The process of removal of dockage in a seed lot and preparation of seed for marketing is called seed processing. The price and quality of seed is inversely related to dockage, which should not exceed a maximum level permitted for different crops for seed certification.
Due to the operation of processing the level of heterogeneity of seed lot gets narrowed down.
The heterogeneity occurs in a seed lot due to following reasons:
Variability in soil for fertility, physical, chemical and biological properties
- Variability in management practices (irrigation, application of nutrients etc.)
- Variability in ability of the seedling for utilizing the inputs
- Variability in pest and disease infestation
- Position of pod or fruit in a plant or the position of seed in a pod.
Principle of seed processing: the processing operation carried out based on the principle of physical differences found in a seed lot.
| Suitable machineries
|Seed size – varied from small to bold
||Air screen cleaner cum grader
|Density- ill filled, immature to well Matured light weight to dense seed
||Specific gravity separator
|Shape – round to oval and different shapes
|Surface texture – smooth to wrinkled and rough
||Roll mill / dodder mill
|Colour of the seed – light color to dark colors
||Electronic color shorter
|Conductivity of seed – low to high
Requirement in seed processing
- There should be complete separation
- There should be minimum seed loss
- Upgrading should be possible for any particular quality
- There should be have more efficiency
- It should have only minimum requirement
Types of materials removed during seed processing
- Inert materials
- Common weed seeds
- Noxious weed seeds
- Deteriorated seeds
- Damaged seeds
- Other crop seeds
- Other variety seeds
- Off-size seeds
Sequence of operation in seed processing
Sequence of operations are based on characteristics of seed such as shape, size, weight, length, surface structure, colour and moisture content. Because each crop seed possesses individually seed structure. Therefore, sequence of operation will be applied proper equipments. However, It is also involved stages following as
Separating or Upgrading
Storage or Shipping
The flow charts illustrating the types of materials removed from harvested produce during processing.
Receiving The field run produce after threshing is received in the processing plant.
Seed movement /basic steps in seed processing plant