AUXILIARY WORK. 



131 



III th«> cij^ht (^xperiiiuMits doscribod ))y Mr. Hsiwlcy the perccntac^es 

 of iH't train in fruit of the spra3^ed trees over the unsprayed wore as 

 follows : 



Table 35. — Percentages of net gain in fruit shoion in eight spraying ejcpcrimrnla conducted 



by Mr. Smith Ilawley, of Ludington, Mich. 



a See table 34. 



Owing- to the fact that Mr. liawle^'^'s experiments were conducted 

 with different varieties of peach, an accurate comparison can not be 

 instituted between them. From the very excellent results obtained in 

 experiment 8, where the unsprayed trees lost 90 per cent of their 

 leaves and the sprayed trees only 3 per cent, and where the net gain 

 in fruit b}' the sprayed trees was 1,^24 per cent of the yield of the 

 unsprayed trees, the writer ])elieves Mr. Hawley's conclusions are 

 correct, viz, that the spray used in this experiment gave the best 

 results. That the same spray did not give equally striking contrasts 

 in experiments 2, 4, and 5 is probably due mainly to the fact that 

 the trees of these experiments were not of the same variety as those 

 of experiment 8, but were much more resistant to disease, hence no 

 spray could have produced in the former experiments the same con- 

 trast between sprayed and unsprayed trees. That the trees of experi- 

 ments 2, 4, and 5 were not as badly diseased as those of experiment 8 

 is shown to be a fact, for the unsprayed trees of the latter experiment 

 lost 90 per cent of their leaves from curl, while those of the former 

 experiments lost only .50 per cent. The same evidence is given by the 

 fruit. The unsprayed trees of experiment 8 bore only 3. 7 pounds of 

 fruit per tree, while the unsprayed trees of experiments 2, 4, and 5 

 averaged 45.7, 11.6, and 32.4 pounds of fruit per tree, respectively. 



From the preceding facts it appears that the most active and satis- 

 factory spra^^ used by Mr. Hawley was that containing 5 pounds of 

 copper sulphate, 5 pounds of quicklime, and 45 gallons of water. This 

 is especially interesting from the fact that this spray also gave the 

 best results among the 35 formulae tested by the writer in the Sacra- 

 mento Valley. 



The relative value of the stronger sulphur spray (formula A) and the 

 Bordeaux mixture used by Mr. Hawley (formula C) is well brought out 

 in an experiment conducted by him on a somewhat similar scale, but 

 with a single variety of peach — Hills Chile. This experiment admits 

 of very satisfactory comparisons being drawn, and is summarized in 

 the following table: 



