3504 



WALNUT 



WALNUT 



(1913). Davidson, W. M., "Walnut Aphis in Cali- 

 fornia," United States Department of Agriculture 

 Bulletin No. 100 (1914). Tylor, A. R., "Spraying for 

 the Control of Walnut Aphis," University of Cali- 

 fornia Circular No. 131 (1915). Fawcett, H. S., 

 "Melaxuma of the Walnut," University of California 



3993. Drying walnuts in California. 



Experiment Station Bulletin No. 261 (1915). Batchelor, 

 L. D., "Problems in Walnut Breeding," Journal of 

 Heredity, Vol. VII, No. 2 (1916). L . D . BATCHELOR. 



Commercial possibilities of walnuts other than Persian 

 in the United States. 



Theoretically, the commercial possibilities of a num- 

 ber of walnut species in this country are large and 

 encouraging. The genus Juglans, to which all true 

 walnuts belong, either as native or as planted trees, 

 covers practically every cultivated section of the 

 United States wherever suited to hardwood growth. 

 Apparently some of its representatives may be taken 

 to many new small localities where it is now not found. 

 The nuts of practically all species possess kernels rich 

 in food properties and exceedingly pleasing to the taste. 

 Most of its species are fairly rapid growers and develop 

 into shapely trees. Rightly chosen and well cared for, 

 they may be used most effectively as ornamentals and 

 as nut-producers at the same time. The eastern black 

 walnut, Juglans nigra, is exceedingly valuable for tim- 

 ber purposes, and its planting is now strongly urged 

 by the foresters; to a large extent the various native 

 walnuts and their hybrids make the best stocks now 

 available for the Persian walnut. 



Practically, there is little doubt but that each of 

 these species will ultimately be developed for purposes 

 of nut production, although in common 

 with most new industries the progress will 

 be slow and beset with more or less disap- 

 pointment. It should be borne in mind 

 that these walnuts are wild and unculti- 

 vated species and cannot be expected to 

 respond to cultivation with the same readi- 

 ness as species which have been selected and 

 cultivated for centuries. 



The principal problem now before the 

 prospective planter appears to be one of 

 varieties. It is well established that seed- 

 lings vary greatly in all essential character- 

 istics and, therefore, are less desirable than 

 are budded or grafted trees of suitable 

 varieties. However, to date, there are fewer 

 than a half-dozen varieties of black walnuts 

 offered by the nurserymen, and so far as 

 generally known, there is none of butter- 

 nuts or other kinds of walnuts, exclusive 

 of Persian. Therefore, for the present, 

 planters must depend very largely on seed- 

 ling trees, for which, although they are 

 generally condemned by the leading horti- 



culturists, there are at least four substantial reasons 

 for using, as follows: (1) Budded and grafted trees are 

 as yet offered by the nurserymen only to a very 

 limited extent; (2) the available varieties are new and 

 practically untried; (3) the prices necessarily asked by 

 the nurserymen are beyond the reach of many who 

 would otherwise plant walnut trees; (4) desirable varie- 

 ties are liable to result from the planting of nuts from 

 choice trees. 



Definite steps are now being taken toward the 

 development of these species and already some dis- 

 tinct progress has been made; but as yet it is very 

 doubtful whether commercial planting of trees of any 

 species of Juglans, other than J. regia, for purposes of 

 nut production alone, is to be recommended. In gen- 

 eral, it is unwise to attempt the growing of trees for 

 the dual-purpose of timber and nut production, as for 

 the former, the trees should be set close together in 

 order to induce the development of long trunks with a 

 minimum of top, while for the latter purpose, they 

 should be given orchard space between in order to 

 allow for the development of low heads, large tops, and 

 a maximum fruiting surface. But in view of the uncer- 

 tainty of outcome with any of the present available 

 varieties and the value of black walnut timber, it is 

 possible that trees of this species might wisely be 

 planted at one-half or one-quarter the usual orchard 

 distances apart, with the idea of allowing them to 

 become forest trees, if for any reason the nuts should 

 not justify their retention for orchard purposes. It is 

 very doubtful whether any other species of walnut 

 could be recommended for such use, as with the pos- 

 sible exception of the two forms of hybrids common in 

 California, Paradox and Royal, no other species of 

 walnut is now being seriously considered for forest- 

 planting and, except in rare instances, neither of these 

 Californian forms produces nuts of value in commer- 

 cial quantities. 



Without doubt, the most promising place for walnut 

 planting at the present time is about the home grounds, 

 both in the city and in the country, and along the 

 fence-rows everywhere. Very often walnuts yielding 

 both beauty and product could as well be planted as 

 trees of other species capable of affording beauty and- 

 shade only. In the country, few grounds are so crowded 

 that there is not room for a few walnut trees, which 

 could be procured at small initial cost and which could 

 be developed into useful trees at practically no further 

 expense. If one-quarter of the American farmers 

 were to plant even two walnut trees about their prem- 

 ises, it is difficult to estimate what would be the aggre- 

 gate increased value to such farms by the end of a 



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3994. Walnut orchard in southern California. 



