iiii m 1 1 ill UNIVERSITY Or Digitized by the Internet Archive in 2012 with funding from University of Illinois Urbana-Champaign http://archive.org/details/circularsbullet444663depa GENERAL IKFORMATION FOR ILLINOIS ITOT GROWERS A, S. Colbyl/ The follcfwlng "brief comments may "be helpful in answering some of the in- quiries of those interested in nut growing in this state. While certain nut species well adapted to northern United States are among the most palatahle nut fruits on any market, canmercial nut production in the north is not as important as in the west and south. In certain localities of southeastern and southwestern Illinois, however, the crop from the native pecan groves is often of important cash value. One of the greatest opportunities for profit and pleasure in northern nut growing at present may he found in planting nut trees about the heme, especially on the farm. Suitable kinds and varieties may he planted profitably on fertile but otherwise unused spots around buildings (where they may help to enframe the house and provide shade), along fences and ditches, on steep hillsides and in other so-called waste spaces. Seedlings already growing may often quickly be made more profitable by top-working them with scions of superior varieties of the same or closely related species. The necessity for a close relationship between stocks and scions is es- pecially impoirtant with the chestnut. Nut Variety Recommendations for Home and Commercial Planting Chestnut— £/ Filbert — (European) Barcelona, Bolwyller, Daviana, Du Chilly, Italian Red; (Anerican) Rush, Winkler Heart Nut — ^Bates, Faust, Fodermaier, Stranger Hican — (Shellbark-Pecan Hybrids) Des Moines, Gerardi Shagbark Hickory —Glover, Kirtland, Romig, Swaim Other Hickory Hybrids — Fairbanks (Shagbark X Bittemut), Pleas (Pecan X Mockemut) Pecan— Busseron, Greenriver, Indiana, Kentucky, Major, Niblack, Posey (These varieties are more satis- factory in southern than in central Illinois and are not recommended for northern Illinois ) Walnut — Allen, Grundy, Ohio, Rohwer, Stabler, Stambaugh, Thomas, Ten Eyck Some Factors Which Influence Nut Production Until more is known about the pollinating habits of nut varieties in gen- eral, each planting should include a few trees of several varieties of each of the species which is chosen. Cross-pollination is thus rendered more probable, and better nut crops will result. 1/ Professor of Pomology, Department of Horticulture. 2/ Chestnut blight is now generally prevalent in Illinois, Trees of highly desirable varieties, including Boone and Fuller, formerly profitable in orchard plantings, are dying out as a result of the disease. New plantings are likely to become in- fected and the trees killed within a very few years. Some of the Chinese and Japanese chestnuts are strongly resistant to blight and are now being planted conservatively with reasonable prospects of a favorable outcome. (Note C, A. Reed's pamphlet on chestnut planting under References on page h,) 'v!a n:r-;c;iD tsvi axc^ijji axys KoiTAfKC'nii iAj=HV5SD \i-^cflc ■!D3 ^It^v^rtB r:. ■dT ■'ta&'i-6o'; ■piaoiii'-z, ©IB Q3&S&3 be&isfJ irt&dttoi' : •o ai c-Qvo-xg nsoog QriiSaa slid* ssd-xI: q hvn marlchf orij jijvoV.-' oOw'jij vi"ijii ■Qal&rnQlci nl bruJo'X fed '^aiE Jx^ ■ " ■ •...-■■u ...... :..- - .- iXda&rioiq ho.f aslqi ocT ^aitc eiOidrsixsT .bxxs aJixiti oIq.-;v„.;v . ..■.;.-.. :;:;. boB Qsssod ed& ossstJxte of qlod x^in yfi^''-^ Qtrrd-vr) &^lbl]:ss.-.- ^e!9o..Bq£. \ CTilJ^X'a. .c».^~.'.)' .i.ci.'^.'.!l>.. ,i.i..,ij 'j.-<'i.i "i'j J, cikii -J.'.;..i ■rr >.-; ^ i- ■ • ■,;,,,.. ^, aacr ■(ai)X^s,iV^, .. - ..• - ■.-.:' - ■:■.:. ^TiOt^M ^xAou&itByL ^afL&tbal ^-isri'srisaT . • ■ -a.£d*.sa 5- ■,■' 3s«5X;ts£'3:aT 93S.dT) vosol' ^?iOiiXdJ:''. ( aiicnilXI msiid-'xcn io"3: £i3£>nf>inc(S»08tf. &on. .5x18 ^aXdsdoiq; aionr J>i^T;'jl)n.„'i &nd:t 8i rro.f'torr:^ 'ocfa mron. •■) Rf; ifo.r.ciV ^ jcyd-J-tH' Y.lt'.'-^J.. -al ■Xcffs^ti"'.' oC J.O ■fpr ■'-"'' ■ ' - ^' t;." . , ., ,trrf d" .^ - odit 'i;.,. j.urii.-:^.^ ::; oi: .. .:-d:ytv hB.U'r:'. •?^o^:;:t -; ■.'iX^ao-i-i' q aXcfsfiG;^!-.;'! xiJ'l tn^^iX'-" d-i.j'n;.;^-;:-;ifc no The age at which nut trees ccme into bearing varies, depending upon the kind, the variety, the soil, and cultural care. Very young trees often set a few nuts, some or all of which drop "before maturity. When grown in good soil, and otherwise well cared for, chestnuts and "black walnuts sometimes "bear a few nuts two or three years after planting; hickories and pecans may need twice that time or oven more. However, most kinds require seven to fifteen years to attain sufficient size to bear important money crops. When well-established trees are top-worked with good varieties and are given good care, earlier crops of reasonable size may be expected than when young trees are set. If the nuts fail to mature and to fill out properly, resulting in either undeveloped or shrunken kernels, the condition is likely to be due to one of the following causes: ineffective pollination, too short a growing season, too little or too much moisture at critical periods, infertility of soil, or premature defoliation by insects, diseases, or other natural causes, Eapid temperature changes, especially sudden drops to several degrees below normal accompanied by high winds, often kill filbert catkins in winter or spring. The new shoots of black walnut, hickory, and pecan are also subject to damage by late spring frosts, especially in low spots which form frost pockets. Weather conditions in Illinois are normally unfavorable for growing and fruiting either the Persian (English) walnut or the southern pecan. IVfeny