Present situation of technological Development of Walnut Industry in China

   I. Walnut Variety breeding

   Walnut cross breeding in China began in the middle and late 1960s. Liaoning Economic Forest Research Institute, Shandong Fruit Research Institute, China Forestry Research Institute and other scientific research institutions made outstanding achievements, and common walnuts were used as hybrid parents. Liaoning No. 1, Zhonglin No. 1 and Xiangling have been bred successively. In 1990, identified by the Ministry of Forestry, 16 new early-bearing walnut varieties popularized in China were evaluated, which have become the main force in the improvement of walnut varieties.

The picture shows walnut

   II. Reproductive technology

Before the eighties of the 20th century, the reproduction of walnut in China was mainly based on seed reproduction. Walnut seed reproduction, in the case of natural pollination, the offspring vary greatly, individuals often have phenotypic differences, and the results are late, which can not meet the needs of production. At present, grafting propagation is the main means to achieve improved varieties and high yield of early fruit.

   can be divided into two types: branching and budding of walnut according to the difference of grafting. At present, walnut skin and tongue grafting is recognized as the branch grafting method with the highest survival rate, and its survival rate is generally more than 8o%. As a result, the wide application of high connection technology in production is promoted. Walnut bud grafting technology, with the successful application of rootstock early planting, grafting and multiple harvesting techniques, the current survival rate is more than 95%, which has greatly promoted the pace of improved walnut varieties.

   III. Tree management

The shape of    walnut tree should be sparse layer shape or natural happy shape, and the shaping should be done sooner rather than later, and it should be completed within 5-7 years. The main task of pruning the first fruit tree is to cultivate all levels of backbone branches so that they can form a good tree skeleton as soon as possible. The main task of tree pruning in full fruit period is to adjust the balance of tree potential in time, adjust the contradiction between growth and fruit, and prolong the life of full fruit period. The task of pruning aging trees is to renew and rejuvenate the crown with empty branches and new branches. The results of the study on high-yield cultivation techniques of young walnut trees show that young trees should be pruned, otherwise early fruiting varieties are prone to premature senescence, which directly affects the yield.

   IV. Pest control

At present, more than 120 species of pests and 30 kinds of diseases are known to be harmful to walnut by   . From the point of view of the whole country, the species, distribution and damage degree of diseases and insect pests are different in different places. Walnut diseases and insect pests directly affect the yield and quality of walnut, which has aroused widespread concern.