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Agriculture > Spices > Pepper (Piper nigrum)

Crop Management

Diseases

Diseases in the Main Field

Foot rot disease

Foot rot (quick wilt disease) caused by Phytophthora capsici occurs mainly during the southwest monsoon season. All parts of the vine are vulnerable to the disease and the expression of symptoms depend upon the site or plant part infected and the extent of damage.

Symptoms:

One or more black spots appear on the leaves, which have a characteristic fine fibre like projections at the advancing margins, which rapidly enlarge and cause defoliation.

The tender leaves and succulent shoot tips of freshly emerging runner shoots trailing on the soil turn black when infected.  The disease spreads to the entire vine from these infected runner shoots and leaves, during intermittent showers due to rain splash.

leaf collar root infection

If the main stem at the ground level or the collar is damaged, the entire vine wilts followed by shedding of leaves and spikes with or without black spots.  The branches break up at nodes and the entire vine collapses within a month.

If the damage is confined to the feeder roots, the expression of symptoms is delayed till the cessation of rain and the vine starts showing declining symptoms such as yellowing, wilting, defoliation and drying up of a part of the vine. This may occur during October-November onwards. These vines may recover after the rains and survive for more than two seasons till the root infection culminates in collar rot and death of the vine.

Management:

The disease can be controlled by adopting integrated disease management strategies.

  1. Phytosanitation:
  2. All infected or dead vines along the root system are to be removed and burnt. Wherever water stagnation is a problem, effective drainage of both surface and sub-soil is to be ensured. To avoid soil splash and consequent disease initiation and spread, a legume cover in the plantation should be ensured. Runner shoots are to be pruned or tied back to vines before the onset of monsoon. At the onset of monsoon, the branches of support trees may be lopped off to allow penetration of sunlight and avoid build up of humidity.

    Apply 1 kg lime and 2 kg neem cake per standard per year as pre-monsoon dose. The application of neem cake should be four weeks after lime application.

  3. Chemical control:
  4. For the control of Phytophthora foot rot, any of the following control measures can be adopted.

    After the receipt of monsoon showers (May-June), all the vines are to be drenched over a radius 45-50 cm with 0.2 % copper oxychloride at the rate of 5-10 litres per vine. This varies according to the age of the plant. A foliar spray with 1% Bordeaux mixture is also to be given. Drenching and spraying are to be repeated just before the northeast monsoon. A third round of drenching may be given during October if the monsoon is prolonged.

    After the receipt of a few monsoon showers (May-June), all the vines are to be drenched over a radius of 45-50 cm with 0.12% potassium phosphonate at the rate of 5-10 litres per vine. This varies according to the age of the plant. A foliar spray with 0.3% potassium phosphonate is also to be given. A second drenching and spraying with 0.3% potassium phosphonate is to be repeated just before the northeast monsoon. If the monsoon is prolonged, a third round of drenching may be given during October.

  5. Bio-control:
  6. Inoculate pepper vines with native arbuscular mycorrhizal fungi, Trichoderma and Pseudomonas fluorescens at the time of planting in the nursery and field, and apply during the pre-monsoon period in the established plantations to control foot rot. In the field, apply the biocontrol agents around the base of the vine

    Note:(1) All chemical control measures are prophylactic in nature and application of chemicals in advanced stages of disease will not be effective in combating the disease, (2) In Phytophthora sick fields, use only chemical control measures.

  7. Replanting / Rejuvenation:
  8. Total replanting has to be undertaken in gardens where the mortality is 50-60% or above. Where the mortality is below 50%, timely plant protection measures as described above should be given to all the existing vines as prophylactic measure and gaps filled up. Gap filling or replanting should be taken up only after a period of one year. At the time of replanting, soil drenching with Bordeaux mixture or copper oxychloride should be given. While replanting, farmers should be encouraged to use recommended varieties.


Pollu disease (Anthracnose)

This disease is caused by Colletotrichum gloeosporioides and can be distinguished from the pollu (hollow berry) caused by the beetle by the presence of characteristic cracks on the infected berries. The disease appears towards the end of the monsoon. The affected berries show brown sunken patches during early stages and their further development is affected. In later stages, the discolouration gradually increases and the berries show the characteristic cross splitting. Finally, the berries turn black and dry. The fungus also causes angular to irregular brownish lesions with a chlorotic halo on the leaves.

Management:

For the control of fungal pollu or anthracnose caused by Colletotrichum gloeosporioides, spray 1% Bordeaux mixture, once before flowering starts (late June and early July) and then at berry formation stage (late August). Minimize shade in the garden.

Foliar spray of carbendazim @ 1g/l or a formulation containing combination of carbendazim + mancozeb @ 1g/l during the month of June can effectively control the disease.

Wherever Phytophthora foot rot management is undertaken properly, separate control measures for pollu disease may not be necessary.

Note: Since Bordeaux mixture application for pepper is to be given mostly at a time when the monsoon is very active; it is to be ensured that a sticker is added to the fungicide. The cheapest and most effective sticker is rosin washing soda mixture.

(1) Preparation of Bordeaux mixture (1%)

Dissolve 1 kg of powdered copper sulphate crystals in 50 litres of water. In another 50 litres of water, prepare milk of lime with 1 kg of quick lime. Pour the copper sulphate solution into the milk of lime slowly stirring the mixture all the while. Test the mixture before use for the presence of free copper, which is harmful to the plants, by dipping a polished knife in it. If the blade shows a reddish colour due to the deposits of copper, add more lime till the blade is not stained on dipping. Always use wooden, earthen or copper vessels for the preparation of Bordeaux mixture.

Preparation of sticker rosin washing soda mixture: In order to confer sticking qualities to Bordeaux mixture, rosin washing soda mixture, may be added. The addition of the sticker is particularly recommended for sprayings conducted during rainy season. For preparing the mixture, 10 litres of water out of 100 litres required for preparing Bordeaux mixture may be kept apart. Boil 10 litres of water, preferably in an earthen pot and add 500 g of good quality washing soda (sodium carbonate). Boil again until the solution becomes slightly dark in colour. Add 1 kg of powdered rosin (arpoos) in the boiling washing soda solution. Reduce the flame for avoiding frothing, foaming and spilling over. Boil the solution for 5-10 minutes till black bubbles appear. Cool the solution until the temperature reaches below 45ºC. The cooled mixture (10 litres) is then added slowly to the prepared Bordeaux mixture (90 litres) under vigorous stirring.


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

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 at 0.05%.


Phyllody disease

Phyllody infected vineThis 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. Planting material should not be collected from such vines.


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.

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

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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