Ware potatoes were produced from true potato seed by transplanting seedlings to the field in different growing periods to
evaluate environmental constraints of this production method in the Nile delta. In the autumn season, with high temperatures
and long-day conditions during seedling culture in the nursery and transplant establishment in the field, seedling development
was fast, and transplants resumed growth within 5 days of transplanting in the field. Tuber yields ranged between 120 and
160 dt ha
−1. In the spring season, with low temperatures and short-day conditions during the initial growing phase, seedling development
in the nursery was slow and biomass partitioning between above ground organs (stems, leaves) and tubers was shifted towards
the tubers. This partitioning was further enhanced by transplanting the seedlings in the field. Seedlings recovered only slowly
from transplanting or died.
It is concluded that potato production via transplants is poor in the spring season when premature tuberization of seedlings
in the nursery leads to slow field establishment and low tuber yield.
Additional keywords physiological ageing - premature tuberization -
Solanum tuberosum L. - transplanting shock