The method developed by Ryu Chol Ryong, a researcher of the Forestry Management Station in Unjon County, North Phyongan Province, draws attention of experts.

In this regard, Ryu told KCNA:

In the past it was difficult to graft pine-nut twigs on pine trees, as pine tree and pine-nut tree nearly equal in their osmotic pressures.

But the new method makes it easy to supply nutrients to pine-nut twig from pine tree by lowering its osmotic pressure.

Thanks to this method, Unjon County has made a big progress in creating pine-nut tree forests in only several years. And the growth rate of pine-nut twig grafted to pine tree is 60 cm in a year, 6 times faster than the previous grafting.

His research finding called "The Method of Grafting Pine-nut Twig by Controlling Osmotic Pressure" was highly appreciated at the 29th National Festival of Science and Technology.