Abstract
The allocation of dry matter, reserve nutrients and flower bud formation of Japanese pear (Pyrus serotina Rehder) cv. Kosui grown under plastic house (PL) were compared with those grown in the open field (OF). Experimental trees were grown under frames covered with polyethylene vinyl-acetate film from early March to mid-May. Materials were sampled in late November and December.
1. Shoot: root ratio of tree under PL was higher when compared with that of trees grown in OF. It was notable that all organs, especially roots of covered trees had lower carbohydrate reserve contents than did those sampled from trees in OF. Mineral contents in most of the organs under PL were also lower than were those of OF.
2. Covered trees had 49% more axillary flower buds on shoots and 46% less flower buds on spurs than did those of OF. Current shoots under PL were thinner and shorter than were those in OF.
