A/%^ : >9 r S. DEPARTMENT I >F AGRICULTURE, Bl l:l \i OF PLANT [NDU8TR"Y I ire J G \i i.ow n i THE SUBSTITUTION OF LIME-SULPHUR PREPARA- TIONS FOR BORDEAUX MIXTURE IX THE TREATMENT OF APPLE DISEAS1 BV W. 11 SCOTT. Pathologist in Charge <>r Obchari>t5prating Experiments \m> Demonstrations, Fruit-Disease I n\ estigations. • MWWJTOI : <- HI Rh.U OF PLANT IMUSTRT. Chief of Bureau, Bbvbrli T. Galloway. Assistant Chief o] Bureau, Q. Harold Powell. Editor, .1. E. R(X K.WELL. Chief Clerk, J lmes E. Jones. £Clr. 54] 2 It I ' Mil. SI BSTIT1 TIONOF LIME-SULPHUR PREPARA- TIONS FOR BORDEAUX MIXTURE l\ THE TREATMENT OF APPLE DISEASES. INTRODUCTION. If. iv,-. 'iit years Bordeaux mixture has come into ill favor among the apple growers on account of i t ^ injurious effect upon the fruit and foliage of certain varieties, and there i- a growing demand fora reliable fungicide which can !><• used for the control of apple diseases without producing such injury. Bordeaux mixture i- undoubtedly the best all-around fungicide known, and it is unfortunate that the apple growers have to consider the possibilitj of giving it up: but tin- ruaseting of the fruit and the burning of the foliage caused In it are so objectionable that it seems highrj desirable, if not necessary, to adopt a less injurious fungicide even at the risk of a partial sacri- fice of emciencj in the control of diseases. 'The subject of Bordeaux injury has recently been admirably discussed bj Prof.U. P.Hedrick,* of New York, ami 1>\ Prof. ('. S. (Yamhill, of Qlinois, and will he considered onrj incidentally in this paper. During the past three years the writer ha- been working on the problem of securing a satisfactory substitute for Bordeaux mixture and not without some success. The self-boiled lime-sulphur wash which was developed primarily for spraying peach tree- has been found t«> tie an excellent >pra\ for the control of mild cases of apple diseases and to be entirely harmless to fruit and foliage. The con- centrated lime-sulphur solutions, hoth commercial ami home pre- pared, when diluted to contain about 1 pound- of sulphur to ."in gal- tcknowledgmenl whereby made of the heart] tion and assistance til.- miter oi this paper in his investigations bj the Strathmore < Orchard Companj . of Mount Jackson, Va., and the Kim Springs Orchard Company, oi FishersviUe, Va and also by Messrs. M F. Gilkerson ofStaunt< l A - Ballard, of Cr the experiments and demonstrations were conducted G II. Powell, Act • Bulletin 287, NY .-ricultiir.il Experiment Station. I'm* e Bulletin 135, Illinois Agricultural Experiment Station. \'*Q9. [Cli d 4 LIME-SULPHUR PREPARATIONS FOR APPLE DISEASED. Ions of water have proved to be about as effective in the control of apple scab and leaf-spol i - Bordeaux mixture and to be much less injurious. Prof. A. B. Cordlev," in 1908, seems to have been the first to point out the possibility of dilute lime-sulphur solutions as a substitute for Bordeaux mixture in the treatment of apple diseases, especially scab. In an address before the 1907 meeting of the American Pomological Society, the writer l gave results of experiments which he conducted in Arkansas, showing that a self-boiled lime-sulphur mixture might be expected at least partially to control bitter-rot and scab. Again in the Western Fruit Grower of January, 1909 (pp. o-G), the writer showed that the commercial lime-sulphur solution registering 32 degrees on the Baume scale, when used at a strength of 1 gallon to 25 gallons of water, would control apple scab on the Winesap about as well as Bordeaux mixture without materially injuring the fruit or foliage. In the same issue of the paper just mentioned (pp. 6-7), Prof. R. Kent Beattie reported the satisfactory control of apple scab by very much stronger solutions of the commercial lime-sulphur — 1 to 11, 1 to 14, and 1 to 17 — and he reported no injury whatever to foliage or fruit. In 1908 the writer* controlled the cherry leaf-spot in Illinois with the commercial lime-sulphur solution. 