SEED PRODUCTION

SEED PRODUCTION

Method of Seed Production
  • Like other biennial crops root to seed and seed to seed method can be followed.
  • In the seed to seed method, root rot is usually very high as compared to the replanted method.
  • The whole roots with the tips cut (to examine the colour) are planted, keeping the crown exposed.
Root to seed method
First Season:
  • Mother roots production
Time of Sowing
  • Sowing of seed crop should be done from 15th June to 15th July depending upon duration of variety, climatic condition and areas where seed production is to be done. Generally, severe winters and mild summers with less rainfall is considered best for quality seed production.
Preparation of Field
  • Prepare the field to a fine tilth by repeated ploughings and harrowing followed by levelling.
  • In addition to root crop, apply 150-200q/ha of well rotten FYM at the time of preparation of land.
  • At the time of final leveling, also mix entire quantity i.e. 40-50kg/ha each of P and K and nitrogen @75-100kg/ha is top dressed after weeding.
Irrigation
  • It should be done at 8-10 days interval depending on the weather and crop requirement. critical stages are umble formation and seed setting.
Selection of roots for transplanting
  • Uproot the plants when they have fully developed roots for making stecklings
  • Selection of root is made on the basis of varietal characteristics, size of tops whether short or heavy, colour of skin, shape and size of roots etc.
  • The colour of flesh, colour and size of core are most important root characters to be considered.
  • The core should be of the same colour as the flesh and as small as possible.
Planting of selected roots
  • In case of European cultivars, after meeting the low temperature requirement, the selected roots after their tops are clipped and the tips pruned (stecklings) are reset in a well prepared field.
Method of replanting
  • The trimmed roots are reset in field at a distance of 45× 30 cm or 45× 45 cm
  • The soil is then firmed, pressed and topped around the roots.
  • Soon after transplanting, the field is irrigated.
Flowering and Seed Setting
  • Carrot plant bear compound umbels.
  • It is king umbel (primary umbel) or umbel of the first order that flower first.
  • Secondary, tertiary and other orders of umbels flower at an interval of 8-12days from each-other.
  • The temperate cultivars start bolting by third week of April in hills of India.
  • Flowering starts by end of May.
  • Bolting and flowering in tropical types occurs during early spring.
  • The seed setting in late formed umbel is extremely poor.
Pollination
  • Insects are the pollinating agents in carrot. Hence bees and house flies seem to be the most important pollinators.
  • The carrot flower is protandrous hence it ensures cross pollination.
Isolation
  • Seed field must be isolated from fields of other varieties and fields of same varieties not conforming to varietal purity. The most important requirement for certification is to maintain at least 1000m distance for foundation seed production and 800m for certified seed production.
Roguing
  • Rouging should be done at three stages.
    • Early: check for off type foliage
    • Lifting and replanting: check for root characteristics like shape, size, colour, texture, sponginess, forked and cracked roots.
    • Flowering stage: check for isolation, diseased plants and weeds.
Harvesting and Threshing
  • The best time of harvest is when the secondary umbels (heads) are fully ripe and tertiary heads begin to turn brown.
  • Seed is commonly harvested by hand picking. 2-3pickings are required.
  • After drying heads are threshed and cleaned.
  • After cleaning, the seed is rubbed by hand to remove the bristles on the surface and graded by means of sieves.
  • Before storage the seed moisture content should be reduced to 8per cent.
Seed Yield and 1000 Seed Weight
  • At present, expected yield of open pollinated cultivars in the temperate region is about 500-600kg/ha.
  • The 1000 grain weight is 0.8gm.
SEED CERTIFICATION STANDARDS
A. Field Inspection

Mother root production stage
  • A minimum of 2 inspections should be made as follows:-
  • The field should be inspected after 20-30 days of the sowing in order to determine isolation, volunteer plants, out crosses, off-types and other relevant factors.
  • The 2nd inspection should be done after the mother roots have been lifted to verify the true characteristics of roots.
  • A minimum of 4 inspections should be made as follows:
  • The first inspection should be done before flowering in order to determine isolation, volunteer plants, out crosses and other relevant factors.
  • The second and third inspection should be done during flowering to check isolation, off types and other relevant factors.
  • The fourth inspection should be done at maturity to verify the nature of umbels.
1. Field Standards
a. General Requirements
Isolation:
Carrot seed field should be isolated from contaminants as shown in table:
Contaminants
Minimum Distances (m)
Mother root production
Seed production stage

Foundation Certified Foundation Certified
Fields of other variety 5
 5
 1000
 800
Fields of same variety. not conforming to varietal purity requirement for certification 5
 5
 1000
 800

b. Specific requirements
Factors Max. Permitted (%)

Foundation Certified
*Roots not conforming to varietal characteristics including forked roots 0.1
 0.2
**Off types (Plants)
0.10
 0.20
      • *Maximum permitted at second inspection at mother root production stage.
      • **Maximum permitted at after flowering and at seed production stage.
C. Seed Standards
Factors
Standard for each class
Foundation Certified
Pure Seed (Minimum ) %
95
 95
Inert Matter (Maximum ) %
5
 5
Other crop (Maximum ) Number/ kg
5
 10
Total weed seed (Maximum ) Number/ kg 5
 10
Other distinguishable var. (Maximum ) Number/ kg 5
 10
Germination (Minimum) %
60
 60
Moisture (Maximum) % 8
 8
For vapour proof containers (Maximum ) % 7
 7
     
Last modified: Wednesday, 20 June 2012, 3:56 AM