284 Appekdix. 



bark or bark roughened through age, some insects would escape and occasional 

 ones might appear upon the new growth and upon fruits. In general, wherever 

 any one of the washes was brought into contact with the scales the insects 

 were killed. On smooth trees, any considerable number of scales left unharmed 

 is evidence of lack of thoroughness in spraying ; but no heavy wash or spray 

 mixture need be expected to reach the scales that are clustered beneath close- 

 clinging pieces of rough bark or hidden in deep cracks and crevices. 



"The winter of 1903-04, following these treatments, was the coldest for 

 years ; and untreated trees in many localities, especially trees weakened by dis- 

 ease or by insect attack, suffered severely. This fact makes it somewhat difficult 

 to interpret fairly the variable results of these spraying tests ; but comparison 

 could be made with a large number of check trees in three orchards of different 

 general condition as to varieties, vigor of growth, and amount of scale infestation. 



"In the most vigorous scale-free orchard at Geneva, the coating of lime 

 and sulphur considerably reduced both bloom and foliage upon Fitzgerald peaches 

 and Reine Claude plums ; but after the blossoms dropped the sprayed trees 

 showed marked improvement and by the end of the season equalled the checks 

 in appearance, but bore a smaller crop of fruit. It seemed as though all the 

 trees were lessened in vitality by the severe winter and that the sprayed ones 

 were also affected by the spraying ; but that the check to fruit production caused 

 by the spraying allowed the sprayed trees to recuperate faster. Had the un- 

 sprayed trees been well infested with scale, the advantage at the close of the sea- 

 son would probably have been with the treated trees, notwithstanding the in- 

 jury due to the spray mixture. 



"In the other Geneva orchard bloom was somewhat less profuse on the 

 sprayed trees, but the injury was less than in the first orchard. Sprayed 

 Morello cherries, apples and pears showed slight diminution of bloom ; but crab 

 apples suffered no injury. Trees in this orchard that were much infested with 

 scale were severely injured by the winter. 



"In the Long Island orchard the sprayed trees, except those reduced in vigor 

 by the scale or injured by the winter, were unaffected by the spraying. The 

 sprayed apples sliowed. later in the season, increased vigor and healthfulness as 

 a result of control of the scale. 



"As a whole the work shows that sulphur washes applied in the fall may 

 under certain conditions cause injuries such as sometimes attend the excessive 

 use of these sprays in the spring. But it is believed to be advisable, when 

 experience has shown that it is impossible to spray all of the trees in the spring, 

 to employ fall spraying for the treatment for the hardier varieties of fruits — as 

 the increased vigor and usefulness of the trees arising from the control of the 

 scale will more than compensate for probable losses in fruit yields. 



"All of the washes tested proved equally effective in the destruction of the 

 scale. The addition of caustic soda or salt to a lime-sulphur wash cooked by 

 fire or steam did not add to its effectiveness. While satisfactory in the present 

 experiment, later tests with the lime-sulphur wash prepared without external heat 

 showed that there may be considerable variation in the different preparations 

 which may be largely avoided by using high-grade lime and knack in the cooking 

 operations. The washes that are well suited to the needs of average orchardists 

 are the lime-sulphur wash boiled by fire or steam and the lime-sulphur-caustic 

 soda wash, prepared without external heat. In conducting the experiments this 

 spring the following method was adopted for the preparation of the lime-sulphur- 

 caustic soda wash as it is an easier way of making the mixture. First the sul- 

 phur was made into a thin paste with hot water and was then poured over 

 and well distributed throughout the lime. Additional water was used as needed 

 to keep the lime-sulphur material in a rather stiff paste. As soon as the lime 

 was slaked the full amount of caustic soda was added and stirred until the boil- 

 ingaction had ceased. Enough water was then poured in to make the required 

 amount of wasn. By using boiling water in making a paste of the sulphur and 

 slaking the lime much less time is needed to prepare the wash." 



