APPENDIX. 383 



DESTRUCTIVE MEASURES. 



Of the destructive or killing methods recommended, the "'freezing" 

 method and the use of carbon bisulphide are unsuccessful and unsafe. Boil- 

 ing water and similar methods have been successfully emi)loyed, but they 

 -are impracticable on a large scale and may injure or kill the tree. 



"Digging om<" method — The "digging out" method is the only thoroughly 

 ■successful and safe way of killing the peach-tree borer. This method is 

 expensive in time and labor, but our experience leads us to believe that any 

 •other equally as successful method will cost just as much. To make it a 

 success, the "digging out" should be thoroughly done, not only on every 

 tree in the orchard, but also on all "old relics" of peach trees in the imme- 

 diate neighborhood. A half-dozen such "old relics "' left untreated near by 

 served to thoroughly restock our orchard with borers every year, so that 

 our " digging out '" method, although practiced thoroughly each year, never 

 reduced the niimbers of the borers below the danger limit. This is a very 

 important factor in the success o| the "digging out" method. Under cer- 

 tain millennial conditions, we believe the numbers of borers could be reduced 

 to the minimum in an orchard by this method alone. Practically every 

 peach grower, who makes any pretensions of fighting the borers, digs them 

 out at least once a year. Many then apply some wash or other device, but 

 curiously enough, they usually attribute any success they may seem to have, 

 not to the " digging out '" process, where most of the credit usually belongs, 

 but to the other preventive applications. As our experiments show, how- 

 ever, the application of certain preventive measures after the borers have 

 been dug out, is not a waste of energy where several " old relics" are left 

 untreated near by, or if a neighbor's peach orchard a few rods away is 

 neglected. As these conditions usually prevail in the neighborhood of most 

 peach orchards, we doubt if the "digging out" or any other method used 

 alone, with a few possible exceptions, can be depended upon to reduce the 

 number of borers to the minimum. But we believe there are several com- 

 binations of this destructive method with a preventive application which 

 will give better results than either one alone in most orchards, and will keep 

 the pest under control. Dig out the borers in .June or in .June and September 

 in northern peach-growing districts. 



PREVENTIVE MEASURES. 



Plants — There is little evidence to show that the odor of any plant, like 

 red cedar or tansy, will have any influence on the numbers of the borers 

 when such a plant is set with the tree ; such plants would not be desirable 

 adjuncts to peach growing for other reasons. 



Tobacco — It has been recommended to pile or scatter various substances 

 around the base of the tree to keep out the borers, but only two of these 

 deserve serious consideration. 



Nearly a century ago good results were reported from the use of tobacco 

 wound around the base of the peach trees. We tested tobacco stems (midribs 

 -of the leaves) from a cigar factory, and the results astonished us. Evidently 

 the tobacco kept out from two-thirds to five sixths of the borers. We are 



