THE WALNUTS PERSIAN WALNUT. 33 



number, considering the risk of crop failures on some trees to make safe the invest- 

 ment of so much capital for so long a time as is required to bring them into profitable 

 bearing. Certain experiments with hardy varieties newly introduced seem to indicate 

 that the possible range of profitable culture is much broader than has been found true 

 in the case of the Los Angeles nut, or Mission nut, which has been planted almost to the 

 exclusion of all others. Felix Gillet, to whose enterprise the introduction of the late 

 blooming and hardy French varieties is due, writes that he feels warranted by his 

 experience in saying that walnut culture can be carried on successfully on the whole 

 Pacific Coast by planting "none but the hardy kinds, and planting them on plateaus, 

 hijlsides, rolling land, alongside roadways, around large fields and vineyards, in I 

 cordons and avenues, on soils not well adapted to other crops, and where the walnut 

 in the course of time will grow to gigantic dimensions." 



GROWING THE ORCHARD. 



Stocks. The Persian walnut is grown both in this country and Europe, mostly on ^ 

 its own roots. In fact the larger part of the orchards consists of seedling trees. In 

 Europe budding and grafting have long been practiced, and in some cases the black 

 walnut (Juglans nigra) has been used as a stock. Michaux recommended to European 

 growers that it be budded on the black walnut because of the greater value of that 

 wood, and Baltet states that he has been successful in cleft grafting on the black 

 walnut as a tall standard, thus securing " a twofold profit from the timber of the stem 

 and the fruit produced by the graft." In California it was long ago found that the 

 California black walnut could be used as a stock for the Persian walnut. Wickson 1 

 mentions a tree on the grounds of John It. Wolfskill, in Solano County, budded in 

 1875, which had attained a height of 50 feet and spread 60 feet in 1888. Its annual 

 yield of nuts is stated to be 200 pounds. B. M. Le Long, president of State board 

 of horticulture, reports having some years ago budded 500 trees of the wild California 

 stock, growing in the mountains east of Los Angeles. He used the prong method, 

 and met with good success. Mr. Le Long states that contrary to the common belief 

 that fruit grown on such stocks would have darker, thicker shells, an examination of 

 fruits thus grown showed no observable difference in either flavor or color. From the 

 fact that the tree is hardy farther north than it is fruitful, the question of stocks is 

 not an important one except for the South, where its roots are damaged by root knot. 

 But for the Gulf States and Georgia, the finding of resistant stocks seems to be the 

 only possible way of making walnut growing profitable. / 



Dr. Seal, in his researches on root knot, comes to this conclusion, and thus describes 

 the damage done to young trees by the Anguillulce: 2 " In nurseries of young fruit trees 

 the greatest mischief occurs. The soil is usually carefully prepared by heavy fertilizing 

 and culture, and the seeds of the peach, orange, and English [Persian] walnut are sown 

 for stocks. When the tender shoots first appear many wither and die at once; others 

 grow vigorously till the end of the first season, when they are usually budded with 

 known and valuable varieties of fruit. The next spring these buds put out tardily and 

 make a weak growth; the leaves become spotted or yellow, then drop; the bud dies; 

 feeble, straggling shoots sprout around the stem, which maintain a sickly vitality till 

 the first drought, when the tree dies, and an examination discloses the cause in the 

 knotty, decaying roots, without rootlets or fibrilla}. With older trees taken from 

 healthy locations and set in infected soil the programme varies. The peach and the 

 fig often grow vigorously one or two years and bear fruit that is very prone to drop 

 immaturely, then the tree takes on an irregular growth of stunted limbs and small 

 leaves. The tips of these limbs die back gradually to the body of the tree. If the 

 soil is clayey the tree will put out feeble sprouts often for several years. With the 



1 California Fruits, page 502. 



- Bulletin 20, page 12 Division of Entomology, United States Department of Agriculture. 

 6480 - 3 



