Carrot 178 by m2FN34y

VIEWS: 7 PAGES: 10

									                                           Carrot
                                      Booklet No. 178
                               Vegetable Production: VPS - 35
Contents
Preface
I.     Introduction
II.    Climate
III.   Soil
IV.    Varieties
V.     Land Preparation
VI.    Sowing
VII.   Manures and Fertilizers
VIII. Irrigation
IX.    Interculture
X.     Pests, Diseases and Disorders
XI.    Harvesting and Yield
XII.   Storage and Marketing
XIII. Seed Production
XIV. Uses and Composition
XV.    Economics of Cultivation.

Preface

       Carrot is a very valuable vegetable crop of India. It has got fleshy edible roots which are
rich source of carotene, the precursor of vitamin A. It has a number of medicinal and nutritional
uses. Its roots are used as salad, vegetable, pickles and as canned products. This booklet
describes the scientific cultivation of carrot in detail.

Dr. K.T. Chandy, Agricultural & environmental Education

I. Introduction

        Carrot (Daucus carota) belongs to the botanical family Umbelifereae and is locally called
gajar, gajpar, etc. It is a cool season crop and is grown all over the world in spring, summer and
autumn in temperate countries and during winter in tropical and subtropical countries. It has got
fleshy edible root portion which is botanically designated as conical root. As in radish, the carrot
also has two groups: Asiatic and European (temperate) types. The world-wide consumption of
carrot has increased over the years and it is now one of the most popular vegetable crops.

        Carrot is believed to be the native of Europe, Asia and North Africa and possibly North
and South America. It was probably cultivated by the ancient people but was not a common food
plant. Asiatic type probably originated from Central Asia.

       The Asiatic carrots are generally red coloured because of anthocyanin pigment. The
European types are orange coloured because of carotene, a precursor of vitamin A. In India
mostly Asiatic type is grown probably due to appealing red colour. It is grown throughout the
country.

II. Climate
       Carrot is essentially a cool season crop. A temperature of 15 to 20oC is reported to be
conducive to the development of maximum growth, best colour and normal shape of the root.
Higher temperature helps in the production of shorter and thicker roots, while lower temperature
produces longer and slender roots. Indigenous varieties and exotic varieties acclimatized in India
can withstand considerable heat. The moisture necessary for proper germination of carrot seed
should be 20 per cent, though it can germinate under fairly dry conditions. There should be
continuous moisture supply in the soil to keep them succulent. Dry weather followed by wet
weather is conducive to produce high quality carrot.

III. Soil

       Although carrot can be grown on all types of soil, it thrives well on a deep, loose and
loamy soil. For early crop a sandy loam soil is preferred, but for high yields silt to silt loam soil is
desired. The long, smooth "slender roots desired for fresh market can successfully be grown on
well drained light soils. Carrots grown on heavy soils tend to be more rough and coarse than
those grown in light sandy soils.

        Carrots do not grow well on a soil that is highly acidic. The optimum pH of soil should
range between 6.0 -7.0. The carrot seeds are slow to germinate and the young plants are very
delicate hence the soil should not have any tendency to bake or crust.

IV. Varieties

        Many varieties of carrots, some indigenous but mostly introduced from Europe and
America, are grown in India. Important among the exotic types grown in India are Chanteny,
Danvers, Nantes, Early Horn and Early Gem. Chanteny and Danvers are known for their long
tapering roots and excellent quality. Early Horn and Early Gem are famous for their earliness and
for their tender and mild flavoured roots. Usually the Indigenous varieties are coarser in texture
and possess less flavour than exotic types. Besides, these types are hardier than exotic types
and colour development is also poor in indigenous cultivars. The carrot cultivars may be classified
on the basis of shape of their roots or on temperature response.

A.Classification based on shape of the roots

I. Long rooted
Roots may be 25 cm or more in length, generally these perform best in comparatively light soil.

2.Half -long rooted
Root length does not usually exceeds 20 cm.
i. Roots cylindrical with straight or slopping shoulder, ego Nantes.
ii. Roots tapering with blunt or semiblunt tip, ego Chanteny, Imperator, etc.

