Spices and Condiments (1+1)

Pests and diseases

Pests
Among the insect pests, a few small longicorn beetles (Hoplia retusa and Saula ferruginea) and an ash-weevil (Cratopus retuse) bite holes in the flowers and others destroy the column. In addition to these, there are a few caterpillars and certain earwigs, snails and slugs which live on the tender parts of the plant. Grasshoppers and crabs are also found cutting the growing tips of plants during the establishment stage of the plantation. Poultry birds sometimes cause considerable damage to the roots while scratching the mulch placed around the plants. Regular surveillance and the removal of pests reduces their damage to a great extent.
An aphid, Cerataphis variabilis, has been observed occasionally infesting the leaves which can be controlled by spraying 0.02% Dimethoate @ 250 I/ha. The insecticide may be sprayed as soon as the pest appears. If necessary, the spray can be repeated at fortnightly intervals or Demecron @ 200 mVha can be sprayed at monthly intervals.
During the processing and storage, the pods are attacked by Tyrophagus sp. of mites.

Diseases
Diseases are more serious than pests, as they sometimes cause heavy losses in crop production. The important diseases of this crop are described below.
Root-rot (Fusarium batatis var. vanillae)
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This is the most serious problem, severely limiting vanilla production. The pathogen affects the roots first causing a browning and later the death of the roots as well as the underground part of the stem. The plant ceases to grow, the stems and leaves become flaccid and the stem begins to shrivel, leading to the ultimate death of the planet. Drenching with 0.1% Bavistin or Methyl Benzymidazole carbomate as a soil drench and foliar spray helps in controlling the disease, besides following suitable phytosanitary measures.
Stem-rot or wilt (Fusarium oxysporum var. vanillae)
This disease can be controlled by removal of the diseased plants along with the surrounding soil. The control strategy for this disease is as follows: • Removal of weeds around the plants • Mulching the base of the stem with dry leaves before and after the monsoon. • Avoiding injury to roots • Drenching the base of the stem with 0.5% Bordeaux mixture or 0.2% Copper oxychloride. • Pre-treatment with non-pathogenic Fusarium is reported to suppress the disease incidence. The extracts of clove leaves have been found to be antifungal in vitro and may be useful as a soil amendment to control the disease in the field.
Anthraconse (Calospora van iliac)
This is a very serious disease attacking the stem apex. The wilting of the leaves and roots, dropping off of the beans after turning black are the symptoms. The disease is aggravated by excess moisture, a prolonged rainy season, excess shade and over-crowding. Phytosanitation, removal of the excess shade, avoiding over-crowding coupled with spraying 0.1% Bavistin help to check the disease. Fruit-rot and flower-rot are the other diseases that have been observed on this crop. During processing and storage, the pods are susceptible to moulds (mainly Penicillium and Aspargillus sp.).
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