LETTER OF SUBMITTAL. FEBRUARY 1, 1890. SIR: I have the honor to submit herewith a report on the experi ments made in 1889 in the treatment of fungous diseases of plants. Respectfully, Hon. J. M. RUSK, B. T. GALLOWAY, Chief of the Section of Vegetable Pathology. 5 TREATMENT OF THE FUNGOUS DISEASES OF PLANTS. INTRODUCTORY. Early in the spring of 1889 plans were made for an extended series of experiments in the treatment of plant diseases, and with but few exceptions these were all carried through to the close of the season. In order that the experiments might be conducted under as widely differing conditions of climate, soil, etc., as possible, agents were selected in the States of New Jersey, Virginia, South Carolina, Mississippi, Missouri, Michigan, and Wisconsin. The work was confided to thoroughly practical, competent men, living in localities having all the conditions. favorable for the growth of the particular crop experimented upon. For example, the bulk of the work upon the treatment of black-rot anthracnose, and mildew of the grape vine was carried on at Vineland, N. J.; Charlottesville, Va.; Greenville, S. C., and Neosho, Mo., these all being grape-growing regions of considerable notoriety, and having been for years subject to the ravages of the pests already mentioned Apple-scab was treated in Michigan and Wisconsin, two States where apples are largely grown, and where the scab is always more or less destructive. Bitter-rot and rust of the apple were treated in New Jersey and Virginia respectively, while the powdery mildew, a fungus which is especially destructive to apple seedlings in the nursery, was under investigation in Maryland. Following is a list of the diseases treated, together with the localities where the experiments were made: POTATO.. Black-rot [(Læstadia Bidwellii Sacc.), V. & R.] Powdery mildew (Uncinula ampelopsidis, Pk.) Rust (Ræstelia aurantiaca, Pk.) Blight (Micrococcus amylovorus, Burrill) ... Leaf-blight (Sphærella fragariæ, Tul.) New Jersey, Virginia, South New Jersey, Maryland. * Do. Do. Mississippi. New Jersey, Mississippi. Do. New Jersey. Rot(Macrosporium solani, Rav.and Fusarium solani, New Jersey, South Carolina. MELON Mart.) Blight (Cladosporium fulvum, Cke.). Blight (Septoria)... South Carolina. *Circular No. 8 giving a full account of the treatments of this disease and the apple powdery mildew has already been issued. In addition to the work outlined above, a large number of grapegrowers in different parts of the country treated their vines for mildew, anthracnose, and rot. A number of these have voluntarily sent in reports, a summary of which will be found in the accompanying pages. For the benefit of those desiring to know the results of experiments made in France and Italy in 1889 in the treatment of black-rot and mildew we have given an abstract of some of the most important reports on the subject, together with a short review of a recent paper by B. Fallot on the amount of copper in wines made from grapes treated with copper compounds. Aside from the experiments made in the treatment of grape maladies the work undertaken the past season is for the most part entirely new. Mistakes under such circumstances could not well be avoided, but after all it is only by seeing our errors that we are able to correct them. SUMMARY OF VOLUNTEER REPORTS ON VINE DISEASES. STACY PETTIT, FORT SMITH, ARK. Mr. Pettit applied the Bordeaux mixture b three times to one hundred and fifteen vines, chiefly Moore's Early, Delaware, and Concord, making the sprayings on May 20, June 15, and July 5. The Lewis Combination Force Pump was used for the work, the total cost of which was $2.10. The season was wet and cool, yet black-rot caused very little damage. Results.-Mr. Pettit thinks that the treatment saved his crop, his fruit being the finest sold in the Fort Smith market. Ten Brighton vines netted him $10, or $1 per vine. The Delawares also yielded a fine crop, but the Concords and Wordens did not ripen evenly, consequently their value was diminished. JOHN HERTLEIN, SPILERVILLE, LOGAN COUNTY, ARK. This is the third year of Mr. Hertlein's experiments, the resuits, as heretofore, being highly encouraging. Six hundred vines were treated five times; first, in February, with a strong solution of iron sulphate; second, April 22, with a modified Bordeaux mixture containing 2 pounds of copper sulphate and 2 pounds of lime to 22 gallons of water; third, fourth, and fifth, with the same preparation at intervals of two weeks. The remedies were applied with a Champion hand pump and graduating nozzle, bought of the Field Force Pump Company, of Lock. port, N. Y., this machine giving entire satisfaction. Owing to the fact that the blue-stone could not be obtained it was necessary to defer the first application to a part of the vineyard for ten days. On May 1 the first spots of black-rot were noticed on the foliage of three untreated vines of Niagara, Brighton, and Berckman's; the first rot on the berries of these vines was observed May 29. On June 4, nearly all varieties, except Norton, Ives, Delaware, and Montefiore, were affected with rot. At this date Mr. Hertlein commenced picking off the rotting grapes, this practice having been followed for years. June 28, the second attack of black-rot was noticed. This time it made a clean sweep of all untreated vines. The season was wet with frequent heavy dews and fogs, furnishing just the conditions for the development of fungous parasites. Results. The loss in the treated vineyard was very slight, only about 2 gallons of rotten fruit being picked from the entire six hundred vines, half of this amount coming from sixty vines which received the first application ten days late, as mentioned above. Mr. Hertlein concludes his report as follows: Of the Vergennes grape, which I prize highly for a fine white wine, I could in former years hardly save 25 per cent. This year my loss of this variety is 1 per cent., Concord one-sixth of one per cent., Brighton one-half per cent., Niagara one-half per cent., and so on in proportion. Norton, Delaware, Ives, Montefiore, Clinton, no rot at all. The cost of treatment was a little less than one-half cent per vine, labor included. I think next year I shall experiment with a few rows, making only two applications, as cheapness is one main factor. I believe that the main infection of rot is before or at the time of bloom, and that it only takes more or less time to develop; however this may be, I, for my part, do not fear black-rot any longer, but would advise every one to use these preventives early, as soon as the first three or four leaves are formed. The vines I washed in February with the copperas solution gave the best results, and I advise all grape-growers to try it, at least on those varieties most subject to rot. I will give you a few notes concerning some of my neighbors' vineyards. One has a little vineyard on low ground, and last year he did not have a sound bunch in the whole vineyard. I urged him to try the remedy this year and he obtained a tolerably good crop of grapes, notwithstanding he commenced rather late |