varieties of these nuts advertised as hardy and very promising have been planted in this sec- tion with disappointing results, A variety of Persian walnuts hardy in the Carpathian Mountains of northern Europe has been introduced by the Reverend Paul C, Crath, of Toronto, Canada, and is now available for trial, A descriptive pamphlet may be obtained from S, H, Graham, Bostwick Road, Ithaca, New York, who has a sup- ply of the trees for sale. Suggested Sources of Nut Tree Nursery Stock Benton & Smith, Wassaic, New York Duis Nut Nursery, Shattuc, Illinois Mtt. Dependahl, Delhi, Illinois Jos, Gerardi, •Fallon, Illinois Hazel Hills Nursery Co,, River Falls, Wisconsin Indiana Nut Nursery, Rockport, Indiana J, F, Jones Nurseries, P.O. Box 356, Lancaster, Pennsylvania Nut Tree Nurseries, Downingtown, Pennsylvania E. A, Riehl Farm, Godfrey, Illinois Snyder Brothers, Inc., Center Point, Iowa H, F. Stoke, li<-20 Watts Avenue, N. W., Roanoke, Virginia Sunny Ridge Nursery, Swarthmore, Pennsylvania Whitford Nursery, Farina, Illinois These names are representative of firms specializing in nut tree propaga- tion and featuring the best named varieties. Many nurseries handling a general line sell only seedling trees (not named varieties). Most seedling trees are unsatisfac- tory if early and productive bearing of good nuts is desired. In such cases prospective planters should insist upon varieties by name. Budded or grafted trees are more expensive than most other fruit trees because of greater expense in propa- gating, growing, and digging, but they will usually remain longer in productive otli dr CSlS:.St' -.■■r ixsxl.t -'Tei>rx».- >B I^crxci: jri:^ Ho "^fiXi ujtiw ^2i'ioY wt>l'i .,KfJoii- .'j.Lwc^e; • ui'JHJ • r; £tX&ii'.->oc J, V,' 'I ,0,^ ^89iT:9atwH aeriob . X tem/;^ ■.JTr(-.-.Tp nseio ' null •";;^/:. -3- "bearing. Also, fewer trees are usually needed to fill the space chosen for their planting, "because most kinds reach a large size at maturity. Planting Distances for Nut Trees Planting distances for nut trees vary, depending upon the kind and variety, the soil, and sometimes the amount of space available. It is unwise to crowd the trees, since they reach maximum production only when allowed sufficient area for root and top growth. Black walnuts in good soils take full advantage of 60- foot planting distances. The new Carpathian walnuts promise to he large trees and require kO to 50 feet as a in:j?.imuni planting space. Native hickories and pecans grow nearly 100 feet tall when given sufficient feeding area, and northern named varieties should be planted not closer tlian 50 feet apart. In orchard planting, Chinese and Japanese chestnuts should he allowed from 35 to ^0 feet each way. Heart nuts and filherts are relatively small trees at maturity and may he set ahout 25 feet apart. Early Care of Hut Trees Nut trees should he carefully planted and well cared for. At planting time, it is usually advisable to cut hack the tree somewhat, unless the nurseryman has already done so. Do not crowd the root system into a small hole. Set the tree at least as deep as it stood in the nursery. Firm the soil ahout the roots as the hole is heing filled. In windy locations the tree should he staked until it has become established. Mixing dampened peat moss with especially heavy or light soil will greatly Improve its physical condition, particularly with respect to its moisture -retaining capacity, and will give the young tree a better start. Mulching with peat moss, straw, or similar material is helpful during dry weather, but the mulching material should be removed in the late fall. The ground about the tree should not be packed hard by stock or other means. Watering may be necessary during the first and second growing seasons, and the ground should be soaked well at intervals during the hot weather. The formation of a shallow basin at the base of the tree facilitates artificial watering and retains rainfall. An arsenate of lead spray in early summer controls walnut caterpillars. Protection against rabbit and mouse injury should be provided during the fall and winter months. Wrapping the newly set tree with paper, or shading the trunk, will help to prevent sunscald and damage from borers the first year or two after plant- ing. A minimum of pruning is necessary the first few years and should be con- fined to the removal of crossing and crowding branches, especially those which arise close to the ground. Pruning wounds should always be covered with a protective coating. References to Literature on Nut Ciilture Books: The Nut Culturist--A. S. Fuller Nut Growing- -Dr. Eotert T. Morris Tree Crops, A Permanent Agriculture- -J. Russel Smith Standard Encyclopedia of Horticulture- -L. H. Bailey Hortus--L. E. Bailey The last two hooks on the foregoing list include, under appropriate headings, basic information on nut culture. U. S. Depaarbment of Agriculture Publications : Farmers' Bulletins too!/ - Pecan Culture with Special Reference to . Propagation and Varieties Sk'^y - Important Pecan Insects and Their Control 995I/ - Preventing Wood Rot in Pecan Trees 1392 - Black Walnut for Timber and Nuts 1501 - Nut -Tree Propagation Mimeographed Pamphlet Chestnut Planting Again Attracts Interest (hy C. A. Reed) Miscellaneous Puhllcation 502 - Nuts and Ways to Use Them Leaflets 71 - Fertilizers for Pecan Soils 8^1- - Planting Black Walnut The 1925 Yearbook of the U. S. Department of Agriculture includes consider- able infonnation on nut culture and a discussion on the nutritive value of fruits, vegetables and nuts. The I937 Yearbook of the U.S.D.A. includes a comprehensive chapter on nut breeding which is available from the Superintendent of Documents, Government Printing Office, Washington, D. C, as Yearbook Separate I59O (10^), The historical information on nut varieties is of considerable value. Illinois Publications (exclusive of many papers on grov/ing nuts in Illinois, to be found in the annual reports of the Northern Nut Growers' Association) Nut Growing for Pleasure and Profit--E. A. Riehl, Trans. 