WINTER WASHES TRIED AT WIS LEY, 1914-15- 231 



retailer might sell at half that price in 40-gallon barrels direct from 

 the maker. It is not fair to compare the two. We have tried to 

 get a fair basis of comparison on the figures supplied, taking the 

 retail price of a gallon ; but not too much stress has been laid on this 

 point, as all the data were not available. 



6. Effectiveness. This is the real consideration, and no wash has 

 been considered as effective unless it complied with the very simple 

 requirements of the tests : namely, to clean off moss, lichen, alga?, 

 or other superficial growths from the trunks of the trees to which 

 the washes were applied. No wash was considered at all unless it 

 quite clearly and definitely cleaned lightly "mossy " trees. 



In this connexion it is to be noticed that a winter wash may be 

 too drastic, its repeated application being likely to injure the bark ; 

 only two washes exhibit this characteristic, but it is important, and 

 the best washes should clean the trees without removing an undue 

 amount of bark or injuring the bark below. 



Application. — Nineteen washes in all were tried, under, as far as 

 possible, similar conditions. They were made up fresh on the day 

 they were applied, sprayed in turn from the same machine with a 

 pressure of 40 lb. to the square inch, and applied on the same day to 

 trees selected as being as nearly as possible equally mossy. The trees 

 were : — (1) Young bush apples, of which the trunks were sprayed. 

 (2) Old Apple trees, of which the trunks were sprayed to 6 feet from 

 the ground. (3) Young Plum trees of which the trunks were sprayed. 



The first spraying was on January 20 ; after ten washes had been 

 applied light rain stopped the work. Ten days later these were 

 examined, and it was evident that the trees could be definitely classed 

 according to the effect. 



On February 5 the whole twenty washes were applied to one young 

 Apple, two young Plums, and one old Apple each, the whole being done 

 in one day. The day was fine and cold ; light rain fell next day. The 

 washes were numbered, and no further information was then available 

 as to names, composition, or prices. As each was applied, it was noted 

 if the wash " wetted " well, its appearance or smell, whether it had 

 mixed in cold water, and whether, in application, the operator was 

 inconvenienced by its being caustic. The trees were scrutinized on 

 February 23 and at later dates. Their appearance was noted in 

 each case in comparison with the control tree next. As the effects 

 produced do not appear equally rapidly in all, the first definite marking 

 was not done till March 23, and this has been checked since. Four 

 independent observers noted separately. Two washes of known 

 composition were used as controls. One was a very common wash, 

 the other an entirely new substance under test as an insecticide. 

 The first table on the following page is a marking produced as an 

 example of the manner in which the judging was done. 



As some of the washes did not definitely fall into any class, they 

 were repeated on the same trees, this constituting a repeated applica- 

 tion such as is sometimes recommended. In all, fourteen markings 



