تعیین مناسب ترین تراکم و تاریخ کاشت بذر افرا (پلت) و توسکای ییلاقی در نهالستان

Acer velutinum is one of the native and fast growing species of northern forests of Iran. Thousands seedling of maple are produced in the nursery yearly. The cost of seedling production can be decread by use of suitable seedling density and planting time. In adition, this strategy make less harm to trees. These seedling establish more sucssesfully in forestation programs. This design was carried out in split-plot model with two factors of seedling density in four level (a1=21gr., a2=29gr., a3 =36gr., a4=43gr.,) and planting time in ten level (b1=8/30, b2=9/15, b3=9/30, b4=10/15, b5=10/15, b6=10/30, b7=11/15, b8=11/30, b9=12/15, b10=1/25) and four repeatation. This design was carried out in Vanamak nursery of Neka-choob company in Mazandaran province. After leaf falling and before transfer of seedlings, quality and quantity factors of seedlings such as seedling quality, diameter, total hight, number of seedling and number of transferable seedling were evaluated and then analized by SAS program. Results showed that there were significant differences between treatments. Seedling density affected on seedling quality and number of seedling and seedling hight but did not affect on collar diameter. Time of planting was effective on measured parameters. On the base of results seeding density of a2=29 gr and planting time of December was suggested for nursery condition . Key words: Acer, Nursery, planting time, Seedling density. Isamic Republic