Other Seeds

Spinachbeet(Palak)

Climatic Requirements

Palak is a cool season crop, but has a much wider range of adaptability to climatic conditions. It produces seed freely in theNorth Indian Plains.

Land Requirements

Land to be used for seed production shall be free of volunteer plants. In addition,the soil of the selected fields should be rich in organic matter.

Isolation Requirements

Palak is corss-pollinated by wind. Air currents may carry the pollen toconsiderable distances. Seed fields must be isolated from fields of other varieties of palak, or of the same variety not conforming to varietal purity requirements for certifidcation, and from Swisschard, sugarbeet or stockbeet and gardenbeet, by at least 1600 metres for foundation seed production, and 1000 metres for certified seed production.

Time of Sowing

For seed crops, sowing should be done in October toNovember

Preparation of Land

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

25-30 kg per hectare.

Sowing of Seeds

Sow the seeds in rows 20 to 25 cm apart. Place the seeds close to each other at the depth of about 2 cm. Sufficient soil moisture is required for good germination.

Fertilisation

Apply 35-40tonnes of well-rotted farmyard manure at the time of land preparation; and 100 kg of amonium sulphate or C.A.N. as top -dressing after every cutting..

Irrigation

Frequent irrigations according to season are required to obtain a good yield.

Interculture

Keep the fields free of weeds, especially in the early growth period. the field should be kept completely clean of pig weed (Bathua), after the crop has been left for seed.

Insect and Disease Control

Adopt recommended IPM methods

Roguing

Careful roguing for off-types, early bolters, and pig weed plants is necessary. the first roguing may be done at preflowering stage to remove off-types on the basis of foliage characters. Subsequently early bolters, off-type plants and pig weed plants may be removed immediately, as and when they are noticed.

Harvesting and Threshing

Harvesitng of the crop should be done when most seed is firm, before shattering. The crop is cut by hand and allowed to dry in the field. Afterdrying is complete, the seeds can be threshed by flailing them with sticks. After cleaning the seed must be dried to nine per cent moisture, before storage.

Seed Yield

The average seed yield is about 1000 to 1500 kg per hectare.

Lettuce

Climatic Requirements

Lettuce requires a relatively long cool (12 to 18 C) growing season, particularly cool nights and low rainfall at harvest time. High temperatures are undesirable. Heading is prevented and shooting to seed induced at temperatures between 21 to 26C . Lettuce is susceptible tofrost.

Land Requirements

Land to be used for seed production shall be free of volunteer plants. In addition, the soil ofselected fields should be well-drained, fertile and with high organic matter.

Isolation Requirements

Lettuce is manily self-pollinated, but one to six per cent cross pollination due to insects has been reported. Seed fields must be separated from fields of other varieties, and fields of same variety not conforming to varietal purity requirements of certification, at least by 50 metres for foundation seed production and 25 metres for certified seed production.

Time of Sowing

October

Preparation of Land

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

Nursery sowing - 0.5 to 0.75 kg per hectare.

Sowing and transplanting of Seeds

Seeds may be sown on raised nursery beds in rows 3 to 4 cm apart. and seedlings transplanted at a distance of 30 to 45 cm x 20 to 30 cm, when they are five to six weeks old

Fertilisation

Apply20- 25 tonnes of well-rotted farmyard manure 125 kg of Superphosphate, at the time of soil preparation and 250 as top -dressing in two doses (early spring, and in May when the stalks emerge).

Irrigation and Interculture

Frequent hoeing and weeding is necessary for proper aeration of soil and to keep down the weeds. Water should be supplied to keep uniform moisture conditions in the soil. Drainage is as imporant as supplying irrigation, for excess of soil moisture may cause rotting.

Insect and Disease Control

Adopt recommended IPM methods

Roguing

Lettuce varieties fall in two groups namely, heading types and loose leaf types. In the first group there are: cabbage head types, having crisp leaves and head cabbage type; Butter head types, having soft smooth leaves, usually do not form the type of head typical of cabbage types; and cos types, having upright, cylindircal and rather thin heads. the second group (loose leaf tyeps) are non-heading and varieties differ in leaf shapesand sizes.

