Berthier Station
By Fabienne Colas et Michèle Bettez
Figure 1. Dimensions of a conventional tunnel and a
“cathedral” tunnel.
Figure 2. View of two “cathedral” tunnels during winter.
The covers are in a lowered position. The steep pitch of the walls prevents the accumulation of snow on the structure.
Material
The European larch indoor seed orchard is composed of 27 clones, in which the number of copies varies from 1 to 28. The Japanese larch orchard is composed of 19 clones, with the number of copies varying from 1 to 36.
Grafts are cultivated in 104-L pots in a “double pot”
system inserted in the ground. The wall of the interior pot is pierced in order to provoke aerial pruning of the roots (Fig. 3).
A layer of gravel about 2 cm thick is placed in the bottom of the exterior pot to help with drainage. Inserting pots in the ground saves 50 cm in height, and both stabilizes the trees and eases handling. Trees are placed in staggered rows to optimize available space and improve light penetration to the crowns (Fig. 4). Irrigation and fertilization is done using a drip system.
Figure 3. Grafts are grown using a “double pot” system.
The upper pot is pierced to allow aerial root pruning to take place. The lower pot contains 2 cm of gravel to assist with drainage.
Figure 4. Summer view of Larix kaempferi in a “cathedral”
tunnel. Pots are placed in staggered rows to facilitate spring operations.
Graft selection for pollen collection and pollination After cone harvesting in the fall, trees with fl ower buds are identifi ed and then assembled in cathedral tunnels. The following spring, when it is easy to distinguish between male and female fl owers, the trees are selected either for pollen collection (minimum of 300 male fl owers per tree) or to be pollinated (minimum of 50 female fl owers per tree).
Pollen collection
Branches are tied together on trees having enough male fl owers, and then placed in a Kraft (DD60) paper bag that will be attached to the trunk (Figs. 5 and 6).
Pollen is then sieved (VWR, 120 mesh, 20 cm diameter, 5 cm high) to eliminate debris (cone scales, pieces of bark and twigs). It is ready to be used or stored.
Figure 5. Grafts whose branches are tied together to simplify bagging for pollen collection.
Figure 6. L. kaempferi graft bagged in the spring for pollen collection. The tree is tilted to facilitate pollen deposit.
The bag is closed using pliers to assist with opening and collecting pollen (see arrows).
Figure 7. During pollen dispersal, pollen falls to the bottom of the bag and is collected using a vacuum.
Figure 8. Vacuum and nozzle used to collect pollen. Pollen accumulates in the bottle, which is emptied and cleaned between clones.
Pollination
On trees with enough female fl owers, all male fl owers are manually removed (emasculation) to ensure that seeds will be produced from the applied pollen. Pollen is applied using a portable electrostatic pistol (Gema Voltstatic model 11024, ITW Gema, Indianapolis, Il, USA) adapted from the model developed by the CEMAGREF (Philippe and Baldet 1997). The pistol and associated equipment are attached to a cart designed by the Forest Research Directorate that can be rapidly moved around in the tunnel (Fig. 9). Each graft is pollinated twice, two days apart, while the female fl owers are at their maximum receptivity (Fig. 10).
Figure 9. Cart designed to carry the electrostatic pistol and associated material (bottle of compressed air, battery for electricity, battery charger, and air fi lter) (photo Fabienne Colas).
Figure 10. Pollinating using a portable electrostatic pistol.
Cone harvesting and seed extraction
Cone harvesting is carried out in September and October.
Cones are placed in cone bins for a period of at least eight weeks for post-maturation. Seed extraction and seed quality tests are done by the Berthier Forest Seed Centre. Extracted seeds are placed in a bank for future production of hybrid larch seedlings.
Reference:
PHILIPPE, G., P. BALDET, P. 1997. Electrostatic dusting: an effi cient technique of pollination in larch. Ann. Sci.
Forest. 54: 301-310.
Information contacts:
Michèle Bettez, agr.
Development Team
Berthier Tree Seed Centre (BFSC) michele.bettez@mrnf.gouv.qc.ca 418 836-3787 poste 245
Fabienne Colas, biologiste, DESS Researcher, Seed and plant production (Direction de la recherche forestière) fabienne.colas@mrnf.gouv.qc.ca 418 643-7994 poste 6526
Notes
Description
Principal objective
Production of Japanese larch seeds (Larix kaempferi [Lamb.] Carr.) adapted to the climate of the St. Lawrence River valley, Québec, Canada.
Location
Municipality Batiscan
Province Québec
Latitude 46° 31’ 05’’ N
Longitude 72° 15’ 03’’ W
Area 1.8 ha
Current owner Gouvernement du Québec (since 1992)
Owner when established Compagnie Internationale de papier du Canada (CIP)
Manager Direction générale des pépinières et des stations piscicoles (DPSP) du ministère des Ressources naturelles et de la Faune du Québec (MRNF) Climate, soil and topography
Mean annual precipitation 1 000 to 1 100 mm Mean annual temperature 4 to 5 °C
Length of growing season 170 to 180 days
Altitude 5.5 m
Slope 0%
Deposit Loam 45% sand – 34% silt – 21% clay
pH 5.09
Initial objective
Establish a Japanese larch seed orchard by retaining 800 of the best individuals in a progeny test of 8,000 trees selected for:
1. frost hardiness and absence of damage 2. growth
3. stem and crown form Modifi ed objective
Establish a Japanese larch seed orchard of about 500 trees distributed from among the 20 best provenances selected according to the same criteria as those listed in the initial objectives.
First collaborators Service Canadien des Forêts (Institut forestier national de Petawawa) Ministère des forêts du Québec (Service de la Recherche forestière) Material
8,000 bareroot Japanese larch trees, produced from 79 provenances, of which 42 are from Hokkaido Island, Japan. The 37 other provenances are divided among the following places: Honshu Island (Japan), Finland, Denmark, Germany, Scotland and Québec.
Dispositif expérimental
Dispositif initial constitué de 10 blocs (répétitions) de 20 parcelles.
Une parcelle contenait 4 rangées (2 m entre les rangs) de 10 plants (1 m entre les plants sur la ligne) pour un total de 8 000 plants (10 blocs x 20 parcelles x 4 rangées x 10 plants) (Figure 1). Les 79 provenances (+ 1 répétée) se retrouvaient tous dans chacun des blocs selon un hasard partiellement contrôlé (à cause des 42 provenances d’Hokkaido).
Experimental design
Initial experimental design of 10 blocks (repetitions) of 20 plots. A plot contained 4 rows (2 m between rows) of 10 plants (1 m between plants in a row) for a total of 8,000 plants (10 blocks x 20 plots x 4 rows x 10 plants). The 79 provenances (+ 1 repeated) are found in each block using a partially controlled hazard design (because of the 42 provenances from Hokkaido).