Page:Tree Crops; A Permanent Agriculture (1929).pdf/355

 #Hickory-pecan hybrids.
 * 1) Black walnut—several varieties.
 * 2) Persian walnuts—several varieties.
 * 3) Japanese walnuts (heartnut) several varieties.
 * 4) European filbert—many varieties.
 * 5) American hazelnut—several varieties.
 * 6) Hazel-filbert hybrids—several varieties now are or soon will be available.

He can probably secure now or soon a few Chinese seedling chestnuts from the Department of Agriculture, or he can buy any year some Chinese chestnut seed. By the time his trees are large enough to graft he can probably secure cions of some blight-proof oriental chestnut or hybrid.

For forage crops he can secure grafted mulberries, grafted persimmons, both native and oriental, honey locust seedlings, or honey locust seed from which to grow trees to be grafted in place a little later when good varieties are known.

The best producing oak trees within ten miles of the place of residence of most people of the United States will make interesting grafting experiments.

Interplanting of different species will be an important device in tree-crop farming. To provide early returns quick-maturing species can be alternated with slow-maturing. To secure fertility leguminous and non-leguminous trees may be interplanted so that the non-legumes may derive nitro-