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Agriculture > Spices > Vanilla (Vanilla planifolia)

Crop Management

 

Plant protection

Vanilla plants are, in general, free from any major pests and disease incidence. Among insect pests, a few small Lamellicorn beetles and ash gray weevil bite holes in the flowers and often destroys the column. In addition, caterpillars, earwigs, snails and slugs lives on tender parts of the plant such as shoot, flower buds, immature beans etc. Grasshoppers and crab are also found to cut growing tip of plants during the establishment stage of the plantation. Regular surveillance and removal of pests can reduce their damage to a great extent.

Root rot, shoot tip rot, stem and bean rot as well as immature bean dropping are the fungal diseases noticed. Phytosanitation measures are to be adopted in the plantation for controlling the diseases. Application of organic manure in excess and heavy mulching in plant base are to be avoided. Fungicides such as 1 % Bordeaux mixture and 0.2% copper oxychloride may be applied as prophylactic measure. Application of Pseudomonas @10-15 gms. per litre of water will also control spread of disease.

Conditions such as poor nutrient availability, excessive shade or the lack of it, damage to roots and stems, over crowding of vines, excessive use of manures, excessive moisture, water stagnation and poor drainage very often lead to pest and disease problems.

Disease management

The major fungal diseases reported in vanilla are root rot, stem rot, stem blight, fruit rot, shedding of beans and shoot tip rot. Pathogenic fungi like Phytophthora, Fusarium and Sclerotium mainly cause these diseases. These are found in the soil and atmosphere and multiply and become very active during favourable atmospheric conditions.

Fusarium attack is mainly observed during August-September when there is high humidity in the atmosphere. Phytophthora attack is found during heavy rainy season ie June- July.

To prevent the chances of multiplication of these fungi and spread of these diseases, the following should be adhered to.

  1. Avoid excessive use of manure, mulch and irrigation
  2. Cut and remove disease affected plant parts and burn them
  3. Do not use planting materials procured from infected gardens
  4. Avoid close planting of vines and over crowding. Follow the recommended spacing
  5. Viral disease affected vines should be uprooted and burnt
  6. Do not use implements, which have been used on disease-affected plants, on healthy plants without thoroughly washing and cleaning them

Bio control in fungal disease management

The use of beneficial organisms such as Trichoderma and Pseudomonas are recommended to prevent and control the growth of the fungi. They also are reported to increase the resistance power in the vanilla plant against the injurious fungi. In addition some of them are growth promoters.

To prevent the occurrence of fungal diseases, the plants should be sprayed with one per cent Bordeaux mixture. Simultaneously, 50 g of Trichoderma mixed with 2.5 kg of powdered cow dung should be deposited at the base of the plant. This should be done before the onset of the monsoon in the first week of May.

About two weeks after the application of Bordeaux mixture [third week of May] Pseudomonas should be sprayed on the plant.

The spray material should be prepared either using the Pseudomonas in powder form @20 gm per liter of water or 10 ml of liquid Pseudomonas per litre of water.

Depending on the size of the plant, 100 to 500 ml of the preparation should be sprayed on the plant.

Under no circumstances, both Bordeaux mixture and Pseudomonas should be sprayed at the same time as Bordeaux mixture is injurious to Pseudomonas.

Since the initial deposit of Trichoderma will deplete due to rains, the application of Trichoderma at the recommended dose should be repeated during September.

This should be followed by another round of Pseudomonas spray. It will be beneficial if the application of both Trichoderma and Pseudomonas is repeated in November after the cessation of rains.

The above recommendations relate to organic methods of prevention of fungal diseases. There are also some chemical fungicides available in the market. However both chemical fungicides and beneficial organisms should not be used simultaneously at short intervals.

If the fungal diseases are not brought under control even after following the above cultural and management practices the following measures may be adopted in disease control.

Other recommended practices for management of fungal diseases

Sl. No.
Disease
Symptoms
Causal Organism
Control Measures
1
Root rot Browning of roots leading to rooting and decay. Yellowing of leaves, stem and leaves becoming flaccid, shrivelled and giving a drooping appearance Fusarium, Sclerotium Cut and remove the affected roots, reduce mulch. Soil drench and spray the plant with 0.2 percent COC (Baistin, Baenfil or Dorosan @ two or three litre per plant
2
Stem Blight Appearance of brown spots on leaves and stems follwed by yellowing of the leaves and rotting of leaves and stem Phytophthora Spray 1 percent Bordeaux mixture or 0.4 percent Potassium phosphonate (Akomin, Phytophos)
3
Stem rot Water soaked lesions giving stem a brown coloured appearance resulting in rotting of tissues, leaves turning yellowish and drying off Fusarium Cut and remove the affected portions. Spray 0.2 percent Carbendazim (2 gm/L). Repeat spray after one month
4
Bean rot Rotting and shedding of beans Phytophthora Spray 0.2 percent Carbendazim and 1 percent Bordaeux mixture alternatively at weekily intervals or spray 0.4 percent Potassium phosphonate
5
Immature bean shedding Yellowing of immature beans at tips, followed by splitting of the beans and shedding Fusarium Spray 0.2 percent Carbendazim at 15 days interval
6
Shoot tip rot Decaying of shoot tip and leaves at the tip Fusarium, Sclerotium Spray 0.2 percent Carbendazim at 15 days interval

 

Important points to be remembered in disease management

  1. Never apply Bordeaux mixture or other fungicides and bio control agents simultaneously or within fifteen days of the application of one or the other
  2. Phytosanitation is essential for the effective functioning of fungal bio-control agents and other beneficial microorganisms
  3. Disease affected plants should be destroyed immediately
  4. Do not take planting materials from disease affected plants

Important prophylactic measures:

  1. Timely shade management
  2. Avoid excess moisture
  3. Allow free movement of air
  4. Avoid overcrowding of vines by keeping adequate spacing
  5. Avoid excessive mulching during rainy season and mulching with materials that are not easily decomposed
  6. Avoid excessive manuring and use of fresh cow dung
  7. Apply recommended doses of bio agents like Trichoderma, Pseudomonas, Bacillus etc
  8. Collect and destroy the parts of plants showing disease symptoms
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