A Study on Grafting Techniques on American Black Walnut(Juglans nigra L.)

Systematic comparison and research were conducted on different grafting technique and the main affective factors of survival rate with three clones of American black walnut(Juglans nigra L.).The results show:First,the summer big-square patch bud grafting technique is the most feasible grafting method with the grafting survival rate reaching as high as 96.2% and 50 days of suitable grafting time;Secondly,the in-chamber shoot grafting technique can be the main grafting method in areas lacking in nursery for shoot collection or in areas of rainy summer,which can achieve higher grafting survival rate and lower grafting cost if the grafting seedlings are replanted into the field in time after grafting.Thirdly,the thin grafting shoots is useful in the T-bud with xylem grafting technique,and the green shoots grafting at the top as the supplementary grafting method,and also was used to the unsuccessful grafting individual plant.The study was conducted over a period of three years,and solved the bottle-neck problem that the more bleeding was brought based on the grafting of American black walnut,and developed a series cultivating methods of the grafting seedling,including the winter shoot grafting technique in-chamber,the spring shoot grafting technique in the field,the summer big-square patch bud grafting technique,and the autumn square patch nonbudding grafting technique,by which we can cultivate the grafting seedling in any season of a year.