Pregermination promotes even crop emergence, better Gibberellic Acid (GA) absorption, and shortens the growing cycle. This process is vital if tubers have a short dormancy (10-12 weeks after lift), and when growing in cooler conditions.
Prior to planting and application of GA, remove tubers from storage and pregerminate at 22-25°C and 85% RH for 7-10 days to trigger emergence of growing shoots.
Stable temperature and humidity throughout this process are critical. Ensure some airflow (use a fan) in the pregermination room. 24 hour lighting appears to help the process.
Smaller 1.5 and 2cm ( T1) tubers have much less ability to withstand temperature and humidity fluctuation - these are normally NOT pregerminated.
Once the growing shoots have emerged a minimum of 5-10mm, apply GA prior to planting.