Effect of heat and its timing within a polyhouse on flowering in potted Douglas-fir trees
| Autor: | Stephen D. Ross |
|---|---|
| Rok vydání: | 1992 |
| Předmět: | |
| Zdroj: | Canadian Journal of Forest Research. 22:736-739 |
| ISSN: | 1208-6037 0045-5067 |
| DOI: | 10.1139/x92-099 |
| Popis: | Female and male flowering in potted Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) rooted cuttings treated with gibberellin A4/7, with and without naphthaleneacetic acid, were inhibited by heat treatment in a closed polyhouse with a temperature regimen of 28:15 °C (day:night) relative to the flowering achieved in an open-sided polyhouse with near-ambient temperatures. The effect was greater for an early heat treatment (from vegetative bud burst to end of shoot elongation), which bracketed cone-bud differentiation, than for a following late heat treatment of similar duration. Effects of the early plus late heat treatments were additive. It was not the objective of this study to determine the optimal temperature regimen for flowering. However, other than possibly in locations where low temperatures prevail during cone-bud differentiation in spring, heat treatment within a polyhouse appears to be neither a necessary nor desirable adjunct to gibberellin A4/7 for promotion of flowering in potted Douglas-fir. |
| Databáze: | OpenAIRE |
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