3. Short stump rooted
These cultivars are suitable for growing in heavy soils.
i. Heart shaped, ego Oxheart
ii. Oval, ego Early Scarlet Horn
iii. Round, ego French Forcing.

B. Classification based on temperature response on flowering

1. Temperate or European types
These cultivars are biennial in character and require low temperature treatment (4.8 to 10 oC) for
flowering. These do not produce seeds in the plains of India. For example, Nantes, Chanteny,
Imperator, etc.

2. Tropical or Asiatic type
        These cultivars do not require any temperature treatment for flowering. They seed freely
in the plains of India.

Characteristics of some of the important varieties of carrot are given below.

1. Pusa Kesar
        Pusa Kesar is a selection from a cross between Local Red and Nantes Half Long. The
leaf top is markedly shorter in this variety than that of Local Red. The roots develop on narrow
central core which is also sufficiently red coloured unlike the yellow or white core in Local Red.
Pusa Kesar contains high amount of carotene (38 mg/l00 g). A notable feature of this variety is
that the roots stay about a month longer in the field than Local Red without showing any sign of
bolting. It can tolerate higher temperature than Nantes and is suitable for sowing from early
September to mid November.

2. Nantes
        It is an European variety grown in plains of India for root production. It is half long, slim,
well shaped with stump and forming a small thin tail. It has delicious flavour, fine grain texture and
self-coloured core with orange -scarlet flesh colour.

3.Chanteny
         It is also an European type having attractive roots with deep reddish orange colour. The
root is smooth, half long with thick shoulders, gradually tapering towards a distinctly stumped end.
The flesh is beautiful rich orange, sweet and fine textured with indistinct core.

4.Imperator
         It is believed to be a cross between Nantes and Chanteny and is extensively grown for
fresh market. It is a mid season to late maturing variety with large and strong foliage. Roots are
15 to 17.5 cm long and 2.5 to 4.5 cm in diameter, with short tapered end, deep orange core and
slightly less pigmented core.

5. Danvers
        This cultivar is grown for fresh market as well as for processing. It is a mid-season cultivar
with large and strong foliage. Roots are 12.5 to 15 cm long, 2.8 to 4.5 cm in diameter with
tapering to short -tapering or slightly rounded end, deep orange cortex and a slightly more yellow
core.

V. Land Preparation

         For cultivation of carrot, the field should be worked deep to a good tilth and properly
manured. If the soil is not thoroughly prepared and if it has clods or undecomposed organic
matter, good quality and well shaped roots cannot be produced. Root deformity usually occurs in
the fields which are under prepared. The land should be ploughed to a depth of 30 cm. Manuring
should prrferably be done in the previous year.

VI. Sowing
        Carrots are grown from seeds sown directly in the field where the crop is to mature. In
South and Central India, they are cultivated mainly on the hills and the seeds are sown during
January-February, June-July and October-November. When climatic conditions are favourable,
carrots can be grown almost round the year and successive sowings may be done every fortnight
to obtain continuous supply of roots. Seeds are sown from August to December in the northern
plains of India. In the hills, it is sown during March to July.

       Carrot seeds are sown either by broadcasting or by drilling in lines. Seeds are mixed with
fine sand before sowing to facilitate even distribution. The seed rate varies from 8 -10 kg per
hectare. Line to line distance should be kept 45 cm and the depth of sowing should be maintained
1.0 to 1.2 centimeter. After sowing, seeds are covered with soil. When the young plants have
come out, they should be thinned out to 5 -8 cm apart depending upon the stage when they are to
be consumed. Medium sized roots, however, are considered the best for table use.

VII. Manures and Fertilizers

        As a good supply of organic matter is essential for root crops, about 25 tonnes per hectare
of well rotten farmyard manure is applied and mixed well into the soil to a depth of 20 -25 cm to
ensure an even distribution. This enables the roots to grow to a normal shape instead of
becoming short and forked. When organic manure is applied, the need for fertilizers is reduced.
An application of 40 kg of phosphorus and 50 kg potash per hectare is recommended for higher
yields. Where organic manures are not available, it is advisable to apply 80 kg nitrogen, 60 kg
phosphorus and 60 kg potash per hectare. Half the amount of nitrogen should be applied along
with phosphorus and potassium before sowing. Remaining nitrogen should be applied with
second irrigation. The phosphatic and potassic fertilizers should be placed 10 cm deep in furrows
opened by disc plough.

