I 



PLANT DISEASES IN 1908. II 



The lime-sulphur mixture was prepared as follows : — 



15 pounds of fresh stone lime was placed in a 50 gallon barrel 

 and a 3 gallon bucket of boiling water poured over it with con- 

 stant stirring. As soon as the lime began to slake 10 pounds of 

 sulphur was poured over it and then another bucket of water 

 added with continual stirring with a hoe, being careful not to 

 allow the lime to burn. When the lime appeared to be nearly all 

 slaked but while the mixture was still boiling violently the barrel 

 was covered with several thicknesses of burlap and then with 

 boards, and allowed to remain closed for one hour. The mix- 

 ture was then diluted, strainedt the same as bordeaux mixture, 

 made up to 50 gallons and at once sprayed on the trees. In the 

 letter already referred to Air. Scott stated that later experiments 

 showed that 10 pounds of lime to 10 pounds of sulphur served 

 the purpose as well as 15 pounds, therefore the smaller amount 

 was used in making the mixture for the two latter sprayings. 



The trees were sprayed three times, — May 14, just as the 

 leaves were unfolding, June 10, shortly after the blossoms had 

 fallen and again on July 6. A part of one row of trees in the 

 center of the orchard was left unsprayed for a check. Neither 

 spray produced any visible injury to foliage or fruit. Both 

 adhered well to the trees, the bordeaux somewhat the best. 

 Some of the spray in both cases could be seen on the limbs and 

 leaves when the apples were picked, and with the Bordeaux on 

 some trees it showed so plainly that it was necessary to wipe the 

 fruit. 



Unfortunately many of the trees of the varieties susceptible 

 to scab failed to set fruit so that it was impossible to secure 

 apples from several trees illustrating each treatment as was 

 intended. The best that could be done was to select four 

 Fameuse trees, one from '-ach lot, bearing on an average some- 

 what less than a barrel apiece. The fruit was picked and very 

 carefully sorted by a class of University students under the 

 direction of Professor V. R. Gardner. The per cent of fruit 

 free from scab was as follows : — 



Treatment 3-3-50 Self-boiled Self-boiled Unsprayed 

 bordeaux lime-sulphur, lime-sulphur, check 

 hot water cold water 



Per cent of fruit 



free from scab 50 33 16 i 



t A strainer with the bottom placed at an acute angle was found 

 particularly well adapted for this purpose. 



