How To Grow Knol Khol Vegetables

How To Grow Knol Khol Vegetables

Botanical Name    :  Brassica oleracea var. gongylodes

Family                     : Cruciferae

Chromosome No  : 2n = 18 

                                                                                     

Knot cabbage is an autumn vegetable. Compared to cabbage and cauliflower, it is cultivated in a very small area. Knot cabbage is also called Gandh Gobhi, Cabbage Turnip or Knol Khol and Kohl Rabi in Germany. It is mainly grown in Kashmir, West Bengal, Maharashtra, Assam, Uttar Pradesh, Punjab and some parts of South India. It is liked very much by the people of Kashmir and Karnataka.

History and Origin - The place of origin of Knot cabbage is considered to be the coastal countries of Northern Europe. Nowadays, Knot cabbage is cultivated on a large scale in Northern Europe. Usually it is grown near cities. Some people also grow it in home gardens.

Nutritional Value - The fleshy part above the surface of the ground turns into a stem, which is consumed as a vegetable. In early varieties, soft leaves are also used as a vegetable. Late varieties are sometimes used as fodder. The food table of Knot cabbage is shown below-

    How To Grow Knol Khol

                                             (Nutrition Value of Knol Khol per 100 gm) 

Moisture                         : 92.70 g Protein                            : 1.10 g Fat                                   : 0.20 g Minerals                         : 0.70 g Other Carbohydrates  : 3.80 g Fiber                               : 1.50 g Oxalic Acid                    : 10.00 mg Phosphorus                    : 35.00 mg Iron                                : 0.40 mg Magnesium                   : 18.00 mg Sodium                          : 112.00 mg Potassium                     : 37.00 mg Copper                          : 0.90 mg Sulfur                            : 143.00 mg Thiamine                      : 0.05 mg Riboflavin                     : 0.12 mg Nicotinic Acid               : 0.50 mg Vitamin C                     : 85.00  IU Vitamin A                     : 36.00 IU Calories: 25.00

Climate - Cauliflower is a cool and humid season crop. In temperate regions, its early varieties have the problem of bolting whereas this problem is not found in subtropical regions. High temperature after planting delays bolting. For its successful production, the highest and lowest temperatures are considered to be 24°C and 4.5°C respectively, whereas the monthly average temperature is considered to be 15°-20°C. Compared to other cool season vegetables, it is a crop that tolerates extreme cold and frost. In the plains of northern India, it is cultivated during the Rabi season. Some varieties are sensitive to low temperatures (below 10°C) for the development of inflorescence; in such varieties, inflorescence (bolting) occurs even if the temperature remains below 10°C for a week after planting. Cauliflower is grown in the Kharif season in South India.

Soil - Cauliflower can be grown in different types of soils. But fertile sandy loam soil with proper drainage is most suitable for it. Its pH value is 6.5 - 7. It is considered best for its cultivation. More acidic or more alkaline soils are considered to be obstacles in its successful production.

Improved Varieties

Some improved varieties of cauliflower are available. Generally, its improved varieties have been imported from foreign countries. The characteristics of some of its major varieties are mentioned below-

                 Is Khol Rabi Easy To Grow

King of North - Plants of this variety grow up to a height of 20-30 cm. Its leaves are dark green in colour. Its nodes are flat round and its leaf sheath is large which spreads over the node. It is ready after 60-65 days of planting.

Lawn Green - Its nodes are green, round, large in size. The nodes are soft, tasty and have white pulp. The crop is ready 76 days after planting. This variety is suitable for growing in the high hills of the western Himalayas. It gives a yield of 225-250 quintals per hectare.

White Vienna - This is an early introduced variety. Its plants are dwarf. The nodes are light green, round, smooth and of medium size. Its pulp is white like cream, soft and has a mild fragrance. It gives a yield of 150-200 quintals per hectare.

Purple Vienna - This variety is comparatively a little late. Its nodes are purple, round, smooth and of medium size. This variety ripens about a week later than White Vienna. The formation of nodes starts after 55-65 days of planting. This variety gives a little more yield than White Vienna.

