Best Viewed in Mozilla Firefox, Google Chrome
Package of Practices
  • A compendium of state specific and location specific recommended package of practices are provided under this head. You may be interested to see that, thanks to our IP based customisation, that only your state (the state from where you are accessing RKMP) specific information is available.
  • You are on travel? Please select the state to which you belong. You have access to your state specific content as well.
  • Look for the related information heads on right side box. Click on any of them to get the access to the appropriate information.


Seed Grading

1. The main purpose of grading is to separate the seeds according to size and weight for establishing its commercial value.

2. A uniform size and weight of seed is desirable in commercial seed processing.

3. A variety of equipments used for this purpose include; gravity separator, air screen cleaner cum grader, length grader, indented cylinder grader etc.


Seed and Grain Cleaning

Seed cleaning:

The main purposes of seed cleaning are to remove the greatest possible amount of impurities, which may be either the seeds of other plant species, broken seeds or inert matter including dirt and insectdebris.

Grain cleaning:

1. Rice crop after threshing contains 8-10% non-grain type contaminants like straw, chaff, dust, impure grains, sand and soil clods.

2. These contaminants need to be removed through cleaning process to obtain pure grain.

3. Properly cleaned grains add value to the produce, help it for longer and safer storage and smooth milling operation.


Screening or Sifting


In the Screening or Sifting process, the small size heavier contaminants like sand and soil particles, weed seeds etc are removed by sieving the grain through a smaller size screen (1.4 mm or less sieve opening)




 Winnowing is the process of removing lighter contaminants like straw, chaff, dust etc either by dropping the materials from a height against natural wind then fanning manually or by using a mechanical blower.

Guidelines for good winnowing methods:

 1. A polyethylene sheet is spread on the ground.

2. The uncleaned grain is placed in the winnowing tray.

3. It is dropped from a height of about 1.5m against the natural wind to separate the light undesirable materials.

4. Fanning manually with the winnowing tray does further cleaning.

5. Hand/ power operated fan/blower may be used if natural wind is not enough and to reduce human drudgery.

6. The heavy undesirable contaminants still remain with the grain which can be removed with a grader

Copy rights | Disclaimer | RKMP Policies