VIII. Irrigation

        First irrigation is done just after sowing followed by another irrigation after 4 to 6 days.
Keep the soil moist between the furrows till the seedlings come out. The fields are irrigated
sparingly in winter and at a fortnight interval when the weather is dry. Never irrigate the carrot
field heavily otherwise it will result in excessive foliage growth, poor quality roots and the maturity
will be delayed. The field should be irrigated lightly before harvesting which will make uprooting of
the crop easy.

IX. Interculture

        Carrot seeds germinate 8-10 days after sowing and as soon as the plants become well
established, they should be thinned out and about 5 to 7.5 cm plant to plant distance should be
maintained. This operation helps in reducing overcrowding of the plants, avoiding deformed root
formation and securing a better yield. Those sown by broadcasting are not thinned. The surplus
plants growing in lumps are removed leaving only one plant at one place.

        Weeds are a serious problem in carrot fields. Timely control of weeds is essential to avoid
heavy loss in yield of top quality roots due to weed competition. In the early stage the crop must
be kept free from weeds which can be achieved by frequent hoeing. It (hoeing) also facilitates
proper soil aeration and root development. In western countries chemical control of weeds in
carrot field is quite popular. An application of 100-200 litres of Stoddard solvent per hectare kills
most of the annual weeds and grasses. Spraying should be done when foliage is dry and
preferably in the morning hours.
X. Pests, Diseases and Disorders

       Major insect pests, diseases and physiological disorders of carrot are described here
along with suitable control measures.

A. Insect pests
       Insects are not major problem in carrot production and only a few species of them may
damage the crop to some extent. Important ones are described here.

1. Carrot rust fly
         This fly is about 42 mm long and dark green to black in colour. The maggot (larva) of this
fly is slender, yellowish white in colour and about 6.3 mm in length. The larva burrows into the
roots, often causing them to become mis-shapen and subject to decay and render them unfit for
marketing. If the roots are injured severely, the leaves become rusty or even dried.

       Attack of this pest can be lessened by adjusting the sowing of time, as the studies have
sown that the pest is most active during a particular period of the year. Application of Dimethoate
(0.1%) @ 600 to 800 litres per hectare, two to three times, gives satisfactory , control of the pest.

2. Lygus bug
        It is a serious pest of seed ,crop of carrot. It is believed that low viability or low germination
of carrot seeds is associated with the injury causes the Iygus bug. The pest damages the embryo
of the seed, sometimes the seed is without embryo. Seed treatment with insecticides may control
this pest. One or two sprays of Malathion (0.2%) before flowering will also control this bug.

3.Nematodes
       Besides the insect pests, nematodes may also cause serious damage to the crop making
the crop completely unfit for the market. The most important nematode damaging carrot is
species of Pratylinchus, but Heterodera carotae and Meloidogyne sp. are also common.

       Soil treatment with Nemagon or Sannema or DD can appreciably reduce the nematode
population in carrot field.

B. Diseases
There are five main diseases severely affecting the carrots.

1. Cercospora leaf blight
       This is a fungal disease caused by Cercospora carotae. This disease is of worldwide
occurrence but is more common in temperate zones.

         The initial symptoms appear on the leaves are elongated lesions along the edge of the
leaf-let segments causing lateral curling of the leaflets. Away from the margin, the spots are sub-
circular, grey to brown or black in colour. As these spots increase in number, the intervening parts
of the lamina die thus causing the entire leaf to shrivel or curl black. On the petioles, dark lesions
develop, sometimes girdling the petiole and killing the leaf. The fungus does not attack fleshy
carrot roots. Foliage symptoms are similar to an Alternaria blight when the attack on leaves is
similar.
Control
         Well drained soil and three year or longer crop rotations are important cultural practices
against this disease. Hot water treatment of seed at 500C for 15 minutes reduces the seed
inoculum of the pathogen.
       If the disease is causing severe damage to foliage, spraying can, be done with Dithane M-
45, copper oxychloride or Ziram.

