manner in which this is being done and some of the more important results accomplished during the year are set forth under the following heads:

FOREST PATHOLOGY.

The continued spread of the chestnut-bark disease, particularly southward and westward, has caused great public alarm. The method of destroying advance infections devised by this department and described in previous publications has been energetically applied in Pennsylvania, and recently also in New York. There is every reason to believe that the disease in these two States can be limited to the eastern counties. The State appropriation for this work in Pennsylvania is $275,000. In the New England States it will probably still be possible to keep the disease to the west of the Connecticut River; but this is essentially a local issue, with little bearing on the welfare of other States.. What is done in western Maryland, in Virginia, and in West Virginia, however, is a matter of national importance, for the fate of the chestnut in the southern Appalachians, where the finest and most extensive stands of chestnut timber occur, depends upon the checking of the bark disease in these States during the next three years. This department can cooperate to any extent in the study of all phases of the disease and in the location of advance infections, but the actual destruction of diseased trees must, for legal reasons, be exclusively a State function. It is therefore to be hoped that these critical States will be able promptly to follow the vigorous example of Pennsylvania. No other tree disease of equal seriousness is known to science, and unless prompt, united, and effective action can be taken there is every reason to believe that the chestnut tree will be practically extinct in certain sections of North America within 10 years.

On account of their important relation to reforestation, dampingoff and other diseases of forest-tree seedlings have received special attention. The results of the past season's work. have confirmed the previous report of absolute success in controlling the serious "blight" of coniferous seedlings by slight and perfectly practicable changes in the management of water supply and shade. For two seasons past the use of sulphuric acid in preventing the damping-off of coniferous seedlings in the Forest Service nursery at Halsey, Nebr., has been successful. If these results are confirmed by work in other localities and other years, damping-off, so far as coniferous seedlings are concerned, will cease to be an uncontrollable factor in reforestation. The use of sulphuric acid as a soil fungicide originated in this department, as reported in previous publications.

It is unfortunate that at this time, when interest in reforestation. is at its height, we should knowingly import a destructive European

nursery disease. Yet this appears to be the case. The white-pine blister rust, referred to in previous reports, is unquestionably still being imported. All importations that could be located have been inspected and all visibly diseased trees destroyed, but there are no means of locating all importations. The importation of white-pine seedlings should be flatly prohibited, as the damage which this disease can do, and probably will do, if once established in America, is out of all proportion to the value of all white-pine seedlings ever imported or ever likely to be.

Data collected in the forest-disease survey have indicated that in America timber decay and tree disease are second only to forest fires as causes of loss. In theory it is easy to remove diseased trees in the forest when cuttings are made, leaving only healthy individuals for seed trees, and so continually improve the health of the forest; but in practice so many questions of economy and differing local conditions are involved that many difficulties must be overcome. The Bureau of Plant Industry has given a great deal of attention to working out this problem, in active cooperation with the Forest Service. To this end, pathologists have been stationed in four of the six National Forest Districts. In District 5 great progress has been made in so conducting timber sales that all dangerously diseased trees are removed and only healthy and desirable individuals are left to propagate the future forest. Probably the most important function of these "district pathologists" is to look out for dangerous new diseases. There is every reason to believe that if the chestnutbark disease, for example, had started in a National Forest District having a pathologist it would have been eradicated as a matter of routine before infection became general. Great epidemics of this kind are as serious in their effects as forest fires, and there is no reason why as strenuous efforts should not be made to control them.

CROWN-GALL AND OTHER PLANT DISEASES.

An important line of work carried on during the past year has been a continuation of the study of crown-gall of plants, with special reference to its relation to malignant animal tumors. The new facts we have learned are, in brief: (1) That bacteria occur also in the secondary tumors; (2) that in most cases the secondary tumors are connected with the primary tumor by a deep-seated strand of tumor tissue, from which the original bacterium has been cultivated out; (3) that the cell structure of the secondary tumor is like that of the primary tumor, e. g., when the primary tumor occurs on the stem and secondary tumors subsequently appear in the leaves the structure of the leaf tumors is that of the stem. A bulletin is in preparation which will fully illustrate these new features.

The work in the bud-rot of the coconut palm has been completed, the very interesting discovery having been made that the organism associated with typhoid fever and not hitherto known to be a plant parasite is the cause of the bud-rot disease. A bulletin on the subject is now in press.

DISEASES OF FRUITS.

A feature of the fruit-disease problems of the year has been the prevalence of physiological diseases, particularly of the apple. In the Eastern States physiological troubles have occurred in the form of corky spots in the flesh of apples, accompanied by more or less distortion in the shape of the fruit. The York Imperial, the Ben Davis, and other commercial varieties have been affected so seriously as to injure the sale of fruit from orchards. These troubles are attributed mainly to the abnormal climatic conditions of the 1911

season.

A group of diseases, such as rosette and chlorosis, has developed in eastern orchards so as to attract attention, and they have increased greatly in the Western States. The extreme climatic conditions of the season have resulted in more injury by the new combination sprays of lime-sulphur and lead arsenate, but nevertheless these sprays are proving to be the most universally satisfactory remedies

that have ever been devised.

