Pests and Diseases of Turmeric
Pests of Turmeric:
The caterpillar bores into rhizomes and feeds on it. Control: Spray 0.1 % Malathion.
Caterpillar remains in leaf folds and feds within. Control: Spray 0.05 % Dimethoate.
The scales, damage the rhizomes both in field and in storage Control: Dip seed rhizomes in 0.05 % Malathion or Dimethoate for 30 minutes before storage or planting.
Diseases of Turmeric:
Small oval, rectangular or irregular brown spots appear on either side of leaves and soon become dirty brown. Yield is reduced. Control: Spray 0.2 % Diethene M-45.
Brown spots of different size appear on the upper surface of young leaves. The spots are whitish or grayish in the center. Subsequently, the whole leaf gets covered and leaves dry up. The rhizomes do not develop well. Control: Spray 0.3 % Zineb or 1 % Bordeaux mixture.
Leaves dry up starting from the margins. Collar region becomes soft, water soaked and the plants, collapse, Rhizome decay follows.
- Treat the seed rhizomes with 0.3 % Diethane M-45 for 30 minutes before sowing and also before storage.
- Under field conditions, drench the beds with 0.3 % Diethane M-45.
- Starts from Feb. and continues till April.
- Rhizomes are ready for harvest in 7-9 months after planting.
- Longa type – 9 months, Amada type – 8 months and Aromatica type – 7 months.
- State: Turmeric is harvested when leaves start yellowing and ultimately the stem dries down. The plants are-cut close to the ground.
- The crop is irrigated lightly for easy digging.
- Harvesting consists of digging of underground clumps of rhizomes with Pick axe or digging fork.
- Fingers are separated from mother rhizomes.
- 250-300 q/ha for fresh rhizomes.
- Cured Produce: 20-25 % of fresh rhizome by weight.
Preservation of Seed:
- Rhizomes for seed are heaped in the shade of trees or in well ventilated sheds and covered with turmeric leaves.
- Sometimes the heap is plastered over with earth mixed with cow dung.
Quality of Finger:
- Should be free from chemichrome .
- Extraneous matter should be less than 2 %.
Quality of Powder:
- Chemichrome test should be negative .
- Total ash less than 9 % .
- Moisture less than 13 % .
A volatile oil is obtained by steam distillation of ground turmeric after 8-10 hours. The oil is pale yellow to orange yellow in colour. The aroma of oil is due to tumerone and artumerous.Turmeric oleoresin is obtained by solvent extraction method and is highly valued.