PEPPER

Spike shedding

Spike shedding especially in varieties like Panniyur-1, at higher elevations like Kodagu and Idukki is one of the emerging serious diseases. It is seen in serious condition when the pre-monsoon showers are delayed and flowering and spiking occur during June-July. These spikes predominantly produce female flowers instead of bisexual flowers. Heavy spike shedding may occur due to lack of pollination.

Management:

Irrigation of vines from second fortnight of March coupled with prophylactic spraying with Bordeaux mixture 1 % or carbendazim 0.2% reduces the intensity of spike shedding.

Stunt disease

This disease is caused by viruses.  The vines exhibit shortening of internodes to varying degrees.  The leaves become small and narrow with varying degrees of deformation and appear leathery, puckered and crinkled.  Chlorotic spots and streaks also appear on the leaves occasionally.  The yield of the affected vines decrease gradually. 

Two viruses namely, Cucumber mosaic virus and a Badnavirus are associated with the disease. The major means of spread of the virus is through the use of infected stem cuttings. The disease can also be transmitted through insects like aphids and mealybugs.

Management:

Use virus free healthy planting material

Regular inspection and removal of infected plants; the removed plants may be burnt or buried deep in soil

Insects such as aphids and mealybugs on the plants or standards should be controlled with insecticide spray such as dimethoate or monocrotophos @ 0.05%.

Phyllody disease

This disease is caused by phytoplasma.  The affected vines exhibit varying stages of malformation of spikes.  Some of the floral buds are transformed into narrow leaf like structures. Such malformed spikes show leafy structures instead of floral buds, exhibiting phyllody symptoms.  In advanced stages, the leaves become small and chlorotic, and the internodes are also shortened.  The affected fruiting laterals give a witches broom appearance.  Severely affected vines become unproductive.  In severely affected vines the entire spike is converted into small branches, which appear chlorotic, and the vines decline rapidly.  The infected vine becomes unproductive within 2 to 3 years. 

Management:

The infected vines are to be destroyed to prevent the further spread of the disease.

Slow decline (slow wilt)

Occurrence and symptoms:

Foliar yellowing, defoliation and dieback are the aerial symptoms of this disease. The affected vines exhibit varying degrees of root degeneration due to infestation by plant parasitic nematodes. The diseased vines exhibit foliar yellowing from October onwards coinciding with depletion of soil moisture. With the onset of southwest 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 and the diseased vines gradually lose their vigour and productivity. The affected vines show varying degrees of feeder root loss and the expression of symptoms on the aerial parts occur after a considerable portion of the feeder roots are lost. The root system of diseased vines show varying degrees of necrosis and presence of root galls due to infestation by plant parasitic nematodes such as Radopholus similis and Meloidogyne incognita leading to rotting of feeder roots. The damage to feeder roots is caused by these nematodes and P. capsici either independently or together in combination. There is no spatial segregation of plant parasitic nematodes and P. capsici in the soil under field conditions. Hence, it is necessary to adopt a combination of fungicide and nematicide application for the management of the disease.

Management:

Severely affected vines, which are beyond recovery, should be removed from the plantation and destroyed.

The pits for planting should be treated with phorate 10 G @ 1 5 g or carbofuran 3 G @ 50 g at the time of planting.

Nematode-free rooted cuttings raised in fumigated or solarized nursery mixture should be used for planting in the field.

Phorate 10 G @ 30 g or carbofuran 3 G @ 100 g/vine should be applied during May-June (with the onset of south west monsoon) and September-October. Along with phorate the basins should be drenched with either copper oxychloride 0.2% or potassium phosphonate 0.3% or metalaxyl 0.125%.

In areas severely infested with root knot nematodes, cuttings of the resistant variety 'Pournami' may be planted. Biocontrol agents like Pochonia chlamydosporia or Trichoderma harzianum can be applied @ 50g/vine twice a year (during April-May and September-October). The fungus load in the substrate should be 108 cfu/g.

While applying nematicides, the soil should be raked in the basin of the vine lightly without causing damage to the root system and the nematicide should be spread uniformly in the basin and covered with soil immediately. Sufficient soil moisture should be ensured at the time of nematicide application. The control measures should be taken up during early stages of the disease.

Waiting period of insecticide / fungicide:

Dimethoate 20 days
Quinalphos 20 days
Mancozeb 30 days

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Last updated: 23-06-2008