Not curative.go for preventive measures.Quarantining
ontrol and Treatment: The Colletotrichum fungus produces thousands of small hot-dog-shaped spores that can readily be moved by splashing water, air movement, and workers. A strict sanitation program is crucial to control the spread of this pathogen in a production facility. Fungicides containing mancozeb (Protect T/O™, Dithane®) are effective. Fungicide applications are usually discouraged because chemical residues diminish the marketability of flowers and plants. Anthurium plant breeding programs both in Hawaii and Florida have incorporated disease resistance into many of the current cultivars. Newer cultivars are highly resistant to this pathogen and rarely exhibit black nose. The fungus attacks many temperate and tropical crops and can cause damage to roots, stems, leaves, and flowers. However, in Anthurium the pathogen is highly specific, only attacking the spadix portion of the flower (the nose).
transparent polyethylene film (0.1 mm thick) for 30 days gives satisfactory control
.Management To reduce the disease incidence, humidity may be kept low by providing proper air circulation. Disease-free planting material should be used.
The base of the cutting is discolored, with an elongated brown area extending upwards.The bacteria invade xylem vessels and spread to infect the young shoots. The vessels are disrupted and the host plant produces meristematic tissues. This new tissue causes an uneven development of cortex which splits open longitudinally. Carnation wilt, a vascular disease may be induced by mechanical plugging, a toxin or a combination of factors. Carnation cuttings wilted when placed in a filtrate of a bacterial suspension of B. caryophylli.In the naturally infected carnation plants the xylem vessels are found partly plugged. Lysis of xylem vessels, is also observed. Infection is carried to upper portions of the branch into the leaves. Bacteria are not found in parenchyma tissues. Carnation cuttings suspended in bacterial filtrates in which proteins and other large molecular compounds are removed did not wilting symptoms.Management Use of cuttings taken from upper parts of the healthy stock plants are less liable for infection and hence advocated as a control measure. Diseased plant debris should be collected and burnt. Overhead watering and splash watering should be avoided. Disease-free planting materials are to be used. Role cultivars viz., Elegance, Northland and Starlite are less susceptible to bacterial wilt.
Control Since there are no chemical sprays for virus control once a plant is infected with a virus there is little the flower grower can do. The only current method for controlling virus diseases is through the use of virus tested material in conjunction with strict hygienic practices. To prevent infection of this virus-tested material, the carnation grower should enforce hygiene regulations for example, washing hands with hot soapy water before handling plants, aphid-proof glasshouses, sterilisation of cutting and propagating instruments etc).
Good sanitation will reduce the chance of infection– remove diseased leaves Aggressive spring pruning will remove a large source of fungus Prune to allow air circulation, and water without wetting the foliage
Tissue may drop out of the center of the spots, giving infected leaves its other name of “Shot Hole Fungus” Fungus overwinters on leaves and canes Can cause leaf drop that weakens the plant In extreme cases, it can result in complete defoliation Sanitation is best means of control – remove diseased leaves, and dispose in trash Plant spacing, use of drip lines or soaker hoses rather than sprinklers should help Prune out canes that have infections in fall – dispose in trash, not in compost pile Fungicide used for black spot is usually effective
Spores are moved to other plants by wind or blowing rain Can affect any part of a plant except roots Note the grayish fuzzy growth on the cane that indicates botrytis Wet or very humid weather may be highly favorable for the spread of the disease Good ventilation is also essential in reducing disease incidence Fungus may overwinter in dead plant tissue
Time fall prune so tips will dry and harden before winter Dormant spray can protect pruning cuts Disinfect pruners before moving to another bush In spring, remove infected canes and spray for fungal disease Fungicides that control black spot on ornamentals will also help to control canker
Don’t water in the evening so that the leaf surface is wet over night Fungicide you use for powdery mildew or black spot is usually effective
Successful disease management begins prior to the start of each crop. Knowing the diseases most likely to infect the crop is helpful in anticipating the potential problems that may arise. However, with so many new plant introductions each year, the susceptibility to disease is not always known. Experience has shown that most new plant material is susceptible to many of the same diseases that have frustrated growers for decades.
Diseases of anthurium Carnation and Rose.Prepared by Varu Gaitonde.
Dept.of Genetics and plant breeding.
GKVK UAS Bangalore
•Leaf yellowing (chlorosis) is usually the first symptom
•The disease spreads rapidly throughout the vascular
system of the plant, turning veins in the leaves and stems
a brown, bronze color .
•Bacterial ooze (brown slime) will be present if cuts are
made into the stems of highly infected plants. Plants will
exhibit wilt symptoms even though adequate soil
moisture is available.
Black Nose Disease
: Colletotrichum gloeosporioides
• Symptoms: Black nose can cause havoc in
cut-flower and potted-plant production.
Flowers and flowering potted plants
cannot be sold with this condition.