111. Hort, Soc. 5it, 1920 Chestnuts for Illinois- -R. B. Endicott, Trans „ 111. Hort. Soc. 55, 1921 Nut Growing in Illinois- -A. S. Colby, Trans. 111. Hort. Soc. 58, I92I1 Possibilitles of the Nut Industry in the Middle West--J. A. Neilson, Trans. 111. Hort. Soc. 63, 1929 1/ No longer available for general distribution but can usually be found in libra- ries featuring agricultural literature. S'tij.jlL'J s./i/i no di !,j',: .'iu ^ abiJi' \kiSS .sctaH -5- Planting Black Walnuts in Illinois— Publication #11, Dept. of Conserration, Division of Forestry, Springfield, 111., 1938 Some Results of Selection in the Northern Pecan — A. S. Colhy, Proc. Amer. Soc. Hort. Sci. ^, I938 Directory of Markets for Illinois Forest Products~J. E. Davis, Natural History Survey and Univ. of 111,, lyQmeo., 1959 Organization Interested in Securing and Disseminating Inf carmation Memhership in the Northern Nut Growers* Association, G, L. Slate, Secre- tary, Agricultural Experiment Station, Geneva, New York, is open to those interested. Annual meetings are held in different sections of the country, where "both newly planted and bearing trees are studied following a program of papers and demonstra- tions. The annual reports, of which hack numbers and an index, published separately, are available, constitute an invaluable working library for the practical nut grower. The American Fruit Grower (monthly), 1370 Ontario Street, Cleveland, Ohio, is the official organ of the association, which sponsors a column of material interesting to nut growers in each issue. Partial List of Dealers in Northern Nut Kernels Bordo Products Company, 5^1 North Franklin Street, Chicago, Illinois E, E, Funsten Company, 1517 Morgan Street, St, Louis, Missoviri The James A. Harper Supply Company, 505 West 5th Street, Kansas City, Missouri Kelling Nut Company, 5^5 East Illinois Street, Chicago, Illinois Louisville Coffee Company, 22^1- West Main Street, Louisville, Kentucky National Association of Bakers Supply Houses, Henry & Henry, 304 Michigan Avenue, Buffalo, New York National Confectioners Association, 111 West Washington Street, Chicago, Illinois National Wholesale Grocers Association, 6 Harrison Street, New York, New York H. W, Smith Company, I89 West Madison Street, Chicago, Illinois Joseph A, Stanka, Nut Brokers, 565 West Washington Street, Chicago, Illinois Caution ; Write or interview buyers before sending first shipment . Kernels must be properly cleaned, cured, and packed. Several of these firms will sometimes buy unshelled nuts. No discrimination is intended in emitting other firms on this partial list. Also, no guarantee of reliability of the dealers listed is made or Implied, -—1 3tOj3J.v.;. -- -.vv.i. J. 2d& ill nr.lJo^IciL. 'ic -.•. axaC'C ox r nnij^n -3 TinJituo^rd nl .li.sd'as'jo^nl .ax:?i:a-3:s.!:ri«siO ' .. m aw ' i yk .i niii.a ■ii m -«»j.^«w».w.^.ii«ii»,iiii i m m i.i n i. mu b iiwi la— . ■ !■■ ^ » & * r .»i p, ** ^ ■^w4^,i^>'., «^' - J./ii. U.'^ i3vri"XX j.ibX Av^vJiiii =?Xecn:s:,. .■.'.■lelBSa ,i.>: '1^ xich: ~ aiorixXx" , erilivj^ r.rroJ ..t«ftf-t8 ff.t?M .+q*=)W 4Sf^ .TCb^^ VrrsTiT , ;t3e-i: , cfQett'. t arssTlc ^riS-s^' , OiX^ J. 1, ■•rsoJiiJ; i"o sj -7- grafting in order that the stubs -will finish hleeding "before the scions are set and the excess sap will not "be so likely to drown out the scions. It may "be advisable at this time to remove seme "branches which may later interfere with the growth of the scion. Just "before grafting, an additional three to six inches should "be cut off carefully with a sharp fine-tooth saw to provide a fresh working surface. The sawed surface should then "be smoothed with a knife at the places where scions are to "be set, A flattened area which often occurs on the trunk makes an excellent place in which to set a scion for the side graft. It Tas;y he desirable to choose a place for grafting a few inches a'bove a side trench. The hark on the side of the stu"b is then slit straight down from one and one -half to two inches, and a small wedge of "bark on each side of the initial cut is removed to make the opening at the top from one-fourth to three-eighths inch in width, depending upon the size of the scion to be used. The sides of this cut should be beveled underneath as the wedge is removed. A spreader stick, preferably of hickory or some other hard wood, should be shaped to correspond to the shape of the scion but a little shorter and narrower. This is inserted between the bark and the wood of the stub where the cuts have been made, to loosen the bark. The spreader should be left in place while the scion is being prepared. In preparing scions, a section of healthy one-year-old wood from four to six inches in length and approximately five-eighths inch in diameter should be selected, "With a sharp knife, the butt end of the scion should be shaped into a tongue one and three-quarters to two and one-quarter inches long by making a sloping cut and exposing the cambium layer. The tongue should be smoothly tapered from shoulder to point, where it should be as thin as possible without feathering. Then about two-thirds of the thickness of the scion should be cut away, extending in beyond the pith on the back of the tongue and