Treatments for induction of cold hardiness in Picea abies (L.) Karst. and Pinus sylvestris L. seedlings pre-cultivated under light-emitting diodes : impact of photoperiod and temperature including energy consumption and seedling quality after cold storage

• In Nordic climates, the weather allows a narrow time window during spring and summer for forest seedlings to be transplanted from indoor growth to outdoor conditions. If a new method for year-round cultivation under LED lamps is to be successfully introduced in forest nurseries, a cold storage phase for batches produced outside of the vegetation period needs to be included in the concept. Different short-day treatments for induction of cold hardiness in very young seedlings of Picea abies and Pinus sylvestris cultivated solely under LED lamps were investigated. The study compared a combination of two photoperiods (5 h or 8 h) at three different temperatures (5°C, 10°C or 20°C) applied during five weeks. Chlorophyll fluorescence, shoot electrolyte leakage and molecular testing for gene expression of cold acclimation were used to assess the treatments. After a period of three months in cold storage at 2°C, the vitality of the seedlings was evaluated using a root growth capacity test. Lower temperatures during the treatments, especially for Pinus sylvestris, had a significant effect on inducing cold hardiness. The results showed that the photoperiod should not be overly reduced to allow photosynthesis and generation of carbohydrate reserves but it could be optimized to reduce electricity consumption.

Ämnesord

LANTBRUKSVETENSKAPER  -- Lantbruksvetenskap, skogsbruk och fiske (hsv//swe)

AGRICULTURAL SCIENCES  -- Agriculture, Forestry and Fisheries (hsv//eng)

Nyckelord

Cold hardiness

containerized forest seedlings

photoperiod and temperature

seedling cold storage

seedling quality

short-day treatments

year-round cultivation under LED lamps

Cold storage

Electrolytes

Energy utilization

Gene expression

Light emitting diodes

Plants (botany)

Seed

LEd lamps

Forestry

Energy and Built Environments

Energi och samhällsbyggnad

Publikations- och innehållstyp

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art (ämneskategori)