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Flowers> Chrysanthemum>
Pests
Aphids
(Macrosiphoniella sanborni) :
Greenish-black nymphs and chocolate brown adults
suck the cell sap from growing shoots and lower
surface of leaves. Damage by aphid's results in
loss of vigour, yellowing and premature leaf fall
and stunted growth of attacked plants. Honey dew
secreted by aphids favours development of sooty
mould. The pest also acts as a vector of viral
diseases.
Control : Spraying
of Monocrotophos @0.05% or Phosphamidon @0.02%
at 15-20 days interval controls aphid population
effectively. Grubs and adults of Coccinellid beetles
prey upon the aphids and effectively wipe out
their population.
Thrips (Frankliniella
sp.) :
Slender, white coloured nymphs and black adults
feed on tender leaves causing silvering, mottling
and distortion of leaves. Damaged flowers look
discoloured, withered and dried due to scorching.
Severe infestation adversely affects quality and
quantity of flower production.
Control :
Spraying with Monocrotophos (0.04%) twice or thrice
at 15 days interval controls thrip population.
Drenching the soil with good insecticide also
helps in reducing the population.
Leaf Folder (Hedylepta
indicata) :
It occasionally attains a status of serious pest
on chrysanthemum. Pale-white coloured eggs a laid
singly or in small groups on lower side of leaves.
Green coloured larvae with brown head fold leaves
together and feed on chlorophyll. The affected
leaves get skeletonized and dry. The larvae also
damage flowers.
Control :
Cutting and burning infested plant parts reduces
pest infestation. Two or three sprays of Methyl
Parathion or Quinalphos @0.05% gives effective
control of leaf folders.
Bud Borer (Helicoverpa
armigera):
Female adult deposits round, cream coloured eggs
singly on bracts and petals of buds. Larvae feed
on growing flowers resulting in considerable flower
loss.
Control: Collection
and destruction of damaged buds and flowers reduces
further damage. Setting of light traps helps to
control adult population by attracting them. Sprays
of Endosulfan (0.07%) or Methyl Parathion (0.05%)
taken up at the appearance of eggs on buds and
tender foliage controls borer damage.
Hairy Caterpillar (Spilosoma
obliqua) :
Female moth lays eggs in clusters on lower side
of leaves. Black coloured matured larvae feed
voraciously on leaves and buds and cause severe
defoliation.
Control : Collection
and destruction of egg masses and leaves infested
with early larval instars of hairy caterpillar
reduces pest build up. Deep ploughing in summer
exposes pupae to predators.
Termites (Microtermes
obesi) :
Termites mainly feed on roots. In case of severe
infestations they spread to stem portion of the
bark. Attack by the pest becomes severe under
dry soil conditions. Damaged plants wilt, dry
and finally die if infestation is very high.
Control :
Deep ploughing destroys the termite colonies.
Proper irrigation and avoiding dry soil conditions
prevents pest build-up. Drenching the soil with
Chlorpyriphos @0.05% or Endosulphan @0.1% before
planting protects plants from termite attack.
Lesion Nematode (Pratylenchus
coffeae) :
The nematode causes heavy rot damage, which subsequently
leads to poor growth of
chrysanthemum. The symptoms are in the form of
stunting of plants with premature yellowing and
drying of leaves, reduced flower size and dark
lesions on the roots.
Control : Application
of neem cake @ 1ton/ha or Carbofuran @ 2kg/ha
reduces the nematode population.
Bud and Leaf Nematode
(Aphelenchoides ritzemabosi) :
The nematode causes considerable damage to the
foliage of chrysanthemum. Interveinal
discolouration of leaves and their death is the
characteristic symptom.
Control :
Hot water treatment of suckers at 46°C for
5 minutes and spraying 0.02% Thionazin or 0.01%
Methyl Parathion on aerial parts is recommended.
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