1 gallon to 40 gallons of water, and with the self-boiled lime-sulphur, as well as with Bordeaux mix- ture. During the same year experiments with the lime-sulphur solu- tion for apple scab, conducted by the writer d in Nebraska and Arkansas, gave good results, and similar experiments conducted in New Hampshire during the same year by Dr. Charles Brooks' in cooperation with the writer showed the commercial solution to be almost as effective against apple scab as Bordeaux mixture. Mr. Errett Wallace t reports that in experiments which he con- ducted in New York during 1909 the commercial lime-sulphur solu- tion at a strength of 1 gallon to 30 gallons of water did not injure fruit or foliage and was as effective in controlling apple scab as Bor- deaux mixture, although the disease was not serious in the orchard treated. Although none of the experiments referred to above were exhaustive, the evidence thus far points to the lime-sulphur solution as a valuable substitute for Bordeaux mixture, at least in the treat- ment of apple scab. a Rural New Yorker, .March 7, 1908, p. 202. & Proceedings, American Pomological Society, 1907, pp. 39— to. < ("ir. 27, Bureau of Plant Industry, V. S. Dept. of Agriculture, 1909. pp. 12 18. rff'ir. 27, Bureau of Plant Industry, U. S. Dept. of Agriculture, L909, pp. \~> 17. < 19th and 20th Annual Reports, New Bampshire Agricultural Experiment Station, pp. 385-389. / WCstcrn Fruit Grower, January, 1910, pp. 24-25. [ fir. 54] I.I mi -ii i-il i R l'i:i PAR mONS FOR \ITI I DIS D Experiments conducted by the Bureau of Plant fndustrj during 1909 give further evidence of the value of the lime-sulphui fungicides For summer use. These experiments cover .1 wide range of conditions, having been conducted in Virginia, Michigan, and Arkansas. Eleven varieties were treated. Four different brands of the commercial lime-sulphur solution and a similar home prepared solution were tested a( various strengths. The commercial brands istered from 31 to 33 degrees "ii the hydrometer scale. They were used alone and in combination with arsenical poisons. This paper contains a brief discussion of these experiments, with sugg< tions as ii> the substitution of lime-sulphur preparations for Bordeaux mixture in the treatment of apple disco THE IMPORTANCE OF CAREFUL SPRAYING. The acreage in apple orchards in this country is rapidly increasing, ami in the future the production of apples will undoubtedly be much greater than at present. The writer is of the opinion, however, thai there will be do serious overproduction and thai there will always be ood demand for good apples, while the poor stuff so common on our market - to-day will not pay i he expenses of handling. It should be the aim of every orchardist to produce and market nothing l>ut first-class fruit, and if he does this he may reasonably expect always in obtain good returns from his investment. Spraying is the one operation above every other orchard practice which determines the market value of the fruit produced and yel in many instances it receives the least attention of all t he orchard w ork. The successful orchardist of the future will he the man who, among other things, studies the conditions existing on his own farm and sprays his trees according to the needs of each varietj for the control of the particular troubles which occur in his locality . The course of treatment best suited for the orchards of the Shenandoah Valley <>f Virginia may not necessarirj give the best results in orchard- situ- ated east of the Blue Ridge in that State, and again the treatment for certain varieties of apples may he different from that required for certain other varieties growing in the same locality. The course of treatment should be planned not only with reference to the dis- es to he controlled, hut also with reference to the probable effect of t he fungicide upon the fruit and foliage of the variety to he t reated. The Ben Davis, for example, i- so seriously russeted by appli tions of Bordeaux mixture that often most of the fruit sprayed with this fungicide is rendered second da--. In Virginia this variety does n,.t suffer materially from the attack- of scab, bitter-rot, or other serious frail diseases, the leaf-spot which is easily controlled being it- chief fungous enemy. The Ben Davis in Virginia and in [Cli 6 LIME-SULPHUB PREPARATIONS FOR APPLE DISEASES. other similar situations may therefore be successfully sprayed with a weak fungicide which will control the leal-spot, sooty fungus, and slight seal) infections without injury to the fruit or foliage. The York Imperial is another variety which has no serious disease of the fruit, and in addition it is not subject to Bordeaux russet, so common on the Ben Davis, but the foliage 1 is susceptible to leaf-spot and is often badly injured by applications of Bordeaux mixture, so that it is desirable to spray this variety also with a less caustic mixture. On the other hand, the Yellow Newtown" is seriously subject to the attacks of bitter-rot and must be