Turnip

 

Climatic Requirements Turnip is best adapted to cool or moderate climates where rainfall averages 700 to 1000 mm. It requires two seasons to produce seed. Excessive heat during flowering interferes with the reproductive process and flowering. this root vegetable has two distinct races,namely, the biennial temperate and the annual asiatic. the former produces seeds only in the temperate parts, and the latter can be sown for seed both in the plains as well as in the hills. It may, however, not be really economical to produce seed of anual types in the hills. In India, the seed of temperate varieties is produced in the hills and asiatic varieties in the plains.  
Land Requirements Land to be used for seed production shall be free of volunteer plants. The soils of selected fields should be deep, light and friable and the fields well-drained.  

 

Isolation Requirements

Turnip is corss-pollinated by insects. . Seed fields must be isolated from other vareities, fields of the same variety not conforming to varietal purity requirements of certification and other cruciferous crops namely, Chinese, cabbage,rape, mustard and rutabaga, at least 1600 metres for foundation seed, and 1000 metres for certified seed production.


Method of Seed Production

Like other biennial crops, its seed can be produced in situ (seed to seed) or by transplanting (root to seed).

Seed to Seed method: The crop is allowed to over-winter in thefield and produce seed in the following spring in their original position.

Root to seed method: The turnip seed is usually produced by root to seed method. In this method, during autumn the roots, when fully developed, are uprooted and selection of true-to-type roots is made. Underdeveloped, deformed, diseased and off-type roots are rejected. After pruning, the tap root and clipping the tops, leaving the crown intact theselected roots are replanted in freshly prepared soil in such a way that the whole root is covered under the soil, leaving the crown exposed.
In the plains , the seed of the Asiatic types ofroot crops are generally raised by planting cut roots. The usual practice is to remove half to three-fourths of the lower root before planting. This process reduces the yield considerably. It is, therefore, advisable to cause as little injury to roots as possible before transplanting.

  

Cultural Practices

ROOT TO SEED METHOD

FIRST SEASON - Raising of Stecklings

Time of Sowing For proper development of roots, the sowing should be done during the last week of August or first week of September. Extra early varieties like "Early Milan Red Top" and "Japanese White Milan" can be sown by end of September.  


Preparation of Land For transplanting prepare the field to a fine tilth by ploughing and 3to 4 harrowings followed by leveling.


Source of Seed Obtain breeder's/foundation seeds from source approved by a seed certification agency.


Seed Rate 2.5 to 3.75 kg per hectare. The roots produced on one hectare are sufficient for transplanting 2.5 to 3 hectares.


Sowing of Seeds It is advisable to sow the crop on ridges set at 45 cm apart, than in flat. This helps in better development of roots and drainage. Seeds should be sown thinly. Keep the ridges moist until germination is complete. Thin out plants to a distance of 7 to 8 cm within the rows when the plants are ten to fifteen days old.


Fertilisation A light dose of 20-25 tonnes of well-rotted farmyard manure per hectare, applied before land preparation; This should be supplemented by 35 kg nitrogen, 50 kg phosphorus and 50 kg potash per ha as basal application before sowing. Another dose of 35 kg nitrogen be top-dressed when the roots just start forming.


Irrigation Irrigate at short intervals depending on the weather conditions and requirements.


Interculture One weeding and one earthing-up during the early stages of growth is necessary for proper development of roots.


Insect and Disease Control Adopt recommended IPM methods


Harvesting of roots Uproot the plants (stecklings) when they have fully developed roots (70-80 days from sowing)


Selection of roots for transplanting

The uprooted roots should be laid bare side by side to facilitate selection. Small and otherwise undesirabled roots not conforming to the standard shape and colour should be discarded.

SECOND SEASON (SEED PRODUCTION)

Preparation of selected roots for transplanting After selection the tops of the roots are clipped and their tails are pruned. They are then reset in a well-prepared field.  

 

Brief Cultural Practices

1. Preparation of land: For transplanting prepare the field to a fine tilth by ploughing and 3to 4 harrowings followed by leveling.

Method of transplanting: Stekclings are best planted duirng the second half of December as later plantings are prone toserious attacks of aphids. the selected stecklings prepared in the manner already described are reset in the field at a distance of 60x30cms. The soil is then firmed and tapped around the roots. Soon after transplanting the field is irrigated.

Manuring:Apply 10-15 tonnes of well-rotted farmyard manure at the time of land preparation; At the time of sowing supplement it with 50 kg phosphorus . Topdress 25kg nitrogen per ha in the prebolting stage and another dose of 25 kg nitrogen before flowering starts.

Interculture: One hoeing and earthing-up is necessary during March, so as to give support tothe plants, which may otherwise lodge because of heavy winds during the flowering and fruiting season.

Supplementary Pollination: The turnip is pollinated by insects. To ensure good seed set, pollination of maximum flowers is necessary. Honey-bees are important agents of pollination. In large seed fields it is advisable to place bee hives nearby, to increase pollination.

Other cultural practices are the same as described for the previous season..

 

 

 

Roguing rogue out undesirable roots, namely, off-type, diseased or mailformed root, at the time of transplanting.
Subsequent roguings for off-type and other crop plants may be done at the bloom stage. Rogue out diseased(seed-borne diseases) and severely insect damaged plants from the field as required from time to time.		  

 

Harvesting and Threshing Harvesting of the seed crop may be done when the seed pods are reddish brown. Harvesting before thisstage gives shrivelled seeds and a late harvest results in seed shattering.
Harvesting is done by sickle. Cut seedstalks near base of crown, preferably in the early morning. The threshing can be done by beating the seed stalks with sticks, or by thresher, and the seeds can be cleaned by winnowing Dry the seeds to six per cent moisture content before storage.		  


Seed Yield The average seed yield is about 600 to 800 kg per hectare.