Trials on production of Biul (Grewia optiva Drumm ex Burr) planting stock in root trainers

To deal with the problems of root coiling and distortion, scanty lateral root development and frequent shifting operations in polybag-grown seedlings in nursery, root trainer production system is used. The technology for producing quality planting stock of many forestry species in root trainers has been developed successfully since last two decades. In Biul however technology for producing stock in root trainers has not been tried till date. For better survival and early establishment of the Biul seedlings after out planting it is important to produce better quality planting stock in the nurseries. It is a well established fact that planting stock produced in root trainers possesses certain advantages over existing polybag or bare root production systems such as lesser inputs required, well developed fibrous root system, non-existence of root coiling etc. Keeping all this in view trials were carried out to compare the growth performance of Biul seedlings raised in five types of root trainers namely Hiko pots 150, 250 and 300 cc and single cell bullet type 300 and 500 cc along with polybags of size 23 × 15 cm and as bare-rooted. The results indicated that among root trainers, the best growth and biomass of nursery stock was produced in root trainers of size 500 cc. However the above ground biomass was better in polybag-raised nursery stock of Biul owing to more potting media than in root trainers. The root structure development was found to be best in 300 cc single cell bullet type root trainer. Various seedling quality parameters were estimated and it was found that root trainer-raised stock excelled over polybag or bare root nursery stock.