Cabbage

Climate

Cabbage thrives  in a relatively cool, moist climate with moderate to heavy rainfall, well distributed during the growing season.  It can withstand frost in the head stage, but otherwise freezing temperatures are destructive.  It requires a dormant period of cool temperature to bolt and initiate seed stalks and flowers.  Cool temperatures, however, are effective only after  stem diameter is one cm, at least.  In temperate climates, this occurs during the winter after the first seasons growth.  Flowering  and seed production follow  in the second year.  Headed plants form seed stalks when exposed to mean temperature of about 5C for six to eight weeks.  As little as two weeks of such temperature suffice with immature plants.  In India, seed production of cabbage is possible only in hill areas.

Land and Isolation requirements

Land to be used for seed production shall be free of volunteer plants.

The soil of selected field should be deep, fertile, well-supplied with organic matter with a pH value 5.5  The field should be well-drained.

Methods of Seed Production

Being a biennial, the cabbage requires two seasons to produce seed.  In the first season the heads are produce, and in the following season seed production follows.  The seed crop can be left in situ or transplanted during autumn.  In situ method is usually followed for certified seed production and the latter for nucleus production.

In the in situ method , the crop is allowed to over-winter and produce seed in their original position, that is, where they are first planted in the seedling stage.  In the transplanting method,  the mature plants are uprooted.  After removing whorls the plants are immediately reset in a well-prepared new field, in such a way that the whole stem below the head goes underground with the head resting just above the surface.

Three methods have been devised to produce seed of cabbage.

Stump Method:

In this method, when the crop in the first season is fully mature, the heads are examined for trueness to type.  The plants with off-type heads are removed.  Then heads are cut just below the base by means of a sharp knife, keeping the stem with outer whorl of leaves intact.  The beheaded portion of the plant is called “stump”.  The heads are marketed and the stumps either are left in situ, or replanted in the second season i.e., during autumn.  The following spring, after the dormancy is broken, the buds sprout from the axils of all the leaves and leaf scars.

Advantages

  1. Gives extra income by way of sale of heads.
  2. The crop matures twelve to fifteen days earlier than the head intact method.
  3. Seed yield is slightly increased.

 

Disadvantages:

In this method, flowering shoots are decumbent and require very heavy staking, otherwise they breakdown very easily while inter culturing or spraying.

Stump with Central Core Intact Method

In this method, when the crop is fully mature in the first season.  The heads are examined for trueness to type.  Plants with off-type.  Plants with off-type heads are removed and rejected.  Then the heads are chopped on all sides with downward perpendicular cuts in such a way that the central core is not damaged.  This is an improvement over stump method in that the shoots arising from the main stem are not decumbent.  During the last week of February and until 15th March when the heads start bursting, two vertical cross-cuts are given to the head, taking care that the central growing point is not injured.  In the absence of such cuts, the heads burst out irregularly and sometimes the growing tip is broken.  The operation is completed by going around the field twice or thrice during this period.

Advantages:

  1. Shoots arising from the main stem are not decumbent, hence very heavy staking is not required.
  2. Seed yield is increased.

 

Disadvantages:

  1. The chopped heads cannot be marketed.

 

Head Intact Method:

In this method, when the crop is fully mature in the first season the heads are examined for trueness to type. The plants with off-type heads are removed from the field. The head is kept intact  and only a cross-cut is given to facilitate the emergence of a stalk.

Advantages:

  1. The removal of heads (stump method) or chopping of heads on all sides (central core intact method) is not required.  This saves time and labour.
  2. Very heavy staking is not required.

 

Disadvantages;

1. The seed yield is slightly low as compared to stump, or stump with central core intact method.

Cultural Practices

1.Time of Sowing and transplanting: The sowing time of different varieties should be so adjusted as to complete head formation by the end of October or first week of November, by which time the mean temperature falls to 10C or below; at this temperature the heads stand best for over-wintering.

