478 



Garden and Forest. 



[Number 189. 



tributed to their environment. Mr. Meehan replied with 

 great good humor that his critics evidently did not under- 

 stand what was meant by the term environment ; and 

 then Mr. Fernow added that if there was doubt as to the 

 meaning of the term environment, there was also ambiguity 

 in the use of the term variation, which might be structural 

 or functional, and it was necessary to know whether we 

 were talking about morphological variation or biological 

 variation. The discussion became enveloped in a haze of 

 uncertainty, as it appeared that none of the gentlemen 

 were quite sure what the others were talking about, and it 

 finally closed in a thick fog. It was very instructive and 

 interesting, however, to the laymen. 



Mr. J. M. Samuels, the Chief of the Horticultural Division 

 of the Columbian Exposition, was an interested attendant 

 on the meetings, and in the name of Director-General Davis 

 he invited the society to hold their session of 1893 in 

 Chicago. He also assured the society that the Director- 

 General would appoint any man whom they should name 

 as the head of the Division of Pomology. 



We add below extracts from a few more of the important 

 papers offered : 



RECENT PROGRESS IN THE TREATMENT OF THE DISEASES OF 

 POMACEOUS FRUITS. 



Professor B. T. Galloway, of the Department of Agricul- 

 ture, read a paper on this subject, which was substantially 

 as follows : 



The treatment of plant diseases is a subject of such recent 

 origin that comparatively few are aware of the progress made 

 in this line of work during the past few years. At the Boston 

 meeting of this society, held only four years ago, it is doubtful 

 if any one could have told how Pear-scab, Apple-scab, Cherry- 

 leaf blight, or any of the numerous other diseases of poma- 

 ceous fruits, could be cheaply and effectually prevented. 

 Nevertheless, the losses occasioned in this country by some of 

 the maladies of pomaceous fruits have been enormous. Take, 

 for example, the apple crop. At the very lowest estimate the 

 damage to this one fruit in 1890 by scab alone exceeded six 

 million dollars. The damage done to Pears, in both nursery 

 and orchard, by leaf-blight, scab and cracking is probably as 

 great as that of the Apple. Add to this the damage to Cher- 

 ries, Plums, Peaches and similar fruits by such diseases as 

 mildew, leaf-blight, rot and yellows, and the sum amounts to 

 no less than fifty million of dollars annually. How to prevent 

 this damage is a problem which has long confronted the fruit- 

 grower, yet it was not until the year 1886 that the na- 

 tional Government, through its Department of Agricul- 

 ture, established a branch for the investigation of plant dis- 

 eases. This division, for so it is designated, has been con- 

 stantly at work since its organization, endeavoring to throw 

 light on the prevention of plant maladies. 



The usual method of work is first to make a careful study of 

 the diseases in the field and laboratory, and to follow this with 

 practical field experiments, first on a small scale, and later 

 more extensively if the results justify it. In accordance with a 

 plan of this kind the work on Pear-leaf blight was commenced 

 nearly three years ago, and is still being carried on. First it 

 was necessary to study the life-history of the Fungus causing 

 the disease, as it was only with a full and complete knowledge 

 on this point that an intelligent effort in the way of treatment 

 could be undertaken. As a result of the laboratory and field 

 work along this line it was found that to successfully prevent 

 the disease it would be necessary to protect the young unfold- 

 ing leaves from infection by the spores or reproductive bodies 

 of the Fungus which had passed the previous winter in the 

 fallen foliage. As a mere statement this problem may not 

 seem like a difficult one. The fact is, however, that a great 

 many difficulties have been encountered, and while some have 

 been overcome, others remain to be mastered. 



The time of the first application, when the leaves are about 

 half-grown, being settled, the next questions to solve were (1) 

 the kind of preparation to use in order to cheaply and effectu- 

 ally protect and not injure the foliage ; (2) the number of appli- 

 cations necessary, and (3) the cheapest and most practical 

 means of making the applications. Without going into details 

 it may be said that in treating nursery stock the best results 

 have been obtained from six or seven applications of the Bor- 

 deaux mixture, applied with a Knapsack pump and improved 

 Vermorel Spraying nozzle. The Bordeaux mixture is so well 

 known that a description of its preparation is unnecessary, the 



standard preparation containing six pounds of copper and four 

 pounds of lime to twenty-two gallons of water. While the 

 best effects from this mixture have been obtained when Knap- 

 sack pumps were used, it does not always pay to use such 

 machines for work on a large scale. Where one has 30,000, 

 or even 50,000, stocks, two Knapsack pumps can do the work. 

