METHODS OF COMBATING THE MISTLETOE. 27 



though new branches are put forth the violent drying out at the 

 sawed-ofT end of the branch extends back to the new branches, and 

 they are killed. In such a case there would manifestly be much 

 help in painting the cut surface with a heavy coat of tar or asphalt 

 paint, or some other waterproof substance. This is advised in any 

 case where a wound is made, as in scrapmg with a pruning hook or 

 in cutting ofT small branches. It is questionable whether wholesale 

 lopping-ofT of large branches is ever advisable. 



POSSIBILITY OF ELIMINATING OLD INFECTIONS. 



Can mistletoe be completely eliminated from large branches or 

 trunks without fatal injury to the host? This bulletin does not 

 pretend to give a satisfactory, or at least a final, answer based on 

 sufficient demonstration, but it may present a statement of the case 

 in the hope of calling forth more activity in the way of attempts to 

 solve the problem practically. 



Under the writer's direction, branches of a 10-inch hackberry were 

 painted or smeared with the following preparations: (1) A strong 

 wood preservative known as ''carbolineum/' (2) asphalt paint, and 

 (3) laundry soap. In each case the mistletoe was shaved off flush 

 with the bark before the preparation was applied. Also in each case 

 a space was treated with the preparation and left without further 

 covering, while a similarly treated space was wrapped closely with 

 burlap. At the end of fourteen months (July 2, 1908) the report 

 was as follows: 



(1) Where carbolineum was used no mistletoe appeared, whether 

 the branch was wrapped or not. The preparation had not percep- 

 tibly injured the branch. 



(2) Where asphalt paint was used and the treated space not wrap- 

 ped, mistletoe reappeared, but not until the following season. Where 

 the treated space was wrapped, no mistletoe appeared after the wrap- 

 ping was removed, eleven months from the date of its application. 



(3-) 'Where laundry soap was used mistletoe promptly reappeared 

 as vigorously as before it was cut back and treated. On the wrapped 

 branch mistletoe began to sprout up as soon as the wrapping was 

 removed at the end of eleven months. 



This report would seem to indicate that a strong preservative like 

 wood creosote or carbolineum may be applied with a brush or cloth 

 in quantity sufficient to kill mistletoe, without seriously injuring the 

 branch or tree. Also that milder preparations, such as asphalt paint, 

 coal tar, and white lead, may be applied with the result of checking 

 the development of young mistletoe shoots, and by the additional 

 precaution of wrapping the branch the parasite may be effectuallv 

 killed. 



166 