treated with a strong fungicide, such as Bordeaux mixture, for the control of this disease. The fruit of this variety is susceptible to Bordeaux injury, but since such injury is produced only by the early applications of the mixture the treat- ment may be so planned as to avoid it. One of the lime-sulphur sprays may be used for the fust and second sprayings after the petals fall and Bordeaux mixture for the bitter-rot treatments which come later in the season. These are some of the finer points to be consid- ered in connection with spraying, and the orchardist who gives them due consideration will obtain the best results in the production of good fruit. VIRGINIA SPRAYING EXPERIMENTS. In Virginia during the season of 1909 the writer, with the assist- ance of Mr. Leslie Pierce, conducted experiments with various lime- sulphur preparations in comparison with Bordeaux mixture for the control of apple diseases. The experiments were made on the Yel- low Newtown, at Crozet; theWinesap, York Imperial, and Ben Davis, at Fishersville; and the York Imperial and Ben Davis, at Mount Jackson. The self-boiled lime-sulphur mixture, the home-boiled lime-sul- phur solution, and the commercial lime-sulphur solution, as well as Bordeaux mixture, were used. The self-boiled mixture was used in two strengths, 8-8-50 6 and 10-10-50 and the home-boiled solu- tion at a strength of 5 pounds of sulphur and 2\ pounds of lime to 50 gallons of water, made by boiling the lime and the sulphur with a small quantity of water over a fire for forty-five minutes. The latter is essentially of the same composition as the concentrated lime-sulphur solution which Prof. John P. Stewart* described and which, according to him, can be kept indefinitely. The commercial lime-sulphur solution was used at the rates of H, If, 2, and 21 gal- a Synonym of Albemarle Pippin. & Whenever formulas for lime-sulphur mixture arc mentioned in this paper the first number shows the number of pounds of lime used, the second the number of pounds of Bulphur, and the last the number of gallons of water. c Bulletin 92, Pennsylvania Agricultural Experiment Station. 1909. Kir. :.1| UMl .--ri.rili K PREPARATIONS FOB MTl I. DI8EA8] 7 Ions to 50 gallons of water. Arsenate of lead ai the rate oi pounds i" 50 gallons was used with the Belf-boiled mixture, the home-boiled solution, and the Bordeaux mixture. The commercial solution was used with arsenate of lead ai the rate "f 2 pounds to .")i) gallons, with Paris green at the rate of 6 ounces to 50 gallons, and without anj poison. In the Mount Jackson orchard the trees were -prayed : First, as booh as the petals fell; second three to four weeks after the petals fell; and third, nine to ten weeks after the petals fell. The Fishersville orchard, <>n account of scab i an additional application, which was made ju-t before the trees bloomed. The Crozet orchard received the same treatment iIk> Mount Jackson orchard, and on account of bitter-rot a fourth application three t" four weeks after the third. In the same orchards spraying demonstrations for the control of insects and diseases were conducted jointly l>\ the Bureau of Ento mology and the Bureau of Plant Industry, following the schedules of applications just mentioned, which were prepared by Mr. A. L. Quaintance and the writer, the former being responsible for that por- tion relating to bisect control. A discussion of these demonstrations will not be included in the present paper. MIK EFFECT <>i I in. SPRAYfi <>\ mi. FOLIAGE. One of the objects of these experiments was t" determine the effect of the several lime-sulphur preparations in combination with arsen- icals on the foliage of different varietii 3 era! times at intervals during the season uotes were made on the condition <>f the foliage of the trees in the experimental plats. The weather was mostly cloudy and rainy from earl} spring until about Jul} 1, so that the con- ditions were favorable to the development of spray injury. During the latter half of the season, however, practical!