leaving the shoulder square at the top in order to insure a firm seat. Some propagators recommend that two or three small notches be cut through the bark in the outside of the tongue so that a small amoujit of sap can collect there to aid in starting callousing. The scion should be inserted in the stock immediately after it is prepared. Properly cut scions should carry two buds above the tongue, with the lower bud on the outside and at the top of the tongue. If the scion has a terminal bud, it should be removed, as it is easy to force and may start growth before a complete union has been made "between scion and stock. Two scions should be set, one each on opposite sides of the stub, except where stock less than one and one-half inches in diameter is being used, in which case but one scion is placed. The stub and scions are then bound with soft twine tied with one or two half hitches at the bottom, and are entirely coated with grafting wax which is brushed on. Strips of cotton cloth are then laid across the top of the stub in such a manner as to cover it completely and extend down the side for at least an inch. The stub is wrapped about four inches down with a narrow strip of cloth which will adhere to the wax. Some propagators make a short cut with a knife through the bark on each side of the stub (not directly below the scions already set) to prevent flooding the scions with sap. The cuts are made about 8 inches below the graft union. The entire graft is then covered with a paper sack of convenient size, tied to the stub and left for about two weeks, A slit should be made in the sack for ventilation. Later, the twine should be cut on one side to prevent injury by girdling, but should not be removed. This Diay be done at the time the sack is removed. Instead of twine, some propagators are using one of the new elastic tapes, which will deteriorate within a few weeks and do not need to be cut. od- a££d- e-- •rr.r '. . -^r-tn - >ifd d-c: • • La xisn:! aexfon. txm ik q&e, 1". ; RBrf .r; ^3 vjwd ' fioija U: j:c qo. •1300 ic » -8- If tlie graft makes a vigorous growth, it will be necessaiy to support it in an upright position for one or two years by fastening a small pole or strip of lumber to the tree and tying the graft to it by some means such as a wire, run through a piece of rubber hose, to prevent chafing. Suckers should be discouraged by cutting back or removal if they tend to dwarf the new growth from the scion. If two scions are used on the stub and both grow, the less desirable one should be removed before the next growing season. With a fine-tooth saw, a slanting cut should be made at the side of the stub to facilitate the removal of the unnecessary graft, and the wound should be covered with wax or similar protective material. I lltir v+.fc ,rf3-wr.ia ewoT. -9- — rront view of Scion Stock wifh V-shaped cut fl V: 1 Side view of Sc ion Scion m place Tied and Readij to Wax EC Eg 8-15-41 H44 W V L -i iioi:)21o IF I) I" ; 1 > ^^V"'"™"' ^5^1 i ■ v^: 1 ^\. ■p-f-' CD »< (D M H) O O* O C?3 l-J M, 2 O "^ H- > 5 3 H- p (» W P Q O O 4 O 3 p: H. H. 4 H- M D3 O C+ O c+^ C H- CO S !-• O cj M e: P />>'■ jl' ':• i/iJi'-^ p CD CD ji p^ a CD •1 '.•A'.Vv., H« J'!v.V^ ■.'^: 3 m -13 IC o r — METHODS FOR REMOVING SPRAY RESIDUE By W. A. Ruth and K. J. Kadow, Department of Horticulture University of Illinois July 1, 1934 As a result of our experiments last year we are making the follow- ing suggestions a,nd recommendations. Analysis ; The washing treatment should iDe based upon, and varied with, the amount of residue that the apples carry when picked, and upon the difficulty involved in its removal. In cases that are at all doubtful , the only safe procedure requires analytical control . It is an obvious fact, which nevertheless requires emphasis, that, without adequate analyses, the growers are entirely in the dark. If a washing process is inadequate, the grower should know exactly how far he must go to meet the tolerances; otherwise he cannot hope to modify his washing process intelligently. On the other hand, without analysis, his washing treatment ma^/ be unnecessarily severe or costly. An entirely satisfactory analytical control calls for several steps. a. An analysis of each variety when the fruit is almost ready to pick. The results of this analysis, and a knov-^ledge of the spray pro- gram and the materials used in spraying, can be used to suggest methods and materials for washing a test sample. Heating the washing solution, increasing the concentration of the acid, the use of a wetting agent in the acid bath or as a predip, and slow progress of the fruit through the v/asher all facilitate removal. b. A test sample should be washed and analyzed. If the federal tolerances are not met, with a reasonable margin of safety, the method should be changed in accordance with the above paragraph and the re- I -2-. suit determined by a further analysis. The tolerances are 0,01 grain arsenic (ASpO^) and 0.019 grain lead per pound of apples. c. If there is any reason to suspect the necessity of a change in the method of washing as the season advances, another analysis should be made. For example, if no means of heating the solution is provided, the terapera.ture of the washing solution may drop before all of the crop of one variety is v/ashed; if this occurs, it will be necessa.ry to analyze the fruit to be certain that it is still meeting the tolerance. Apples washed to test the effect of equipment, solutions, and temperatures should be washed in the equipment that is used to wash the crop, and in exactlA^ the same wa.y. To insure the progress of the apples through