Pigeonpea is one of the most important pulse crops in India. Despite the fact that a large number of high yielding varieties have been released, productivity of this crop remains stagnant at around 700 kg/ha as compared to its potential yield (1500-3000 kg/ha, early – long duration).

Pest attacks

As pigeonpea is grown under a wide variety of agroclimatic conditions and under varied cropping systems of different maturities, it is susceptible to many pest attacks. About 250 species of insects attack this crop.

Early or vegetative pests do not cause huge damage. However, those which attack the flowers and pod borers are the major pests. Major pod borings pests are: grampod borer, plume moth, spotted pod borer, spiny pod borer, field bean pod borer, redgram podfly or Tur pod fly.

Grampod borer larva feeds on pods. Plume moth’s green or greenish brown spiny larva enters the pod partially, and eats the seeds. Spotted pod borer larva is dull white or yellowish caterpillar that feeds on the leaves. Spiny pod borer cause shedding of flowers and young pods. Older pods are marked with a brown spot (rotten patch) due to the build up of faeces inside the pod. If the pods are split open the larva can be seen.

Field bean pod borer larva is green coloured and bores holes on the pods; Pale greenish or yellowish flat larva of blue butterflies feed on flower buds, flowers and young pods, Podfly causes the pods to shrivel and partially eaten seeds are signs of this infestation.

Management

— Remove the weeds.Collect and destroy the egg masses and pupae

— Set up bird perches at 50 perches for a hectare. Set up a light trap to monitor, attract and kill the pod borer moths

— Set up pheromone traps at 12 traps/ha to reduce grampod borer. Mechanically collect grown up larva. Release egg parasite, Trichogramma spp and egg larval parasite

Apply any one of the following insecticides like Azadirachtin 0.03 per cent WSP 2500-5000 g/ha.

(S.Pasupathy is Professor (Entomology) and R.P. Gnanamalar is Professor & Head, National Pulses Research Centre, TNAU,Vamban,Pudukkottai-622 303, e.mail: sundarampasupathy@rediffmail.com, Mobile:9443291019.)

More In: Science | Sci-Tech