13 



stirring will bo necessary. After the wash has been prepared it must 

 be well strained as it is being run into the spray ))uinp or tank. The 

 wash may be cooked m large kettles or, })referably, by steam in bar- 

 rels or tanks. 



This wash has proved entirely efTective in controlling the insect on 

 all ])lants, so far as preserving their life is concerned, and has been 

 especially satisfactory for stone fruits. For the apple, however, it 

 has not in all cases been so satisfactory, as difficulty is experienced, 

 especially in the case of large trees, in making the application suffi- 

 ciently thorough to kill all the scales. The spotting of the fruit by 

 the progeny of those that escape renders it unsightly for market pur- 

 poses, though its intrinsic value is but little reduced. The presence 

 of the scale is furthermore very objectionable for the reason that cer- 

 tain foreign governments and certain States in this country rigidly 

 quarantine against fruits showing the presence of this insect. Con- 

 siderable loss on fruit exported thus results to orchardists and 

 dealers." 



Some apple growers rely principally upon the oil sprays, or use 

 them at least every other year, alternating with the lime-sulphur 

 wasli, and in this way keep the scale w^ell in check. 



CONCENTRATED LIME-SULPHUR SOLUTIONS. 



The inconvenience experienced in preparing the lime-sulphur wash 

 by cooking with steam or in open kettles at home has been one of 

 the principal objections to this spra}^. Certain manufacturers have 

 therefore put on the market concentrated solutions of lime-sulphur 

 wash, which have only to be diluted with water for use. These com- 

 mercial washes have proved to be about as eftective in controlling 

 the scale as the well-cooked lime-sulphur wash, and, although some- 

 what more expensive, have been adopted by many commercial 

 orchardists in preference to the home-pre])ared spray. They are 

 especially useful for the smaller orchardist, whose interests do not 

 warrant the construction of a cooking plant. In other ways, too, 

 they possess advantages; for instance, those using the commercial 

 washes may have always on hand a stock solution, so that the spray 

 may be quickly prepared and advantage taken of favorable weather 

 conditions. 



HOMEMADE CONCENTRATED LIME-SULI'HUR SOLUTIONS. 



The question of the preparation at home of concentrated Ume-sul- 

 phur solutions which will not crystallize upon coolmg, thus duplicat- 

 ing essentially the commercial product, has been the subject of inves- 



o Experiments made by the Bureau of Entomology indicate the practicability of 

 successfully fumigatin<f scale-infested apples intended for export or other trade. (See 

 Bui. 84, Bur. Ent., U. S. Dept. Agr., 1909.) 

 [Cir. 124] 



