The Demonstrating Research On Walnut Grafting Technology In Yangquan

Walnut is the most widespread tree in genus walnut (Juglans) of walnut family(Juglandaceas) . It is a kind of woody and grain plant which mainly produces kernels and itis also an important plant for economics, commercial timber and greening. .It tastes good andis rich in nutrition, so it is a high-class materials for nourishing food, traditional Chinesemedicine and food- processing. Chinese walnut product has a main position in the world.According to the problem of low seeding ratio, low survival ratio of grafting and poor profit of old garden, choosing the early produced varieties of Yuanfeng, Zhonglin 3, Liaohe 1 and the late produced varieties of Jinlong 1, Jinlong 2 as materials at typical lime, granite rough soil to do this experiment, which based on different time, different method, and different varieties. The main purpose of this paper is to research the best grafting technology of walnut in Yangquan Shanxi, and provide fertility technology in the these areas. The main result of this paper are as follows:1 In the lime soil and semiarid region of Yangquan, the best way for rootstock planting is seed soaking planting in spring. The proper time is at the first ten days or middle ten days of April after the soil thaws. The seeds sowed in spring have high seedling rate, and the seeds planted in autumn come out early and evenly, grow strongly. It is the first choice of intensive farming.2 In semiarid mountainous area of Yangquan, the main factor which restricts walnut tree growth is water. Seed soaking strengthen management during seeding stage is the important method to improve seedling ratio and growth. (1) Seed treated by water can come out earlier and can have a higher growth than the seed without treatment. It also has the effect of disinfecting. So it is the best way to deal with the seed; (2) During the growing period, the seedling with watering two times, scarification and weeding often, this making the plants grow better than those by rough management in the height, thickness around the roots. In one word, the above method is of indispensability.3 Yangquan belong to continental monsoon climate. There is lower temperature, strong wind and little water, and this influence the walnut. Seeding growth, and it is likely for the branches to get dry or wither. In winter, earth-filling is one of the necessary methods to avoid it. After the leaves fall in late November, earth-filling can ensure the young plant pass through the winter safely, thus increasing the survival radio.4 The three key factors influencing survive ratio of grafting are grafting time, varieties and method. In Yangquan, adopting 5 square shaped bud, grafting in the middle or late June when the temperature rises to over 20℃ can ensure the high survived ratio, help to heal upwell and bleeding little. The best variety for grafting is Jinlong 2.5 The original soft walnut in Yangquan harvests late and has a low yield, and it often has a good harvest year and then a poor one the next year. So it is necessary to change the variety. The trees eight to ten years old are the ideal material for grafting. The proper grafting period should he in April when the temperature rises quickly and the bleeding damage for rootstock is less.6 The best variety for top-working grafting is Jinlong 1 in Yangquan. The avidity between Jinlong 1 and soft walnut is stronger than that with Liaohe 1. Further more, it has a bigger crown, stronger growing tendence and better resistance. The best grafting method is tongue grafting by cutting in the truck, and it's survival ratio is obviously higher than cleft grafting. Moreover, the method has the advantages of simple operation, low cost and low percent of infection by pests and diseases.7 The grafting varieties of walnut bear early, and these trees have better quality fruit and much more yield. Changing variety by grafting is the important way to reconstruct old garden. (1) After grafting, it needs two years for early-produced walnut and four years for late-produced to yield. It's yield per tree is much more than that of the original walnut. Especially the Jinlong 1, which has very prominent adaptability and higher yield. (2) The range of yield changing between harvesting year and poor-harvesting year of Liaohe 1 is only 4.9%, and that of Jinlong 1 is 6.5%. On the other hand, that of soft walnut reaches 78.6%. worse still, it has no harvest at all. Sometimes, changing variety by grafting is the import way to overcome the problem of different yields between harvesting year and poor-harvesting year.