8 MAINE AGRICULTURAL EXPERIMENT STATION. I912. 



chards. Cooperative work under the supervision of the Station 

 horticulturist was therefore begun in three orchards in the near- 

 by town of Greene, owned by Messrs. H. Philbrook, J. Coburn 

 and H. Keyser respectively. The writer wishes at this time to 

 express his appreciation of the interest shown and the aid fur- 

 nished by these gentlemen. A discussion of the work and 

 results obtained in the Greene orchards will be made separate 

 from the work at Highmoor. 



It is a well recognized fact that in using the lime-sulphur 

 preparations instead of bordeaux mixture in orchard spraying 

 we are substituting for a spray that at the time of application 

 is insoluble, one that is soluble and more or less caustic in 

 nature, according to the strength of the solution. The basis, 

 therefore, for the proper use of lime-sulphur sprays has been 

 the determination of the strength of the stock solution, and its 

 dilution for use according to its density. Simple instruments 

 for this purpose and dilution tables graded for a scale of den- 

 sities have been, and still are the only safe means of using 

 lime-sulphur as a summer spray which,, so far as known, will 

 insure both fungicidal effectiveness and freedom from spray 

 injury. 



Nevertheless it is a matter of practical interest and impor- 

 tance to determine what may be the limits of dilution for a 

 specific density, in regard to injury and to efficiency; in other 

 words, can a solution of a known density be safely used at a 

 reasonably greater strength than that indicated by its place in 

 the dilution table, or can it be diluted beyond the amount indi- 

 cated in the table, and still be an effective fungicide ? 



EXPERIMENTS AT HIGHMOOR FARM, ipii. 



The experiment for this year, therefore, in addition to se- 

 curing further comparative notes on the effectiveness of lime- 

 sulphur and bordeaux mixture, aimed at the accumulation of 

 data bearing on the points discussed above. 



Both the lime-sulphur and the bordeaux preparations were 

 home made. The latter was of 3-3-50 strength and the lime- 

 sulphur was made according to the boiled stock solution for- 

 mula.* A reliable commercial brand of lead arsenate was 

 used throusfhout. 



* Explanation of bordeaux 3-3-50 and directions for making and 

 ■diluting concentrated lime-sulphur solutions are given in the Appendix. 



