Cultivation of Knol – Knol (Brassica caulorapa)
Cultivation of Knol – Knol (Brassica caulorapa)
Botanical Name:
Brassica caulorapa L.
Family:
Cruciferaceae.
Khol Rabi which is the german name for cabbage turnip resembles an above ground turnip. It is also called knol-knol. The fleshy edible proration is an enlargement of the stem, which develops entirely above ground and is used as a vegetable. It is excellent vegetable if used at its early stage before it becomes tough and fibrous. The edible portion is globular to a slightly flattened stem.
Climate:
Knol- Knol is a cool season crop and thrives in a relatively cool moist climate. It can withstand extreme cold and frost better than other cool season crop. Seeds of knol- knol germinate well at 15 0 C to 30 0 C.
Soil and its Preparation:
Knol- Knol is successfully grown on all types of soil. But the sndyloam and clay loam soils are best suited for knol-knol crops.
The land should be well prepared and of good tilth for sowing of Knol- Knol, 5- 6 ploughing should be given to prepare a good tilth. After ploughing, planking is essential to make soil puverised and leveled. Harmful weeds and stubbles of previous crop should be removed before the transplanting of this crop.
Aldrin or Heftaf or Heptachlor 5 % or BEC 10 % should be applied @ 10 – 15 kg percent with the last preparatory tillage to check the infestation of termites and cutworm.
Sowing of Seed:
a) Time of Sowing:
Knol-knol is normally propagated by seeds. It can also be propagated by cuttings such as tip cutting and leaf cutting. The seeds are sown in lots from the end of August to the end of November for a continuous crop. Time of sowing of seeds varies according to the variety viz.
|
Variety |
Tine of sowing seed in Nursery |
Time of transplanting in the main field |
|
Early |
August |
September |
|
Main |
September |
October |
|
Late |
October |
November |
b) Seed rate:
1 to 1.5 kg seed is sown in nursery to cover one hectare of land.
Transplanting:
3 to 4 week old seedlings become ready for transplanting. Ridges and furrow type of layout is used. The seedling is transplanted at a distance of about 30 cm. from row to row and 20 cm. from plant to plant. Closer spacing of this vegetable increases the yield. After transplanting, the seedlings should be watered and protection may be given from sun rays for 4 – 5 days.
Manures and Fertilizer:
Mix 15 -20 tones of FYM to soil at the time its preparation. At the time of transplanting add 75 kg n, P and 50 kg K/ ha, second dose of 50 kg N should be given 1 ½ months after transplanting.
Interculture Operation:
Hoeing and weeding should be done after each irrigation when the soil comes in working condition. The plant should be earthen up after 25 – 30 days of transplantation.
Irrigation:
As stated the seedlings, after transplanting, should be watered for four to five days. Irrigation should be given an interval of 6 to 7 days. But the field may be irrigated when soil is deficient inn moisture.
Harvesting:
Knol-knol should be harvested when swollen stem reach a diameter of 5 to 7 cm and before it becomes tough and woody. The plants are pulled out from the land. It is generally marketed after removing both leaves and roots.
Yield:
250- 300 quintal yield per hectare is obtained.
Varieties:
As recommended by IARI, New Delhi.
Early: earliest, white Vienna etc.
Late: Purple, Vienna, etc.