This presentation is done by Export Agriculture students of Uva Wellassa University of Sri Lanka as a requirement for the subject which is “Fruit & Vegetable production”. Note that the information included here is relevant to Sri Lankan condition.

1. KNOL KHOL
PRESENTED BY :- N.U.M.PERERA
UWU/EAG/11/0041
V.P.A.DILRUKSHI
UWU/EAG/11/0040
(Brassica caulorapa)

2. INTRODUCTION
 Family:- Cruciferaceae
 Origin: Northern Europe
 Also known as Kohlrabi, Kohlrabi greens, Navalkol, Gunth
Gobhi, Ganth gobhi
 The Whole plant is edible however, it is mostly used for its
bulged swollen stem
 It is excellent vegetable if used at its early stage before it
becomes tough and fibrous
 Major growing areas : up country of SL

3. MORPHOLOGY
• formation of knob (tuber) which arises from a thickening of the
stem tissue above the cotyledons
• The fleshy edible proration is an enlargement of the stem, which
develops entirely above ground and is used as a vegetable
• The edible portion is globular to a slightly flattened stem

4. Climatic Requirement
 cool season crop
Temperature
 It can withstand extreme cold and frost better
than other cool season crop
 Germination - 15 0C to 300C
 Tuber production- 100C to 200C
 The low temperature - develops anthocyanin
pigments on knobs or plant parts
 Continuous hot weather is detrimental which
induce knob development

5.  soil
 successfully grown on all types of soil
 But the sandy loam and clay loam soils are best
suitable
 pH 5.5-6.8
 A soil rich in manures and fertilizers produces
excellent knobs
 does not grow well in highly acidic soil

6. VARIETIES
• White Vienna
• Purple Vienna
• Grand Duke
• Gigante Purple Danube
• White Danube

7. WHITE VIENNA :
• variety this is an early variety with globular, light green, smooth,
tender, medium-sized knobs having creamy-white tender flesh
with delicate flavor
• plants are dwarf, leaves and stems are medium green
• yield potential of 150–200q/ha
• It matures 55–65 days after transplanting
• takes 50–60 days for knob formation

8. PURPLE VIENNA
• Medium size
• one week later than White Vienna
• Knobs are purplish-blue with greenish-white flesh
• It has purple leaves
• . It requires 55–65 days for knob formation with slightly better
yield potential than White Vienna

9. KING OF NORTH
• plant height of 20–30cm foliage is dark green, knob flattish-
round, leaf sheath large and well-spread over the knob
• It matures 60–65 days after transplanting
• . Early varieties mature 30–45 days after planting & characterized
by the horizontal position of the lower leaves
• The late varieties mature 70–100 days after planting

10. LAND PREPARATION
• 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
• planking is essential to make soil pulverized and leveled
• The beds and channels are prepared to facilitate irrigation
• weeds and stubbles of previous crop should be removed
before the transplanting of this crop

11. NURSERY MANAGEMENT
• usually propagated by seed
• can also be propagated by cuttings such as tip cutting and
leaf cutting
• 60cm wide and 2.5m long nursery beds are prepared
• For minimizing the seedling damage, the nursery beds
should be treated with formalin (40% formaldehyde diluted
in 5–6 parts of water or captan )
• Then covering nursery beds for 2 days

12. • Soil is aerated well for at least 4 days before sowing
• Seeds are sown in rows at a distance of 5–6cm for ease in
manual hoeing, weeding and thinning
• A depth of 1.5–2cm is optimum since deeper sowing
delays the germination
• Time of Sowing:
Variety Time of sowing seed in
Nursery
Time of transplanting in
the main field
Early August September
Main September October
Late October November

13. • Then nursery bed is covered with grass to conserve
moisture for uniform germination
• Watering according to whether condition
• mulch is removed just before the seed germination to control
damping off

14. TRANSPLANTING
• 3 to 4 week old seedlings become ready for transplanting
• Ridges and furrow type beds used
• spacing 25cm × 25cm, 25cm × 30cm, 25cm × 40cm or
30cm × 45cm depending on climatic condition
• seedlings should be watered and protection may be given
from sun rays for 4 – 5 days

15. MANURING AND FERTILIZATION
• Knol-khol responds well to manuring, as it is a heavy feeder
• At the time of transplanting add N - 75 kg/ha , P - 50 kg/ ha
• second dose of 50 kg N should be given 1 ½ months after
transplanting

16. AFTER CARE
• Weeds are removed from field by hand weeding
• generally 2-3 weeding are done in the initial stage of growth
• the field must be kept free from weeds
• plant should be earthen up after 25 – 30 days of
transplantation

17. • The knobs may become elongated - in close spacing due to
lack of light as in knobs growing in the shade
• The production of elongated knobs may also be induced by
high temperature and excess of N

18. IRRIGATION
• Knol-khol requires a continuous supply of moisture for
uniform growth and development of knobs
• after transplanting, should be watered for 4 to 5 days(as
stated the seedlings, after transplanting, should be watered
for four to five days)
• should be given an interval of 6 to 7 days
• thereafter irrigation is done when needed, depending on soil
and weather conditions

19. PEST & DISEASES
Pests
• Aphids
• Thrips
• Mustard saw fly
• Semi looper
• Nematods
• Caterpillars & beetles

20. Thrips
Aphids
Mustard saw fly
Semi looper

21. DISEASES
• Damping off
• Leaf spot & blight
• Club root
• Black rot
• Root fly

22. PEST & DISEASES CONTROL
• Pruning of the old leaves
• Weed control & clean of field
• Use chemical & organic pesticides (foliar spray of garlic
extract at 3% concentration, Spray Trichoderma at 2-3 %
against root fly & black rot)

23. HARVESTING
• knobs are harvested by cutting the stem just below it by a
sharp knife or sickle before they are fully grown
• 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
• generally marketed after removing both leaves and roots

24. Storage
• It can be stored in 3 – 4 days under ordinary conditions
• Cold storage can be stored for more number of days wrapped
knobs store well with better quality comparatively unwrapped
knobs

25. HEALTH BENEFITS OF KOHLRABI (KNOL-KHOL)
• rich in the antioxidant , so helps fight cancer
• contains high amounts of vitamins C, E and carotene
• considered good sources of dietary fiber
• contains sulphoraphanes and other isothiocyanates, which
are believed to stimulate the production of protective
enzymes in the body
• have antidiabetic activity