Very satisfactory results have come from the researches on apple mildew and its treatment. Experiments on this disease in the Watsonville district of California, in cooperation with the local authorities, have developed a satisfactory method of control by spraying.

The cedar rust, or orange rust, of the apple, which was so common in the Appalachian fruit belt last season, was very much less abundant during 1911. Most of this was the result of climatic conditions, though the application of control measures, such as cutting down the cedars and spraying, helped to reduce the disease.

Spraying experiments on the pecan scab were continued for the third season, and Bordeaux mixture was demonstrated to be a specific for pecan scab in Georgia. The pecan rust on nursery stock was studied and complete success obtained in controlling it by spraying.

Peach spraying work for the control of peach scab and brown rot was conducted in West Virginia, Delaware, and Michigan. A portion of the work was experimental, for the purpose of testing new fungicides and perfecting the self-boiled lime-sulphur treatment, but most of the work was in the nature of demonstrations. The results were very striking, and showed conclusively that where one or both of these diseases are prevalent the net profits from a peach crop may be doubled, or in some cases quadrupled, by spraying at the proper time.

Apple spraying experiments and demonstrations were conducted in several widely separated districts, and it was again shown that lime-sulphur properly diluted is a more satisfactory fungicide for certain apple diseases than Bordeaux mixture. However, owing to the severe weather conditions of the season, the combination of limesulphur and arsenate of lead caused considerable burning of the fruit in a few orchards, but this trouble was not so serious as to discourage the use of this spray.

The grape anthracnose is very destructive to both fruit and vine. Certain varieties in some localities are attacked every year by this disease. The department has demonstrated the past season that this malady can be satisfactorily controlled by proper spraying of the vines while in a dormant condition. Further confirmation of previous results in the control of black-rot of the grape has also been obtained. Very promising results have been secured in controlling the anthracnose of the cranberry, which has been found to be a prevalent cause of loss in some cranberry districts. Considerable progress has also been made in the study and control of other small-fruit diseases.

DISEASES OF COTTON AND TRUCK CROPS.

Diseases of the potato have assumed unusual prominence throughout the country during the past season. Physiological disturbances have combined with several parasitic diseases in bringing about a general reduction of the crop. Blackleg and both the early and late blights have been sufficiently severe to emphasize the importance of a more general adoption of preventive treatment by growers, but by far the most serious damage has been caused by potato wilt, a disease which usually assumes an inconspicuous form, causing premature ripening followed by dry-rot in storage. The unusually dry season, which retarded the early growth of the plants, was very favorable for the development of wilt. The resulting epidemic has served to emphasize the wide distribution of this disease and has given it a new importance. Studies are under way which should lead to a more thorough knowledge of the causes and the means of control.

Investigations on the diseases of sweet potatoes have been inaugurated and substantial progress made. The causes of the more important troubles are now known, some of them for the first time, and means of control are being studied with encouraging results.

The disease-resistant varieties of cotton, cowpea, and watermelon which the department has developed are being brought into more general trial by thoroughly organized cooperative arrangements with growers in the infested sections. This organization is being extended as rapidly, as the nature of the problem and the facilities of the department will permit.

Cooperative demonstration work on the control of truck-crop diseases by proper spraying methods is a new form of work inaugurated to bring the latest results along these lines to the attention of growers. An important feature of this work is the development of special machinery and technique to meet the demands of the varying conditions of culture and climate in different sections.

PATHOLOGICAL INSPECTION WORK.

The necessity of pathological inspection of all foreign importations has long been recognized, and in the early years the mycologist was called upon at irregular intervals, i. e., whenever importations were received by the department, to make examinations. As the Office of Foreign Seed and Plant Introduction developed and extended its geographical range, inspection of the department's plant imports has been definitely systematized by means of regular examinations, and printed health certificates or written reports for treatment or quarantine are furnished as occasion requires. The same methods are followed in connection with the congressional seed distribution, crop physiology and breeding investigations, and the Office of Gardens and Grounds. Card indexes are maintained for a complete file of observations and results. Advance information is furnished agricultural explorers, that they may be aware of diseases indigenous to certain countries or geographically restricted, thus enabling them to avoid unnecessary expense in making collections which would have to be condemned at Washington.

NEED FOR TRAINED PLANT PATHOLOGISTS.

The growing need for trained plant pathologists to take up numerous problems which are now being presented to this department for solution is extremely urgent. While the universities and colleges appear to be doing what they can, it happens usually in our work that men fresh from college do not have the requisite outlook or the necessary training to obtain practical results in this field. Usually we have to give them several years of additional training in order to make them most serviceable to the advancement of agriculture in these lines. Every year requests come to us from the experiment stations and similar institutions in the United States to name persons well qualified for appointment to positions involving plant pathological research in these various institutions, and, unfortunately, in a very considerable number of cases we have to say that, glad as we would be to recommend persons, there are none in sight with the necessary training. This lack of a sufficient number of trained pathologists works to the serious disadvantage of agriculture in this country. The department would be glad to have in training an additional number of young men for such positions.