240 REPORT OF OFFICE OF EXPERIMENT STATIONS. 



the San Joso scale but other rehited species which are not directly 

 suscei)til)le to the action of poisons. Tn fi^ivinjij an account of the 

 experiment station work aloiiii: tliis line it is perhaj)s well to begin 

 with the liine-sulphur-salt wash. 



THE LIME-SULPHUR-SALT WASH. 



The linie-sulphur-salt wash, also known as California wash on 

 account of the fad that it was first brought into prominence in that 

 State, is now generally reconnnended by station entomologists as the 

 best remedy for scale insects. At the California Station " experi- 

 ments were carried on lo determine the effect of variations in the 

 amount of lime and other ingredients in this wash. Various amounts 

 of lime were used, ranging from 20 to 50 pounds per GO gallons of 

 water. In all cases the San Jose scale was killed, and the amount of 

 lime necessary to combine with the sulphur was found to be about 

 equal parts by weight. In general the percentage of scales affected 

 by the wash was greater wliere there was a scarcity of lime. This was , 

 especially true wliere heavy rains occurred after spraying. Similarly 

 tl\e amount of sulphur per GO gallons of water was made to vary from 

 5 to 40 pounds. AVhere the smaller quantities of sulphur were used 

 there was a falling off in the efficiency of the wash. When the 

 amount of salt was varied little difference in the results was discern- 

 ible, even where the salt was entirely omitted. The station, however, 

 does not feel prepared to recommend the disuse of salt in the wash. 

 The California Station also compared the cost of making a lime- 

 sulphur wash without boiling with that of the ordinary boiled wash. 

 It was found in this comparison that the cost of the two methods, as 

 involved m a day's work with the power outfit, applying 2,000 gal- 

 lons per day, was $35.40 for the wash boiled by fire and $45.75 for the 

 wash made with caustic soda. The formula finally determined upon 

 as the most satisfactory from every point of view calls for 30 pounds 

 of lime, 12 pounds of sulphur, and 10 pounds of salt for each GO gal- 

 lons of water. This wash was found effective against all scale insects 

 and some other related species except the brown apricot scale, for 

 which a resin compound containing resin, caustic soda, fish oil, and 

 Avater is recommended. The California Station reconnnends that the 

 lime-sulphur-salt wash be applied in winter to dormant trees. In 

 some instances the wash was applied to apricot trees in bloom without 

 injury, but this procedure is not recommended. 



The Connecticut State Experiment Station ^ carried on experi- 

 ments with lime-sulphur-salt wash on 11,500 trees, chiefly peach, 

 pear, and apple. The California wash proved to be about equally 



a California Sta. Bui. 166. 



6 Coufiecticut State Sta. Buls. 144, 146 ; Bui. Immediate Inform. 1. 



