Seedling Selection

The objective is to get even plants so seedling selection is very important. Having a set procedure for this can help.
 

Time of selection

• If the cotyledons are large enough, the plants are ready to be sorted.
• Rootstocks after 5 to 8 days.
• Variety after 8 to 11 days.
• Always start the selections with the smallest seedlings first, this will give the best results.
   

Grading size

The standard is to sort into 3 sizes. Current varieties have a high and uniform germination percentage which should give:

• 40% on the first selection
• 40% on the second selection
• 10% - 15% on the third selection
• 5% not usable
• Grading can be done by hand but using a machine gives a more consistent result

Plug water content

The plugs need to be fully saturated during the grading process if using a machine to make sure that they are heavy enough to stay in the cups. If grading by hand this also helps to maintain the water content during handling.
 

Plug spacing after grading

Space the plugs after grading at half the original density in the tray (120 per tray in a 240 tray) to give the seedlings more space.
 

Climate after grading

After grading, the plants should go back into the same climate until grafting.

Watering and nutrition

Always check the water content before 10.00 am and regularly during the day.

• EC 2.0
• pH 5.3 - 5.4.
   

During this period it is important that the plugs have a high oxygen level for optimal healthy root growth.