ISHS Acta Horticulturae 587: International Symposium on Asian Pears, Commemorating the 100th Anniversary of Nijisseiki Pear
A NEW APPROACH TO CONTROLLING THE FLOWERING DATE FOR JAPANESE PEAR USING REFLECTIVE FILM TECHNIQUE |
| Authors: | H. Honjo, Y. Kobayashi, M. Watanabe, R. Fukui, T. Sugiura |
| Keywords: | Pyrus pyriforia, ecodormancy, endodormancy, flowering control, non-woven PE film, reflective film |
| Abstract:
This study was conducted to develop the method of controlling the flowering date of Japanese pear (cvs. Kousui and Housui). The covering methods with reflective film (Du Pont, Tyvek) were used. Exp.1: In early November, 1998, 40 trees each were used for 4 treatments; 1) covered above the top of the trees, 2) mulched under the trees, 3) covered above and under the trees and 4) control. Exp.2: In early November, 1999, 40 trees each were assigned for 3 treatments; 1) covered above the top of the trees, 2) mulched under the trees and 3) control. A half of the 1) and 2) trees were switched to 3) at the end of December, and the rest of the 3) trees were converted into 1) or 2) in early February. Covering above the trees prevented temperature rise in the daytime and kept canopy temperature warmer than the open field at night. The diurnal range of temperature under covering became smaller than that in control. On the contrary, the diurnal range for the film mulching was expanded more than that in control. In Exp.1, flowering started first in treatment 3), and thereafter followed in the order of 1), 2) and 4). Flowering in treatment 3) began 4 days earlier as compared with control. In Exp.2, flowering started first in 1) to 3) switch treatment and the 3) to 2) switch, followed by 2) to 3) switch, 3), 2), 1), and 3) to 1) switch. Difference between the first and last flowering treatments was about 10 days. Covering over the trees before endodormancy break forced flowering, but covering during ecodormancy retarded flowering. By contrast, mulching under the trees during ecodormancy forced sprouting and flowering. | |
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