Effect of collection date and storage conditions on field performance of Populus hardwood cuttings

Survival and height growth of seven hybrid Populus clones were evaluated for hardwood cuttings collected from September to December, and stored at temperatures from −20 to 2 °C. Field survival was less than 18% for cuttings of all clones collected in September and for cuttings of four clones collected in October and stored at −20 °C. Field survival and height growth during the first growing season were not significantly different for all seven clones collected from October to December and stored at −20 to 2 °C. However, since shoots and roots had begun to emerge from cuttings held at −3 and 2 °C at the end of the storage period, and cuttings at −20 and −10 °C were soaked in water for a week before root emergence and planting, nursery managers gain flexibility by storing cuttings at lower temperatures. Performance of three clones evaluated during 1981–1982 at temperatures from −10 to 2 °C followed the same patterns. Field performance of cuttings of five clones stored in moist mulch and plastic bags did not vary significantly by treatment at two nurseries, but survival of those stored as entire whips varied by location and clone.