Incremental Growth and Survival of Containerized Cryptomeria Japonica Seedlings as Affected by Varying Levels of Nitrogen Fertigation

The study was aimed to determine the effect of varying levels of nitrogen fertigation on growth of Cryptomeria japonica seedlings in nursery conditions.The germinated seedlings were fertilized at weekly interval with ingestad pretreatment nutrient solution with nitrogen doze @ 0 (without fertigation), 3.00, 6.00, 9.00, 12.00, 15.00, 18.00 and 21.00 mg dissolved in 50 ml of water along with fixed levels of P, K, Ca and Mg seedling^-1 week^-1 upto 28 weeks. Nitrogen fertigation increased seedling height, biomass, relative growth rate, seedling quality index and other parameters. Quality seedlings of Cryptomeria japonica were produced at the nitrogen addition @18 mg seedling^-1 week^-1 for first growing season at nursery. It increased seedling height by 84.6% collar diameter by 35.5%, total seedling dry weight by 226.2%, as compared to control. Seedling survival (97.2%), relative growth rate (0.248) and seedling quality index (0.093) was recorded highest at 18 mg nitrogen application rate. For raising quality seedlings of Cryptomeria japonica, 18 mg of N week^-1 seedling^-1 may be applied during the first growing season to obtain maximum overall growth and biomass production.