G56 ANNUAL REPORT OF Tll^ Off. Doc. 



luakiug' and iiiiiiurilies in the best of our coniniei'cial limes, however, 

 we found definitely that for orchard conditions Ihe best ratio of in- 

 gredients is ai»proxiujatel,y one pound of high calcium lime to two 

 pounds of sulphui'. 



In connection with the matter of concontratictn, llie relation ex- 

 isting between volume, density and ultilization of materials was 

 determined. The greater densities, obtainable with lower volumes 

 of concentrate, were shown to be associated with less economical 

 use of materials, and hence to be undesirable. Where storage con- 

 ditions are to be met, however, a final volume of 1 to 1.1 gallons 

 of total product is about right in I lie home preparation, for the 

 weights of ingredients named above. Otherwise somewhat greater 

 volumes may be used, diluting according to density in all cases. 



The sediment in properly made ccjncentrates was found to actually 

 occupy less than 10 per cent, of the total volume, though by settling 

 alone it apparently occupied 30 to 50 per cent. Most of it is un- 

 objectionable in the home preparation, but for more readily remedy- 

 ing its coarser portions, we have recently made a new type of strain- 

 er, the construction of which is shown in the accompanying figure. 

 The usual clogging is avoided in it by straining upward, the coarse 

 particles falling away from the screen instead of accumulating on 

 it as in other strainers. 



The amount of sediment was found to be influenced by the manip- 

 ulation, by the ratio and purity of the materials, and by the amount 

 of boiling. The best index for completed boiling is the evident dis- 

 solving of the sulphur granules. 



Ordinary winter temperatures were found not to exert any per- 

 manent effect on the concentrates, the only danger in freezing 

 apparently being the possible breakage of containers, and the freez- 

 ing points loAvered with increase in density, acids and carbon dioxid, 

 however, readily break down the solution. 



In connection with the use of lime-suliihur, the first definite sys- 

 tem of dilution according to density was developed, foliage tests 

 were made, some of the conditions influencing spray injury were 

 determined, and the thorough control of scale on apple by summer 

 applications alone was demonstrated. This was accomplished with 

 three sprays, the first being applied immediately after the young 

 began to emerge with the others following at intervals of about 

 ten days, where additional young were observed. The amount of 

 spray injury was found not to depend exactly upon density of appli- 

 cation, but rather upon the density attained on the leaf before 

 evaporation is complete. This was affected by the abundance of ap- 

 plication, the density of the material applied, and the size and loca- 

 tion of the drops retained by the leaves, the younger leaves and 

 under surfaces being most vulnerable. Injury is also especially 

 liable to occur after applications of bordeaux or after previous appli- 

 cations of lime-sulphur which have broken the epidermis. This ac- 

 counts for some of the anomalous cases of severe injury that have 

 come to our attention during the last two seasons. 



The recent work at various stations cannot be adequately treated 

 in the present space. The general outburst of activity along all 

 lines of sulphur sprays has been quite remarkable. The excellent 

 work of Scott at AVashington in showing the usefulness of the self- 