Other improved varieties

Some improved varieties of cauliflower are available, which include Saran's Earliest Purple, Goliath White, (Sadashiv) Early White Vienna, Early Purple Vienna (Varma Pocha, Kyoto No. 3 etc.

Land preparation - For cauliflower production, prepare the land like cauliflower.

Manure and Fertilizers - Cauliflower requires a lot of nutrients. Tests have shown that 100 kg nitrogen, 85 kg phosphorus and 170 kg potash are required per hectare of land to produce 20 tons of cauliflower. Applying nitrogen in excess leads to excessive vegetative growth of the plants and the crop is ready late. Applying nitrogen multiple times is beneficial. It is advisable to use manure and fertilizers after soil testing. If soil testing is not possible due to some reason, then in that case, apply the following amount of manure and fertilizers per hectare:

Farm Yard Manure - 10-15 tons

Phosphorus - 50-70 kg

Nitrogen - 100-120 kg

Potash - 80-110 kg

Cow dung manure should be spread evenly in the field before preparing the field. Half the amount of nitrogen, full amount of phosphorus and potash should be applied at the time of final ploughing and the remaining amount of nitrogen should be divided into two equal parts. The first part should be applied 3 weeks after planting and the second part should be applied at the time of nodule formation. Fragrant nodules are obtained by giving optimum amount of nitrogen and potash.

   How To Grow Knol Khol From Seeds

Functional disorders like browning, whiptail and buttoning occur due to deficiency of boron, molybdenum and nitrogen. Nitrogen deficiency is overcome by spraying 1-2% urea and this method is also suitable from the economic point of view. To overcome the deficiencies of common micronutrients, 0.2-0.3% solution of multiplex should be sprayed. To overcome the deficiency of boron, 10-15 kg borax should be applied at the time of soil preparation or two sprays of 0.3% borax solution should be given. In highly acidic soils, ammonium molybdate @ 200-300 g/hectare (0.01%–0.1%) should be sprayed because plants are unable to absorb molybdenum from these soils.

Sowing - Knol-khol is an autumn crop, hence its sowing time is the same as that of cauliflower and cabbage. Its seeds are first sown in the nursery which are sown in August-September. To get its continuous crop, seeds are sown at some interval. The plant becomes ready for planting in 4-5 weeks, 1 kg seed is sufficient for planting in one hectare field. Before sowing the seed, it should be treated in hot water of 50°C temperature for 1/2 hour. After this, the seeds should be treated with Apron 35 at the rate of 2 grams per kg of seed and then sown. Usually 2.5 meter long and 60 cm wide beds are made. 100 grams of NPK mixture should be added in one square meter area. Apart from this, 2.5-4.0 kg of cow dung manure should also be mixed well in the soil. The nursery should be soaked well in 40% solution of formaldehyde. 5 liters of water per square meter is sufficient. Seeds should be sown in rows at a depth of 1.5-2.0 cm. After sowing, the nursery is covered with grass.

The nursery should not be watered one week before transplantation.

Transplantation - Transplantation of Knotted Cabbage depends on the climate and fertility of the soil. Usually it is planted at 25 cm x 25 cm, 25 cm x 30 cm, 25 cm x 40 cm or 30 cm x 4.5 cm. If it is planted too close, the size of the nodes remains small and the yield is more. Early varieties are planted at a lesser distance and late varieties are planted at a greater distance.

Irrigation and water drainage - Like cabbage and cauliflower, it should be irrigated regularly. If the growth is blocked or slow, the knoll becomes hard and fibers are produced in them. If the growth is fast, the nodes burst, as a result of which they are not edible. Usually the first irrigation should be done immediately after planting and later irrigation should be done at an interval of 10-15 days. There should be no shortage of moisture in the soil at the time of development of nodes.

If due to any reason, excess water gets accumulated in the field, then immediate arrangement should be made to drain it, otherwise the crop turns yellow and dies.

        How To Grow Knol Khol At Home

Weed Control

Many weeds grow with the cabbage crop which adversely affect the growth and yield of the plants. Therefore, weed control is very important to prevent them. Since cabbage is a shallow rooted crop, shallow weeding should be done. Once the weeds are established, weeding to remove them adversely affects their root system and also reduces the growth of the plants. Weeding should not be done when the knots are being formed. At that time, weeds should be removed by hand.

