PEAR PESTS 



1655 



Spraying 



A tobacco extract containing 2% per 

 cent nicotine, diluted at the rate of 1 to 

 60 in a 6 per cent distillate-oil emulsion, 

 kills all the thrips touched and pene- 

 trates well into the pear cluster buds. 

 The pubescent covering of the individual 

 buds in the cluster, being resistant to 

 water, seems to act on the dilution in dis- 

 tillate-oil emulsion in much the same 

 manner as the wick upon oil in a lamp. 



Bistillate-Oil Emulsion 

 Home-Made Freparation 



To make soap use this formula or some 

 multiple of same: 



Water, gallons 6 



Lye (98 per cent) , pounds 2 



Fish oil, gallons 1% 



Put the water in a caldron or boiler 

 and add the lye. "When the lye is thor- 

 oughly dissolved and the water boiling, 

 pour in the fish oil, stirring in the mean- 

 time, and boil slowly for two hours. 

 When the soap has boiled sufficiently it 

 should give a ropy effect when stirred 

 and brought up upon the ladle. This 

 formula gives about 40 pounds of mod- 

 erately firm soap. 



Growers are cautioned to buy only gen- 

 uine fish oil and not a fish-oil compound 

 or a mixture of fish oils and vegetable 

 oils. Herein lies part of the secret of 

 the penetrating efficiency of the distillate 

 emulsions made by using animal-oil soap 

 as the emulsifier. The cost of the soap 

 is $0.0165 per pound made from fish oil 

 at 35 cents a gallon. 



The distillate-oil stock emulsion should 

 be made as follows: 



FORMULA* 



Hot water (boiling) , gallons 12 



Fish-oil or whale-oil soap, pounds 30 



Distillate oil (raw) 30° to 34° Baume, 



gallons 20 



Have the water boiling hot when put 

 into the spray tank and add the soap 

 immediately while the agitator is run- 

 ning at a good speed. When the soap is 

 all thoroughly dissolved, pour in the oil 

 slowly, keeping the mixture well agi- 

 tated while the oil is going into the tank. 



* For a spray tank of 200 gallons capacity, 

 five times this formula can be made at one 

 time 



When all the oil is in and well mixed, 

 pump out through the nozzles at good 

 pressure (not less than 175 pounds) into 

 storage tanks. 



No one should attempt to make this 

 stock emulsion without a power spray- 

 ing machine, as thorough agitation and 

 high pressure are important requisites. 

 Also, care should be used in having 

 measurements reasonably exact, the 

 water boiling hot and soap thoroughly 

 dissolved before any oil is put in. This 

 stock emulsion contains approximately 

 55 per cent oil, and to make a 3 per cent 

 emulsion use 5% gallons of this stock in 

 each 100-gallon tank. To dilute, first put 

 the stock emulsion in spray tank (have 

 the agitator going), and then add the 

 water, keeping the agitator running all 

 the time. This is important with the 

 commercial preparations as well as with 

 the home-made emulsions. For the com- 

 bination sprays of oil emulsions and 

 nicotine solutions, the nicotine should 

 be added last, that is, after the oil emul- 

 sion has been diluted to the desired 

 strength. These solutions should not be 

 mixed together without first diluting one 

 of them. 



This concentrated emulsion will cost 

 the grower about 5 cents per gallon, as 

 most of the various distillates used for 

 spraying cost from 5 to 10 cents a gallon 

 in drum lots and home-made soap costs- 

 about 2 cents per pound. 



Experiments conducted thus far indi- 

 cate that success is more uniformly ob- 

 tained by using an untreated raw dis- 

 tillate 32 to 34 degrees Beaume with com- 

 paratively high flashing point. 



It was found that fruit from sprayed 

 trees was nearly free from scab, was 

 larger, and on account of yield and qual- 

 ity showed a net profit of $127.44 per 

 acre over the non-sprayed. Similar re- 

 sults followed the use of spray in pear 

 and cherry orchards. 



RecomjoieiidatioBs 



Spraying is by far the most satisfac- 

 tory means for controlling the pear 

 thrips on all classes of deciduous fruit 

 trees. However, to spray successfully 



