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 pollination a pollinator tree. Working from an old Spanish variety, "Tuono", researchers in 2008 started making available new self-fertile varieties that more closely match the qualities of the popular "Nonpareil" almond—including varieties "Lone Star" and "Independence". While self-fertile trees do not require pollen from a second tree variety for fruit / nut set, they still depend upon insect pollination for good production. Almond growers with self-fertile almonds report excellent nut set with half (or less) the number of bees in the field. Like apples, pears are self-incompatible and need to attract insects in order to be pollinated and produce fruit. One