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is published in TAX JOURNAL OF MYCOLOGY, Vol. VI, No. 3. I only give here some of the more important conclusions taken from this report. They are as follows:
(1) On Plat I, treated with Bordeaux mixture, there was saved $32.40 worth of fruit at an expenditure of $6.51, leaving a profit of $25.89, or 397 per cent. On Plat II, treated with ammoniacal copper carbonate solution, there was saved $25.92 worth of fruit at a cost of $4.32, leaving a profit of $21.60, or 500 per cent. On Plat III, treated with copper carbonate in suspension, the value of the fruit saved was $6.48, the cost of treatment $2.25, leaving a profit of $4.23, or 188 per cent. On Plat IV, treated with Bordeaux mixture and ammoniacal solution, the value of the fruit saved was $19.44, the expense of treatment $3.31, leaving a profit of $16.10, or 482 per cent.
(2) While the amount of fruit saved by the Bordeaux mixture was greater than that by the ammoniacal solution the latter preparation is after all the cheapest. In other words, there was more profit in using the ammoniacal solution than the Bordeaux mixture.
(3) A mixed treatment consisting of Bordeaux mixture and ammoniacal solution is more profitable than a treatment of Bordeaux mixture alone, but not as profitable as the ammoniacal solution alone.
(4) There is nothing whatever to be gained by treating with the carbonate of copper in suspension when the ammoniacal solution is at hand.
In regard to the amount of copper found on the grapes at the time of harvest it was shown that a person would have to eat from a ton to a ton and a half of fruit to obtain a poisonous dose of this salt.
Treatment of pear, cherry, and strawberry leaf-blight* as affecting nursery stock.- This work was conducted in the nurseries of Frank. lin Davis & Co., situated on the Pennsylvania Railroad about 25 miles northeast of Washington. The details of the experiment as well as those given under the next heading will be published in THE JOURNAL OF MYCOLOGY, copies of which will be sent on application.
The work so far as it relates to the experiments in the treatment of pear leaf-blight was in the main a repetition of that done last year. This season, however, a number of new fungicides were tried but none of them proved as satisfactory as the Bordeaux mixture, The discovery that this preparation, when properly applied, will prevent this most injurious disease, marks an era in successful nursery work. During the present season the nurseries of Mr. Davis were visited by tree-growers from all over the country and in every case they expressed the greatest satisfaction at the results of the treatment. Mr. Davis's abiding faith in the copper remedies, and especially in the Bordeaux mixture, is shown by the fact that this season he used over 2,500 gallons of the latter alone. Briefly stated, the most satisfactory method of treating the disease under consideration is to spray first with the Bordeaux mixture when the leaves are about two thirds grown, then follow with other applications of the same preparation at intervals of about twelve days until five or six sprayings in all have been made. The cost of such a treatment need not ex. ceed 75 cents per thousand trees.
This year for the first time, as far as we are aware, a systematic endeavor was made to control a disease of the cherry which has come to be known among nurserymen as leaf-blight. This disease attacks the cherry leaves about the middle of June or the first of July, caus
* Entomosporium maculatum, Lév., Cylindrosporium padi, Karst., Sphærella fragaria, Tul
ing them to at first become spotted then turn yellow and fall. Frequently the trees will be completely defoliated before the middle of August, and as a result growth is checked and the plant is stunted.
In treating the disease the present season the best results were obtained from the use of the ammoniacal copper carbonate and the Bordeaux mixture. As far as the efficacy of the two fungicides is concerned there is little choice. The ease with which the ammoniacal solution is prepared and applied, however, makes it more desirable in the end. The treated trees retained their foliage until frost, and in many cases made a growth of nearly 2 feet more than the untreated. Six sprayings in all were made, beginning on May 1 and continuing at intervals.of twelve days. The total cost of the treatment for trees three years old was approximately one fourth of a cent per tree.
As the experiments in the treatment of strawberry leaf-blight do not necessitate any elaborate details, we will give an account of the work in full.
On April 18 a plat of the Wilson strawberry containing five rows each 90 feet long and running north and south was staked off and prepared for treatment. The ground sloped gently towards the south and had evidently been somewhat neglected, as the plants were thickly matted and full of weeds. The rows were numbered 1, 2, 3, 4, and 5. On the 28th of April rows 1 to 3, inclusive, were sprayed, while the others were left unsprayed for comparison. At this time considerable leaf-blight had already appeared, but the plants were in nowise seriously injured by the disease. Of the three rows treated No. 1 was sprayed with ammoniacal copper carbonate solution; No. 2 with Bean's sulphur powder one half pound to 5 gallons of water; No. 3 with potassium sulphide solution, one half ounce to 5 gallons. The sprayings were repeated on May 13 and May 23.
