WALNUT 



t;ro\vth till' tirst year, many uf tlirui not mure than C, 

 iiiolii's. Alter this ilic i;r.iwth i^ rapid. Tin- trees are 

 tied to stakes witli stri|is ,,f elotli. since tin-y are \vv\ 



tli'e tree Ijy 



WALXL'T 



1961 



ivm: 



.f 



litf 



nt tliro 

 e. At 



irst 



tender when jrrowiiiL;-, 



the wind quirlily causes any otlie 



tiu' liark. AValntit tree's are pruned 



snuiU liiuljs are allowed to start ahuut 



the trunk, but later these are pruned otV 



to a heiirht of 4 feet. Some of the lonq-er 



growths are shortened back while the 



trees are youiii;; and after thev are older 



the low limbs which beml dowu'in the way 



of ciUtivaring are removed. 



The Santa" Barbara Softshell be-ins t>. 

 bear the third year fr.uu plautiug, but 

 does not produce profitable crops before 

 the tifth or sixth year. Precocity in bear- 

 ing is not a desirable cpiality in Walnuts, 

 since no Walnut tree will produce a prof- 

 itable crop until it attains sutbcient size 

 to support it. Hardsli.dl trees do not 

 bear as young, and they are not regulai- 

 bearers, 



Waluut orchards in California receive 

 thorough tillage. They are heavily irri- 

 gated in winter, and plowed about S in. 

 deep in the spring. After this they are 

 irrigated aud cultivated until the nuts be- 

 gin to fall. — aliout the 1st of September. 

 Late irrigati(.ui tills out the ntit 

 causes the hull to open readily. Heavy 

 fogs are also desirable duriug harvesting. 

 The nuts are shaken down and pricked tip. 

 They are then spread in trays about 5 

 in. deep until dry, when they are bleached 

 and shipped to market. Walnuts were 

 formerly bleached with fumes of sulfur, 

 but this was fotmd injurious to the nut. 

 They are now usually dipped in a solution 

 of chloride of lime (chlorinated limei and 

 sal-soda, to which a stilficient aniount of 

 siilfurie acid has been added to set tree the chlorine. 



The nta,ioritY of Wahnit-growers are organized into 

 local associations. Bepresentatives of these associa- 

 tions form the executive conuuittee of the Southern 

 California Walnut-Growers' Association. This execu- 

 tive committee provides the form of contract which 

 the local associations may enter into with brokers, 

 price. The local associations are man- 



trii-ts in southern Calif. jr 

 ette, Chaberte, I'arisienU' 

 rieties are hardier in res 



U : 



•dlini^s 

 id are : 



I, viz., Pr;i?]iarturiens, Ulay- 



Franiiuette. etc. These va- 



II resistam-e of frost and leaf-burn 



beat. They are largely root-grafted upon 



->t the California Hhodi Walnut in the nilr- 



so being top-grafted upnn .ild native trees. 



R. .1. W|eK-,.x. 



several wa^"^ 



2711. Juglans cinerea c 

 the eastern state'3 

 (X%.) 



Sometimes known a- 

 White WainuT. 



In sonic- the growers blea<. 

 their own crop, while in 

 others the association performs 

 r)iis work at its own packin.ii- 

 lionse. 



Tlie Walnut tree has very few 

 ]iests. The reil spider snuie- 

 tinie--; attacks the trees, but it is 

 not onsidered a serious |)esr. 

 * >f late years a bacterial growtli 

 ha-^ developed to a considerable 

 extent wliicli is more seriou-^. 

 This attacks and destroys tin- 

 immature nut and the --niall 

 liml)s (.if the tree. 



AuTirrR Stalev. 



The Walnut in Central 

 ( 'Ai,JFnr;NiA. Walnut -^towiuh; 

 is i|uite rapidly extending in 

 both tlie I'oa^t and iiitoriorval- 

 lov reLHoii.^ of I 'entral ( 'alifonda 

 and is ii]--i.i siici.-.>-^fiilJy accoju- 

 plished in favoralde situations 

 in the fouthills up to an eleva- 

 tion of i'.onn ft. Thr-re are also 

 many instances of Thrifty and 

 j'irolitic troi.'.s in iiortheT'ii f'ali- 

 foriiia and southern On-gon. 

 This northward extension of 

 successful Walnut growing is 

 conditioned upon the use of tlir 

 best French varieties and the 

 rejection of the varieties popu- 

 lar to llie i-hief commercial dl--- 



Walnut Bacteriusis, — Chief among the more serious 

 diseases of Juglnns rtijia in the Tnited States is a bae- 

 terial blight of the nut, branch and leaf of that tree. 

 This^blight now has its greatest development along the 

 Pacific coast, especially in C)range and Los Angeles 

 counties. California. The germ which causes this' dis- 

 ease is a newly described species of Pseudomonas [P. 

 JHiihoidis). Oitt'ereut effects of the disease are shown 

 in Fig. 27U. 



The organism of Walnut bacteriosis winters in the 

 fallen nuts, in the diseased tissues of affected branches, 

 and especially in the pith cavity of the latter. New in- 

 fections occur as soon as spring growth begins, taking 

 place near the growing point of branches, in the open- 

 ing leaves, and upon the young and tender nuts. The 

 finer lateral veins i.f the leaves and the adjoining par- 

 enchyma are destroy i.-d. and the midrib is often af- 

 fected. Tlie injury resulting from infection of the branch 

 will largely depend on tlie tenderness of the latter at 

 the time and point of infection. If the tissue is tender 

 a canker-like spot will Ik- eaten through to the pith, or 

 the entire end of tin- shout may be destroyed. If the nut 

 is infected while small, its complete destruction usually 

 follows, the digestive acti-m of the germ involving hull, 

 shell and kernel. Xuts infected early in the sea.son 

 mostly fall when small, while later infections frequently 

 result only in the destmction of the hull and the black- 

 enintr <''t the outer layers of the shell, the tissues hav- 

 ini:: be(.'onie too hard for the furtlier progress of the dis- 

 ease. As in the case of ]iear blight, rapidly growing 

 trees are mm-e subject to injury than those making a 

 slower and luir<lier growth. The spread of the micro- 

 organism thronirh infected branches is generally onlv 

 loi'al — it randy extends more than a few inclies from 

 the point of infection. A marked blackenine- df the in- 

 jured parts results from the rapid oxidation of the tan- 

 nic acid they contain, though this is not distinctive 

 of injury from this disease. PsrudomoiKfR jiif/J'nulis 

 is actively motile; hence fogs, rain or dew aid in its 

 spread and increase the number of infections. The 

 water of i]'riL''atinn may carry the germ for miles. 



The destructi<in uf the tissues ,,f the ^^";llnut istffected 



