介绍几种改换核桃良种高新技术李明云（陕西省商南县林业站商南，７２６３００）商洛地区现有核桃树１０６５万株，年产核桃１万ｔ左右。目前挂果树达５５０多万株，但就产品而言，单产一直徘徊在０．５ｋｇ上下，远低于全国２．５ｋｇ的水平。１９９５年５月，地区行署组... Introducing several high-tech walnut varieties Li Mingyun (Shangnan County, Shaanxi Forestry Station Shangnan, 726300) 10.65 million existing walnut trees in Shangluo, with an annual output of about 10,000 tons of walnuts. At present, there are more than 5.5 million hanging fruit trees, but in terms of products, the yield has been hovering around 0.5kg, much lower than the national level of 2.5kg. May 1995, the regional administrative department ...