Goal: To consistently fill propagation trays evenly, while avoiding excess settling or compaction.
Tray filling practices affect how much solid, air, and water are in each cell. Excess settling reduces the cell volume available for root growth. Excess compaction reduces air porosity which can limit root growth. Uneven filling across the tray results in uneven drying and plant size.
Step 1. Requirements
You will need: A ruler, plug or liner tray, and propagation substrate
Step 2. Fill propagation trays
Each time the substrate type and tray size is changed, fill 3 trays with the adjusted flat filling equipment. The dibble may be used, but do not sow seeds or cuttings, and do not cover with vermiculite.
Step 3. Irrigate to container capacity
Bring the substrate to container capacity by passing through a water tunnel for 3 to 4 times, through a subirrigation conveyor, or by using a fine mist nozzle with hand irrigation.
Step 4. Measure settling
After the tray drains for 30 seconds, drop the irrigated tray onto a table from an 8-in (20-cm) height twice. Measure the settling (loss in surface height). This can be done with a ruler by measuring from the plastic tray ridge down to the substrate surface, or quickly estimated by eye.
For more information: Contact authors Jinsheng Huang and Paul Fisher of University of Florida IFAS Extension. Thanks to our Floriculture Research Alliance at University of Florida sponsors including A.M.A. Plastics, Blackmore Co., Everris, Fafard et Frères Ltd (Canada), Fine Americas, Greencare Fertilizers, Pindstrup, Premier Tech Horticulture, Quality Analytical Laboratories, Sun Gro Horticulture, and leading young plant growers. August 23 2014.