Triploid (seedless) watermelon seed sowing recommendations
Eyal Vardi, Ph.D
Background. The most common reasons leading to poor germination in triploid watermelon seeds are excess of water in the sowing media and low temperatures.
In Triploid watermelon seeds, the seed coat is thicker and has larger air space compare to diploid watermelon. Under excess of water, the uptake of oxygen into the embryo might be restricted and as a result the germination decrease. Therefore, triploid watermelon seeds are very sensitive to increased moisture conditions.
Recommended steps for sowing of triploid watermelon seeds:
- Drain well the soil mix- a thumb rule is to squeeze the soil mix without any water coming out.
- Warm the soil mix to temperature of 85oF (30oC). Can be achieved by adding warm water or warming the trays in advanced.
- After sowing do not re-wet the seeds till emerging.
- Keep the trays in germination room prior to emerging. The warm temperature and low moisture should be kept.
- During growth in the nursery the seedling should be exposed to temperature above 77oF (25oC).