TRANSPLANTING LETTUCE SEEDLINGS

INSTRUCTIONAL SHEET FOR STUDENTS

PROPAGATION BY AIR-LAYERINGOBJECTIVESStudents should be able to: Demonstrated the steps involved in Air-layering propagation.

Explain the reason for using rooting hormone and scraping of cambium

layer on stem.NOTESPROPAGATION BY AIR LAYERINGAir layering or marcotting is a form of asexual plant propagation. This is a form of propagation that involves the use of plant parts, other than seeds to produce new plants. The process of Air-layering involves a system whereby new plants are formed on a stem while still being attached to the parent plant.

SAFETY WARNING1. Care should be taken when using the budding knife so as not to cause injury to oneself or others.

2. Gloves should be worn at all times to insure that rooting hormone does not come into contact with skin.

MATERIALS AND EQUIPMENT NEEDED:1. Plants to layer

2. Rooting hormone

3. Secateurs

4. Sharp sterilized budding knife

5. Damp cocoa moss

6. Clear plastic wrap

7. String

8. Brush

9. Latex gloves.STEP INVOLVED IN THE PROCESS OF AIR-LAYERING

1. Select a branch from a healthy plant. Stems of pencil size thickness or larger are best and remove any leaves that are present.

2. The chosen stem is girdled i.e. using a sharp budding knife two circular cuts are made on the stem at 3c.m. apart.

3. A third cut is then made to join both circular cuts and the bark of the stem is removed. (See Figure A)

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Figure A: Diagram showing the three procedures made to remove the bark at the layering site on the plant

4. The cambium layer is gently scraped at the exposed region.The cambium is gently scraped to prevent re-generation of phloem tissues as the plant will try to heal the wound created for root development

5. The exposed layer is covered with rooting hormone using a paint brush. Rooting hormone stimulates rooting at the layering site

6. Moistened cocoa moss is applied around the exposed area.

7. The plastic polythene is then wrapped around the cocoa moss and tied at both ends with string.

8. Leave to set for 3-4 weeks to allow for callus and root formation

9. Sever the layered plant from parent with secateurs, remove plastic and transplant new plant.

POST OPERATION

Remember to clean working area, wash tools, return them to the storage area and thoroughly wash hands.