NEU' FIELDS. 



575 



ber of these, all of which are doing valuable work. 



It was not until 1885 that the importance of in- 

 vestigating the fungous diseases of plants was recog- 

 nized by the National Government, and it was largely 

 through the efforts of the botanists of the country 

 that this was brought about. Commissioner Col- 

 man's attention being called to the matter, he placed 

 the work in charge of F. L. Scribner, who had been 

 for some time connected with the department. Mr. 

 Scribner resigned in 1888 to accept a position in 

 the Agricultural Experiment Station of Tennessee, 

 since which the. work has been in charge of the 

 writer. From the small beginning made five years 

 ago this branch of the department has steadily 

 grown, until to-day it stands on an equal footing 

 with the other divisions. 



Its work is naturally divided into two classes : 

 studies in the laboratory, with a view of tracing the 

 life histories of the various fungi in order to discover 

 the best methods of combating them ; and field ex- 

 periments or practical tests of such preventive 

 measures as the laboratory work may suggest. To 

 carry on this work successfully, a corps of trained 

 experts is kept constantly employed in the lab- 

 oratory, while special agents in different parts of 

 the country devote a good share of the growing 

 season to experimenting with the remedies. 



Let us now see what have been some of the 

 practical results of this work. In the first place, 

 grape growers everywhere have been made ac- 

 quainted with the causes of such diseases as 

 black-rot, downy mildew and anthracnose ; more- 

 over, it has been proved to their entire satisfac- 

 tion that these diseases can be prevented by 

 proper treatment. Between two and three thous- 

 and grape growers in all parts of the country used 

 the remedies in i88g, and, from estimates based 

 on reports received from about thirty, we know 

 that the actual saving in money to these, above all 

 expenses, was something over ?io,ooo. Our 

 agents last year, in treating potatoes for blight 

 and rot, succeeded in saving 75 per cent, of the 

 crop. On this basis, the amount saved to the 

 entire country, if all the infected districts had 

 been treated, would have been something over a 

 million dollars. 



To give a more detailed example of the practical 

 value of this work, we will furnish the results of 

 an experiment made by us in treating pear leaf- 

 blight. The actual cost of treating a block of 

 5,000 trees has been a Httle less than %ioo. This 

 includes treating the trees seven times last year, 

 before and after they were budded, and four times 

 this season. Out of the 5,000 trees, not 500 were 



lost, and as the block now stands it is worth at least 

 §7,000. Heretofore it has been an unusual thing 

 to bud half of the stocks ; in fact, the loss from this 

 source is usually about 60 per cent. Assuming, 

 however, that the loss would have been 50 percent., 

 we, at an expenditure of ^100, saved ^3,500. 

 Many examples of this kind might be given, but 

 enough has been said to illustrate our point. 

 Figures i to 4 will also enable the reader to judge 

 something of the effects of treatment. Fig. i shows 

 a pear tree attacked by leaf-blight, while Fig. 2 

 shows an adjacent one which had been treated with 

 fungicides. The grape clusters are from photo- 

 graphs, and represent fairly well the difference in 

 the fruit, as seen the 25th of July of this year on 

 treated and untreated plats. By the time the fruit 

 usually ripens there will probably be none on the 

 untreated plats to harvest, while the treated will 

 without doubt yield from four to eight pounds per 

 vine. 



Now let us notice the discoveries made in the 

 matter of fungicides or remedies for plant diseases, 

 and also bring to mind the recent improved methods 



Fig. 3, Fungi and Neglect. 



of applying these substances. Ten years ago about 

 the only fungicide used was the flowers of sulphur. 

 Now, thanks to the investigators of this country and 

 Europe, a score or more of substances are in con- 



