PEPPER

Plant protection

Pests

Pollu Beetle

Occurrence and symptoms:

The pollu beetle (Longitarsus nigripennis) is the most destructive pest of black pepper and is more serious in plains and at altitudes below 300m. The adult is a small black beetle measuring about 2.5m x 1.5mm, the head and thorax being yellowish brown and the forewings (elytra) black. Fully-grown grubs are creamy-white and measure about 5mm in length.

The adult beetles feed and damage tender leaves and spikes. The females lay eggs on tender spikes and berries. The grubs bore into and feed on the internal tissues and the infested spikes turn black and decay. The infested berries also turn black and crumble when pressed. The term pollu denotes the hollow nature of the infested berries in Malayalam. The pest infestation is more serious in shaded areas in the plantations. The pest population is higher during September-October in the field.

Management:

Regulation of shade in the plantation reduces the population of the pest in the field. For the control of pollu caused by the flea beetle Longitarsus nigripennis, spray any one of the following insecticides namely, dimethoate, quinalphos, or monocrotophos at 0.05% concentration. The spraying is to be given at the time of spike emergence (June-July), at berry formation (September-October) and once again at berry maturing stage, if needed. It can also be controlled by spraying cypermethrin 0.01% twice, first at the berry formation stage and the second one-month after the first spray (Sept-Oct.).

Leaf gall thrips

Occurrence and symptoms:

Infestation by leaf gall thrips (Liothrips karnyi) is more serious at higher altitudes especially in younger vines and also in nurseries in the planes.  The adults are black and measure 2.5 – 3.0 mm in length.  The larvae and pupae are creamy white.  The feeding activity of thrips on leaves causes the leaf margins to curl downwards and inwards resulting in the formation of marginal leaf galls.  Later the infested leaves become crinkled and malformed.  In severe cases of infestation, the growth of younger vines and cuttings in the nursery is affected.

Management:

Spray monocrotophos or dimethoate @ 0.05% during emergence of new flushes in young vines in the field and cuttings in the nursery.

Scale insects

Occurrence and symptoms:

Among the various scale insects recorded on black pepper, mussel scale (Lepidosaphes piperis) and coconut scale (Aspidiotus destructor) cause serious damage to the vines at higher altitudes and also to older cuttings in nurseries in the planes.  Females of mussel scales are elongated (about 1mm length) and dark brown and coconut scales circular (about 1mm diameter) and yellowish brown.  Scale insects are sedentary, remaining permanently fixed to plant parts and appear as encrustations on stems, leaves and berries.  They feed on plant sap and cause yellowing and wilting of infested portions; in severe cases of infestations the affected portions of vines dry up.  The pest infestation is most severe during post monsoon and summer periods.

Management:

Clip off and destroy severely infested branches. Spray monocrotophos or dimethoate (0.1% each on affected vines); repeat spraying after 21 days to control the infestation completely. Initiate control measures during early stages of pest infestation. In nurseries spraying neem oil 0.3% or Neemgold 0.3% or fish oil rosin 3.0% is also effective in controlling the pest infestation.

Top shoot borer

Occurrence and symptoms:

The top shoot borer (Cydia hemidoxa) is a serious pest in younger plantations in all black pepper areas. The adult is a tiny moth with a wing span of 10 – 15 mm with crimson and yellow forewings and grey hind wings. The larvae bore into tender terminal shoots and feed on internal tissues resulting in blackening and decaying of affected shoots. Fully-grown larvae are grayish green and measure 12-15 mm in length. When successive new shoots are attacked, the growth of the vine is affected. The pest infestation is higher during July to October, when numerous succulent shoots are available in the vines.

Management:

Top shoot borer can be controlled by spraying monocrotophos (0.05%) or dimethoate (0.05%) on the tender shoots and flushes. The spraying has to be repeated to protect newly emerging shoots and flushes.

Nematode infestation

Occurrence and symptoms:

Foliar yellowing, defoliation and die back are the aerial symptoms of this disease.  The affected vines exhibit varying degrees of root degeneration due to the infestation by plant parasitic nematodes.  The diseased vines exhibit foliar yellowing from October onwards coinciding with the depletion of soil moisture.  With the onset of South West monsoon during May/June some of the affected vines recover and put forth fresh foliage.  However, the symptoms reappear in subsequent seasons after the cessation of the monsoon.  Thus the diseased vines gradually lose their vigour and productivity exhibiting typical declining symptom.

The root system of diseased vines shows varying degrees of necrosis, and root galls due to the infestation by plant parastitic nematodes viz., Radopholus similis and Meloidogyne incognita respectively leading to rotting of feeder roots which is further aggravated by soil borne fungi like Fusariurn sp., Rhizoctonia sp. and Phytophthora capsici, Phythium sp.

Management:

For control of the burrowing nematode Radopholus similis and the root knot nematode Meloidogyne incognita, adopt the following measures:

1. Use nematode free rooted cuttings for raising new plantations.
2. For the nematode infested vines, apply phorate / carbofuran @ 1 g ai/vine twice in a year. The first dose is to be given in May-June at the onset of monsoon and the second dose in the last week of October or early November. The chemicals are to be applied around the vines in shallow basins and incorporated into the soil.
3. Root knot nematode can be effectively managed by the application of bacterial suspensions of Bacillus macerans or B. circulans prior to planting of vines or just before the monsoon period in established plants (Ad hoc recommendation)

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