Effect of seed sowing date, irrigation and weed control on some quantitative and qualitative characteristics of Pinus brutia seedlings in nursery

Pinus brutia is one of the most important species respect to low ecological needs and tolerance against winter drought and summer heat. This species is used in degraded ecosystems and dry and semidry shrub lands in Iran. It is an important species for urban green space as well. This experiment was performed as complete randomized and factorial design with three treatments, sowing date (autumn and winter), irrigation periods (every 2 and 4 days) and weed mechanical control (every 7 and 14 days) with four replications and 15 vases (per replications) in Zaghe nursery in Khorramabad city. At the end of the first growing season, measurements included biomass and vitality rate. Results showed that the effect of treatments on amount of biomass was significant. The maximum of biomass was showed in winter sowing, every 2-days irrigation and every 7-days weeding. Effect of irrigation on shoot/root ratio was significant and maximum rate concluded in every 4-days irrigation but conversely effect of sowing date and weed control and composition of treatments were not significant. Effect of treatments including, sowing date, weed control and composition of treatments on vitality rate were significant. Maximum vitality achieved at autumn sowing with every 2-days irrigation and 7-days weeding. Based on the results, for decreasing of nursery costs, the duration of irrigation can be extended and winter sowing can be replaced by autumn.