The cost of the treatment, including labor in preparing and applying the remedies, chemicals, etc., was, for the plat treated with the ammoniacal copper carbonate solution, 13 cents; plat treated with Bean's powder, 8 cents ; plat 3, treated with potassium sulphide solution, 3} cents. Basing our estimates on these figures the cost of treating an acre with each of the foregoing preparations would be approximately as follows: For the ammoniacal solution, $21; Bean's powder, $12; potassium sulphide solution, $6. We feel safé in saying that in treating as much as an acre the cost would be lessened at least 25 per cent.
At the time of the second spraying it was an easy matter to distinguish the row treated with the ammoniacal solution on account of its brighter and more thrifty foliage, comparatively free from leafblight. The other rows at this data were all badly diseased, there being little if any difference between the treated and untreated. On May 23, when the last spraying was made, the difference between the row treated with ammoniacal copper carbonate and the others was even more striking than when noted ten days previous. What made the result of more interest and importance was the fact that a portion of this same row which extended beyond the experimental plat and which in consequence was not treated, was as badly diseased as the unsprayed rows of the plat.
Treatment of pear leaf-blight and scab in the orchard.-In addition to our nursery work in the treatment of pear leaf-blight it was thought best to make some attempt to prevent the injury to fruiting pear trees from the attacks of the leaf-blight and scab fungi. This work was carried on in the orchard of Dr. W. S. Maxwell, near Still Pond, Maryland.
In the case of pear leaf-blight an attempt was made to throw some light upon the following questions: (1) The relative value of the Bordeaux mixture, the ammoniacal copper carbonate solution, a solution of copper acetate, copper carbonate in suspension, and mixture No. 5, as preventives of this disease; (2) the number of sprayings necessary to obtain the best results; (3) the proper time of applying the remedies; (4) the cost of the various treatments.
Summing up briefly the results it may be said that so far as effectiveness of the various preparations is concerned they stand in the order named:
Bordeaux mixture (Plate IV), ammoniacal solution (Plate V), copper acetate 3 ounces to 6 gallons of water, mixture No. 5, copper carbonate in suspension.
The difference between the effects of the Bordeaux mixture and of the ammoniacal solution was scarcely perceptible, so that taking the cost into consideration the latter would be preferable.
As regards the number of sprayings and the time of making the same it was found that three early treatments were just as effective as six made at intervals throughout the season. It was further made evident that one late spraying with either Bordeaux mixture or the ammoniacal solution would save a large percentage of the foliage, the former preparation proving much more effective in such a test.
The cost of the various treatments was as follows:
In the treatment of pear scab the same fungicides used in the preceding experiments were employed, the cost per tree being practically the same. The conclusions drawn from the results of this work are:
(1) Early treatments, i. e., before the fruit is half an inch in diameter, are absolutely necessary to prevent the scab.
(2) Spraying after the fruit is half grown is liable to injure the latter.
(3) The Bordeaux mixture and ammoniacal solution are the only preparations which give really satisfactory results.
COÖPERATIVE EXPERIMENTS. Similar arrangements to those of last season were this year made with the director of the Wisconsin Experiment Station by means of which Prof. E. S. Goff, horticulturist of the Station, was enabled to carry on a series of experiments under our direction. The work was conducted on the fruit farm of Mr. A. L. Hatch, 37 miles southeast of the village of Ithaca, Richland County, Wisconsin, the diseases treated being apple-scab, blackberry and raspberry leaf-blight, and potato rot.*
Experiments in the treatment of apple scab. These were planned with a view of obtaining some information upon the following questions:
(1) The comparative efficacy of the ammoniacal copper carbonate solution, Bean's sulphur powder, mixture No. 5, and copper carbonate suspended in water.
(2) The value of spraying previous to the opening of the flowers. (3) The number of treatments necessary to secure the best results.
In this work many important facts were brought out, the most prominent of which may be summarized as follows:
(1) In seasons of excessive rains in early summer the scab on badly infested trees can not be wholly prevented by the treatments given in this experiment.
(2) That of the substances tested mixture No.5 was the most efficient.