} n<> tain fell. In ever} case, except on the Winesap, where Paris green was used with the commercial lime-sulphur solutions, the foliage was badly burned and in some instances the tree-, spraj ed with this combination lost half of their foliage. The Wine-up did nut suffer so much injury from this or any of the other sprays a- did .the other varieties. This variety was used in the experiments of the previous year conducted in Nebraska by the Bureau of Plant Industry, and the fact that the commercial solution at the rate of 2 gallons to 50 gallons of w ater and t'« ounce- of Pari- green caused onlj a slight damage to the foliage indicated that the combination might be practicable. It is evident, however, from the Virginia experiments that it is entirely unsafe to use Pari- L'reen with the lime-sulphur spra\ The commercial Lime-sulphur solution at the rate of i . gallons to 50 gallons of water and 2 pounds of arsenate of lead injured the foliage [CJi 8 LIME-SULPHUR PREPARATION. S FOB APPLE DISEASES. only slightly, scarcely enough to he noticeable to the casual observer. At the rale of 2 gallons to 50 gallons of water with arsenate of lead this preparation injured the foliage considerably, so that a small per- centage of the leaves dropped off. (See PI. I, fig. 1.) This injury was manifested by a slight scorching around the margins and at the tips of the leaves, and in some cases by the formation of irregular brown spots. Even here, however, the injury was scarcely more severe than that caused by 3-3-50 Bordeaux mixture on the same varieties. (See PL I, fig. 2.) At a strength of 2 to 50 without any poison the commercial solu- tion injured the foliage slightly more than the same mixture with the addition of arsenate of lead. The same is true of the 1 ' to 50 strength. The arsenate of lead apparently reduced the caustic properties of the sulphids, rendering the mixture less injurious to apple foliage. This is probably due to the fact that a portion of the sulphur is taken out of solution to combine with the lead, forming lead sulphid and arse- nate of lime. The same solution at a strength of 2 V gallons to 50 gallons of water .with and without arsenate of lead injured the foliage very badly, causing a partial defoliation of the trees. This is much too strong for use in the Eastern .States, although Professor Beattie, 6 of Wash- ington State, recommended even a stronger solution. It appears from these tests that 2 gallons of the commercial solution to 50 gallons of water is the maximum strength that can be used on apple foliage with any degree of safety, and that H to 50 is much safer and is about as strong as one should risk in spraying a large orchard. The home-boiled solution, containing 5 pounds of sulphur and 2\ pounds of lime to 50 gallons of water, with 2 pounds of arsenate of lead, caused very little or practically no injur}*. This is practically the same as the commercial solution diluted to contain 2 gallons t<> 50 gallons of water, hut the foliage injury caused by the latter was more conspicuous. The self-boiled lime-sulphur and arsenate of lead caused no injury whatever: in fact, the foliage sprayed with this mixture had a bright- green, vigorous appearance throughout the season. (See PI. II, fig. 1 .) The leaves were noticeably larger, the buds were plumper, and the trees made more growth than those sprayed with the other lime- sulphur preparations and with Bordeaux mixture. The Bordeaux mixture caused considerable spotting and yellowing of the leaves on the York Imperial, Ben Davis, and Yellow Newtown, a Whenever formulas for Bordeaux mixture are given in this paper, the first number indicates (he number of pounds cf copper sulphate used; the second, the number of pounds of .-tone linn', and the last, the number of gallons of water. ''Western Fruit Grower, January. 1*.K)9. pp. 6-7. [Cir. 54] I Plate I ... - • -v . - ..-*■■ *>■■., y & v ' FlG. 1 . Bln D-v . IS TfiEl • SPRAYED WITH COMMERCIAL LlME-SuLPHUR 2 TO 50 , SHOWING Some Leaf Injury. Fishersville, Va., September 29, 1909. I Fig. 2. -A Row of Ben Davis Trees Sprayed jEauxMu' : -hersville, Va, September 29, 1909. UM l BULPB I PARA i I0N8 i OB iPT\ E DI81 9 hut n,t\ little on the Winesap vari< me of the injured I dropped from time to time.so thai thefoliageon manj tr< w ha1 thinned out toward the end of the Beason, but thedami iioi be considered verj i rious. i in; CONTROl Ol DI8EAS1 In the orchards in Virginia where these experiments were con- ducted Done of the apple diseases excepl leaf-spot developed to a serious extent, bo thai the test was do! a severe one. The apple leaf- 9 pol amon throughout this State, was entirely controlled l>\ all the mixtures used. The self-boiled lime-sulphur made the best show- ing in this connection, because it not onlj controlled the leaf-spot but did not injure the foliage, and apparently had a stimulating effect on thetre* 3 PI. II All the lime-sulphur preparations, as well as the Bordeaux mixture, controlled the soot] fungus and an undetermined ruil spot" which was common th<> past season in Virginia. 