 For more than this, however, it is best to use horse-power 

 machines. We have recently devised two machines of this 

 kind : the first, a cart machine, holding twenty-five gallons, 

 made to pump automatically, drawn by one horse and requir- 

 ing two men and a boy to operate it. Four rows are sprayed 

 at a time, so that it is not difficult to spray 100,000 or 150,000 

 Pear-seedlings a day with it. With a Knapsack pump 20,000 

 to 25,000 seedlings of this kind is a good day's work. 



The second form of horse-power machine is simply a barrel 

 mounted upon wheels or runners and provided with a force- 

 pump which is worked by hand. With a horse, two men and 

 a boy, four rows can also be sprayed at one time with this ap- 

 paratus. The work cannot, however, be done as rapidly as 

 with the automatic pump, although, owing to better control of 

 the machine, it can be done more thoroughly. The cost of 

 the automatic machine will range from forty dollars to fifty 

 dollars, while the last-described apparatus complete can be 

 fitted up at home for fifteen dollars. This includes wheels or 

 runners, pump, suction and discharge hose, four nozzles and 

 gearing for attaching the horse. A special feature of the 

 machine we have devised is the pump, which is a modifica- 

 tion of the one we use on our Knapsack Sprayer. Most of 

 the force-pumps capable of supplying four nozzles are expen- 

 sive, ranging in price from eight dollars to twenty dollars. 

 The one under consideration can be made for two dollars and 

 a half, and it is as durable and effective as any of the more 

 expensive pumps. By attaching the pump to the automatic 

 machine already mentioned the price of the same may be 

 materially decreased. In fact, we are now perfecting an auto- 

 matic apparatus that will spray four rows at a time, and which, 

 we think, can be made for twenty-five dollars. The plan is to 

 devise a machine so simple that the various parts may be ob- 

 tained from most any reliable implement dealer and put to- 

 gether at home. All the machines mentioned can be used for 

 various purposes, such as spraying Potato and Tomato-vines, 

 Grapes, nursery stock and orchard trees. 



Laying aside the question of machinery, let us turn again to 

 the treatment of nursery stock and briefly summarize our pres- 

 ent knowledge of this subject. We may say (1) that leaf- 

 blight of the Pear, Plum, Cherry and Quince are best controlled 

 by Bordeaux mixture, applied first when the leaves are one- 

 third grown, and thereafter at intervals of twelve or fifteen 

 days, until six or seven sprayings in all have been made ; (2) 

 that the ammoniacal solution of copper carbonate, applied the 

 same as the Bordeaux mixture, is most successful in combat- 

 ing powdery mildew of the Apple. In the orchard, however, 

 the ammoniacal solution has, for various reasons, been more 

 satisfactory for Pear-leaf blight and scab than the Bordeaux 

 mixture. It is also found that three or four early sprayings 

 give as good results as six or seven made at intervals during 

 the growing season. This statement may not hold good in 

 the nursery where, as yet, no experiments have been made to 

 test the matter. 



The first extended experiments in treating Apple-scab were 

 made in 1889 by Professor Goff, of Wisconsin, and Professor 

 Taft, of Michigan, under the direction of the Division of Vege- 

 table Pathology. It was then demonstrated that scab could 

 be cheaply prevented by at least two of the copper prepara- 

 tions, namely, ammoniacal solution and modified Eau Celeste. 

 The cost of the treatment averaged about twenty-five cents 

 per tree, while the increase of perfect fruit on the treated trees 

 over the untreated ranged from twenty-five to seventy-five per 

 cent. In 1890 we continued the experiment, endeavoring to 

 obtain information on a number of other points, chief of which 

 was the value of early as compared with late treatments, the 

 number of treatments necessary to obtain the best results, and 

 the comparative efficacy of three fungicides, two containing 

 copper and one devoid of this chemical. An attempt was also 

 made to cheapen the treatment without decreasing their effi- 

 cacy. It was found that early treatments, particularly those 

 made just as the flowers were opening, were better than late 

 ones. Three early sprayings — one when the flowers were just 

 opening, one when the fruit was the size of peas, and one two 

 or three weeks later — proved as effective as five, six or even 

 seven sprayings made at intervals during the summer. The 

 best fungicide was one originating with us last year, and sent 

 out under the name of Mixture No. 5. It consists of equal 

 parts of ammoniated copper sulphate and ammonium car- 

 bonate. It was used at the rate of from eight to twelve ounces 