Roguing should be compelted before bolting starts in loose head varieties, or when heading is complete in heading varieties. Directo bolters, ill-formed plants, off-type plants, diseased plants affected by mosaic, yellow mosaic and wild lettuce plants should invariably be removed from time to time as required.

Harvesting and Threshing

Lettuce seeds ripen unevenly, and fully mature seed shatter readily. It is advisable to harvest when 30 to 50 per cent of the seeds in the heads show white pappus or fluff and a good number of heads after opening have turned brown or dark brown but have not shown out the pappus. the plants are cut by hand and left to dry on the ground for a few days. Later, the seeds are collected by gently shaking them.

In the case of heading varieties such as Great Lakes which donot produce flowering shoots so profusely, it may be desirable to collect the seeds periodically by shaking the tops and collecting the seeds from the burst out heads in trays.

Seed Yield

The leafy types usually produce 500 to 600 kg seed per hectare. However, the variety, great lakes, produces only 100 to 125 kg seed per hectare.

Radish

Climatic Requirements

Radish is best suited to a cool moderate climate,especially in the vegetative stage, but due to its rapid growth it has a wider distribution. for seed rpoduction, a less humid climate is desirable. Long spells of hot dry periods are not suitable for seed production. Temperatures of 32C or above, can cause the stigma to dry and the pollen may fail to germinate.

For seed production, the radish varieties can broadly be divided into the following three groups:

  • Temperate varieties(e.g. Chinese types) which produce satisfactory seed in the temperate hills by overwintering. These varieties flower very late in the plains. Seed of these varieties is produced only in the hills.
  • those temperate varieties (e.g. White lcicle, Rapid Red, Woods long Frame, Scarlet Globe, French Breakfast) which are very quick in root development in the plains, but behave just like winter varieties for seed produced in the hills. In the hills, the seed for these varieties can be produced both from autumn and spring sowings. The autumn sown crop gives higher seed yields and matures earlier.
  • Tropical varieties (e.g. Pusa Reshmi, Pusa Chetki, Japanese White, etc.) which produce seed freely in the plains. The seed of these varieties is usually produced in the plains. but good quality seed of some of these varieties (e.g. Japanese white) can also be produced in the hills.

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

Radish is corss-pollinated by insects, chiefly honey-bees, seed fields should not be located too close to clover crops, since bees tend to visit clover in preference. Seed fields must be isolated form other vareity fields of radish, and fields of the same variety not conforming to varietal purity requirements of certification, by at lest 1600 metres for foundation seed, and 1000 metres for certified seed production.

Method of Seed Production

Both seed to seed and root to seed methods can be employed for raising seed of radish. Seed to Seed method, for varieties which do not stand transplanting well, is preferred forraising certified seed. The nucleus seed,however, is invariably produced by root to seed method.

Time of Sowing

  • For hills - The autumn sowings preferably may be done in ealry October. Spring sowing can also be done in March, as soon as the land can be prepared. However, the autumn sowings gives higher seed yields.
  • Plains: The sowing is done at normal time, that is, early october.

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

Asiatic Varieties 10kg/ha
Temperate varieties 12kg/ha

Sowing of Seeds

The seed should be sown on ridges.

Fertilisation

Apply 20-25 tonnes of well-rotted farmyard manure at the time of land preparation; At the time of final levelling mix in the soil 35 kg nitrogen, 50 kg phosphorus and 50 kg potash per ha as basal application. another dose of 35 kg nitrogen be top-dressed when the roots just start growing.

Thinning

Thin the crop after 20-25 days to maintain a plant to plant distance of 10-15 cm.

Spacing

Row to row spacing for Asiatic types is 45 cm and for temperate types 30 cm

Irrigation

Irrigate at eight to 10 days interval depending on the weather conditions and requirements. During early warm weather it may be necessary to irrigate at four to five days interval.

Interculture

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

Insect and Disease Control

dopt recommended IPM methods

Harvesting and Threshing

Uproot the plants (stecklings) when they have attained edible maturity (30-70 days, depending upon the vareity)

Selection of roots for transplanting

After harvesting , each steckling is critically examined for foliage and root characteristics namely, size, shape, colour, texture,sponginess etc. Stecklings having off-type foliage or roots not conforming to vareity characteristics must be rejected. Also, the diseased, malformed, forked or any other undesirable types are also rejected.