'I Ih> weather was so dry after midsummer that bitter-rol did nol develop sufficiently to test the value of the lime-sulphur sprays for its control. Considerable Bcab developed on the unsprayed Winesaps in the Fiahersville orchard, so that a partial test of theefficacj of the 3everal sprays in the control of this disease was afforded. Only one strength to 50 "I" tlu- commercial lime-sulphur was used on this variety. The crop from four trees in each of the more important plats was picked and sorted, and the results are shown in the following table: Tabu I /.' Com men I fruit. itli. Per It will be Been from this table that the scab was held down to less than l per cent of the crop by the commercial lime-sulphur, to ."•, per cent by Betf-boiled lime-sulphur, and to about 2 per cent by Bordeaux mixture, and that 30 per cent of the unsprayed fruit was affected with the disease. This disease was well controlled by all the mixtu bul it will be noted that it was not particularly had on the unsprayed trees, so that tin- test could not be considered a seve ne. None of the Winesaps were sprayed with the weaker commercial prepara- tions nor with the home-boiled lime-sulphur. [fir. .".I] 10 LIME-SULPHUB PBEPABATIONS FOB APPLE DISEASES. In this experiment the comparative effect of the different mixtures on the codling moth was determined, and, as shown in Table I, the com- bination of lime-sulphur and arsenate of lead controlled this insect aboul as well as Bordeaux mixture and arsenate of lead. It seems, therefore, thai the poisonous action of this arsenical is not reduced by combining it with the lime-sulphur preparation. THE EFFECT OF THE BPRAY8 ON THE FR-tJIT. Ill all the orchards treated the fruit sprayed with the several lime- sulphur mixtures was smoother and more highly colored than that sprayed with Bordeaux mixture. The Bordeaux mixture russeted the fruit of the Ben Davis SO that it did not have the ''finish'' required for fancy apples, and a small percentage of it had to he dis- carded as culls on account of the roughened appearance due to the mixture. The Yellow Newtowns were russeted considerably and the Winesaps only slightly, while the York Imperials showed practically no russet effect. The lime-sulphur preparations caused no russeting, or at most very little where the strongest solutions were used, and the fruit sprayed with these mixtures was smooth, clean, and well colored. The difference in color between the fruit sprayed with the Bordeaux and that sprayed with the several lime-sulphur preparations was very striking, and this feature alone would make the latter sprays preferable to the former if other things were equal. EXPERIMENTS IN MICHIGAN. Experiments similar to those in Virginia were conducted at Douglas. Mich., in cooperation with the Bureau of Entomology, and the results were much the same. The work was done by Mr. R. W. Braucher under the writer's direction in the orchard of Mr. C. W. Gavlord. The trees were sprayed just before they bloomed (May 19 and 20), as soon as the petals fell (June 1 and 2), three weeks later (June 23 and 24), and ten weeks after the petals fell (August 10 and 11). There were six plats of from 13 to 20 trees each, including the Wegener, Baldwin, Rhode Island, Roxbury, and Ben Davis varieties. The commercial lime-sulphur solution, diluted to contain 2 gallons to 50 gallons of water, without any arsenical, was applied to plat 1 : the same solution, with the addition of 6 ounces of Paris green, was applied to plat 2; ami the same solution, with the addition of 2 pounds of arsenate of lead, was used on plat 3. Plat 4 was sprayed with self-boiled lime-sulphur (10-10-50) and 2 pounds of arsenate of lead, and plat 5 was sprayed with 3-4-50 Bordeaux mixture and 2 pounds of arsenate of lead, while plat (> was left unsprayed. The plats sprayed with the commercial lime-sulphur solution, espe- [Clr. 54] I Bureau of >' Plat II Fio. 1,-York Imperial Apple Tree Sprayed with Self-Boiled Lime-Sulphur, Show- ing Luxuriant Foliage. Fishersville, Va., September 29, 1909. / Fio. 2. -Unstayed York Imperial Apple Trees Almost Defoliated by Leaf-Spot, Located in the Same Orchard and Photographed at the Same Time as that Shown in Figure 1. I.IMI >( I.I'll I i: Prtl PAB VT10NI >K VI II i DISI I 1 n;ill\ plal -. began to show considerable foliage injurj after the second application, and on tin- account the solution was diluted to contain onh i gallon in I" gallons of