2. Alternaria blight.
        This is also a fungal disease caused by Alternaria dauci. This disease commonly occurs
along with Cercospora blight and the symptoms of these two blights are much alike. However ,
Alternaria blight occurs mostly on older and weaker leaves.

       In affected plants, small, dark brown to black irregular spots are formed on the leaves.
They have a yellow halo and usually first start from the leaf margins. The irregular shape and
more consistent dark brown to black colour distinguishes the symptoms from Cercospora blight.
Control measures are the same as for Cercospora blight.

3 Bacterial blight and root scab
        This disease occurs only on carrot. The seed crop is more severely affected than root
crop. In the seed crop, the bacterium (causal organism) becomes seed-borne and thus can be
disseminated to far and wide places. Fleshy roots are also damaged. Small, irregular, yellow
areas appear first on the leaves, soon they turn into dark brown and water -soaked spots. The
centers of these spots become dry and brittle. They are surrounded by an irregular halo. The
segments of leaflet curl and are killed. On petioles and stems, dark brown streaks are formed.
Bacterial exudate may also appear on the leaves, petioles and stems. The inflorescence in a
seed crop is killed if the infection occurs before the unfolding of the umbels.

       Bacteria are washed down from the foliage to the soil which infect the fleshy roots. Brown
to maroon lesions are formed on the fleshy roots and develop into slightly raised or slightly
depressed, laterally expanded pustules showing flakes of dead tissues. When these pustules
crack open, bacterial exudate may ooze out.

Control
        No chemical treatment is known against this disease. The principal control measures are:
selection of field for carrot cultivation away from the previous years carrot fields, long duration
crop rotations, and hot water treatment of seeds at 500 C for 15 minutes.

4.Bacterial soft rot
        This disease is caused by the bacteria Ervinia sp. and is a very destructive disease of
carrot roots in storage and transit. These organisms are present in the soil on decaying crop
refuge and attack wounded or bruised roots in the field as well as during storage and transit. High
temperature favours the fast development of soft rot.

         The infected tissues often become watery or slimy and as the rot progresses, the watery
extrusion becomes evident. A foul odour from the decayed roots distinguishes it from the fungal
soft rot.
Control
         Control measures include careful handling of roots during harvesting, grading or transit so
that all bruises on root surface can be avoided. The root surface should be kept dry and stored at
00 C temperature with 90% relative humidity.

5. Carrot yellows
       This is a viral disease and is one of the most serious diseases of carrot in certain areas
where carrots are grown intensively and the vector (virus carrier) is present. On carrot, the
disease appears as a marked yellowing of the younger central leaves, while the outer older
leaves are usually reddish or purple. The youngest central leaves are dwarfed and the petioles
are sometimes twisted. Occasionally, a dense growth of adventitious, chlorotic shoots develops at
the center of the crown. The leaflets on the shortened petioles are sometimes reduced to short
filaments, which often dry. Due to development of adventitious shoots, the plant gives a rosette
like appearance. The fleshy roots are also affected and their growth is checked and numerous
bunched rootlets arise from elevations on the main fleshy roots.

Control
       Except for vector control no other method is known against this disease. Regular (weekly)
spraying of insecticide is recommended to prevent the build-up of the insect vector population.

C. Physiological disorders
Two main physiological disorder of carrot are described here.

1. Carrot splitting
        Although splitting or cracking of carrot is a major problem in many carrot growing areas,
sufficient attention has not been paid towards this disorder. A number of factors are responsible
for carrot splitting, mainly genetical factors. Application of heavy doses of nitrogen and wider
spacing also increase splitting. Generally, large roots are more likely to split than small roots. Split
carrots have a larger tops in relation to the size of the roots than the smooth carrots.

                    To prevent carrot splitting, application of nitrogenous fertilizers should be
optimised and proper spacing should be maintained. Besides, varieties which are more
susceptible to splitting should not be cultivated.

