Diseases
The important fungal diseases are:
Leaf spot (Colletotrichum and Gloeosporium)
Leaf blight (Pythium)
Collar blotch (Penicillium thimmi)
Collar rot (Sclerotium)
Orchid wilt (Sclerotium rolfsii)
These can be controlled by application of mancozeb, carbendazim etc. at the recommended dose. Spraying should be done prior to the commencement of monsoon and at fortnightly intervals during heavy monsoon. Important virus diseases are mosaic and ring spot. Destroying the affected plants can control spread of these diseases.
Pests
The common pests attacking orchids are thrips, aphids, spider mite, soft scale, mealy bugs, orchid weevil, ants etc. Insecticides at suitable concentration can control all the insects. Other very serious pests of orchids are snails and slugs. They feed on the tender young shoots, roots and buds. Hand-picking is effective, if the number of plants is less. They move out during late night and hide before early morning. Damage is caused during this period. All the pests can be controlled by application of contact and systemic insecticides at appropriate concentration.
Harvesting
The spikes are harvested when all the buds of the spike except two or three are open depending on the genus.