1. Important Diseases
of
Anthurium,Carnation
and Rose
Varsha Gaitonde
Sr MSc
Dept.of Genetics and plant breeding.
GKVK UAS Bangalore

2. Diseases of Anthurium

3. Anthurium Blight
Xanthomonas axonopodis pv. dieffenbachiae
• A bacterial disease.
Source-affected plant residues.

4. Bacterial Wilt
Ralstonia solanacearum
•Symptoms:
•Leaf yellowing (chlorosis) is usually the first symptom
observed.
•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.

5. 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
stems.
• Source-Splashing water,air movement and
workers.

6. Root Rots
Rhizoctonia  Root Rots - brown, mushy roots due
Pythium
to too much water.
Phytophthora  Wilt, yellowing.
 Abscission of leaves from the base
Sclerotium
up.
Fusarium
 Death of the roots results.
Pythium,Phytopthora and Rhizoctonia
Pythium
Pythium spp

7. Diseases of Carnation

8. • 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
plant.
• When older plants are infected, similar symptoms
are produced but the older leaves may show
chlorosis followed by an indistinct purple-red
discoloration.
• The vascular tissues of infected stems is stained
dark brown.
• Mature plants show wilt symptoms over a period of
several months before they die and eventually
become straw coloured.

9. Alternaria leaf spot (Alternaria
dianthi)
• Symptoms
• 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
cankers

10. . Bacterial wilt (Burkholderia
caryophylli)
• 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
remain discolored.
• Source-Infected samples,and weed
hosts.

11. • 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

12. • Carnation etched ring virus (CERV)
• Carnation mottle virus (CarMV)
• Carnation latent virus (CLV)
Carnation necrotic fleck virus (CNFV)

13. Alternaria saponariae
Alternaria blight
= Alternaria dianthi
Alternaria dianthicola
Anther smut
Calyx rot
Ustilago violacea
Stemphylium botryosum
Pleospora tarda [teleomorph]
Charcoal rot
Macrophomina phaseolina
Downy mildew
Peronospora dianthicola
Fairy-ring leaf spot
Fusarium bud rot
Fusarium stem rot
Mycosphaerella dianthi
Cladosporium echinulatum [anamorph]
Fusarium tricinctum
Fusarium graminearum
Gibberella zeae [teleomorph]

14. Diseases of rose

15. • Powdery Mildew
Air borne.
Fungal thread on leaf surface
Sphaerotheca pannosa
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
cycle.

16. Black Spot
Diplocarpon rosae
• 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

17. Downy Mildew
Peronospora sparsa
•
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
leaves

18. Anthracnose
• Initially spots are small and black - easily confused with
blackspot
• 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
with blackspot
• Can be severe under cool, moist spring conditions
Sphaceloma rosarum

19. Botrytis Blight
• When the weather is cool and
wet, the conditions are right for
this fungus
• Most common symptom - young
flower buds droop, turn black at
the base
• Later produce
the cottony
grey-black
mycelium of
the fungus
Gail Trimble
Botrytis cinerea

20. Rose Canker
•
•
•
•
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
causing fungi
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
black
Coniothyrium spp

21. Rust
• A fungal disease common in many areas,
easily identified
•
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
weather
• Fungus overwinters on infected leaves
and canes
• Spores are wind borne
• Can defoliate the plant
Phragmidium spp

22. Bacterial Crown Gall
Agrobacterium tumefaciens
• Bacterial disease usually seen
on bud union, or on the trunk
• Thrives in warm, sunny
weather; not active in cold
weather
• Cork-like substance that will
turn brown and harden as it
ages
• Plants will usually be stunted
in their growth habits

23. Rose Mosaic
Prunus Necrotic Ringspot Virus
• Probably the most commonly found
virus in roses
• Mosaic is primarily transmitted by
propagation
• 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
quality blooms.
• Transmitted by infected
stock,cuttings.

24. 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
Roundup®

25. 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
media.
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.

26. • 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
include:
• 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.

27. • 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.

28. Cultural Practices
• 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
location

29. • Carefully check both the foliage and roots for
disease.
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
•
•

30. •
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.

31. Monitoring
•reviewing crops for plant growth regulator (PGR) application or
for irrigation.
•monitoring or applying a fungicide:
•
date
•
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).

32. • Biosecurity
• 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.
• Disinfectants
• Agribrom - used to control microbial slimes in greenhouse evaporative
cooling systems and to control algae and microbial slimes in irrigation
systems.
• 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.

33. Biological control
• Rootshield is registered as a bio-fungicide for
suppressionof Fusarium, Pythium and Rhizoctonia on all
ornamental crops.
• 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.
•

34. Chemical control
• 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.
(1mm)
• Apply chlorothalonil, propiconazole, myclobutanil,
ziram, mancozeb + thiophanate methyl, triadimefon,
or triforine for rust.

35. Resistant varieries
• Rose-PM• Charisma ,Pascali Rose ,Parade
Chicago Peace, Prominent Sarabande
,Europeana Pink Peace, Saratoga ,Margarita
etc.
• Black spot-Angel Face, Ivory Fashion, Proud
Land, Carrousel, Miss All-American Beauty,
Queen Elizabeth .

36. Questions?
Thank You