Plant Sanitation- 



510 



[December 1911. 



Or more if needed. 



This formula does not state definitely 

 the quantity of water necessary to obtain 

 an emulsion free from oil, as the amount 

 to be used often varies, After the stock 

 emulsion has been thoroughly mixed try 

 a few drops in a glass of water, and if no 

 oil appears the emulsion is ready to be 

 diluted with the water for spraying. It 

 is recommended to use 1 gallon of the 

 stock emulsion to 25 gallons of water for 

 trees without fruit. 



Kerosene and Crude-Oil Emulsions. 



Kerosene emulsion was one of the first 

 sprays to be used by the fruit growers 

 on the island. The results from one 

 spraying with a solution 1 to 5 parts of 

 water have not been satisfactory, only 

 the crawling young and those bearing 

 the first covering being killed. 



Crude oils have given better results. 

 This oil does not evaporate as readily as 

 the refined or lightei oils, therefore re- 

 maining on the trees for a longer period 

 and killing more scale. A smaller per- 

 centage of oil is required in the crude-oil 

 formula. These emulsions break down 

 more quickly than the kerosene emul- 

 sions, and for this reason are not used 

 to so great an extent- It has been shown 

 by experiments that the destructive 

 power of crude-oil emulsion, 1 to 15 or 18 

 parts of water is equal to that of kero- 

 sene emulsion 1 to 5. 



While the price of these two cils is the 

 same, kerosene makes a more expensive 

 emulsion than the crude oil, as it is not 

 so highly diluted, this difference in the 

 cost of the two emulsions being about 1 

 cent per gallon. 



Kerosene Emulsion. 



Kerosene emulsion made with whale- 

 oil soap is one of the oldest insecticides 

 in use- It is not as difficult to make as 

 the crude and miscible oil emulsions. It 

 is not, however, as effective in control- 

 ling scale, but as it is easily made and 

 does not separate.it is still used by many 

 fruit growers. The formula is as fol- 

 lows : — 



Kerosene ... gallons 2 

 Water ... ,, 1 



Whale-oil soap ounces 8 



Put the kerosene oil in a spray pump. 

 Dissolve the soap in the water by boiling 

 and pour the solution into the oil ; mix 

 the whole by pumping for about 10 

 minutes, directing the stream back into 

 the pump. If a large quantity of the 

 emulsion is being made, it should be 

 pumped longer. A creamy mixture 

 should be obtained, which will hold up 

 from two to three weeks 



Kerosene and' Crude-Oil Emulsions 

 with Crude Carbolic Acid. 

 During 1908 crude carbolic acid was 

 used in combination with both crude oil 

 and kerosene emulsions. These emul- 

 sions were tested microscopically and 

 appeared very different from the emul- 

 sions made without the crude carbolic 

 acid. The oil particles are more finely 

 divided, in some cases their diameter 

 being only one-third to one-fourth the 

 size of those in emulsions made without 

 the carbolic acid. The killing power of 

 these emulsions is greater than those 

 made without carbolic acid, and they 

 are more stable. Very little, if any, free 

 oil could be found, even after the emul- 

 sion was allowed to stand several hours. 



It seems quite possible that the carbo- 

 lic acid will prove beneficial as a fungi- 

 cide, but not to such an extent a9 the 

 sulphur in the lime-sulphur mixture. 

 Crude carbolic acid varies greatly in 

 strength. 



The formula for kerosene emulsion 

 containing crude carbolic acid 100 per 

 cent, (dark), is as follows :— 



Kerosene ... ... gallons 2 



Water „ 1 



Whale-oil soap (hard)... pound i 

 or — 



Whale-oil soap (soft) ... quart 1 

 Crude carbolic acid, 100 



per cent, (dark) ... pint 1 



This emulsion should be made the 

 same as kerosene emulsion. The car- 

 bolic acid is emulsified in the hot water 

 with the soap. 



Crude cat bolic acid has been used in 

 the various crude-oil sprays for ants, 

 and the tests show that the amount of 

 free oil which usually appears on these 

 emulsions is practically eliminated- 



Crude-petroleum Emulsion with 

 Sal Soda. 



This formula has been used on trees 

 which were infested with purple and 

 white scales and sooty mold. 



Crude petroleum 

 Water ... 

 Whale-oil soap ... 

 Sal soda... 



gallons 5 



5 



pounds 2£ 

 i) 2 



Place the oil in a barrel. Dissolve the 

 soap and sal soda in boiling water. Mix 

 the two by pumping back into the 

 barrel for 15 to 20 minutes. Stock 

 emulsions made according to this 

 formula have given satisfactory results. 

 Use one part stock solution to 15 parts 

 of water. 