(3) Early treatments, especially previous to the opening of the flowers, are extremely important.
(4) Sprayings in midsummer are at best of doubtful value.
(5) On trees badly affected with scab the fruits that develop may be so far reduced in size by the fungus as to diminish the crop nearly 20 per cent. This, moreover, is doubtless a small part of the injury produced.
Raspberry leaf-blight--This was treated with the Bordeaux mixture and mixture No. 5. The disease, which is caused by a fungus known as Septoria rubi, makes its appearance on the leaves often as early as the middle of June in the form of whitish or faintly brownish spots. The spots frequently become so numerous as to completely cover the leaf, and as a result the latter dries up and of course becomes utterly useless to the plant. When fruiting canes are attacked in this way the fruit never matures or if it does it is small, dry, and tasteless. The varieties of raspberries selected for the experiment were Cuthbert for red and Tyler and Gregg for black; those of the blackberry were Stone's Hardy and Ancient Briton. All were growing in somewhat dense rows, and at the time of the first spraying, May 31, presented a thrifty appearance and gave promise of a good crop of berries. At this time the leaves were nearly full grown and the flower buds, though visible, had not yet opened. Forty feet of row of each variety selected for the experiment were treated at the different sprayings with each of the fungicides named. Treatments were given on May 31, June 5, 18, 28, July 7 and 14. In the treatment of June 28 the Tyler and Cuthbert raspberries were omitted, as there were unmistakable indications of injury to the foliage. In the treatment of July 7 and 14 all of the raspberries were omitted as the fruit was beginning to ripen.
It was shown by these experiments that(1) The foliage of the raspberry is delicate and can not endure applications of a corrosive nature.
(2) The foliage of the blackberry, though more resistant than that of the raspberry, is more susceptible to injury than that of the apple.
(3) None of the treatments given are to be recommended for the raspberry, and of the materials used only the copper carbonate solution can be pronounced beneficial in the case of the blackberry.
* Fusicladium dendriticum, Septoria rubi, and Phytophthora infestans.
E.cperiments in the treatment of potato-rot.-The results of this work, which was carried on under my direction by Professor Goff, are eminently satisfactory. Without going into details, which will be published in a special bulletin, I will say that the Bordeaux mixture was applied six times, the result being an increase in the yield of the treated plats over the untreated of from 25 to 50 per cent with comparatively little expense.
WORK OF FIELD AGENTS.
The field agents this year were located in New Jersey, Virginia, South Carolina, and Missouri, their work for the most part being confined to experiments in the treatment of grape diseases. As the reports of these agents can not well be condensed I have reserved them for publication in a special bulletin.
SOME PRACTICAL RESULTS OF THE TREATMENT OF PLANT
DISEASES. The question has occasionally been asked what is the real value in dollars and cents of the treatment of plant diseases. Everyone who has carried on work of this kind knows how difficult it is to obtain exact reports, especially from farmers, fruit growers, and others who, as a rule, make no pretense to skill in bookkeeping. In a few cases, however, we have been able to collect reliablo data which show what can be accomplished by proper care and attention to details. In the case of Mr. Berry's vineyard, already mentioned, 7777 Concord vines were made to yield $84.24 worth of fruit at an expenditure of $17.42, a clear profit of $66.62. This result, it must be borne in mind, was obtained from an experimental vineyard where the object was not so much the production of a large yield of fruit as to test the relative value of a number of fungicides. It is safe to say that had we used the Bordeaux mixture on the entire vineyard the value of the yield would have been increased to at least $100, while the expense of treatment per vine would have been materially decreased.
Mr. D. M. Wyngate has a large vineyard near Marlborough, New York, and at my request has furnished a careful estimate of the profit derived the present season from treatments suggested by this Division. His vineyard contains 7,450 Concord and 1,000 Delaware vines. The vineyard last year was not treated and yielded 19,690 pounds of fruit, which sold for $625.87. This year the same vineyard was treated seven times, as follows:
(1) March 1, simple solution of copper applied to canes and posts. (2) Just before blossoming with Bordeaux mixture B.
(3) Just after the grapes had formed with Bordeaux mixture same as 2.
(4) July, same as 2 and 3.
(5, 6, and 7) At regular intervals between July 10 and August 25, with eau céleste.
The total cost of the foregoing treatment, including a Eureka sprayer, was $112.52, divided as follows: Eureka Sprayer..