• The first symptoms observed are small,
brown to black flecks on the floral spadix
(nose) These spots rapidly enlarge,
become watery, turn brown to black, and
may totally encompass the spadix. The
spadix may eventually fall off. Growers
may also observe black, spore-containing
structures (acervuli) on dead leaves and
• Source-Splashing water,air movement and
Rhizoctonia Root Rots - brown, mushy roots due
to too much water.
Phytophthora Wilt, yellowing.
Abscission of leaves from the base
Death of the roots results.
Pythium,Phytopthora and Rhizoctonia
• Fusarium wilt(Fusarium oxysporum f.sp. dianthi)
• In young plants, the first sign of the disease is fading
or graying ,wilting of the leaves and young stems.
• It is followed by eventual collapse of the whole
• When older plants are infected, similar symptoms
are produced but the older leaves may show
chlorosis followed by an indistinct purple-red
• The vascular tissues of infected stems is stained
• Mature plants show wilt symptoms over a period of
several months before they die and eventually
become straw coloured.
Alternaria leaf spot (Alternaria
• The blight or rot at leaf
bases and around nodes,
which are girdled. Spots on
leaves are ashy white.
• The centre of old spots are
covered with dark brown to
black fungal growth.
• . Branches die-back at the
girdled area and black crusts
of conidia are formed on the
. Bacterial wilt (Burkholderia
• The upper parts of established
plants turn pale and wilt.
• The stem develops elongated
discolored stripes and split.
• The roots are rotted partially and
the cortical tissues become sticky
and shows discoloration.
• The leaves are twisted. The roots
• Source-Infected samples,and weed
• Carnation vein mottle virus (CVMV)
of "colour breaks" and calyx splitting are greater. CVMV is
spread from plant to plant by aphids and is found wherever
carnations are grown
• Powdery Mildew
Fungal thread on leaf surface
Common in crowded plantings where air circulation is poor
The fungus can over winter on infected canes, and leaves left
on the bush.
spores move to new growth foliage in spring to begin disease
• One of the most common diseases of roses
• Disease cycle typically begins on leaves or canes infected
the previous season
• Leaves less than two weeks old are the most susceptible
• Lower areas are more likely to be infected as spores are
splashed up on new foliage during rains or irrigation– will
continue up the stem - as disease spreads, leaves go from
green to yellow and then drop
A very serious disease that can affect all roses!
May appear only when favorable conditions of
humidity over 85% and temps of 65 - 75° F
Under cool and moist spring conditions, young
leaves, stems and flowers may show purple to
red or brown irregular blotches that tend to
follow the leaf veins
Advanced infections will have yellowing of
• Initially spots are small and black - easily confused with
• Spores believed to be carried by water or rain to new
leaves and stems
• As disease progresses, spots become purple to brown
and centers turn gray or white with dark margin
• This light-colored center best defines the difference
• Can be severe under cool, moist spring conditions
• When the weather is cool and
wet, the conditions are right for
• Most common symptom - young
flower buds droop, turn black at
• Later produce
A fungal disease that can
affect any part of the plant,
but most common on
stems and canes
After a cold wet winter,
pruned stems provide
wound sites for canker
Canker can also enter thru
leaf scars – do NOT tear off
leaves during fall pruning!
The stems will yellow,
often have red spots and
later become brown or
• A fungal disease common in many areas,
Appears on the underside of the foliage
as red-orange spots
• Thrives in cool, moist weather
• The summer stage is cyclic, and may
repeat every 10 to 14 days in favorable
• Fungus overwinters on infected leaves
• Spores are wind borne
• Can defoliate the plant
Bacterial Crown Gall
• Bacterial disease usually seen
on bud union, or on the trunk
• Thrives in warm, sunny
weather; not active in cold
• Cork-like substance that will
turn brown and harden as it
• Plants will usually be stunted
in their growth habits
Prunus Necrotic Ringspot Virus
• Probably the most commonly found
virus in roses
• Mosaic is primarily transmitted by
• Usually appears in spring as a
distortion of growing tips and leaves
• Symptoms include coloration
patterns (shown), distorted leaf
growth, slow to develop, and fewer
• Transmitted by infected
Rose Rosette Disease (RRD)
• Exact cause unknown
• The distinctive red stems,
misshapen leaves are symptoms
• The main host is R. multiflora
• New growth appears unusually
soft and pliable
• RRD is suspected to be carried
from plant to plant by mites
• Can be confused with plant
damage from chemicals like
Basic IDM stretegies
pH of the growing media - pH strongly influences the
availability of micronutrients such as iron and manganese and
can influence the development of the root system in the growing
Nutrient levels and their balance - These affect the plant tissue
content and can trigger toxicity or deficiency symptoms. This
tissue is typically more susceptible to attack by pathogens.
EC (electrical conductivity created by soluble salts) - High
EC can damage root hairs creating a wound site for attack by
root disease pathogens.
Moisture-holding capacity - Media must hold sufficient
available water to prevent desiccation of the roots once the root
system becomes pot-bound.
