Many varieties have a dormancy period where germination levels are low. Several treatments can be used to break dormancy and improve seed growth.
Expose seeds to high temperatures (40−42°C) for 1−2 days prior to sowing.
Seed priming - Soak seeds for 4−8 hrs and re-dry prior to sowing. Seeds must be sown within 1−2 days after priming.
Pre-germination - Submerge seeds in water for 12−24 hrs or until small shoots appear at the end of the seed. In colder weather, seeds may need to be soaked for 36−48 hrs. Drain and dry the seed in bag for 24 hrs in a shady area where air can circulate around the bags. If bag temperatures exceed 42°C, some seeds will be damaged. Broadcast or drum seed before the roots exceed 5mm in length. When calculating the planting rate, allow for expansion of 10-30% in seed weight.