SECOND SEASON

Preparation of selected roots for transplanting

After selection the tops are cut off in a such a way as to leave the small undeveloped leaves together with about 2 cm of the petioles of older leaves. It is the usual practice to cut 1/3rd of the lower root protion in asiatic types, but the whole roots are set in European varieties. These 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: The stekclings selected and prepared in the manner described earlier are reset in the field at a distance of 60 x 45 cm. The soil is then firmed and tapped around the roots. Soon after transplanting the field is irrigated. The fields are then checked after 10-15 days for mortality and the gaps are filled well in time to have uniform crop stand.

Manuring: Apply 20-25 tonnes of well-rotted farmyard manure at the time of land preparation; At the time of final preparation mix in the soil 40kg nitrogen, 5 kg phosphorus and 100 kg potash per ha as basal application. Topdress 40kg nitrogen per ha at the time of bolting and preflowering stage.

Roguing

The palnts with off-type foliage and the direct bolters are eliminated from the field prior to flowering and the crop is left to set seeds. when the roots are lifted they are critically examined for trueness to type. Besides, small sized or oversized stecklings, diseased, forked and off types should be discarded. Normally three roguings should be done, namely, before mturity of roots for off-type foliage, at the time of replanting for verifying root characteristics, such as size, shape, colour, texture etc. and thelast at flowering stage for early and late bolters and off-types. Also, at all times, check carefully for plants affected by designated diseases (black-leg and black rot) and eliminate them.

Harvesting and Threshing

The crop is cut when plants are fully mature. the drier the pods, the more easily will they break open during thethreshing process. The crop is cut by sickle and brought to threshing floor for threshing. there is more often considerable difficulty in threshing the seed from the pod. Frequently, the pod will not greak and let the seed escape. It is, therefore, important to thoroughly dry them before commencing the threshing. Threshing can be done by beating with sticks. the seed after sifting should be dried to six per cent moisture, before storage.

Seed Yield

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

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.

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 and Threshing

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

Brief Cultural Practices

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.

Carrot

Climatic Requirements

Carrot is widely adapted to cool climates, but generally restricted to regions with low rainfall during summer and early autumn. A dry warm atmosphere is desirable for maturing plants that are gough and woody. Seed production is suited to inland regions, away from coastal areas, where conditions are drier for maturing seed.

Like turnip it also has two races, namely, biennial or temperate, and annual or oriental. both the types porduce seed in temperate parts. The seeds of oriental or annual types can be produced in the Northern Plains.

Land Requirements

Land to be used for seed production shall be free of volunteer plants. The soils of selected fields should be deep, with good drainage and fertility.

Isolation Requirements

Carrot is corss-pollinated by insects, including bees.A good nectar supply easily accessible attracts many insects.The seed fields must be isolated from other vareity fields and fields of the same variety not conforming to varietal purity requirements of certification, by at lest 1000 metres for foundation seed production,and 800 metres for certified seed production.

Method of Seed Production

Like other biennials both seed to seed and root to seed methods can be followed.. Generally, the toot to Seed method is followed because in the seed to seed method root rot is usually very high, as compared to the transplanted roots. The whole roots with the tips cut (to examine the colour) are planted, keeping the crown exposed.

Cultural Practices

ROOT TO SEED METHOD

FIRST SEASON - MOTHER ROOT PRODUCTION)

Time of Sowing

The sowing of seed crop should be done from 15th July to 7th August, depending upon duration of variety and climatic conditions.

Preparation of Land

Carrots need deep, loose soil for their best development. Thorough pulverisation of soil is essential. Prepare the field to a fine tilth by repeated ploughing, harrowings, followed by levelling.

Source of Seed

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

Seed Rate

2.5 to 3.5 kg per hectare. the roots produced on one hectare are sufficient for transplanting 3 to 4 hectares under seed production.

Sowing of Seeds

For better development of roots, sowing on ridges is preferred to flat sowing. Double row ridges 75 cm apart produce larger number ofwell-developed roots than single row ridges . The seed takes eight to 10 days for germination. For uniform germination, the ridges should remain moist till germination takes place. Hence, the field should be irrigated just after sowing. Afterwards, when the plants are 5 to 6 cm high, thin out plants to a distance of 6 to 7 cm.