the machine in the normal way, and at the normal rate, it will be necessary'', in most equipment now in use, to wash tv/o or three bushels, which is considerably in excess of the amount required for analysis. A record should always be made of the washing process which a sample represents. All important data should be set dom^n, including the temperature of the solution, the concentration of each ingredient, and the length of time that the fruit takes to pass through the moxhine. The State Department of Agriculture, at Springfield, will. have a man in the field to take sa.mples for analysis, according to Mr. H. M. . Newell, Superintendent of the Division of Standardization and Markets. The man taking the samples will also find out, through the various farm bureaus, . which growers will ha.ve fruit that they will want to have analyzed. In case it should be necessary for growers to send in samples by mail or express, they should be sent to the Division of L ^i«r ^.i^ -3- Foods and Dairies Laboratory, Department of Agriculture, Springfield, Ill.inois. There should be at least four pounds of apples in each sample. The apples selected should carry the heaviest residue, and should be of average or less than average size for the variety and crop. If the package is sent by parcel post, information in addition to the grower's return address, which should be on the container itself, must be in a stamped envelope attached to the package. The grower should indicate hov; he wishes to be notified of the results of the analysis, that is, whether he should be notified by wire or by card. The analysis will be completed, according tollr, Newell, within 24 hours, or less, after the receipt of the sample. Washinp; machinery ; Washing machines now in use float the apples in the washing solution, or flood or brush them with it, or combine two or all of these processes. The most efficient commercial machines flood the apples with the solution as they pass over a series of brushes. Flotation machines (paddle washers) can be ma,de by the grower, ■T-lie cost of the materials should not exceed ^150. Specifications are given in Farmers' Bulletin 1687, "Removing Spray Residue From Apples and Pears." The Department of Horticulture of the University nov/.has a limited number of copies of this bulletin for free distribution. Copies can be obtained for five cents from the Superintendent of Documents, Washington, D. C. Commercial machines which depend primarily upon flotation are also on the market. Our experiments indicate that the appearance of apples washed by flotation may be a serious objection to this process if they have been heavily sprayed with lead, lirae, and oil. Apples washed in this way have a dull finish and appear to carry considerable residue although I IJr.o. Hint!., . ., , , ,,- ., ry (' -4- lead and arsenic may have TDeen reduced to amounts that are well within the tolerance. If the amount of residue to be removed is lighter, or if somewhat different spray materials have "been applied, this objec- tion to washing by flotation may not hold. Apples washed in an under- brush flood machine are bright and look as though they had been en- tirely freed from residue. Thorough rinsing , with a final rinse in fresh water , applied as a spray or flood , is an a b s olute necessity in order to avoid in jury from the washing solution . Two or three gallons of fresh water are re- quired for rinsing each bushel of fruit. The rinse water left in the blossom ends of the apples should not have an acid taste. The water used in the final rinse should run into the rinse tank. The apparatus to spray the apples as they emerge from the rinse tank can consist of pipes drilled with holes along the bottom. It is not an absolute necessity to dry the washed fruit before it is packed, but it is very desirable because of the improvement in ap- pearance and the lessened danger of infection with rotting organisms. Commercial driers, to be used with flotation machines, 8„re available, and are a part of the flood type and underbrush flood type machines. The acid bath ; Hydrochloric acid bath has proved better than sodium silicate as a wash for apples sprayed with a combination of lead arsenate, lime, and oil; it will probably be better whenever lime or materials made from lime are contained in the residue. The acid is much better than any of the commercial materials so far tested. The strength of the acid solution can vary v\fith the amount of residue to be removed and with the difficulty of its removal. It is probably not desirable, even if the load is very light, to use less than 1/2 of one percent actual acid. If the residue is heavy and difficult to remove, 1 l/4 percent actual acid should be used at 110° F. ..{ - s.iJ U 1 -5- (See paragraph, In.iury ) . The strength can be increased to 1 3/4 per- cent at 70° F, without producing injury. Commercial hydrochloric (m.uriatic) acid can be bought in three strengths. these are 28^ actual acid (18° Baume); '^2.