Early varieties like ‘Golden Acre’ should be sown from 10th to 25th July and transplanted when the seedlings are three to four weeks old, during the second fortnight of August.  This sowing time must be strictly adhered to, as the crop from the early sowings have matured heads during September and  starts pre winter bursting and bolting. It is thus liable to be much affected by frost and snow during winter.  Moreover, due to high mean temperatures of September (20C ) the heads get infected with bacterial stock rot, which sometimes is very severe.  The late crop, planted during September does not form heads and bolts directly during spring, and the seed grower is not able to ascertain purity of the crop.

Medium-late varieties like burpee’s Sure Head, and late varieties like Drum Head, which take about 2 1/3 to 3 months to produce mature heads, should be sown during the second and first fortnight of June respectively, and transplanting finished by the first week of August.  The mean temperatures 22.5C, 20C and 14C of August, September and October respectively, afford optimum requirements for growth and head formation. The late transplated crop starts head formation during spring and continues up to June and usually does not produce seed stalks.

2Method of sowing nursery: The seeds are sown in raised nursery beds in a manner similar to that of cauliflower.

3.      Source of seed and seed rate:  Obtain breeder’s/foundation seed from source approved by a seed certification agency. Main season and late varieties – 375 to 400 gm per hectare and early varieties 600-750 gm per hectare.

4.      Preparation of land for transplanting:  Prepare the land to a fine tilth by repeated ploughing and harrowing, followed  by levelling.

5.      Fertilisation: Cabbage grows satisfactorily only when the supply of organic nitrogen is liberal.   For best results apply 50 to 60 tonnes of farmyard manure per hectare, at the time of land preparation. Since the supply of farmyard manure is very limited in the hills, only 25 to 30 tonnes farmyard manure per hectare, is usually applied.  Apply 200 to 300 kg superphosphate and 90 kg of muriate of potash by drilling.  Top-dress two doses of 75 to 100 kg ammonium sulphate at intervals of two to three weeks after transplanting  the seedling.  Give another dose of 200 to 250 kg ammonium sulphate as surface application at the time of seed stalk emergence during March.

6.      Transplanting: Three to four week old seedlings are transplanted.  Transplanting should preferably be done in the evening and the field irrigated immediately afterwards.

7.      spacing: Late varieties        - 60 x 60 cm

                   Medium varieties   - 60 x 45 cm
                    Early varieties        - 45 x 45 cm

8.      Irrigation : Cabbage requires a continuous supply of moisture.  Irrigate the crop as frequently as required.  Heavy irrigation should, however, be avoided when the heads  have formed.  A sudden heavy irrigation after a dry spell may cause bursting of heads

9.      Hoeing and weeding: At least three weedings and hoeings till the end of October are essential.  One weeding and earthing up during November and December and the second during March, when  seed stalks have emerged, control weeds and also help in proper drainage during winter and thereafter.

10.  Insect pest  and disease control: Adopt IPM method.

 

Roguing

The first roguing is done at the time of handling the mature heads. 

The Second roguing is done before the heads start burstling.   The loose-leaved poorly heading plants, and those having a long stem and heavy frame, must be rogued out at this state.  It is highly undesirable  to keep such poor plants in the seed plots.

Harvesting and Threshing

Cabbage starts seed stalk elongation from 10-20th March when the mean temperature rises to 10-13 C.  Flowering and pod formation starts during the first week of April at mean temperature of 13-18.5C.  From 15th April to 15th May, the crop is in full flush of flowering and fruiting.  The ripening of pods commences by 15th June to 20th June and the harvesting continues up to second week of July.  At mean temperatures below 20C during June and July, the maturity of crop is delayed at least by a fortnight and the harvesting may continue up to July end.  To avoid shattering of seeds, the whole crop is harvested in two or three lots with sickles.  Generally, the early plants are harvested first and when the pod colour in about 60-70 per cent of the rest of the crop changes to yellowish-brown it is harvested completely and piled up for curing.  After 4-5 days, it is turned upside down and allowed to cure for another 4-5 days, in the same way.  It is then threshed with sticks and sifted with hand sifters.  After thoroughly drying the seeds they are cleaned and stored.

Seed yield

500 to 650 kgs per hectare.