Fertilisation

Apply 15-20 tonnes of farmyard manure per ha to soil well before sowing, and mix it into the soil thoroughly.Apply 40-50 kg phosphorus and potash per ha at the time of sowing. Top dress once or twice with 75 to 100 kg ammonium sulphate per hectare, after weeding.

Irrigation

Irrigate at eight to 10 days interval as required.

Interculture

Carrot is a slow-growing crop. Therefore, weeding and hoeing should frequently be done, particularly in the early stages. One earthin-up by end of September, orearly October, will keep the crop clean till the close of autumn, when it is uprooted for planting.

Insect and Disease Control

Adopt recommended IPM methods

Harvesting of roots

Uproot the plants when they have fully developed roots.

Selection of roots for transplanting

Thorough selection of roots is made on the basis of character of tops, whether short or heavy, colour of skin, shape and size of roots. The colour of flesh, colour and size of the core are the most important characters to be considered. the core should be of the same colour as the flesh and as small as possible.

SECOND SEASON (SEED PRODUCTION)

Planting of selected roots

After selection their tops are clipped and the tips pruned aand then reset in a well-prepared field.

Brief Cultural Practices

Preparation of land: Carrots need deep, loose soil for their best development. Thorough pulverisation of soil is essential. Prepare the field to a fine tilth by repeated ploughing, harrowings, followed by levelling. Method of transplanting: The selected roots prepared in the manner already described r are reset in the field at a distance of 75 x 22.5-30 cms. The soil is then firmed and tapped around the roots. Soon after transplanting the field is irrigated.

Manuring: Apply 20 tonnes of well-rotted farmyard manure well before sowing, and mix it in the soil thoroughly.At the time of final preparation mix in the soil 250-300 kg Super Phosphate and 100-150 kg muriate of postash per ha Make surface application of 25-300 kg ammonium sulphate per ha during April to May after hoeing and earthing.

Interculture: One weeding during March and another hoeing and earthin-up during April-May is required.

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

Roguing

Roguing should be done at bloom stage. Early bolters and off-types should be removed from time to time as required.

Harvesting and Threshing

The best time for harvesing is when the secondary umbels (heads) are fully ripe and tertiary heads are beginning to turn brown. the crop ripens unevenly, Seed is commonly harvested by handpicking. Two to three pickings may; often be necessary. Afterdrying, the heads are threshed and cleaned. After cleaning, tghe seed is rubbed by hand to remove the bristles on the surface and graded by means of sitters and sieves. Before storage, the seed moisture content should be reduced toeight per cent.

Seed Yield

The average seed yield is about 500 to 600 kg per hectare.

Onion

Climatic Requirements

Onion is the biennial crop and takes two full seasons to produce seeds. In the first year bulbs are formed and in the second year stalks develop and seed is produced. It is a long-day plant. The day length influences bulb onion, but has little effect on induction of seeding. It appears to be day-neutral for seed production. It requires cool conditions during early development of the bulb crop and again prior to and during early growth of seed stalk. Varieties bolt readily between 10 to15 degree C. In the early stages of growth, a good supply of moisture is required and temperatures should be fairly cool. During bulbing, harvesting and curing of seed, fairly high temperatures and low humidity is desirable. Seed production is widely adapted to temperate and sub-tropical regions.

Land Requirements

Land to be used for seed production shall be free of volunteer plants. The soil of the selected field should be rich in organic matter and have a good water-holding capacity.

Isolation Requirements

Onion is largely cross-pollinated crop with up to 93 per cent natural crossing but some self-pollination does occur. It is chiefly pollinated by honey-bees. For pure seed prodution, the seed fields must be isolated from fields of other varieties of onion and fields of the same variety not conforming to varietal purtiy requirements for certification atleast by 1000 metres for foundation seed production and 500 metres for certified seed production.

Method of Seed Production

There are two methods of seed production 1. Seed to seed method. In this method, the first season bulb crop is left to over-winter in the field so as to produce seed in the following season.

2.Bulb to seed method. The bulbs produced inthe previous season are lifted, selected, stored and replanted to produce seed in the second year.

