Methods of rice leaf mite control
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Rice leaf mite has attained a pest status in the Cauvery deltaic
regions of Tamil Nadu. Infestation starts early from the nursery till
stem elongation stage.
Leaf mites feed on upper and lower surface of rice leaves. Usually
they are more numerous on lower surface than upper surface.
Leaf mites are small and microscopic spider mites which pierce the
leaf tissue and suck the exuding sap.
They multiply very fast under congenial conditions and damage the
entire leaf portion under severe infestation.
Damage results in the appearance of yellowish brown specks which
increase under severe conditions and whole leaf turns to greyish white
and dries up.
Usually the initial symptoms of damage are from the periphery of the
rice field and later depending upon wind speed directions the
intensity of leaf area loss is manifested.
Most severe
The damage is most serious during the high temperature time with high
relative humility (June – July). Entire life cycle can take 8-12 days.
Adults are sexually mature when they emerge and mate as soon as
possible. Egg laying begins in 1-3 days, and singly in rows along the
leaf midribs and veins. Incubation lasts 4-9 days.
This is followed by the three immature stages – larva, protonymph and
deutonymph.
The mite is active and breeds throughout the year building large
population during hot weather when the life cycle takes the shortest
time.
Management methods
Use of chisel ploughing once in four years.
Create a rice free period by ploughing down stubbles between crops or
follow rice fallow crops with pulses/green manures maize in endemic
areas.
Maintaining the bunds free from weeds. Seed treatment with Pseudomonas
at 10 grams/ 1kg of seeds.
Topdressing of urea with neem cake (5:1) with LCC (Leaf Colour Chart)
based N and to avoid excess Nitrogen application.
Top dressing of 50 per cent potash fertilizer. Spraying of Profenophos
50 EC 1000 ml/ ha along with khadi bar soap 1.5 kg controls leaf mite.
S.M. JALALUDDIN
G. RAVI
& S. JEBARAJ
Tamil Nadu Rice Research
Institute, TNAU
Aduthurai, Tamil Nadu