Propagation Performance Measurement, Donor Comparison and Batch Evidence
Technician II propagation troubleshooting begins with comparable performance evidence. Rooting success, losses and time-to-root should be tied to donor identity, batch, operator, media, environment, sanitation events and observation timing. Percentages without denominators or genealogy can hide where the problem actually occurred.
Learning objectives
- LO-LH-TECH2-005-01
- LO-LH-TECH2-005-06
Key vocabulary
The number of units meeting the defined successful outcome divided by the eligible starting units for the same defined batch and time point.
How failed or removed units are distributed across donors, trays, operators, locations, dates or other traceable groups.
A testable explanation that source-plant condition may contribute to propagation performance; it is not proof of genetic causation.
Keep denominators and time points consistent
A 90% rooting result at day 14 cannot be fairly compared with an 80% result at day 7 without accounting for the observation window and starting denominator. Preserve removed or excluded units and the reason for exclusion.
Stratify before averaging
Facility-wide averages can hide a weak donor, tray position, operator, media lot or environment zone. Compare traceable groups before deciding the problem is systemic.
Preserve the original production record
If an entry is later found incorrect, correct it through the controlled process while preserving the original value, reason and attribution. Do not rewrite the batch history to make the analysis cleaner.
Worked examples
- Two donors average 88% rooting together, but one is 98% and the other is 62%; the combined average hides the actionable pattern.
- A tray shows lower success than neighboring trays, but it was scored three days earlier; align the time point before assigning a process cause.
Common mistakes
- Comparing percentages with different denominators.
- Averaging donors until a localized pattern disappears.
- Removing failed units from the denominator without a controlled reason.
- Editing source records after seeing the outcome.
Practical application
Build a propagation performance table by donor/batch with starting count, rooted count, loss count, observation day, operator, media, environment notes and sanitation events, then annotate which comparisons are valid.
Lesson summary
Propagation performance review depends on comparable denominators, traceable groups and preserved source records.