Mostly the bulb to seed method is used for seed production because of the following advantages over the seed to seed method.

  • It permits selections of "true-to-type" and healthy bulbs for seed production.
  • Seed yields are comparatively very high. The seed to seed method, however, can be practised for varieties having a poor keeping quality.

Bulbs To Seed Method

Production and storage of bulbs (first year)

  • Sowing time (nursery). Middle of October to middle of November in the plains and April to June in the hills. 1/20 hectare nursery is sufficient for raising seedlings for one hectare.
  • Seed rate. Eight to ten kilogrammes per hectare.
  • Fertilisation. Add 20 tonnes of well-rotted farmyard manure at the time of land preparation and 250 kg superphosphate (single) and 45 kg potassium sulphate at the time of planting. 250 to 375 kg. of ammonium sulphate or CAN may be applied as top-dressing in two to three doses during the growing period.
  • Transplanting. Eight to ten weeks old seedlings are planted in small beds in well-prepared fields. January is the best period.
  • Spacing. Spacing depends upon variety and bulb size and varies from 10 to 15 cm.
  • Irrigation. Fortnightly irrigation during winter weekly irrigation during hot weather. Irrigate sparingly during maturity.
  • Interculture. Keep field free from weeds. Frequent interculture is essential for good bulb development. For controlling weeds, post-emergence application of tenoran at 2 kg per hectare in 800 litres of water, two to three weeks after transplanting, is recommended. Oxadiazon one kg active ingredient per hectare has also given effective control of weeds.
  • Insect and disease control
    Insect Control measures
    Onion thrips Dust with 5% BHC dust at 25 to 30 kg per hectare, or spray malathion 50 EC at 600 to 700 ml per hectareor thiodan 35 EC at 600 to 700 ml per hectare. Three to four applications may be required. Onion maggot Spray sevimol Diseases Damping-off Use treated seed. In cases of seedlings mnortality, drench nursery with 0.3 per cent captan, or thiram,or dithane Z-78 at weekly intervals. Purple blotch Spray with copper fungicides such as blitox 50 at 0.2 per cent.
  • Harvesting and curing of bulbs. Well-matured bulbs should beharvested. Maturity is indicated bythe tops drooping just above the bulb,while the leaves are still green. After harvesting, the bulbs should be topped leavingan half inch neck. Before storage, a thorough selection and curing of bulbs should be done. The length of time required forcuring depends largely on weather conditions and may take three to four weeks. Storage. The essentials of successful storage are:
    a)The bulbs should be well-matured, dried and cured before storage.
    b)Storage should be well-ventilated.
    c)Storage should be done inshallow trays with perforated bototoms.
    d) Storage temperatures should range 0 to 4.5 degree C until three to four weeks prior to planting, when the temperature should be increased to around 10 degree C.
    Planting of bulbs and seed production (second year)

Time of planting bulbs

The best time for planting Bulbs is the second fortnight of October.

Preparation of land

Prepare the field to good tilth. One deep ploughing, followed by three to four harrowings and land levelling are enough.

Seed rate

The seed yield is affected bythe size ofthe bulb. The bigger the bulb size, the higher is the seed yield. However, verylarge sizedbulbs, if used, will needa very high seed rate. If bulb size of2.5 to3 cm diameter, is used for planting, approximately 15 quintals of bulbs per hectare are required if the bulb diameter is 3 to 4 cm.

Fertilisation

Same as described for first year.

Method planting and spacing

Selected bulbs are planted 8 to 10 cm deep in the soil ata distance of 45 x30 cm. The size of beds depends upon the source of irrigation. The sprouted bulbs are planted as such. In unsprouted bulbs, the upper half portion should be removed, leaving the disc-like stem and roots intact. The removal of the upper tops hastens sprouting.

Interculture

Insect and disease control. Same as described for first year.

Roguing of Seed Crop

First year. It is desirable to begin roguing in the fielf before bulbs are harvested, since itisthen possible to detect any plnats having a different foliage colour, or plant type, or late maturing bulbs.

After harvesting, the bulbs should be carefullyrogued forcolour and such off-types as thick-necks, doubles, bottlenecks, as well as any other types which do not conform to varietal type.

