Propagation Instructions
Not all the valuable aspects are depending on the plugs' characteristics and maintenance. Plant material and treatment have, of course, a heavy impact as well.
What concerns starting from seeds, at this point the cannabis industry does not have high-quality, uniform, and stable F1 hybrid varieties of cannabis that allow growers to simply start all plants from seed. That is why most companies use seeds to create mother plants from which they will be taking cuttings for vegetative propagation. The process of creating mother plants takes time and normally a few generations as the growers do phenotype hunting. That means, growers are looking for the preferable characteristics and breed these for their cannabis production.
On average, the vegetative propagation lasts around 2 weeks (between 10 to 14 days). The condition of the mother plants has a great effect on the cuttings made from them. That is why the maintenance of the mothers is crucial for the success, quality of the cuttings, and the number of clones that can be made of them. It is preferably taking cuttings daily or once in 2 days, maintaining equal conditions; identical in length, stem diameter, leaf nodes and node spacing, leaf structure and surface area, and age of the cutting. Have a mother plant system in place and renew mother plans every 3 to 4 months for optimal propagation results.
When clones are placed into the Starter Plugs, the irrigation should be limited as it will enhance root development which is the primary goal of propagation. Give irrigation based on weight of the starter plugs, let the plugs dry out to approximately a WC of 50% before irrigating the plugs again. Too wet conditions will slow root initiation and increases disease pressure. The irrigation EC should be minimum 1.5 mS/cm but depending on variety and light intensity it can be increased to 2.5 mS/cm. Especially last days of propagation when roots are developed and higher light intensities are applied the plants need more feed so adjust accordingly.
Other important climatic condition is light, and although it can differ depending on the variety, the average recommended light period for the cuttings at propagation is 18 to 20 hours, starting with 80 micromoles and gradually increasing when first roots are present to 150 to 200 micromoles. Initially the humidity levels should be very high (>95%) to minimize water loss through leaves. Use for example humidity domes to create moist and warm climate. Large scale growers use climate rooms or humidity tents. This will allow for better air movement and more stable climate. After some days you gradually decrease humidity to about 70% at the end of propagation.