SPRAYING FOR CONTROL OP PEACH BROWN-ROT AND SCAB. 17 



tions had apparently taken place through curculio punctures. In 

 the actual counts of diseased specimens from plat 1, as compared 

 with the unsprayed plat, there was a difference in favor of spraying of 

 32 k per cent in the case of brown-rot and 75^ per cent in the case of 

 scab. These figures do not tell the whole story. The sprayed fruit 

 was larger, more highly colored, and presented a much better appear- 

 ance in the package; it carried to the market in better condition and 

 commanded a higher price than the unsprayed fruit. 



Plat 2 was a block of 1,275 Waddell trees sprayed only once to 

 determine the value of a single application. The spraying was done 

 en April 30, a month after the petals dropped. The intention was 

 to make this application at a time when it would be expected to 

 accomplish the best results against scab. The Waddell is one of 

 the worst of the early varieties to scab, and to control this disease is 

 an important step in the control of brown-rot. 



The sorting record of the fruit from five trees in this block showed 

 that 32 per cent was affected with scab and 12^ per cent with brown- 

 rot. The percentage of scabby fruit ran rather high, but the spots 

 were mostly small and scattered, so that only 2 per cent of the crop 

 was badly affected. If the disease is kept down to two or three 

 spots on each fruit the damage is very slight even though a large 

 percentage of the crop may be so affected. The unsprayed trees of 

 this variety, as pointed out above, had 9H per cent of the fruit 

 affected with scab, while 28^ per cent of the crop was so badly spotted 

 with the disease as to be unmerchantable. One spraying, therefore, 

 made a difference of 59 h per cent in the amount of fruit affected 

 with scab and resulted in an actual saving of 26^ per cent of the 

 crop from destruction by scab. 



COMMERCIAL RESULTS. 



In order to determine the commercial results a record was made 

 of the marketable fruit from each plat. The fruit was brought into 

 the packing house, sorted, and packed in the usual way. The number 

 of trees in each plat varied, ranging from 568 to 1,357, and for con- 

 venience of comparison the average yield for 500 trees in each plat 

 is given as follows: Plat 1, 160 crates; plat 2, 170 crates; and the 

 check or unsprayed plat, 80 crates. 



This record of yield corresponds closely to the results expressed in 

 percentages of diseased fruit as determined by sorting the crop from 

 live trees in each plat. In such large plats considerable variation in 

 the trees and environment would naturally be expected and there 

 was perhaps a sufficient difference between plat 1 and plat 2 to 

 account for the fact that the latter, which was sprayed only once, 

 had less brown-rot and more good fruit than the former, which was 



174 



