EXPERIMENT STATION WORK WITH INSECTICIDES. 245 



* Some of the most extensive and thorough tests of the lime-sulphur 

 washes have been made by the New Jersey stations." The formula 

 first recommended in New Jersey was 50-50-50-150, the mixture to 

 be boiled for at least an hour and a (juarter. As a result of the early 

 experiments at the New Jersey stations, it was concluded that the 

 time of application should l)e late winter or early sprin«: before vege- 

 tation has started. The practice of spraying twice annually, that is, 

 in the fall and the spring, was discouraged on account of the possible 

 injury to peacli trees, ' While it is generally recommended that the 

 California mixture should be applied hot, good results were obtained 

 from this wash after it had become cold. The New Jersey stations 

 recommend the California wash especially for peach trees, but 

 argue that crude petroleum or some soluble form of oil is more reliable 

 on other trees, especially if they are badly infested with the scale. 

 The same formula of the California wash was tested in subsequent 

 years at the New Jersey stations with satisfactory residts. Wliere 

 it was inconvenient to boil the mixture a fornnila was recommended 

 calling for HH pounds of lime, 17 pounds of sulj)hur, and 4i pounds 

 of caustic soda per 50 gallons of water. The New Jersey stations 

 recommend that the lime be slaked with just enough water to allow 

 the process to take place, after which it is boiled with no more water 

 than enough to prevent burning, the sulphur having been added 

 during the process of slaking. The boiling is to be continued until 

 the mixture takes on a deep amber color, after which the salt pre- 

 viously dissolved in water is added slowly to the boiling mass. The 

 boiling period recommended by these stations is one hour. The most 

 recent fornuda suggested for the caustic soda mixture is 80-15-G-50. 

 During the winter and spring of 1903-4, numerous failures were 

 reported to the New Jersey stations in the use of lime-sulphur washes. 

 In fact the majority of orchardists who tried these mixtures reported 

 almost complete lack of success. The failures observed were chiefly 

 in apple and pear orchards, while success was had when the insec- 

 ticide was applied to peaches and plums. The cause of these unfortu- 

 nate experiences on the part of orchardists was not fully determined 

 by the investigation undertaken by the stations, but as a result of 

 these quite general failures the stations were led to reconnnend more 

 emphatically the use of petroleum mixtures or more soluble oils for 

 all orchard trees except the less hardy kinds, such as the peach. 



Very careful experiments under the most severe scientific precau- 

 tions have been carried on for several years at the New York State 

 Station.'' The first experiments at this station indicated clearly that 

 the lime-sulphur-salt wash is a safe and reliable remedy for use 



o New .Jersey Stns. Buls. 102, 109. 178 ; Rpt. 1904, p. 029. 

 t> New York State Sta. Buls. 228, 247, 2r>4, 202. 



