Lifting of Corms and Cormels
After harvesting of flowers or spikes , plants are twisted down to ground level for allowing the corms to mature. Once the spikes are cut out, the leaves begin to turn yellow. Plenty of moisture, followed by a dry period, before lifting ensure the formation of large corms. Gradually the water supply is reduced till the leaves get dried naturally. After 3 – 4 weeks corms and cormels are lifted from the ground. Corms are matured when 25% cormels have become brown which generally take 30 to 45 days from flowering when the leaves also start yellowing. Corms and cormels should be dug out with the help of a spade. Soil should be dug deep in order to take out all the cormels. The corms are checked for any disease infection and the affected corms are discarded.
Curing is one of the essential post harvest operations for successful storage of corms. After lifting and removing the adhering soil, the corms and cormels of each cultivar are kept in trays in a shady but well-ventilated place for about a fortnight. For curing, the layers of corms should not exceed three, which may be cured for five weeks at 21°C.
Cleaning, Grading and Storage
After the corms are fully cured, these are cleaned and diseased ones discarded. The old withered corms are taken out and cleaned. Treating the corms with 0.2% Captan 15 days before storage or dusting with 5% Cythione dust and Dithane M-45 protects them from insects, pests and diseases during storage. After cleaning, the corms and cormels are graded in different grade-sizes. The corms are stored in perforated trays in a well-ventilated cool and dark room with temperatures not exceeding 27OC.
Being smaller in size, the cormels are stored in plastic trays having fine perforations. It is advisable to keep on turning corms and cormels periodically, for preventing their rotting due to poor aeration. The corms are periodically checked during storage and the decaying ones are removed. The cormels of exotic cultivar vary considerably in respect of hardiness, depending upon their size. The small sized cormels (<0.5cm diameter) are fairly hardy and may be stored at room temperature, without decay. However, the large ones (>0.5cm dia.) of exotic cultivar require low temperature during storage and should be kept in cold storage. To avoid chances of mixing, the cormels.
- Central Coastal Agricultural Research Institute, Ela, Old Goa, Goa