Second year, plant only selected true-to type bulbs and remove plants not conforming to varietal characters before flowering.

Harvesting and Threshing

Seed is ready for harvest when first formed seed in the heads get blackened. Two to threepickmingsmaybenecessaryto harvest the heads, at just the right stage. Seed heads are cut, or snapped off,keeping asmall portion of the stalk atached. Seed heads. aftet harvest,. should be thoroughly dried. Air circulation is important while drying seed heads. Hence, the trays or canvases should be filled only to a depth of 15 cm.

Heads can be threshed when seed separates easily from them. Much of the seed falls from capsules during drying. The remainig seed is removed by flailing. The seeds can then be cleaned by immersing them in clean water for five to ten minutes and then drying in the sun or artifically. Before storage, the seed must be dried to six to eight per cent moisture.

Seed Yield

The average seed yield varies from 850 to 1000 kg per hectare

Potato

Seed Production Technology

There are now two independent channels of seed production for hills and plains.

Hill Seed:
The seed produced in hills (2500 metres above sea level) at suitable locations iscalled'Hill Seed'.

Plain seed:
The seed produced in plains at suitable locations is called ;plain seed'. Northern plains have emerged as an important source of potato seed production. The low aphid plains seed is in right physiological condition at the planting time and yields higher than the traditional hill-grown seed. The period of low aphid incidence is given below.
Plains zone Low aphid incidence period
North western plains Oct. to end of Dec.
North central plains Oct. to 10th Jan.
North eastern plains Oct. to 20th Jan.

One healthy seed potatoes are introduced into the system of grwoing them during low aphid period accompanied by a systematic insecticide application, roguing and removal of haulms before the aphids attain critical number and the regrwoth is checked, the health standards for the seed cropcould be maintained for a number of generations. This system of seed potato production has been designated as ;Seed Plot Technique'.

Seed Production in Eastern Plains, Deccan Plateau and Southern latitudes. In these areas the effective low-aphid period is practically absetn. In such situations, reasonably healthy seed consistent with economic yeidl could be produced by using systemic insecticides to reduce the build up of insect vectors and to prolong the growing season of the crop. It should thus be not obligatory to replace seed annually in large quantities from the northern states. Seed could be imported in smaller quantities every eyar and multiplied for one to two clonal generations.

Seed Production in the Nilgiris:
In the Nilgiris, aphid population is lower during summer crop only from those areas which are free from cyst-forming nematodes. The treatment of the seed potatoes with sprout suppressants like CIPC and Fusares, at the rate of 0.5kg per quintal can maintain the seed sotcks in good physiological condition in farm stores in the absence of cold storage facilities. thus the seed stocks from the summer crop can be stored without deteriorationuntil the next planting season that is, September to March-April.

Stages of Seed production: For seed multiplication and certification purposes following stages arerecognised.

  • Foundation I : Progeny of the breeders seed
  • Foundation II: Progeny of the foundation I
  • Certified I : Progeny of the foundation II
  • Certified:II* Progeny of the certified I

(* This is done in case ofthose vareities which have a low rate of multiplication and in years of shortage of seeds)

Land Requirements

A crop of seed potato shall not be eligible for certification if grown on land infested with wart and/or cyst forming nematodes; or brown rot or noncyst forming nematodws within the previous three years; and common scab. Preference should be given to two to three year crop rotation. the soil of selected field should be well-drained, well-aerated, deep and having a pH range of 5.2 to 6.4

Isolation Requirements

A minimum isolation distance of 5 metres for foundation and certified seed class should ber provided all around a seed field to separate it from fields of ther vareities,and fields of the same vareity not conforming to varietal purity and health requirements for certification

Time of Sowing

The sowing should be done from 20th September (when rainfall is low), or 25th September, upto 15th october .Delayed plantings well result in poor yields.

Preparation of Land

Prepare the field to a fine tilth by deep ploughing, 3 to 4 harrowings, followed by levelling.

Source of Seed

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

Seed Rate

seed rate depends upon tuber size. 25 to 30qtl of seed potato per hectare will be sufficient if the usual sized tuber (4 to 6 cm) are used.

Seed Rate

seed rate depends upon tuber size. 25 to 30qtl of seed potato per hectare will be sufficient if the usual sized tuber (4 to 6 cm) are used.