% actual acid (20° Baurae); and 35.4^ actual acid (22° Baume). The 32^ acid is com- monly used. The container should specify the strength, either in per- cent or in degrees Baume. Occasiona^lly the strength is indicated in specific gravity instead of degrees Baume: 28^ equals 1.143 specific gravity; 32^^ equals 1,163 specific gravity; 35.4^ equals 1.180 specific gravity. The acid can be bought in ten- to twenty-gallon glass carboys in wooden containers* It should not be permitted to come into contact with the skin or clothing; if it does, accidentally, it should be rinsed off as soon as possible, and the spots on the skin and clothes should be neutralized with hydrated lime or baking soda., which should be at hand. Care should be observed not to inhale fumes from the con- tainer. An arrangement for tipping the container should be constructed. The acid corrodes metals, so that glass, earthenware, or porcelain measures must be used. Amounts of acid required to secure various dilutions and to make depleted solutions up to full strength are given in the appended table. The washing solution should be made up fresh after each full day's run, or the equivalent of a day's run if the machine is run at less than capacity. The solution should be tested at intervals to see that it is up to strength. The equipment for testing consists of one 10 c.c. bulb pipette (c.c. stands for cubic centimxeter) , one 10 c.c. measuring pipette, a three-ounce glass bottle, and 1,000 c.c. of testing solution. (This will be a little more than a quart, which is 973 c.c.) One thousand -6- c.c. of the testing solution should contain 23 grams of sodium bi- carbonate (chemically pure baking soda) and enough methyl orange to produce an easily visible yellow color. A pharmacist can make up the solution, and the pipette can be bought at or through a drug store. To make a test, transfer 10 c.c, of the diluted acid from the wash tank to the bottle with the bulb pipette. The 10 c.c, mark on. this pipette is the ring around the part of the stem above the bulb. The solution is drawn above this ring by suction, and allowed to flow back to the mark before it is run into the bottle. The measuring pipette is filled to the c.c. mark with the test solution in the same way. The test solution is allowed to run slov/ly into the bottle containing the acid until the color of the solution in the bottle changes to yellow and remains yellow after gentle shaking. Moistening the tip of the finger placed against the end of the measuring pipette helps to control the rate of flow of the solution. One should shake the bottle gently while adding the solution. The number of c.c.'s of the test solution divided by 10 equals the strength of the acid. The test should be repeated, to insure accuracy. The temperature of the washing solution: The temperature of the solution appears to be the most important variable factor in washing. In our experimental work in the fall of 1933 , about six times more lead and arsenic remained; on fruit washed at 65^ F. than on fruit washed at 110*^ F. At still lower temperatures, which are often encountered in the fall, correspondingly greater amounts would have been left. Methods of heating are described by R. H, Reed in a mimeographed paper, "Heating Systems for Warming the Washing Solution in Apple Washing Machines," which should be available from this Station after the first of July. '"'.■ f ' tstiaitis/Si- ~7- Wettinp; ap;ents : The wetting agent most thoroughly tested is Vatsol. This matei'lal increases the effectiveness of the acid solu- tion, especially in flotation washing, where it is added to the acid at the rate of 8 pounds per 100 gallons, making a ifo solution. In machines which agitate the solution, Vatsol produces so much foam that it must be used at a very low concentration if it is used at all. Used at l/30fo (4-g- ounces in 100 gallons) in the underbrush flood type machine it facilitates removal to some extent, Predipping : The function of predipping appears to be to facilitate wetting the fruit with the acid solution v/hen it is passed into the acid bath. The predipping bath should therefore be a solu~ tion of a wetting agent. In flotation machines predipping seems to be unnecessairy , because the wetting agent can be used at full strength in the acid. If the apples are washed in machines which agitate the solution, it is an advantage, under certain conditions, to predip the fruit in ifo Vatsol, The conditions referred to are those which re- tard removal, such as the use of inefficient machinery, too rapid wash- ing, the use of temperatures below the highest safe temperature, and wax accumulation on the fruit due to late picking, etc. The horaei-made washer can be used for predipping. If necessary, acid can be used in addition to the wetting agent, which transforms the predipping machine into an auxiliary washer. In this case, provision should be made for heating the predipping (prewashing) solution if difficulty in removal is anticipated. Spray schedule : Oil-containing sprays applied near harvest make removal especially difficult, The spra^y program advocated by this Station allows for this fact. -8- The exact effect of a spray program cannot "be predicted. The experimental work of last year showed, however, that the residue could "be removed to a point well within the tolerance from G-rimes and Jonathan which received the last spray of lead arsenate (4 pounds per 100 gallons) and lime (8 pounds per 100 gallons), combined with ifo summer oil or 3/h-fo miscible oil, three weeks "before harvest. The total load of lead on this fi'uit_ varied from 0.103 to 0,183 grains per pound. The arsenic varied from .039 to .068 grains (As20v) per pound. A much heavier load could have been removed, because the residue left after washing was so far below the tolerance. These apples were washed in l^fo acid containing l/30^ Vatsol in the underbrush flood type machine for 30 seconds at 110°F. "V/ashing by f lota.tion for 2^- minutes in lifo acid containing ifo Vatsol, at a temperature of 110° F. would have been equally or more effective; the temperature could have been considerably lower. Kinnairds carrying a much heavier residue (.094 grains of AsgO-^ and .292 grains of lead per pound) were washed v/ith equal success. The last spray, of lead, lime, and miscible oil, had been applied six weeks before harvest. In.iury ; The most drastic washing treatment used last year re- sulted in a slight increase in the loss of weight in cold storage in open containers. There was no visible increase in shriveling and the effect was not commercially important. The treatment that produced this effect was flotation at 110° F, for 2-|- minutes in 1^ percent actual acid and ifo Vatsol. The fruit that v/as washed was fully mature. G-reen finiit is probably more subject to injury. To be on the safe side, the temperature of this particular solution should not be above 90° F, , if the fruit is somewhat green, and if the fruit is exposed to the solution for this length of time. This precaution applies f -,.