•50 STATE HORTICULTURAL SOCIETY. 



VEGETABLE PATHOLOGY. 



As is indicated by its name, the division of vegetable pathology devotes 

 its attention to diseases affecting plants. This is comparatively a new 

 line of scientific work, and in consequence much attention is necessarily 

 paid to work of description and classification of fungi and bacteria 

 affecting plants. 



When reports of new plant diseases are received, specimens are secured 

 and a miscroscopic study is made to determine the cause of the disease if 

 possible. Usually this is done by growing the suspected germs in artificial 

 culture media, such as sterilized gelatine or solutions selected for the pur- 

 pose. Inoculations are made on healthy plants, with germs thus grown, 

 and if the diseased condition results it is regarded as satisfactory proof 

 that the germ sought has been isolated. The life history of the germ is 

 then studied, to detect the period in its existence when it is most suscep- 

 tible to attack, and various remedies are tested in a small way until some 

 are found that are thought to be at the same time safe and efficient. 

 These are then tested on a larger scale, under similar conditions, in 

 regions where the disease is most disastrous, with a view to determining 

 the most efficient of the remedies tested, their comparative cost, and the 

 best and most economical means of applying. Results obtained are pub- 

 lished from time to time with directions as to methods and means of 

 application of the remedies. These published results are sent to all 

 persons who apply for them, or who are known to be interested in the 

 matter. 



The methods of preventing and controlling black rot and mildew in the 

 grape are now so well known that tiiey need not be mentioned here. 

 Experiments on that subject have been continued, however, during the 

 present season, and it has been found that much less copperas is required 

 than was formerly used in Bordeaux mixture, thereby reducing the cost of 

 application from $14 per acre to $2 per acre. The experiments on control of 

 twig blight in nursery stock, conducted at Geneva, New York, during the 

 season just past, under direction of one of the assistants in this division, 

 have been made on some three million trees of cherry, apple, quince, 

 pear, and other fruits in nursery, and are regarded as very satisfactory. 

 Work on pear blight, California vine disease, diseases of citrus fruits, rot 

 of sweet potatoes, and a bacterial disease of oats, is in progress, as well as 

 that on a number of diseases affecting greenhouse plants and some fungoiis 

 diseases affecting insects. 



The investigation of peach yellows has been actively continued, and as 

 a result of three years' work with every fertilizer likely to have the desired 

 effect, no instance has been found either of prevention or cure of yellows 

 in the peach by fertilizers. This has been a disputed point among the 

 investigators of the subject and its settlement narrows the field and indi- 

 cates the line of research for future work. A more virulent disease than 

 yellows has been discovered on the peach in Georgia, and the fact that it 

 is readily communicable by bud inoculation has been established. A 

 bulletin is now in press giving the results of these investigations. 



GARDENS AND GROUNDS. 

 I 



The division has charge of the grounds and greenhouses of the depart- 

 ment. Formerly much experimenting was done, particularly with fruits, 



