Raising seedlings/Practice of seed selection

 

Raising seedlings

○ Wet-bed

○ Dry-bed

○ Dapog

○ Protected semi-irrigated-bed

○ Semi-adult seedling for machine transplanting

○ Infant seedling for machine transplanting

 

Practice of seed selection

Rice seed selection practices are sieve, wind, specific gravity selection. The practice in combination of wind selection and specific gravity selection is most effective and used widely.

1. Sieve selection : It is a tool for separating larger solids from smaller solids. It is made of a wire or plastic net attached to a ring. Small pieces pass through the net but the larger one pieces do not.

2.Wind selection : This is the selection made by means of wind which is produced by the use of implements or by natural wind.

3. Specific gravity selection : Seeds are immersed in the solution of a certain specific gravity and stirred well. The seeds of greater specific gravity go down to the bottom, while the seeds of smaller specific gravity float up to the surface. The seeds floated on the surface are removed and the remainder seeds are chosen. This is called the specific gravity selection. In order to obtain the solution used for the specific gravity selection, salt(sodium chloride) or ammonium sulfate is dissolved into fresh water.

① For awnless and non-glutinous of japonica rice ( specific gravity of 1.13 ), 4.8kg salt is dissolved into 18 liters fresh water. ② For awned and non-glutinous of japonica rice ( specific gravity of 1.10 ), 3.8kg salt is dissolved into 18 liters fresh water. ③ For glutinous of japonica rice ( specific gravity of 1.08 ), 3.0kg salt is dissolved into 18 liters fresh water. ④ For indica rice ( specific gravity of 1.06 ), 1.8kg salt is dissolved into 18 liters fresh water. In case of Ammonium sulfate, around 3kg of Ammonium sulfate can be used for specific gravity of 1.06.

 

 

    

Rasing seedlings.hwp

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