-;- l" -9- especially to summer apples. It is not desirable to allow the fruit to "become too mature, in order to avoid the possibility of injury in washing or to improve its color, because of the danger of increased difficulty in residue removal due to wax excretion. Apples should be washed immediately after picking because residue removal is much easier then than later. To prevent apples from remaining in the machine too long, and thereby being injured, most of the machines now in use, including the flotation machines, must be kept constantly supplied with apples, which should be fed into the machine at a uniform rate. -10- Tlie following taole indicates the amount of commercial acid to use in making up 100 gallons of acid wash of various strengths. The table also shows the amount of acid that must be added to a depleted washing solution to bring back its original strength. If, for ex- ample, a test shov/s that the acid is 0,2^ low, it will be necessary to add either 6 pints of 28^ acid, ^ pints of 32^ acid , or 41- pints of 35.4^ acid. Acid ( 3ontent Amount required to make 100 gall ons required in 28% acid (18^B.) 32% acid (20^B.) 35.4% acid (22^B. ) v;ashj Gallons Pints Gallons Pints Gallons Pints \l .._ 3 »~ 2* _•> 2 , 0. .2 M— 6 — » 5 ..^ 4* 0. .3 1 1 ... 7^ »» 7 0. .4 1 4 1 2 1 1 0, .5 . 1 6* 1 4* 1 ^ 0. ,6 2 li 1 7 1 5i 0. .7 2 4 2 1* 2 — — 0. .8 2 7 2 4 2 2 0. 9 3 2 2 6 2 4 1. .0 3 5 3 1 2 6* 1. .25 4 4 3 7 3 4 1. 50 5 3 4 5, . 4 2 1.75 6 2 5 3^ 5 2.00 7 1 6 2 5 5 I H46 I x i >^ SPRAY ESSIDUE BEMOVAL By W, A. Ruth aad K. J. Kadow Department of Horticulture, University of Illinois The work that we are reporting is based upon hundreds of tests and thou- sands of analyses. We shall atternpt to summarize it, putting into words the most important facts. The endless charts that might be shown would only be confusing^ At the same time, successful washing calls for just as close study of details as spraying. The details of washing are new, while the details of spraying have ac- cumulated gradually. As might be supposed, it has been found that spraying and wash- ing are closely related; the materials that are put on must be taken off. Changes in the details of spraying introduce new details and new problems in residue removals EXPERIIjEHTAL mTA General The increase in residue due to one application of s£r^: Analyses of Jonathans August 20 immediately before and just after spraying show that one aijplica- tion of lead, lime, and oil increases the load of lead by approximately l/lO of 1 grain per pound of fruit. The rate of los_s of lead from s^r^red f rui t ; In dry weather, sprayed fruit loses very little residue, and, in wet wea^ther^ the rate of loss depends upon the constituents of the spray as well as upon the rainfall. Even in rainy weather j the rate of loss is slow enough to base a trial washing process upon analyses made a week before harvest, and to permit the readjustment of the washing process in accordance with the result of the preliminary test, provided analyses are immediately available. The ratio of lead to arsenici If the lead tolerance is met 5 the arsenic tolerance v/ill, almost invariably, be met also, because the arsenic weathers off more rapidly than the lead. The lead to arsenic ratio in lead arsenate j as is applied to the trees, is 2 to 1. The present ratio of the tolerance of lead to arsenic is 1«9 to 1, which is almost the same. The ratio on the fruit immediately after spraying is also 2 to 1, but it may increase to 5 to 1 ia 4 or 5 wseksj or less. This year» in southern Illinois, lead usually ran 3.5 or 4 parts to 1 part of arsenic at harvest. In western Illinois, at harvest, it ran 2 or 2^5 to 1, The difference was probably due to drier weather in western Illinois* The lead load therefore cannot be estimated indirectly by multiplying the result of an arsenic analysi® by two, buturast be foundby direct analysis. In this paper it will be necessary to consider only lead residues, althotigh arsenic analyses are available. The effect of omitting lime In spraying ]J£on the lead residue at harvest; The effect of lime in the spray is to increase the rate of lead loss by weathering. Illinois apples sprayed with lime, lead, and oil carried, at harvest, only a third or a fourth the lead retained by apples sprayed with lead, oil and spreader. For this reason, most western Illinois growers were meeting the tolerance easily by washing with comparatively ineffective solutions; that is, in 0,6 to 0,9 percent acid at 60 to 70 degrees, without a- wetting agent. These are not effective temperatures or solutions. The best that can be said is that the solutions and temperatures used could not harm the apples. The growers shipped the wa,shed apples without analyses, and hoped, fervently , that they were meeting the tolerance. They hoped, fervently, but they could not be sure. i-if'.iial'-n '■;o-htkdi:.