Media texture to allow good drainage - Adequate coarsefibred peat is required to ensure sufficient aeration when the
growing media is at full water holding capacity to prevent water
logging and oxygen deprivation of the roots.
• Oxygen content - Adequate media aeration is critical to
healthy root growth and nutrient uptake and preventing
temporary exposure of roots to anaerobic conditions.
• Media temperature - Roots develop best at temperatures
somewhat lower than those required for shoot growth.
High media temperature causes significant root death in
most crops when media temperatures are above 26-28°C.
Aerial environment characteristics that must be considered
• Light levels - Exposure of high light requiring plants to low
light levels or heavy shading often triggers soft, weak
growth that is more susceptible to leaf rot pathogens.
• Temperature Fluctuation resulys in higher incidence of root
and foliar disease problems. For example, crops typically
considered cool crops when grown during high
temperature periods of the year are usually more
susceptible to crown and root rot pathogens.
• Air movement - powdery mildew and botrytis.
Open doors causing drafts and fluctuating leaf
and air temperature or horizontal air fans
(HAF) foliar diseases.
• Relative humidity (RH) - Fluctuating RH with
high RH at night (above 90%) increases the
incidence of foliar diseases.
• Air quality - Chronic low level air pollution
often associated with ethylene-like
hydrocarbons can trigger premature
senescence of older leaves whose tissue is
more prone to opportunistic fungi like Botryis.
• Symptom recognition
• Sanitation and Roguing
• Use footbaths between greenhouse compartments,
• Rogue the plants,and dispose properly. Dedicate
wheelbarrows or soil carts used to discard diseased
material strictly for disposal purposes.
• pathogen exclusion, construction of traps, pruning,
and burning of diseased plants or leaves in a safe
• Carefully check both the foliage and roots for
Maintain proper drainage to eliminate puddles
and wet surfaces, as these provide ideal
breeding sites for fungus gnats and shoreflies.
diseases such as Pythium and Fusarium.
Keep the greenhouse free of weeds that may
harbour diseases. For rose, steam soil before
planting winter crops to minimize the
carryover of root and crown rot pathogens
Avoid extremes, as much as possible, for the
crops. For example, the combination of high
temperature and over-fertilization
promotes Fusarium crown and root rot in
cyclamen, while the combination of high
temperature and high RH is favourable
to Rhizoctonia attacking cuttings during or just
after propagation. Also avoid low temperatures to
prevent outbreaks of Pythium in warmtemperature crops.
•reviewing crops for plant growth regulator (PGR) application or
•monitoring or applying a fungicide:
compartment or section in the greenhouse
crop species and cultivar
stage of plant development
diseases present or suspected
control action (pesticide used, rate, area treated, time taken, etc.)
greenhouse environmental conditions (temperature, RH, light
levels, shading used).
• Biosecurity is a process to protect a geographic area or individual facility
from pests and diseases. It includes reducing the risk of the introduction of
new pests and diseases and eradicating or effectively managing the spread
of those that have already arrived.
• Agribrom - used to control microbial slimes in greenhouse evaporative
cooling systems and to control algae and microbial slimes in irrigation
• A 0.5-1% final solution of sodium hypochlorite bleach -Used when there
is a severe disease out break.Used as a disinfectant.
• Horti-Klor - a chlorinated cleaner or detergent that can be used initially to
remove algae and plant residue from packing equipment, planting lines,
plug trays and coolers. Follow manufacturer's directions.
• Other compounds like Quaternary ammonium chloride, ZeroTol,Virkon
,Floralife D.C.D,KleenGrow,Strip-It etc.
• Rootshield is registered as a bio-fungicide for
suppressionof Fusarium, Pythium and Rhizoctonia on all
• Actinovate SP is registered as a contact biological
fungicide for PM and Botrytis.
• Regalia Maxx supress PMs.
Cyclone, suppress powdery mildew and blackspot on
greenhouse roses when applied as a foliar spray.
• Apply chlorothalonil, propiconazole, fludioxonil,
copper hydroxide, iprodione, mancozeb, or mancozeb
+ thiophanate methyl to control leaf spots.
• Apply chlorothalonil, cupric hydroxide, iprodione,
mancozeb, or fludioxonil for Blight.
• Plant in pasteurized, raised beds. Apply thiophanate
methyl, PCNB or iprodione as a soil drench for soil
borne diseases.Polyethylene film for 30 days for wilt.
• Apply chlorothalonil, propiconazole, myclobutanil,
ziram, mancozeb + thiophanate methyl, triadimefon,
or triforine for rust.
• Rose-PM• Charisma ,Pascali Rose ,Parade
Chicago Peace, Prominent Sarabande
,Europeana Pink Peace, Saratoga ,Margarita
• Black spot-Angel Face, Ivory Fashion, Proud
Land, Carrousel, Miss All-American Beauty,
Queen Elizabeth .