Titre :
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Factors affecting cone and seed production in douglas fir
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Auteurs :
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A. Colangeli ;
J. Owens ;
S. Morris
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Type de document :
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rapport
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Editeur :
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Victoria, CAN : Forestry Canada - Pacific forestry centre, 1989
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Collection :
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Forest resource development agreement report n° 57
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Format :
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19 p.
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Langues:
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= Anglais
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Catégories :
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Matériel végétal, techniques de production, pépinière
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Mots-clés:
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COLOMBIE BRITANNIQUE
;
CANADA
;
PSEUDOTSUGA MENZIESII
;
FRUCTIFICATION
;
GRAINE
;
PRODUCTION
;
POLLINISATION
;
BACTERIE
;
POLLEN
;
VIABILITE
;
AVORTEMENT
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Résumé :
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The causes of reduced seed yield in four Douglas fir (Pseudotsuga menziesii Mirb. Franco) trees at the Dewdney Seed Orchard in 1986 were found to be inadequate pollination (30%), low pollen vigor or viability (14%), embryo abortion (14%) and early ovule abortion (5%). The average seed efficiency (+ or - s.e.) for the four trees was 40 (+ or - 7). Conelet abortion in the four trees, averaged 43%, ranging from 20 to 64% pert tree. Recommendations for increasing seed yield are discussed. Total bacteria and fluorescent Pseudomonas populations were monitored in a Douglas fir Seed Orchard for one growing season and two pollination periods in 1986 and 1987. Seasonal variation in bacterial populations was observed, with the highest levels occurring in the late winter and early spring. Bacterial populations at pollination were higher in 1986 than in 1987. Conelet abortion at pollination was also higher in 1986 (55%) than in 1987 (11%). The results suggest that a causal relationship may exist between bacterial populations and conelet abortion at pollination. The potential role of ince nucleation-active bacteria in inciting frost damage in a Douglas fir orchard is discussed.
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