2.Cavity spot
       This disorder of carrot has been reported from widely scattered geographical areas. The
disorder appears as a cavity in the cortex, in most cases the subtending epidermis collapses to
form a pitted lesion. This lesion may be infected if secondary organisms are present. It has been
observed that cavity spot disorder has been induced primarily because of calcium deficiency.
Therefore, calcium deficient soils should be avoided for carrot cultivation.

XI. Harvesting and Yield

       Carrots should be harvested at proper stage of maturity, otherwise it will become fluffy
and unfit for consumption. In general, the percentage of root splitting, firmness, the contents of
dry matter, carotene and sucrose increase with the age of roots, whereas the contents of glucose
and fructose decrease. Highest yields in carrots have been obtained from earlier harvest.
Generally, the common cultivars attain the marketable stage when their diameter is 2-4 cm at the
upper end.

       In India, harvesting is done manually, whereas mechanical harvesting of carrot is a rule in
advanced countries. It is advisable to give a light irrigation before harvesting because this will
enable easy pulling of roots from the soil without any damage.

        The Asiatic varieties yield higher than the European varieties. The yield of carrot roots
varies in various regions ranging from 135 to 370 quintals per hectare.

XII. Storage and Marketing
       After harvesting the roots are washed, cleaned and topped. Their side roots are also
removed. Desi varieties are sold loose, while exotic varieties are tied in bunches of 6-12 roots
and then sent to market in baskets or cardboard boxes. Diseased, damaged, split and mis-
shapen roots are sorted out before sending them to markets. Fresh carrots cannot be stored for
more than 3-4 days under ordinary conditions. However, long term storage in cold storage is
possible without any appreciable change in quality. Carrot can be stored in good condition for six
months at a temperature of 0-4.4oC with 93-98% relative humidity.

XIII. Seed Production

       Only the Asiatic varieties produce seeds in the plains. The European varieties do not
produce seed in the plains, hence their seed production is limited only to the hills. Since carrot is
a cross pollinated crop, every care should be taken to keep the two varieties away from each
other and the isolation distance given to produce the foundation seed is about 1000 meters.

        The usual technique followed for seed production in carrot is more or less the same as
that of radish and turnip. Usually good quality and high yielding roots of a variety are selected at
the root marketable stage. They are transplanted in well prepared fields after giving proper root
and shoot cuts to ensure better quality and higher seed yield. The selected roots are planted at a
distance of 75 X 20 centimeter. During planting, care should be taken that the crown remains
exposed.

        The selection of carrot roots is made on the character of tops (small or heavy), colour of
skin, shape and size of roots, colour of flesh, colour and size of core, etc. Thorough examination
and selection of true to type plants are absolutely necessary for raising quality seeds. Both early
and late bolters and all diseased, forked or hairy roots should be removed.

         Carrot plants bear compound umbels. It is the king umbel (primary umbel) or the umbel of
the first order that flowers first. The secondary, tertiary and other orders of umbels flower at an
interval of 8-12 days from each other. Anthesis in a single umbel is completed in 7-9 days. The
peripheral umbels flower first followed by inner umbellets.

        The temperate cultivars start bolting by third week of April in the hills of India and
flowering starts by the end of May. The crop is harvested during July-August. Bolting and
flowering in tropical types occur during early spring and the crop is harvested by the end of May.

        Shattering of seed occurs to some extent but it is not a serious problem in carrot. Usually
the crop is harvested when the secondary umbels are fully ripe and the third order umbels have
started to turn brown. The crop may be harvested either mechanically or manually. The harvested
plants are then kept in wide rows in small pilesof3-5 plants for curing. Curing may continue from
5to 14 days or even more depending on the weather condition. Rain during curing may cause
deterioration in the quality of seeds. The seed is then threshed, cleaned and graded. The spines
of the seeds are removed by breaking off the spines through some sort of rubbing action in mills.