<:< TXiHi^i i; j;'^^v'-.rr( •:*;i jfcDi'ixr-'j X^ •■ Ar^i^ <;;■.■■;•.. jOr-XI .{^l-- h-'n^yt:i!, j^^if^ac ^:l<:::-i:.l ■ -.mtrtot^ ^'liirl^o'v r^ i'-'U- 1 ■■•■;■ .b^-,'^1. d:. X^)yu:i-?'.-|-: - ■ j;;- • -g i:)u;iX >=,?■■•■{ ^).^./:,I ;0X.- r'j m..:.:oj. .; :v,^J;;£!^'i».Tv4o"v;^Jjfe^'-^?'A,!a«lo? Sii? "u:lU.: :r- ;■-?:;;.■■■■:. •-v^cv.' nXa^iXIT rri-l;-:-'. -'-v:.!: i^CiSsSiiii X5r^.;-Jvi)l::f.^,'*aa&'S3fq-, SwO C'.^ ;>«Q./::X ; ..-j.^ i: 'C^^^ :u:7n -^ ;X:,v, :./:.'n,:'i:l9nX vlavXi-'-iv-no'^ :i*:;^;' I 2. Dry "brushing ; Several Illinois growers this year were giving their apples a preliminary dry brushing before washing. Because of the inrprovement in ap- pearance it was thought that the brushes might be having considerable effect. Analyses in our laboratory proved conclusively, however, that the dry brushes were having no effect whatever. A imich better plan would have been to precede washing with an eliminator in order to remove the small apples that clog the washers. Dry brushes can be used, if desired, to polish the fruit after the tolerance has been met by washing. The effect of lime in the spray upon residue removal ; Apples sprayed with lime, in addition to lead and oil, are much more successfully washed in acid than apples sprayed with lead and oil without lime, even when they carry as heavy a load of lead. If apples have been sprayed with lime, acid is a much better single wash than silicate. All Illinois commercial apples sprayed with lime, lead, and oil, in 1934, could be washed successfully in acid. Acid is about five times as effective as silicate on lime-sprayed apples. Acid Washing Some of the tests run last year in acid washing were repeated, and new tests were run. The effects of temperature, time, and wetting agents were again tried, both in flotation washing and in brush washing* Temperature in flotation washing ^ Raising the temperature from 70 to 110 degrees decreased the residue by one-half* Although the effect of heat was much greater tttem. last year, it again proved to be important. Time in flotatlqn washixig; At 110 degrees the maximum effect in flotation was produced in 1 minute. At 70 degrees* 1;| minutes was better than 1 minute; 2 minutes was still betterj Vat sol concentra tion in flotations One-eighth percent Vatsol was found to be as effective as 1 percent. It reduced the residue left by 50 percent. It was equally important at 70 and at 110 degrees. If a flotation washer is used, therefore, and the load of lead is heavy, the temperature can be raised, or Vatsol can be used, or both, depending upon the load and the difficulty of removal. Temperature in brush washing ; Raising the temperature had almost Exactly the same effect in the underbrush washer as it had in flotation, Vatsol in brush washing t Vatsol was effective at 70 and 90 degrees, but not at 110 degrees. If an underbrush washer is used, therefore, the maximazm effect can be obtained by raising the temperature of the solution to 110 degrees; at lower temperatures, at least up to 90 degrees, Vatsol can be used to advantage, but without producing the maximum effect of which the machine iis capable, Vatsol at various concentrations, in brush washing } A concentration of l/SO percent Vatsol, which was all that could be used in the brush washer without excessive foaming, was as good as 1 percent Vatsol with #16 defoamer; if there was any difference, the lower concentration was the better. TI.9A? ]^^"YX^ 9iaw. on ^ivjBff -stW Liiiv bk ,,.;\:X&v'" ■ Jjfcihcl '''T ;1T sni:-]:." ■ , ('. iiJBBe'I ". i xxl fXip ■'■ i^ixw. 'ixs ;^/;.'; wan l>n>3 ,i>9cJ ^ir Oil AiiiB'tsitC^-Lei dHc ■tjur;tfiie'■■. ." ''. ■•;.•/';;?: iisiiif't 'At^^ ;;fv-i"';,.^- tV' y^ ■/^i? '? ■-'ft-' '•'■'.' • •, . i ■ 4 ... .-. ., . .|j-J.3,,^e ■;f-i3w ^^cv^i;' W^IXJcT' ix uii ■ ■■" •■• •■) 'i>H^l^^ilXli.'V: :. ■■ .' '*:fA '■■I' X.3. iSw ■^■f ■ .a'#;G'3^ 3-j!fF . ■;.«*■ -i},4-:^ ■ 5. Injury increases with an increase in the temperature of the acid bath, with the duration of immersion, and with the concentration of the acid, it is also increased hy Vatsol. Little or no acid injury followed washing at .70 degrees, . even" this year, but, in our experiments, washing at 110 degrees for 2^ minutes injured sensitive varieties severely. It is fortunate that most western Illinois Grimes, Jonathans, and Willow Twigs could be washed this year in acid at low temperatures and concentrations. I Silicate injury ; Injury from sodium silicate is usually due to incomplete rinsing. Sodium silicate is comparatively hard to rinse off, and the rinse should be especially thorough. This type of injury is confined to the calyx and, where it pro- duces a solid round burned area, somewhat like arsenical injury, but different in the regularity of its outline. Silicate at high temperatures can also induce cracking, which resembles acid cracking in its appearance and distribution, CONCLUSIONS The most important conclusions are, very briefly, as follows; 1, The washing process should be based on the spraying treatment, upon analyses of the fruit for lead, both before and after washing, and often upon pre- liminary tests for injury. 2, Judging from this year's experiments, apples sprayed with lime, lead, and oil can be washed successfully with acid. Sodium silicate should not be substituted, 3, Also judging from this year's results, tandem washing will often be required if lime is not used. 4, Preliminary dry brushing has no value, 5, It is especially necessary to guard against heavy residue on the vari- eties most sensitive to acid. 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