water for the last two sprayinj BB81 LTB Ol i ii i 11:1 \ i m i n I n after the second application was made, accordini Mr. Braucher'a notes, the commercial lime-sulphur plats began to sh«.u f,»li : .Lr<' injury. Notes made al intervals during the season B hoM that the foliage was quite badlj injured by the lime-sulphui solution and Paris green combination and that tin' solution without an arsenical caused almosl as much .lama--', while tin- Bame solution with arsenate of lead was much less injurious Although the dam caused l>\ the lime-sulphur and arsenate of lead combination wae not severe, it was sufficient to discourage the use of the solution at the strength of '-' gallons t<> 50 gallons of water. A strength <>f II gallons to •"><) gallons of water, with arsenate of lead, proved to he practical!} noninjurious in Virginia and would probably he sal. in Michigan. The self-boiled lime-sulphur mixture with arsenate of lead caused no damage whatever. The following table shows the efficiency of the several spraj mix- ture-, in preventing apple scab on the Wagener variety, a- determined by sorting and counting the fruit from eighl trees in each plat: Tabli II Comparison of results of On use of lime-sulphur spn <:> the pr> plat. Commercial Umwulphui Commercial llme-stilpbur solutl i - e-sulphur fruit. As shown in the above table, the scab was held down to an average 1.2 per cent of the crop l>\ the commercial lime-sulphur solution i„:;. 13 percent by the Bordeaux mixture, and to 19. 1^ per cent by the self-boiled mixture, while 81 per cenl of the unsprayed fruit * acabbj SeePl. til.) This experiment, as well as those conducted in Virginia, show- that the lime-sulphur solution is as effective in preventing apple scab a- Bordeaux mixture, while the self-boiled wash i- not 80 u r "«>d in this connection. The arsenate of lead in the commercial lime-sulphur solution held the codling moth down to l.n per cent of the crop and in the case of Bordeaux mixture to cent, thus indicating that the lime-sulphur does not injuriously affect the poison. I fir :. I ] T2 LIME-SULPHUR PREPARATIONS FOB APPLE DISEASES. EXPERIMENTS IN ARKANSAS. At Siloam Springs, Ark., during 1909, Messrs. F. W. Faurot and E. L. Jenne, of the Bureau of Entomology, conducted another set of experiments under the writer's directions. The results of those experiments throw considerable doubt on both the efficiency and safety of the commercial lime-sulphur solution as a summer spray for apple diseases. The Ben Davis, Shannon, Arkansas, and Elkhorn varieties were sprayed with several different strengths of the commer- cial preparation in combination with arsenical poisons. The self- boiled lime-sulphur solution and the Bordeaux mixture were also used. The trees were sprayed five times, as follows: (1) As soon as the petals fell; (2) three weeks later; (3) eight to nine weeks after the petals fell; (4) two weeks later, and (5) three weeks after the fourth application. RESULTS OF THE TREATMENT. The trees sprayed with commercial lime-sulphur solution diluted to contain 1 gallon in 30 gallons of water, with the addition of the usual amount of arsenate of lead, siiowed very little or practically no foliage injury after the first and second applications; in fact, according to notes made on June 30 and July 22, no serious injury followed the third treatment, which was applied on June 2. After the fifth appli- cation, however, the injury increased rapidly, and at picking time half of the leaves were on the ground. It seems that the injurious effect of the mixture was cumulative, the injury being increased by each application. Three applications would, perhaps, have resulted in little or no damage, but five sprayings were evidently more than the trees could stand. Considerable rain fell during May and June, but the remainder of the season was dry. The trees suf- fered severely from drought, which apparently exaggerated the spray injury. On account of the shortage of foliage on the trees a portion of the fruit was sunburned, but no russeting was caused by the spray. This sunburning also occurred on the fruit sprayed with Bordeaux mixture, but to a much less extent. The commercial lime-sulphur at a strength of 1 to 30 in combina- tion with Paris green began to burn the foliage soon after the first application was made, and bv midsummer the trees were almost bare. Arsenite of lime was also used with the 1 to 30 solution, and the results were disastrous. The foliage was burned to a crisp and the fruit badly scorched by the first application. Even the new twig growth was killed to a considerable extent. The self-boiled lime-sulphur and arsenate of lead caused no injury to fruit or foliage 1 . The fruit sprayed with Bordeaux mixture was quite badly russeted and the foliage suffered considerable injury. I fir. 54] • Pla Fiq. 1.