                  A yield of 350 to 550 kg seed per hectare has been obtained from the
European cv. Nantes in Kullu valley and about 2000 kg seed per hectare from the Asian cultivars
in plains, when the proper root and shoot cuts are given. It has been advised that all the seeds
smaller than 1.66 mm gathered from the late harvest should be eliminated

XIV. Uses and Composition
                    Carrot roots are used as vegetables for soups, stews, curries and pickles.
Grated roots are used as salad and tender roots are used as pickles. A preparation called "Gajar
Halwa" is delicious dish prepared from carrot. It is very nutritious and popular in North India.
Carrot jam is also popular and the roots in the form of disc and slices can be dehydrated. Carrot
juice is a rich source of carotene and is sometimes used for colouring butter and other food
articles
.
         Carrot leaves are said to be eaten in many countries. Its tops can be used as a good
source for extraction of leaf proteins. Moreover, carrot tops are used as fodder and also for
preparation of poultry feed.

       An infusion of carrot has long been used as a folk medicine for thread worms. Addition of
large amount of carrot to the diet has a favourable effect on the nitrogen balance in the body.
Carrot also possesses anti-carcinogenic properties.

         Besides its value as vegetable, carrot is cultivated in some countries, especially in France,
for its seed from which oil is extracted. The fruits are collected, dried and the seeds are separated
the essential oil from carrot seeds is used for flavouring liquors and all kinds of food substitutes.
Carrot seeds are aromatic, stimulant, and carminative. They are reported to be useful in diseases
of the kidney and in dropsy.

                  Carrot is valued as a food because it is a rich source of carotene. The
composition of the edible portion of the carrot root is given in the table 1
.
                Table -1 : Composition of carrot root (per 1.00 g of edible portion)

                         Sl.No          Constituents             Amounts
                           1       Carbohydrate                   10.6 g
                           2       Protein                         0.9 g
                           3       Fat                             0.2 g
                           4       Moisture                        86 g
                           5       Fibre                           1.2 g
                           6       Energy                        48 k.cal
                           7       Minerals                        1.1 g
                           8       Iron                           2.2 mg
                           9       Carotene                      1890 mg
                          10       Vitamin C                       3 mg
                          11       Calcium                        80 mg
                          12       Phosphorus                     30 mg
                          13       Niacin                         0.5 mg

XV. Economics of Cultivation

         Carrot is very nutritious and very popular vegetable. Its cultivation is very profitable.
However, the net profit per hectare varies depending upon the season, type of cultivar and
locality. Asiatic cultivars yield higher and, also because of their attractive colour, they fetch higher
prices. Besides, net profit per hectare will also depend upon the availability of labour and a
suitable market for the disposal of the produce.
        The cost of cultivation and net profit per hectare from carrot cultivation can be worked out
with the help of the format given below.

A. Fixed cost
    1. Cost of the land Rs
    2. Cost of farm building and storage structure, etc. Rs
    3. Cost of fencing Rs
    4. Cost of the clearing, leveling and bunding of the land Rs
    5. Cost of farm implements Rs
    6. Cost of permanent irrigation system Rs
    7. Cost of other permanent and semi- permanent structures Rs

B. Recurring cost
   1. Cost of land preparation Rs
   2. Cost of seed material Rs
   3. Cost of manures and fertilizers and other chemicals Rs
   4. Cost of farm power Rs
   5. Cost of farm labour (paid and unpaid)
           a. Ridge preparation Rs
           b. Seed treatment Rs
           c. Sowing Rs
           d. Irrigation Rs
           e. Weeding Rs
           f. Application of manures and fertilizers Rs
           g. Application of insecticides and fungicides Rs
           h. Intercultural operations such as mulching, gap filling, thinning,
                   uprooting diseased plants, etc. Rs.
           i. Supervision Rs.
           j. Harvestlng
           k. Storing and marketing Rs
           l. Any other labour Involvement Rs
   6. Interest on fixed cost (@ 10%) Rs
   7. Rent or revenue paid for land Rs
   8. Depreciation Repair and maintenance Rs
Total recurring cost Rs

C. Income
    1. Income from carrot roots Rs
    2. Income from carrot seeds Rs
    3. Income from the foliage, etc Rs
Total income Rs
Net profit = Gross income -Total recurring cost

                          Purchase value -Junk value
Depreciation = ---------------------------------------
                                 Life span
                     Remark: Junk value is calculated only on those articles which can be resold
after their life span. Life span of building and machinery is 15 years and 10 years, respectively.

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