Herbicides should be used for weed control. Among these, Triflen (Driflurin @ 0.5 liter/ha) and Simeron (Desmetreaene @ kg/ha) can be used mainly. These should be used before planting.

Weed control can also be done by spreading mulch of black polythene sheet. Spray 1-2 kg of Stomp (Pendimethylene) per hectare. After that, weeding should be done 1-2 times.

When the plants reach 20-25 cm height, soil should be added.

Crop Protection

Insects

Aphid - These are small light green or black coloured insects which suck juice from leaves and soft parts. Leaves become crispy and finally dry up and fall.

Control - In case of insect infestation, 0.5% solution of Malathion should be sprayed.

Cabbage Maggot - This insect first attacks small roots and then enters the main root. The plant withers and dries up.

Control - Spray an insecticide called Calomel.

Or

Add Aldrin with irrigation water.

Mustard Fly - Its adults are like very small black flies which lay eggs in the tissues of leaves. Its caterpillars eat leaves at the time of seedling. It damages all the plants of mustard family.

Control - Spraying of 0.02% Malathion solution should be done.

Cabbage butterfly - It cuts and makes holes in cabbage class vegetable plants, causing a lot of damage. In case of severe infestation, leaves, soft stem, flowers and fruits get completely destroyed.

Control - For its control, spraying of 1000 ml endosulfan solution should be done 15 days after transplantation. After this, two more sprayings should be done at an interval of 15 days.

Diamond back moth - The larvae of this insect first make holes in the leaves and enter the stem.

Control - (I) Mustard should be grown as a trap crop along with the crop.

(ii) 4% extract of Neem Kernel should be sprayed.

   How To Grow Knol Khol Plant

Diseases

Damping off - It is caused by various types of fungi, of which Pythium, Phytophthora, Fusarium and Rhizoctonia are the main species. This disease spreads in the nursery. Due to which the radicle and plumule rot as soon as they come out of the seed. The plants which come out of the soil have water logged parts in the stem near the soil due to which the sprouts rot and fall. The leaves wither and dry up.

Control-

- The nursery soil should be light.

- The nursery soil should be treated with 0.2% Phytolan or Captan.

- Do not sow the seeds densely.

- Treat the seeds with Agrosan and then sow them.

- Irrigation should be light and water should not be kept in the beds.

Black Rot - This disease is caused by a bacterium called Xanthomonas campestris. The veins of the leaves turn black or brown and the edges of the leaves turn yellow. The conducting tissue of the main stem also appears black in the transverse section.

Control-

- Disease-free seeds should be sown. 

- Seeds should be soaked in hot water at 48.9°C for 30 minutes.

- Crop residues should be burnt in the field.

- Biennial crop rotation should be adopted.

Black Leg - This disease is caused by a fungus called Foamlingum. This disease first attacks 2-3 weeks after sowing in the nursery. The fungus attacks the base of the stem and the root. When there is a severe infestation of hairs, deep pits are formed on the stem. From where they spread to other parts, as a result of which the stem almost dies at the base and the plant withers.

Control -

- Get seeds from healthy plants.

- Treat the seeds in hot water (50°C) for 30 minutes before sowing.

- Adopt a three-year crop rotation.

How To Grow Knol Khol Vegetables

Black Leaf Spot - This disease is caused by some species of fungus called Alternaria. Small dark spots are formed on the leaves, which combine together to form circular lesions. In humid environment, concentric rings are formed.

Control-

- Burn the crop residues and destroy them.

- Treat the seeds in hot water (50°C) for 30 minutes and then sow.

- Spray 2-3 times of Maneb (0.2%) on the crop.

Harvesting - Harvesting of Knotted Cabbage depends on its variety. Generally, when the knots become 5-7 cm thick, but are fiberless and shiny, they are cut. Usually the crop is harvested 2-3 times a week. For sending to the market, the main root is cut and bundles of knots are made by tying the leaves.

Yield - The yield of Knotted Cabbage depends on many things. The main ones among them are fertility of the soil, climate, variety grown and care of the crop. Late varieties give higher yield than early varieties. The average yield of cauliflower is 200-240 quintals per hectare.