Juglans "J. regia", "Juglans" x Paradox, are widely used as rootstocks for "J. regia" cultivars because of their resistance to Phytophthora and to a very limited degree, the oak root fungus. However, trees grafted on these rootstocks often succumb to black line. In some countries, immature nuts in their husks are preserved in vinegar. In the UK, these are called pickled walnuts and this is one of the major uses for fresh nuts from the small scale plantings. In Armenian cuisine, unripe walnuts, including husks, are preserved in sugar syrup and eaten whole. In Italy, liqueurs called Nocino and Nocello are
Fruit tree pruning and training can also prevent later injury from weak crotches or forks (where a tree trunk splits into two or more branches) that break from the weight of fruit, snow, or ice on the branches. Some sustainable agriculture or permaculture personalities, such as Sepp Holzer and Masanobu Fukuoka, advocate and practice no-pruning methods, which runs counter to the widespread confidence in the idea that pruning produces superior results compared with not pruning. Many books about fruit-growing assert advantages and disadvantages of pruning or not pruning, although without randomized controlled trials, it is hard to separate theorizing and traditional knowledge from