Sowing of Seeds

Whole tubers should be used for planting. Tubers should be under sprouting (sprouts 0.5 to 1cm long) for quick emergence. After 15th October when the temperature goes down, cut tubers can also be sued for planting, as per prevailing local practices. Care must be taken that each piece to be used for planting has two or three emerging eyes and weighs at least 40 gm. by this practice the seed rate isreduced considerably. Plant the tubers 3 to 4 cm deep in the soil having adequate moisture. At planting, tubers should not come into direct contact with fertilisers which should be placed right below the seed potato.

Fertilisation

For a good seed crop, the medium type of soils need 100 to 125 kg nitrogen, 80 to 100 kg phosphorus and 80 to 100 kg potash per hectare. Variations may be made according to the soil tests. Besides the fertilisers, farmyard manure may be added at the rate of 25 tonnes per ha, if soil is poor in organic matter. A leguminous crop before potatoes may also partially replace organic matter requirement. Apply all phosphorus, potash and half of the nitrogen at the time of sowing. Theremaining half of nitrogen should be applied about 35 days after sowing, or when the plants are about 25 to 30 cm high. For best results,the fertilisers should be placed either 5 cm below the tubers, or on the side.

Irrigation

Potato requires light and frequent irrigation. First irrigationshould follow imemdiately after emergence. Subsequent irrigations should be given at proper intervals. the top of the ridges should not be submerged. Restrict the irrigation after the crop has tuberised well. Withhold irrigation by thethird week of December i.e., ten tofifteen days before cutting of haulms.

Interculture

Keep the field free from weed.s At least one earthin-up is a must. It should be done when plants attain the height of 15 cm. Exposed tubers should be covered with soil during subsequent earthin-up.

Insect and Disease Control

Adopt recommended IPM methods

Spacing

Row to row spacing at 60 cm and tuber to tuber spacing at 15 to 20 cm is recommended.

Haulm cutting

The practice of haulm cutting is adopted as a precautionary measure to avoid chances of viral diseases transmission through the vectors like aphids. The haulms must be cut bythe end of December, or at the latest by the first week of January before the aphid population reaches the critical stage (20 aphids per hundred compound leaves). No regrowth should be allowed.

Roguing

Very careful roguing is required for producing a high quality crop of seed potato. the roguing is to be done at the following stages.

First roguing: First roguing should be done 25 days after sowing to remove.

All virus affected plants, and (b) All plants apparently belonging to other varieties and which can be identified from foliage.

Second roguing: It should be done when the crop is fully grown. This would be about fifty to sixty days after sowing. At this time tubers are formed and, therefore, while roguing, not only the upper portion of plant, but all the tubers belonging to the plant should be removedcarefully. Also at thisstage the virus-affected plant as well as off-type, if any, should be removed.

Third roguing: This isthethird and final roguing and should be done just before cutting the foliage. Foliage should not be cut unless this rouging has been completed. At thisstage, all virus-affected lants and off-type plants, if any, along with their tubers have to be very carefully removed, so that no such plants are left in the fields.

Harvesting

  • Time of Harvest: The crop is ready for harvest 10 to 15 days after haulm cutting when the skin of tuber has hardened. Premature harvesting causes handling problems,as the soft skin gets easily peeled off and, further, such tubers cannot withstand longtransportation and storage.
  • Soil conditions at the time harvest: At the time of potato digging, the moisture in soil should be optimum for obtaining clean tubers.
  • Method of harvest and curing: The harvesting of seed potatoes can be done by any of the equipment available in the market for this purpose. Every effort should be made to avoid cuts, bruises, etc. After harvesting, tubers should not be left exposed to the hotsun for a prolonged period (not more than an hour). It should be immediately lifted and carried to an airy shed and kept in piles (height one metre, width threemetres) for seven to ten days so that the superficial moistureevaporates and furtherhardening of skin is achieved. If sheds are notavailable, piles may be made in fiedl and covered with dry haulms.

Sorting and Grading

When the potatoes are properly cured, grading should be done.

After sorting and grading the seed potatoes should be put inclean hessian bags (50 kg size) and the bags appropriately labelled.