High Temperature and Low Moisture Reduce the Storage Requirement of Freshly Harvested True Potato Seeds

Abstract

Freshly harvested, true potato (Solarium tuberosum L.) seeds (TPS) will germinate at 15 ± 5C, but because of dormancy they must be stored for ≈18 months before they will germinate at >25C. Effects of seed moisture content (SMC) and temperature in storage on germination and seedling emergence were periodically tested during 18 months for seeds harvested from three positions on the mother plant. Seeds were stored with 37.,5%, and 7% SMC (on a dry weight basis) at 5 and 45C; sublets were removed monthly (1 to 7 months) from 45C and stored at 5C. Seed dormancy and viability were best preserved in storage at low SMC and low temperature, Seeds stored at 45C and 3 % SMC progressively lost dormancy and, after 4 months of storage, germination was up to 88% after 4 days at 127C. This rate of germination decreased with further storage. Up to 100% emergence occurred in 9 days in seeds stored for 18 months at 45C and 3% SMC. Seeds stored at 45C and 5% SMC lost dormancy in 2 months and <50% emergence occurred after 18 months. Seeds stored at 45C and 7% SMC deteriorated and became nonviable within 6 months of storage. The position of seed development did not significantly affect seed size or weight. However, seeds produced from the bottom third of the plant (lot A) were the most vigorous after dormancy was released with sufficient storage. This suggests that efforts should be made to produce TPS in the primary branches of the mother plant.