— Apples Sprayed with Commercial Lime-Sulphur. Scabby Fruit on Right. Fig 2 —Apples Sprayed with Bordeaux Mixture. Scabby Fruit on the Right. Fio. 4.-Unsprayed Apples. Scabby Fruit on the Right. UMB-8ULPH1 B PBEPABATI0N8 POB Ml'" DI81 \&E&. The hme-sulphur sprays failed to. trol apple blotch (P •oKtarfe), which is the most troubles J of th on U»u1 95percen1 of the an pi jred bail «">■ ''""' and about 10 per cent of the frui! sprayed with tl wash *as so affected. The commercial solution a1 I 30 gave o j ly better results, while Bordeaux mixture almosl completely controlled the disease Bitter roi {GlvmereUa • ! > ""■ " serious in the experimental orchard, was onl) partial controUed bj an , o( the lime-sulphur sprays, while Bordeaux mixture held it in check thoroughly. I. seems from the test that the hme-salphur preparations are of doubtful value in the control of apple blotch and bitter-rot; bu1 of course further tests are necessarj before final coa- clusions can be reached. CONCLUSIONS. The writer feels that the information at hand is nol quite sufficieni upon whirl, to base final conclusions and recommendations It seems evident, however, that a lime-sulphur preparation m one form or another is destined, largely, to take the place oj Bordeaux mix- ture in spraying varieties of apples subject to serious injury iron, applications of the latter. \ lime-sulphur solution containing, when diluted, about l pounds of sulphur to 50 gallons of water appears at present to be the most promising preparation. This may I btained b 3 using the com- mercial solution at the rate of H gallons to 50 gallons oj water, orby preparing the lime-sulphur solution at home and diluting U - i tha each 50 gallons will contain l pounds of sulphur. The mixture at this strength injured apple foliage in Virginia very little, and if these results could be taken as a reliable guide there Deed be no hesitancy in using it; bul under differenl conditions the results might bediffer- ent and the matter must still be considered as more or ess experi- mental V strength of l ', gallons of the commercial solution may prove to be sufficieni in mosl cases, and the danger of injury would then, perhaps, be entirely eliminated. Our experiments of 1908 and 1909, as well as the published records of other investigators, show that the lime^ulphur solution is ap] enth as effective as Bordeaux mixture in the control oj apple scab. Under more severe conditions than those whirl, existed m the exper- imental orchards the treatment might fail; but al present it is very promising. Lime-sulphur will control leaf-spot and other mrnot troubles, as well as apple scab, bul so far it has nol proved to be a satisfactory remedy for apple blotch (Phyllosticta) and bitter-rot. However the experiments on those two diseases have not been car- ried far enough to determine what may be expected of it in this con- nection. 1» sections where spraying for bitter-rot is required the [Or. •"•,] 14 LIME-SULPHUB PREPARATIONS FOB APPLE DISEASES. lime-sulphur treatment for scab and leal-spot could be followed by applications of Bordeaux mixture for bitter-rot. The self-boiled lime-sulphur is entirely harmless to apple foliage and apparently has a stimulating effect, hut it is not as effective igainst scah as the boiled wash. Our experiments show that it will control mild cases of seal) and will entirely prevent leaf-spot, "fruit- spot."' and the sooty fungus, but in sections where scab is a serious disease this wash would probably be inefficient. In the Shenandoah Valley of Virginia, where scab rarely occurs except in a mild form, and under similar conditions elsewhere the self-boiled lime-sulphur would perhaps be preferable to either the boiled wash or Bordeaux mixture. According to the information at hand arsenate of lead is unques- tionably the poison to use with the lime-sulphur mixtures. Instead of increasing the caustic properties of the mixture, as at first feared, it apparently has the opposite effect to some extent and does not lose any of its insect icidal value by reason of the combination. In all the experiments the combination of Paris green and the lime-sulphur solution proved to be quite injurious to