Conifer seedling production in a Romanian tree nursery

Worldwide, conifer growers work hard every season to supply the best quality seedlings for reforestation or landscaping industry. In the last decades, greenhouse and nursery techniques of growing conifers are developing constantly, both for family nurseries and large companies. Each conifer species or variety has its own cultivation technology that starts with seed sowing, grafting or propagation from cuttings.

At Ferma de Brazi tree nursery, in Albac, one of the few Romanian conifer nurseries, bare-root coniferous species are produced on a large scale mainly in wooden and metalic structure polyethylene greenhouses due to numerous technical and economic considerations. The technical advantages of this method allows a crop rotation every year both in greenhouses and outside nurseries and provides a large number of seedlings/m2 which achieve dimensional and morphological parameters for use on reforestation sites.

Conifer growing technology in greenhouses involves sowing the seeds in rills after a previous preparing of a soil layer consisting of decomposed litter, spruce humus and beech humus (Milescu, 2006). Radu et al. (1994) listed a number of seed treatments applied before seed germination, consisting in keeping them in cold water for 24-48 hours or snow for 15-30 days; another method of enhancing germination is cold stratification for 3-5 weeks, at 2-5oC (needed for most Abies, Cedar and Pinus species). Other recommendations include an optimum seeding depth of 0.5-2 cm, correlated with seed size, and rill covering using sieved conifer humus mixed with sand, on a ratio of 3:1. Seed germination generally occurs after about 2-3 weeks, depending on species, irrigation frequency, temperature and humidity inside the greenhouse, while the new plantlet is identified by radicle, hypocotyl and several bent cotyledons which remain attached on the seed in the first days of development.

In conclusion, the traditional method of conifer seedling production is still alive and used with success in some parts of Europe, being a feasible alternative to the automated containerized production, using local, microclimate conditions, and giving “noble value” to the lands in the mountainous countryside.

References:

1. Eng RYN (1991). Temperature, nutrition, light and moisture regimes used at Red Rock Research Station to produce container 1+0 spruce seedlings. Research Report RR 91004-PG, Ministry of Forests, Victoria.
2. Holonec L (2003). Protecţia integrată a arboretelor din judeţul Cluj prin tehnologii moderne şi acţiuni fitosanitare economice, ecologice. Teză de doctorat. USAMV Cluj- Napoca.
3. Matthews RG (1971). Container seedling production: a provisional manual. Can. For. Serv., Ottawa, Ont. Inf Rep BC-X-58.
4. Milescu I (2006). Cartea Silvicultorului. Ed. Universităţii Suceava, Suceava.
5. Radu S, Contescu L, Herţa I, Burza E, Roşca T (1994). Pepiniere- Metode şi procedee pentru cultura în pepinieră a principalelor specii forestiere şi ornamentale. Institutul de Cercetări şi Amenajări Silvice, Bucureşti.
6. Tinus RW, McDonald SE (1979). How to grow tree seedlings in containers in greenhouses. US. Dep. Agric. For. Serv., Rocky Mtn. For. Range Exp. Sta., Fort Collins, Col Gen Tech Rep RM-60.