starts in the roots unless you dig the
plant up. The first obvious signs might be on any leaves touching the soil
where the leaf wilts and turns dark brown. Stems will develop sunken areas of
decay that turn reddish brown. If you pull the plant up, the roots will be dark
brown and mushy.
Conditions Favoring Aster Rhizoctonia Rot
In a greenhouse, rhizoctonia rot can spread rapidly due to
shared potting medium and spores that can splash into other containers in
crowded situations. It is most prevalent in warm, moist weather followed by dry
conditions. Crowding and lack of air flow promote the formation of spores.
In the garden, the fungus can persist in the soil for years
and attacks many types of plants, which makes crop
rotation mostly ineffective. It can even survive in contaminated pots and
containers, or gardening tools and boots.
Good cultural care of the plant can minimize some of the
damage from the disease but, eventually, the plant will succumb to aster stem and
root rot.
Controlling Aster Rhizoctonia
Because this is a soil borne pathogen, control starts with
your soil. If you are using a potting mix, make
sure it is sterile and do not reuse old soil from other plants. Before
planting anything, thoroughly clean
all containers and tools.
In the greenhouse, space plants well away from each other
and use a fan to increase air circulation. Also, avoid watering the plants from
overhead.
Give plants correct cultural care, as healthy plants are
less bothered by the fungus than stressed specimens. If necessary, apply a
fungicide soil drench. Another method of control includes solarization
of soil. The key is sanitation to avoid spreading the disease.