apple foliage, and in the Arkansas work the combination of arsenate of lime and lime-sulphur was exceedingly injurious. According to the results obtained in the Arkansas experiment, three applications of the commercial solution at a strength of 1 gallon to 30 gallons may be made without material injury to apple foliage, but after the fourth application the injurious effect becomes serious, and after the fifth the injury is almost disastrous to both fruit and foliage. It appeal's, therefore, that the injury is cumula- tive and that it is unsafe to make more than three applications, or four if one is made before the trees bloom. SUGGESTIONS FOR TREATMENT. It is at present more difficult to make satisfactory recommenda- tions for spraying apple orchards than it has been for years. Until recently Bordeaux mixture was preeminently the best known fungi- cide for use on the apple, and it was comparatively easy to outline a course of orchard spraying for a given locality, but the advent of new fungicides which, though insufficiently tested, give promise of doing the good work of Bordeaux mixture without its harmful effects, makes the problem more difficult until further experiments shall have shown the exact value of these new preparations. The writer is of the opinion, however, that the information at hand is sufficient to warrant making substitutions for Bordeaux mixture under certain conditions, thus avoiding as much as possible the very undesirable fruit russeting and foliage injury produced by this fungicide. The following tentative outlines for the treatment of diseases of different varieties of apples are suggested: [Cir. r.4 J 1,1 M l SI I I'll I I: I'KI PAHA IION.S KOH UM'LI IMSKASI S, L5 On varieties subject i«> attacks of . 1 1 » i • I < • scab, especially in district* where tlii- disease prevails, use a reliable com rcial lime-sulphur solution (registering aboul 32 degrees on the Baume* scale at the Btrength of I '. lt;» ' ' * *' » - to 50 gallons of water oi an equivalent strength of the homo-boiled solution, with 2 pounds of arsenate of lead. Spray the trees (1) just before thej bloom after the cluster buds open as soon as the petals fall (3) three to four weeks after the petals fall, and (4) nine to leu weeks after the petals fall This course of treatment is intended for the control of apple scab, codling moth, leaf spot . and other minor i roubles. In the treatment of varieties not serious!) subject to scab, or in districts when this disease is not prevalent, the application before the trees bloom maj be omitted, making onrj tliree applications in all. On varieties requiring treatment for bitter-rot, the lime-sulphur solution and arsenate of lead maj be used in the two or three early sprayings, and Bordeaux mixture (3 I 50 and arsenate of lead in the applications required for bitter-rot, as follows: About nine weeks after the petals fall and at intervals of two or three weeks until three applications shall have been made. On such varieties as the York Imperial, Grimes, Ben Davis, Gano, and Wealth) . located in Virginia, Wesl Virginia, Maryland, and other similar sections where these varieties suffer verj little, or nol at all, from attacks of seal), the self-boiled lime-sulphur mixture s s 50 . with arsenate of lead, may be used with complete success Spray the tree - soon as the petals fall; (2 three to four weeks after the petals fall, and (3) nine ii> tfii weeks after the petals fall This course of treatment will control the apple leaf-spot, mild cases <>f scab, and other minor troubles, as well as the codling moth, The advantage of this mixture over the boiled solution i- that it i- abso- lutely harmless to fruit and foliage, while the use of the latter i- attended with seme danger of foliage injury. After another year'- experiment- the courses of treatment here specified will doubtless have to be revised. They are suggested a- a guide in spraying apple orchards until further information on the comparative value of various sulphur Bprays can he obtained. Approved : • I \M I - \Yl I -ON . St en tm i/ of Agricidtun . Washington, 1>. ( '.. February 7, 1910. '• Tin- solution may be prepared by l >• ■! lin^ 16 ]>' o m.l- of sulphur and s pounds of lime with a small quantity ot water tor aboul one li"ur. then -ir.iin and add water to make -W gallons oi spraj ; oi stock solutions may be prepared i rding to Stem method, as described in Bulletin 92 of the Pennsylvania Agricultural Experiment ion [fir 54] o inn ^. SITY ° F FLORIDA 3 1262 08928 9754