Cormel production:
Gladiolus corms are propagated from carmels which grow in clusters on out growth (stolons) between mother and daughter corms. Cormels are usually graded into three sizes: large ≥1.0 cm diameter; medium ≥0.6 cm and <1.0 cm; and small <0.6 cm. Mostly the large size of cormels are used for planting stock production. Carmel stocks should be chosen carefully to prevent the spread of disease into developing corms and preferably should only be from healthy, disease free and roughed block. The cormel should be treated in hot water (53-550C) to eradicate latent fungus, insects and nematodes for 30 minutes. The hot water treatment can be combined with fungicides like benomyl (0.10 kg/100 litres water), captan (0.18 kg/100 litres) or thiram (0.18 kg/100 litres) to compliment the action of hot water. Two days prior to treatment, carmel should be covered with warm water (320C) to soften the husk. The treated cormels should be air-dried in thin layers in sterilized trays and thus placed in cold strong (2-40C) until planted. Dormancy of large carmels is usually broken within four months of treatment. Root bud swellings indicate that cormels are ready to be planted. It is a good practice to soak cormels in water for 2 days just prior to planting to ensure uniform sprouting.
The soil pH should be 5.8-6.5 and chemical fertilizers 280 kg/ha of a 10:4.4:8.3 (NPK) should be mixed. The moist cormels are planted in single row in 10-13 cm wide furrow spaced 60-75 cm apart. Cormels should be carried with about 8 cm of soil, which should be leveled and compressed. The field should be maintained free from weeds opting proper operation. About 130 large cormels are planted/m of row or 1.5 million litre/ha. The soil must be kept moist initially to obtain good germination and later good growth of the crop. The small corms are dug up with a modified potato digger. Yield of around 100 corms larger than 1.3 cm diameter can be harvested per meter of row when large cormels are used. Corms from 1.3 to 2.5 cm diameter are called “planting stock” and are used for the production of flowering size corms.
Planting stock production:
Planting stock treatment is similar to the treatment of cormels except the temperature of the fungicide suspension is decreased to about 430C and the time of submerged is limited to 15 minutes. Small corms <2.5 cm diameter are planted in one or two rows per bed at a depth of 6-8 cm. 50-80 number of corm is planted per meter of rows, depending upon the size of corms. The soil should contained adequate moisture and nutrition for good growth. Irrigation should be stopped prior to harvest to prevent rotting of corms in the field and to facilitate the cleaning of the new corms.
Removal of flowers spikes improves corms size but many producers allow the first flower open to observe purity of the stock and allowing rouging of off type plants. Corms should be cleaned and dipped in a fungicide solution with in two days of digging to obtain maximum effect of fungicide. The corm produced in warm region are dormant and require 3-4 months of cold storage (2-40C) to break this dormancy.
Crops Calendar