30 BULLETIN 616, U. S. DEPARTMENT OF AGEICULTUKE. 



Plat No. 17. Sulphur-soda solution, 2-25. 



18. Resin wash, 1 1-3. 



19. Resin wash, 1-5. 



20. Resin wash, 1-10. 



21. Plain water. 



22. Unsprayed, check. 



Each of the foregoing plats of Series I consisted of two rows of 

 25 trees each, or 50 trees to the plat. The trees were 18-year-old Wash- 

 ington navels, and the entire experimental block was bordered on 

 two sides by trees of the same kind and planting, and on the remain- 

 ing sides by Valencias and a road, respectively. 



Series II: Foothills ranch. 



Plat No. 1. Lime-sulphur solution (33° Bauine), 1-75, and tobacco extract 

 (2f per cent nicotine sulphate), 1-150. 



2. Lime-sulphur solution (33° Bauine), 1-75. and tobacco extract 



(2f per cent nicotine sulphate). 1-100. 



3. Tobacco extract (2| per cent nicotine sulphate), 1-100. 



4. Tobacco extract (40 per cent nicotine sulphate). 1-1.600. 



5. Tobacco extract (40 per cent nicotine sulphate), 1-2,400. 



6. Tobacco extract (40 per cent nicotine sulphate), 1-1,600, and 



cresol soap, 1-400. 



7. Tobacco extract (40 per cent nicotine sulphate). 1-2,400, and 



cresol soap, 1-400. 



8. Plain water. 



9. Unsprayed. check. 



10. Tobacco extract (40 per cent nicotine sulphate), 1-800. 



11. Tobacco extract (40 per cent nicotine sulphate), 1-1.600. and fish- 



oil soap, 1-200. 



12. Tobacco extract (40 per cent nicotine sulphate). 1-2,400, and fish- 



oil soap, 1-200. 



Plats 1 to 8 of Series II consisted of 4 rows of 28 trees each; plat 

 9. of 5 rows of 28 trees: the remaining plats, of 2 rows of 28 trees 

 each. All trees were 4-year-old Washington navels. The only lime- 

 sulphur available for use unmixed in Series II was a quantity which 

 had been exposed to the air for a year. It was used, with misgivings, 

 and the results, which are omitted as of no value, proved conclusively 

 that it had lost most of its insecticidal power. 



1 The stock resin wash (plats 18. 19. and 20) was made fresh for each application, as 



follows : 



Resin pounds 20. 



Caustic soda (98 per cent) do 3.6 



Fish oil pints— 3. 



Water enough to make gallons 50. 



All the ingredients were placed in a 60-gallon iron kettle with 10 or 15 gallons of water 



and brought to boiling. Melting was aided by constant stirring. Hot water was added 



occasionally until the mixture had boiled constantly for about 1A hours and had reached 



50 gallons. 



