Studies on Refinement of Container Size and Potting Mixture for Production of Quality Seedlings in Spruce (Picea Smithiana Wall. Boiss)

Spruce (Picea Smithiana) is an evergreen tree and distributed through the temperate Himalaya at the elevation of 2000 - 3500 m. Natural regeneration of spruce (Picea smithiana) is generally slow and almost negligible due to a number of factors e.g. presence of un decomposed raw humus on forest floor low germinative capacity of seed and infrequent good seed years. In order to supple- ment natural regeneration through artificial means, nursery raising assumes significance. The present study aimed at optimizing the root trainer container size and the potting mixture ingre- dients and their proportion for the production of quality nursery stock of Picea smithiana. Nine combinations of potting mixture ingredients (Forest Soil, Garden Soil, Sand, FYM and Lake weed) were tested in various ratios for the optimization of potty mixture in different root trainer sizes. Simultaneously, three different volumes (150cc, 250cc and 300cc) of root trainers were tested for suitability of container size. Chemical and physical analysis of potting mixture ingredients was carried out for better understanding of nutrient status. The best seedling growth at seven month age in terms of height (5.53 cm), Collar diameter (1.57 mm), fresh shoot weight (0.34 g), dry shoot weight (0.10 g), fresh root weight (0.27 g) , dry root weight (0.03 g), root shoot ratio(2:52), and total fresh biomass (0.61 g) were observed when seedlings were raised in root trainer container size (300cc) filled with potting mixture of (M8) Soil:Sand:FYM (1:1:2) and the lowest growth para- meters were observed in root trainer container size (150cc) filled with forest soil only. Plantable quality seedlings can be recovered within a period of 7 months using potting mixture of Soil, Sand and FYM (1:1:2) and Soil, Sand and Lake weed (1:1:2) ratios in root trainer container size 300cc. * Corresponding author.