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• 1. [Article] Impacts of nursery processing on the survival, growth and physiology of 2+0 Douglas-fir seedlings

  This study compared three nursery handling processes from the time just before lifting to the time seedlings are placed in cold storage after grading, sorting, and packing at the nursery. The seedlings ...

  Citation × Citation Citation Abstract Copy Title: Impacts of nursery processing on the survival, growth and physiology of 2+0 Douglas-fir seedlings Author: Darbyshire, Robyn Lea Willey This study compared three nursery handling processes from the time just before lifting to the time seedlings are placed in cold storage after grading, sorting, and packing at the nursery. The seedlings handled in these different ways were compared first in terms of the temperature and plant moisture stresses they experienced during nursery handling. A second study of their growth and survival in a plantation and in an irrigation experiment was undertaken. The three treatments were: (1) conventional nursery handling with seedlings held for 48 hours in a cool, humid room (about 40°F and 80-90% relative humidity) between lifting and grading; (2) conventional nursery handling with seedlings held outdoors on a covered dock for 48 hours between lifting and grading; (3) bedpacking, where seedlings are lifted and taken directly to cold storage without the extra help handling involved in grading, sorting, and packing. The comparison of different temperature and plant moisture stress at the nursery showed no difference in plant moisture stress (PMS) during the holding period for treatments (1) and (2). Treatment (1) however did keep the seedlings at a lower temperature than (2). Treatment (3) had the lowest PMS and temperature during the holding period. Seedlings planted in a plowed field in a split-plot design showed no significant differences in budbreak, rate of height growth, or survival due to handling treatment after one growing season, but bedpack seedlings showed significantly larger (p=0.01) new terminal length and dry weight than the other two treatments. Though not significant, the same trend occurred for dry weight of new laterals and total shoot dry weight. Seedlings planted in the irrigation study showed significant differences in budbreak, height growth, survival, and final morphology due primarily to the level of irrigation. More work at different nurseries and in different outplanting environments is needed before strong recommendations can be made about bedpacking versus conventional handling. Greater attention to the management of temperature and plant moisture stress during nursery handling may eliminate differences between conventional handling and bedpacking. Title: Impacts of nursery processing on the survival, growth and physiology of 2+0 Douglas-fir seedlings Author: Darbyshire, Robyn Lea Willey This study compared three nursery handling processes from the time just before lifting to the time seedlings are placed in cold storage after grading, sorting, and packing at the nursery. The seedlings handled in these different ways were compared first in terms of the temperature and plant moisture stresses they experienced during nursery handling. A second study of their growth and survival in a plantation and in an irrigation experiment was undertaken. The three treatments were: (1) conventional nursery handling with seedlings held for 48 hours in a cool, humid room (about 40°F and 80-90% relative humidity) between lifting and grading; (2) conventional nursery handling with seedlings held outdoors on a covered dock for 48 hours between lifting and grading; (3) bedpacking, where seedlings are lifted and taken directly to cold storage without the extra help handling involved in grading, sorting, and packing. The comparison of different temperature and plant moisture stress at the nursery showed no difference in plant moisture stress (PMS) during the holding period for treatments (1) and (2). Treatment (1) however did keep the seedlings at a lower temperature than (2). Treatment (3) had the lowest PMS and temperature during the holding period. Seedlings planted in a plowed field in a split-plot design showed no significant differences in budbreak, rate of height growth, or survival due to handling treatment after one growing season, but bedpack seedlings showed significantly larger (p=0.01) new terminal length and dry weight than the other two treatments. Though not significant, the same trend occurred for dry weight of new laterals and total shoot dry weight. Seedlings planted in the irrigation study showed significant differences in budbreak, height growth, survival, and final morphology due primarily to the level of irrigation. More work at different nurseries and in different outplanting environments is needed before strong recommendations can be made about bedpacking versus conventional handling. Greater attention to the management of temperature and plant moisture stress during nursery handling may eliminate differences between conventional handling and bedpacking. Close